Enterobacteriacea

Diagn Microbiol Infect Dis, 2001 Feb, 39(2), 85 - 93
Identification by 16S ribosomal RNA gene sequencing of an Enterobacteriaceae species with ambiguous biochemical profile from a renal transplant recipient; Woo PC et al.; Traditional ways of identification of bacteria by phenotypic characteristics cannot be used for non-cultivable organisms and organisms with unusual biochemical profiles . In this study, an Enterobacteriaceae was isolated in pure growth from the mid-stream urine of a 67-year old renal transplant recipient with urinary tract infection . Conventional biochemical tests did not reveal a pattern resembling any known member of the Enterobacteriaceae family . The Vitek system (GNI+) showed that it was 18% Leclercia adecarboxylata and 55% Klebsiella ozaenae; whereas the API system (20E) showed that it was 99.8% Rahnella aquatilis . 16S ribosomal RNA gene sequencing showed that there was 7 base differences between the isolate and Enterobacter cloacae, 18 base differences between the isolate and Enterobacter asburiae, 17 base differences between the isolate and Enterobacter cancerogenus, 35 base differences between the isolate and K . ozaenae, 27 base differences between the isolate and L . adecarboxylata, and 72 base differences between the isolate and R . aquatilis, indicating that the isolate most closely resembled a strain of E . cloacae . Identification of the organism in this study is important, as the choice of antibiotics would be radically different . In this case, cephalosporins should be avoided regardless of in-vitro susceptibility as cephalosporins are well-known to select for AmpC derepressed mutants in Enterobacter, and previous administration of third-generation cephalosporins is more likely to be associated with multidrug resistant Enterobacter isolates than is administration of antibiotics that do not include a third-generation cephalosporin.

Biochim Biophys Acta, 2001 May 1, 1505(1), 15 - 27
Sodium ion-translocating decarboxylases; Buckel W; The review is concerned with three Na(+)-dependent biotin-containing decarboxylases, which catalyse the substitution of CO(2) by H(+) with retention of configuration (DeltaG degrees '=-30 kJ/mol): oxaloacetate decarboxylase from enterobacteria, methylmalonyl-CoA decarboxylase from Veillonella parvula and Propiogenium modestum, and glutaconyl-CoA decarboxylase from Acidaminococcus fermentans . The enzymes represent complexes of four functional domains or subunits, a carboxytransferase, a mobile alanine- and proline-rich biotin carrier, a 9-11 membrane-spanning helix-containing Na(+)-dependent carboxybiotin decarboxylase and a membrane anchor . In the first catalytic step the carboxyl group of the substrate is converted to a kinetically activated carboxylate in N-carboxybiotin . After swing-over to the decarboxylase, an electrochemical Na(+) gradient is generated; the free energy of the decarboxylation is used to translocate 1-2 Na(+) from the inside to the outside, whereas the proton comes from the outside . At high {Na(+)}, however, the decarboxylases appear to catalyse a mere Na(+)/Na(+) exchange . This finding has implications for the life of P . modestum in sea water, which relies on the synthesis of ATP via Delta(mu)Na(+) generated by decarboxylation . In many sequenced genomes from Bacteria and Archaea homologues of the carboxybiotin decarboxylase from A . fermentans with up to 80% sequence identity have been detected.

Mikrobiol Z, 2000 Nov-Dec, 62(6), 7 - 14
{Use of PCR for the identification of representatives of Lactobacillus and Streptococcus}; Kovalenko NK et al.; REP- and ERIC-PCR genome analysis of lactic acid bacteria of genera Lactobacillus and Streptococcus have shown the presence of REP- and ERIC-repetitive sequences with high degree of homology . Amplification products which separation in agar gel results in formation of a specific fingerprint are obtained under REP- and ERIC-PCR . It is shown that REP- and ERIC-specific primers can be used for PCR identification of both enterobacteria and lactic acid bacteria isolated from different ecological niches.

Mikrobiol Z, 2000 Sep-Oct, 62(5), 23 - 8
{Ecological diagnosis of pyoseptic diseases in newborns using the "Diastaph" disc}; Flegontova VV et al.; The etiological spectrum of pyoseptic diseases was studied in 113 newborns . It was established, that between 187 strains of microorganisms, belonging to 19 species, 73.3% were staphylococci and streptococci, 25.1%--Enterobacteriaceae, 1.6%--Candida albicans . Mixed infection, caused by association of 2-5 Gram-positive and (or) Gram-negative microorganisms, was marked in 51.3% of newborns . In cases of mono-infection (42.5%) staphylococci and streptococci were leading etiological agents . The possibility of generic identification of staphylococci using the diagnostic disks "Diastaph" which contain a new antibiotic batumin has been studied . All the isolated staphylococci strains were highly sensitive to batumin in contrast to other Gram-positive and Gram-negative microorganisms that caused pyodermia in newborns.

Clin Exp Rheumatol, 2001 Jan-Feb, 19(1), 47 - 52
The modulation of chlamydial replication by HLA-B27 depends on the cytoplasmic domain of HLA-B27; Kuipers JG et al.; OBJECTIVE: The intracellular persistence of viable Chlamydia trachomatis (CT) within the joint is thought to initiate and maintain the inflammatory process in CT-induced arthritis . CT-induced arthritis is associated with HLA-B27 . Recently it was shown that HLA-B27, besides being a T-cell restriction element, can directly influence the invasion and/or replication of enterobacteriae and alters salmonella-induced signal transduction . It was the aim of this study to analyze the effect of HLA-B27 on CT-invasion and replication in human host cells . METHODS: Human Hela cells and Hela cells transfected with either HLA-B27 cDNA or controls (HLA-A1 cDNA; HLA-B27 mutant = HLA-B27 without cytoplasmic tail; B27Q10 = HLA-B27 Exon 1-4 linked to Exon 5 of murine Q10) were infected with CT . By direct immunofluorescence chlamydial invasion was determined 4 hours post infection (p.i.), chlamydial replication 2 days and 4 days p.i . The number of infective CT in the different cell lines was determined by titration of the cell lysates on Hep-2 cells with subsequent immunoperoxidase staining . RESULTS: Invasion was not affected by HLA-B27 . However, formation of chlamydial inclusion bodies and replication was suppressed by HLA-B27 . Genetically engineered mutants of HLA-B27 (HLA-B27 mutant, B27Q10) lacking the cytoplasmic tail of HLA-B27 did not affect replication . CONCLUSION: The reduction of chlamydial replication by HLA-B27 depends on the cytoplasmic domain of HLA-B27, thus providing a new hypothesis for chlamydial persistence in HLA-B27 positive reactive arthritis.

Clin Immunol, 2001 Mar, 98(3), 364 - 9
Spontaneous inflammatory disease in HLA-B27 transgenic mice does not require transporter of antigenic peptides; Khare SD et al.; HLA-B27 is strongly linked with a group of human diseases called spondyloarthropathies . Even though HLA-B27 as an MHC class I molecule would be expected to present endogenously processed peptides such as cytosolic or viral proteins, many of the B27-linked diseases begin after an infection with an enterobacteria, an exogenous antigen . In our previous studies, we have described development of spontaneous inflammatory disease in HLA-B27 transgenic mice expressing beta(2)m free heavy chains on the cell surface . In order to address the role of endogenous versus exogenous antigens and a role for Tap genes in the development of spontaneous diseases, mice lacking Tap-1 (knockout) were mated to HLA-B27/human beta(2)m transgenic mice . B27(+)/human beta(2)m(+) double-transgenic mice (without mouse beta(2)m) lacking the Tap-1 gene developed spontaneous inflammatory disease similar to wild-type Tap-1 gene-expressing counterparts . Our data demonstrate that peptide transporters (Tap) were not involved in the development of spontaneous inflammatory disease in B27(+)/human beta(2)m transgenic animals .

Environ Microbiol, 2000 Aug, 2(4), 417 - 27
Detection of abundant sulphate-reducing bacteria in marine oxic sediment layers by a combined cultivation and molecular approach; Wieringa EB et al.; The depth distribution and diversity of sulphate-reducing bacteria (SRB) was analysed in the upper intertidal zone of a sandy marine sediment of the Dutch island Schiermonnikoog . The upper centimetre of the sediment included the oxic-anoxic interface and was cut into five slices . With each slice, most probable number (MPN) dilution series were set up in microtitre plates using five different substrates . In the deeper sediment layers, up to 1 x 10(8) cm(-3) lactate-utilizing SRB were counted, corresponding to 23% of the total bacterial count . From the highest positive dilutions of the MPN series, 27 strains of SRB were isolated in pure culture . Sequencing of a 580 bp fragment of the 16S rDNA revealed that 21 isolates had identical sequences, also identical with that of the previously described species Desulfomicrobium apsheronum . However, the diversity of the isolates was higher with respect to their physiological properties: a total of 11 different phenotypes could be distinguished . Genomic fingerprinting by enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR) revealed an even higher diversity of 22 different genotypes . A culture-independent analysis by PCR and denaturing-gradient gel electrophoresis (DGGE) revealed that the partial 16S rDNA sequence of the isolated D . apsheronum strains constituted a significant fraction of the Desulfovibrionaceae . The high subspecies diversity suggests that this abundant aggregate-forming species may have evolved adaptations to different ecological niches in the oxic sediment layers.

Therapie, 2000 Nov-Dec, 55(6), 691 - 7
{Antibacterial activity of urine after administration of ofloxacin for 5 days}; Drugeon H et al.; The antibacterial activity of ofloxacin was evaluated in urine over a period of 96 h after oral administration for 5 days of 200 mg twice a day in 12 healthy female volunteers . Bacteriostatic and bactericidal activity of urines were studied for five strains of enterobacterias recovered from urinary infections: two strains of Escherichia Coli Nal-S and Nal-R, two strains of Proteus mirabilis Nal-S and Nal-R, and one strain of Klebsiella pneumoniae Nal-S . Mean urinary concentrations of ofloxacin were very high during the first 12 h following last intake . They were still above 7 mg/l till the 48th hour and above 1.6 mg/l till the 72nd hour . Bactericidal activity of urine was present for 72 h in respect of four strains studied at that time; urine was not bactericidal as regards E . coli Nal-R . After 5 days of oral treatment with ofloxacin (200 mg b.i.d.), urine retains a bactericidal activity for at least 72 h against bacterial strains of urinary tract infections.

Mol Biol (Mosk), 2001 Jan-Feb, 35(1), 157 - 62
{Expression of the NS1 gene of tick-borne encephalitis virus in gram-negative bacteria from the mouse nasopharynx}; Morozova OV et al.; Bacteria were isolated from the nasopharynx of BALB/c mice and electroporated with pUR290(NS1)2 containing two copies of tick-borne encephalitis virus (TBEV) strain Sofjin NS1 under the control of the lac promoter . The plasmid persisted in transformants for at least ten passages . The NS1 gene expression was detected in Gram-negative enterobacteria via immunoblotting with monoclonal antibodies against TBEV nonstructural glycoprotein NS1 . Recombinant NS1 was detected in bacterial cells and in the culture medium . Intranasal immunization with recombinant bacteria activated production of antibodies against NS1 in serum of BALB/c mice . The humoral immune response to NS1 failed to protect immunized mice from a TBEV challenge.

Acta Microbiol Immunol Hung, 2001, 48(2), 129 - 41
Detection and toxin production of Staphylococcus aureus in sudden infant death cases in Hungary; Csukas Z et al.; The potential role of microbial agents was investigated in 13 cases of Sudden Infant Death Syndrome and in 9 non-SIDS cases in Budapest between September 1996 and May 1998 . Autopsy, histological examination and microbiological tests were performed on samples of blood, cerebrospinal fluid, pharyngeal samples and lung tissue from infants under one year died suddenly, without previous diseases . The multifactorial pathomechanism of SIDS was suggested by the isolation of toxin producing Staphylococcus aureus-, Enterobacteriaceae and Candida albicans strains in large number and by the detection of Parainfluenza Type 2 virus antigen . S . aureus proved the predominant bacteria in the SIDS cases . Nasopharyngeal microbial flora and S . aureus carrier of 100 age matched healthy infants were tested during the same period . S . aureus was isolated from 54% of SIDS cases and 37% from healthy infants /OR = 1.986 (95% Confidence interval = 0.55-7.33), p = 0243/ . The enterotoxin and TSST-1 toxin producing activity of S . aureus showed the characteristic difference . The toxigenic S . aureus was detected in 46% of SIDS cases and 16% of healthy infants /OR = 4.5 (95% CI = 1.15-17.72), p = 0.010/ . The distribution of toxigenic and nontoxigenic isolates was 86% in SIDS cases and 43% in healthy infants /OR = 7.875 (CI = 0.78-191.89), p = 0.041/.

Folia Biol (Praha), 2001, 47(1), 11 - 3
Cytotoxic effects of colicins E1 and E3 on v-myb-transformed chicken monoblasts; Smarda J et al.; Colicins show a considerable cytostatic activity, which is much less known and understood than their killing activity targeting bacteria of the Enterobacteriaceae family . In this communication, the cytotoxic effects of colicins E1 and E3 on v-myb-transformed chicken monoblasts BM2 are presented . We detected clear reduction of the viable cell number induced by colicins E1 and E3, occurring without apparent changes in cell cycle profiles . The level of inhibition was proportional to the colicin concentration within the limits of 0.5-1.25 microg/ml . This result documents that colicins produced by Enterobacteriaceae exert their cytotoxic effects on leukemic cells.

J Med Microbiol, 2001 Mar, 50(3), 208 - 14
Characterisation of Hafnia alvei isolates from human clinical extra-intestinal specimens: haemagglutinins, serum resistance and siderophore synthesis; Podschun R et al.; Extra-intestinal Hafnia alvei isolates are rarely considered to be pathogenic . To investigate whether such strains are able to produce virulence factors, a total of 70 clinical H . alvei isolates was compared with clinical extra-intestinal isolates of other members of the enterobacterial tribe Klebsiellae (Kiebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens) . Whereas mannose-sensitive haemagglutination (MSHA) was less common in H . alvei (59%) than in K . pneumoniae (86%) and E . cloacae (89%) isolates, the incidences of mannose-resistant haemagglutination indicative of type 3 pili (MR/K-HA) and of serum resistance properties were not lower . All H . alvei strains secreted siderophores but, unlike the other enterobacterial species examined, the siderophore type was neither enterobactin nor aerobactin . Although the low pathogenicity of H . alvei isolates could not be attributed to any of the factors investigated, the mean number of factors expressed by each H . alvei isolate was significantly lower than that expressed by K . pneumoniae and E . cloacae isolates but did not differ significantly from that of S . marcescens . Based on these findings, the low pathogenicity of H . alvei appears to be due to its low frequency of expression of virulence factors as compared with clinically significant species such as K . pneumoniae and E . cloacae.

J Clin Microbiol, 2001 Mar, 39(3), 1190 - 4
Isolation and characterization of a Salmonella enterica serotype Typhi variant and its clinical and public health implications; Woo PC et al.; We report the isolation and characterization of a member of the family Enterobacteriaceae isolated from the gallbladder pus of a food handler . Conventional biochemical tests suggested Salmonella enterica serotype Typhi, but the isolate agglutinated with poly(O), 2O, 9O, and Vi Salmonella antisera but not with poly(H) or any individual H Salmonella antisera . 16S rRNA gene sequencing showed that there were two base differences between the isolate and Salmonella enterica serotype Montevideo, four base differences between the isolate and serotype Typhi, five base differences between the isolate and Salmonella enterica serotype Typhimurium, and six base differences between the isolate and Salmonella enterica serotype Dublin, indicating that the isolate was a strain of S . enterica . Electron microscopy confirmed that the isolate was aflagellated . The flagellin gene sequence of the isolate was 100% identical to that of the H1-d flagellin gene of serotype Typhi . Sequencing of the rfbE gene, which encoded the CDP-tyvelose epimerase of the isolate, showed that there was a point mutation at position +694 (G-->T), leading to an amino acid substitution (Gly-->Cys) . This may have resulted in a protein of reduced catalytic activity and hence the presence of both 2O and 9O antigens . We therefore concluded that the isolate was a variant of serotype Typhi . Besides antibiotic therapy and cholecystectomy, removal of all stones in the biliary tree was performed for eradication of the carrier state.

J Clin Microbiol, 2001 Mar, 39(3), 983 - 9
Controlled clinical comparison of BACTEC plus anaerobic/F to standard anaerobic/F as the anaerobic companion bottle to plus aerobic/F medium for culturing blood from adults; Wilson ML et al.; To determine the optimal anaerobic companion bottle to pair with BACTEC Plus Aerobic/F medium for recovery of pathogenic microorganisms from adult patients with bacteremia and fungemia, we compared Plus Anaerobic/F bottles with Standard Anaerobic/F bottles, each of which was filled with 4 to 6 ml of blood . The two bottles were paired with a Plus Aerobic/F bottle filled with 8 to 12 ml of blood . A total of 14,011 blood culture sets were obtained . Of these, 11,583 sets were received with all three bottles filled adequately and 12,257 were received with both anaerobic bottles filled adequately . Of 818 clinically important isolates detected in one or both adequately filled anaerobic bottles, significantly more staphylococci (P < 0.001), streptococci (P < 0.005), Escherichia coli isolates (P < 0.02), Klebsiella pneumoniae isolates (P < 0.005), and all microorganisms combined (P < 0.001) were detected in Plus Anaerobic/F bottles . In contrast, significantly more anaerobic gram-negative bacilli were detected in Standard Anaerobic/F bottles (P < 0.05) . Of 397 unimicrobial episodes of septicemia, 354 were detected with both pairs, 30 were detected with Plus Aerobic/F-Plus Anaerobic/F pairs only, and 13 were detected with Plus Aerobic/F-Standard Anaerobic/F pairs only (P < 0.05) . Significantly more episodes of bacteremia caused by members of the family Enterobacteriaceae (P < 0.05) and aerobic and facultative gram-positive bacteria (P < 0.025) were detected with Plus Anaerobic/F bottles only . In a paired-bottle analysis, 810 of 950 isolates were recovered from both pairs, 90 were recovered from Plus Aerobic/F-Plus Anaerobic/F pairs only, and 50 were recovered from Plus Aerobic/F-Standard Anaerobic/F pairs only (P < 0.001) . Paired Plus Aerobic/F-Plus Anaerobic/F bottles yielded significantly more staphylococci (P < 0.001), streptococci (P < 0.05), and members of the family Enterobacteriaceae (P <0.001) . We conclude that Plus Anaerobic/F bottles detect more microorganisms and episodes of bacteremia and fungemia than Standard Anaerobic/F bottles as companion bottles to Plus Aerobic/F bottles in the BACTEC 9240 blood culture system.

J Clin Microbiol, 2001 Mar, 39(3), 889 - 96
National epidemiologic surveys of Enterobacter aerogenes in Belgian hospitals from 1996 to 1998; De Gheldre Y et al.; Two national surveys were conducted to describe the incidence and prevalence of Enterobacter aerogenes in 21 Belgian hospitals in 1996 and 1997 and to characterize the genotypic diversity and the antimicrobial resistance profiles of clinical strains of E . aerogenes isolated from hospitalized patients in Belgium in 1997 and 1998 . Twenty-nine hospitals collected 10 isolates of E . aerogenes, which were typed by arbitrarily primed PCR (AP-PCR) using two primers and pulsed-field gel electrophoresis . MICs of 10 antimicrobial agents were determined by the agar dilution method . Beta-lactamases were detected by the double-disk diffusion test and characterized by isoelectric point . The median incidence of E . aerogenes colonization or infection increased from 3.3 per 1,000 admissions in 1996 to 4.2 per 1000 admissions in the first half of 1997 (P < 0.01) . E . aerogenes strains (n = 260) clustered in 25 AP-PCR types . Two major types, BE1 and BE2, included 36 and 38% of strains and were found in 21 and 25 hospitals, respectively . The BE1 type was indistinguishable from a previously described epidemic strain in France . Half of the strains produced an extended-spectrum beta-lactamase, either TEM-24 (in 86% of the strains) or TEM-3 (in 14% of the strains) . Over 75% of the isolates were resistant to ceftazidime, piperacillin-tazobactam, and ciprofloxacin . Over 90% of the strains were susceptible to cefepime, carbapenems, and aminoglycosides . In conclusion, these data suggest a nationwide dissemination of two epidemic multiresistant E . aerogenes strains in Belgian hospitals . TEM-24 beta-lactamase was frequently harbored by one of these epidemic strains, which appeared to be genotypically related to a TEM-24-producing epidemic strain from France, suggesting international dissemination.

Antibiot Khimioter, 2001, 46(1), 15 - 7
{Comparative antibiotic susceptibility in vitro of microbial isolates from patients with complications after gastrectomy for stomach carcinoma and from contents of their large intestine}; Levanov AV; Antibiotic susceptibility of the main isolates from the large intestine contents and pathological substrates of 12 patients after gastroectomy for stomach carcinoma was studied . Three of them developed esophagoenterostomy incompetence, 4 had intraabdominal abscesses and in 5 infection of the operation wound was stated . In all, 30 isolates of enterobacteria, 28 isolates of enterococci and 38 isolates of bacteroides were tested . Antibiotic susceptibility of the isolates from various sources was practically identical, which showed that before surgical operations for stomach carcinoma it was necessary that data on the patients intestine microbiocenosis and antibioticograms of the main isolates should be available to correct severe dysbiotic disorders.

Pediatr Infect Dis J, 2001 Feb, 20(2), 134 - 40
Increase of Enterobacter in neonatal sepsis: a twenty-two-year study; Hervas JA et al.; BACKGROUND: Data on the incidence of Enterobacter infections in neonates over prolonged periods of time are scant . We determined the epidemiology of Enterobacter sepsis and/or meningitis and the trends of infection in a neonatal unit . METHODS: Retrospective review of sepsis and/or meningitis in inborn neonates admitted to Son Dureta University Hospital during a 22-year period . Molecular study by ribotyping of the Enterobacter strains isolated from 1995 to 1997 . RESULTS: There were 513 cases of culture-proved sepsis and/or meningitis in neonates . In late onset infections Klebsiella pneumoniae and Staphylococcus epidermidis were the most frequent isolates in the period 1977 through 1991 . Enterobacter was the most common isolate in the period 1992 through 1998 . During this latter period Candida infections also increased, and the resistance rate of Enterobacter to cefotaxime was higher (59.2%) . Decrease in early onset infections and increase in late onsets (4.6/1,000 live births) were observed in the second period . From 1977 to 1998, 45 episodes of sepsis and/or meningitis by Enterobacter species were identified in 44 patients (8.7% of all neonatal bacteremias) . Three patients with Enterobacter bacteremia died (6.6%, 0.03/1,000 live births) . During 1995 through 1997 5 different clones causing sepsis were identified and 3 were predominant . In 1997 there was an outbreak of Enterobacter disease . After cleaning, cohort nursing and hygiene reinforcement, Enterobacter was not isolated in the next 2 years . No change in the antibiotic policy was made . CONCLUSIONS: We observed a resurgence of Enterobacter infections in our neonatal intensive care unit . The sudden disappearance of this microorganism after reinforcement of hygienic measures, without withdrawing cefotaxime, confirms the importance of patient-to-patient transmission of this nosocomial infection . Further studies are needed to establish the role of antibiotics in the emergence of microorganisms in neonatal intensive care units.

J Bacteriol, 2001 Mar, 183(6), 1870 - 80
Molecular characterization of global regulatory RNA species that control pathogenicity factors in Erwinia amylovora and Erwinia herbicola pv . gypsophilae; Ma W et al.; rsmB(Ecc) specifies a nontranslatable RNA regulator that controls exoprotein production and pathogenicity in soft rot-causing Erwinia carotovora subsp . carotovora . This effect of rsmB(Ecc) RNA is mediated mostly by neutralizing the function of RsmA(Ecc), an RNA-binding protein of E . carotovora subsp . carotovora, which acts as a global negative regulator . To determine the occurrence of functional homologs of rsmB(Ecc) in non-soft-rot-causing Erwinia species, we cloned the rsmB genes of E . amylovora (rsmB(Ea)) and E . herbicola pv . gypsophilae (rsmB(Ehg)) . We show that rsmB(Ea) in E . amylovora positively regulates extracellular polysaccharide (EPS) production, motility, and pathogenicity . In E . herbicola pv . gypsophilae, rsmB(Ehg) elevates the levels of transcripts of a cytokinin (etz) gene and stimulates the production of EPS and yellow pigment as well as motility . RsmA(Ea) and RsmA(Ehg) have more than 93% identity to RsmA(Ecc) and, like the latter, function as negative regulators by affecting the transcript stability of the target gene . The rsmB genes reverse the negative effects of RsmA(Ea), RsmA(Ehg), and RsmA(Ecc), but the extent of reversal is highest with homologous combinations of rsm genes . These observations and findings that rsmB(Ea) and rsmB(Ehg) RNA bind RsmA(Ecc) indicate that the rsmB effect is channeled via RsmA . Additional support for this conclusion comes from the observation that the rsmB genes are much more effective as positive regulators in a RsmA(+) strain of E . carotovora subsp . carotovora than in its RsmA(-) derivative . E . herbicola pv . gypsophilae produces a 290-base rsmB transcript that is not subject to processing . By contrast, E . amylovora produces 430- and 300-base rsmB transcripts, the latter presumably derived by processing of the primary transcript as previously noted with the transcripts of rsmB(Ecc) . Southern blot hybridizations revealed the presence of rsmB homologs in E . carotovora, E . chrysanthemi, E . amylovora, E . herbicola, E . stewartii and E . rhapontici, as well as in other enterobacteria such as Escherichia coli, Salmonella enterica serovar Typhimurium, Serratia marcescens, Shigella flexneri, Enterobacter aerogenes, Klebsiella pneumoniae, Yersinia enterocolitica, and Y . pseudotuberculosis . A comparison of rsmB sequences from several of these enterobacterial species revealed a highly conserved 34-mer region which is predicted to play a role in positive regulation by rsmB RNA.

J Antimicrob Chemother, 2001 Mar, 47(3), 271 - 5
Antimicrobial activity of fluoroquinolone photodegradation products determined by parallel-line bioassay and high performance liquid chromatography; Sunderland J et al.; The fluoroquinolones produce multiple photodegradation products . Little is known about these products, particularly whether any possess antimicrobial activity . To investigate this, we used the parallel-line bioassay to investigate discrepancies in zone of inhibition size in conjunction with high performance liquid chromatography (HPLC) analysis . A continuous flow photochemical reaction unit ('Beam-Boost') was used to partially photodegrade the fluoroquinolones ofloxacin, levofloxacin, ciprofloxacin and moxifloxacin (0.02 mM) by between 15 and 89%, as confirmed by HPLC . The concentration of residual parent fluoroquinolone in each irradiated sample was measured by HPLC and a non-irradiated control solution was prepared at the same concentration . These were compared by parallel-line bioassays using Escherichia coli, Enterobacter cloacae and Klebsiella oxytoca . With ofloxacin and levofloxacin, the zone size for the control solution was significantly less than that of the irradiated solutions, with >15% photodegradation in at least two of the indicator organisms, indicating that the photodegradation products possess antimicrobial activity . No difference was seen with ciprofloxacin at any level of photodegradation with any of the indicator organisms, nor with moxifloxacin at 30 and 54% photodegradation . A significant difference was observed with E . cloacae only, at 83% photodegradation.

CLAO J, 2001 Jan, 27(1), 47 - 52
Microbiological profile of a shipboard environment and the flora on contact lenses of seamen; Theng JT et al.; PURPOSE: The purpose of this study was to culture and identify the spectrum of organisms (and their sensitivities) that contaminate the extended wear contact lenses of seamen in their working environment . A secondary aim was to identify the most appropriate first-line antibiotic regimen to be used on seamen who sustain contact lens-related corneal keratitis on board ship . METHODS: Twenty pairs of contact lenses of 20 seamen in one group and 24 pairs in another group wearing contact lenses were collected at the end of 1 week of extended wear . Groups one and two differed only in the way lenses were stored prior to culturing . All contact lenses were then brought to the microbiological lab within 24 hours for culture and sensitivity testing . RESULTS: The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids . Enterobacterand Pseudomonas species, present in a shipboard environment, were also identified as contaminants on the contact lenses . The organisms cultured from the contact lenses correlated well with those of normal lid flora as well as from the ship environment and are probably derived from these sources . Storage in saline-containing preservatives yielded significantly less positive bacterial cultures from the contact lenses in our study . All bacterial isolates were sensitive to ciprofloxacin whereas several bacteria resistant to cefazolin and gentamicin were identified . CONCLUSION: The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids . Enterobacter and Pseudomonas species, which are normally present in a shipboard environment, were also identified as contaminants on the contact lenses . Ciprofloxacin is effective against all organisms identified as contaminants on the contact lenses in this study . Of all the antibiotics tested, it is probably the most suitable agent against contact lensrelated keratitis under such shipboard circumstances and is thus recommended in these situations.

Environ Microbiol, 2000 Dec, 2(6), 620 - 31
Variations in antibiotic resistance profile in Enterobacteriaceae isolated from wild Australian mammals; Sherley M et al.; We carried out a retrospective analysis of 946 strains of Enterobacteriaceae isolated from wild Australian mammals between 1993 and 1997 . The prevalence of resistance to fixed concentrations of 32 antimicrobial agents was determined, and the respective roles that taxonomic family of the host, state of origin and bacterial species play in defining prevalence and range of resistance were investigated . Our results demonstrated a low but widespread prevalence of antimicrobial resistance in wild isolates . Only amikacin, ciprofloxacin, meropenem and gentamicin inhibited growth in all 946 samples . There was extensive variation in the combination of antibiotics to which isolates were resistant, and multiple antibiotic resistance was common . Geographical location and host group significantly influenced the antibiotic resistance profile of an isolate, whereas bacterial species influenced both the resistance profile of an isolate and the number of antibiotics it was resistant to . The role of these factors in determining observed antibiotic resistance profiles suggests that any study measuring resistance in wild isolates should include the broadest possible range of bacterial species, host species and sampling locations . As such, this study provides an important new baseline for future measurements of antibiotic resistance in the Australian environment.

J Med Liban, 2000 Jul-Aug, 48(4), 278 - 82
Management of urinary tract infections; Nassar NT; Urinary tract infections (UTIs) are commonly encountered in medical practice and range from asymptomatic bacteruria to acute pyelonephritis . Enterobacteriaceae with E . coli being the most prevalent, are responsible for most commonly acquired uncomplicated UTIs and usually respond promptly to oral antibiotics . In contradistinction, more resistant pathogens cause nosocomially acquired infections which often require parenteral antibiotic therapy . Patients with acute bacterial prostatitis, usually caused by Enterobacteriaceae present with a tender prostate gland and respond promptly to antibiotic therapy . Chronic bacterial prostatitis on the other hand, is a subacute infection characterized by recurrent episodes of bacterial UTI where the patient presents with vague symptoms of pelvic pain and voiding problems . Treatment is protracted and may be frustrating . Nonbacterial prostatitis and chronic pelvic pain syndrome produce symptoms similar to those of chronic bacterial prostatitis . Treatment is not well defined due to their uncertain etiologies . Most episodes of catheter associated bacteruria are asymptomatic, where less than 5% will be complicated by bacteremia . The use of systemic antibiotics for treatment or prevention of bacteruria is not recommended, particularly in the geriatric age group, since it helps select for resistant organisms . Prevention thus remains the best option to control it . Few patients without catheters who have asymptomatic bacteruria develop serious complications and therefore routine antimicrobial therapy is not justified with only two exceptions : before urologic surgery and during pregnancy.

J Med Liban, 2000 Jul-Aug, 48(4), 227 - 32
Current status and changing trends of antimicrobial resistance in Saudi Arabia; Akhter J et al.; Due to modern travel and ease of spread of infections, it is desirable to widen knowledge of susceptibility of common bacterial isolates from different parts of the world for optimal clinical management and control programs . Over the past decades, antimicrobial resistance has emerged in all kinds of micro-organisms worldwide including Saudi Arabia . This phenomenon is primarily due to increasing antibiotic use and misuse in humans, animals and agriculture . Additionally, the presence of a large expatriate population and a significant number of visitors to the Kingdom annually for pilgrimage and/or work from all over the world may have also facilitated the importation to Saudi Arabia of drug resistant micro-organisms from other countries . Saudi Arabia has witnessed an increase of drug resistant Mycobacterium tuberculosis, Streptococcus pneumoniae, Staphylococcus aureus and some Enterobacteriaceae in the last decade . We describe the status of antimicrobial resistance in Saudi Arabia which is an important focus of antimicrobial resistance for the Gulf Region.

Cell Mol Life Sci, 1999 Nov 30, 56(9-10), 771 - 8
Bacterial antibiotic efflux systems of medical importance; Kohler T et al.; Multidrug efflux systems endow on bacterial cells the ability to limit the access of antimicrobial agents to their targets . By actively pumping out antibiotic molecules, these systems prevent the intracellular accumulation necessary for antibiotics to exert their lethal activity . Drug efflux appears to be one of the most widespread antibiotic resistance mechanisms among microorganisms, since it has been demonstrated to occur in many Gram-positive and Gram-negative bacteria including medically important species like staphylococci, streptococci, enterobacteria and opportunistic pathogens like Pseudomonas aeruginosa . Efflux pumps can be specific for only one substrate or accommodate a more or less wide range of noxious products . Export of structurally unrelated compounds confers a multidrug-resistance phenotype on bacterial cells . Therapeutically critical levels of resistance can be achieved by overexpression of efflux systems, especially in those species such as P . aeruginosa which possess a low outer membrane permeability . It is suspected that the dual physiological function of active efflux systems is both the secretion of intracellular metabolites and the protection against a variety of harmful substances that the microorganism may encounter in its natural environment.

J Hepatol, 2001 Jan, 34(1), 32 - 7
Bacterial translocation of enteric organisms in patients with cirrhosis; Cirera I et al.; BACKGROUND/AIMS: The aim of the study was to investigate the prevalence and associated risk factors for bacterial translocation in patients with cirrhosis, a mechanism involved in the pathogenesis of bacterial infections in experimental cirrhosis . METHODS: Mesenteric lymph nodes were obtained for microbiological culture from 101 patients with cirrhosis and from 35 non-cirrhotic patients . RESULTS: Enteric organisms were grown from mesenteric lymph nodes in 8.6% of non-cirrhotic patients . In the 79 cirrhotic patients without selective intestinal decontamination, the prevalence of bacterial translocation significantly increased according to the Child-Pugh classification: 3.4% in Child A, 8.1% in Child B and 30.8% in Child C patients (chi2 = 6.106, P < 0.05) . However, translocation by Enterobacteriaceae, the organisms commonly responsible for spontaneous bacteremia and peritonitis in cirrhosis, was only observed in 25% of the cases . The prevalence of bacterial translocation in the 22 cirrhotic patients undergoing selective intestinal decontamination, all Child-Pugh class B and C, was 4.5% . The Child-Pugh score was the only independent predictive factor for bacterial translocation (odds ratio 2.22, P = 0.02) . CONCLUSIONS: Translocation of enteric organisms to mesenteric lymph nodes is increased in patients with advanced cirrhosis and is reduced to the level found in non-cirrhotic patients by selective intestinal decontamination.

Antibiot Khimioter, 2000, 45(11), 6 - 8
{Non-sporulating anaerobic bacteria and anastomosis failure in patients with gastric carcinoma}; Levanov AV et al.; Cases of anastomosis suture failure within the period from 1977 to 1987 and from 1988 to 1998 in 139 patients after various surgical operations for gastric carcinoma were analyzed . Infection in the cases of the anastomosis sUture failure at the early terms was mainly due to representatives of Enterobacteriaceae and at the later terms the failure was mainly due to non-sporulating anaerobes belonging to Bacteroidaceae . The data are indicative of the fact that the use of antimicrobials requires a differential approach.

An R Acad Nac Med (Madr), 2000, 117(1), 163 - 78; discussion 178-83
{Current interest of antipneumococcal vaccination}; del Rey Calero J; Pneumonia acquired in Community (CAP) may be a primary disease occurring in healthy individuals or secondary to predisposing factors or comorbidity . Prevalence of CAP is 2.6 to 5% for all ages, in USA 12%, for over 65 years 30% . Streptococcus pneumoniae is the commonest pathogen 30-50%, H . influenzae in COPD, the atypical pneumonia Mycoplasma pn., M . catharralis, Legionella pn., Enterobacteria, anaerobics often in hospital survey . In children is different RSV, Parainfluenzae type 3, Rhinovirus in the first 2 years old . Others are S . pneumoniae, H . influenzae, Chlamydia sp., etc . Appropriate empiric antibiotic therapy choices are based in guidelines . The most common pathogen is S . pneumoniae, isolates raised resistance rates to Penicillin to 20-50%, 40% in our country and also to Macrolides, with potential clinical failure (21-40%) . Specially in elderly people and with the comorbidity are recommended the 23 valent polysaccharide vaccine, effective in bacteremic pneumonia 70-80% . Is not effective in children under 2 years, for that is important conjugated vaccine Hib (toxoids T, D, CRM197, OMP Nm) to prevent carriers, otitis media and reduce exacerbation of these respiratory infections.

Pathol Biol (Paris), 2000 Dec, 48(10), 933 - 9
{Comparative antibacterial activity of cefotaxime, ceftazidime and cefepime with regard to different strains of Enterobacter aerogenes selected for their resistance to third generation cephalosporins}; Husson MO et al.; After being confronted with the isolation in our laboratory of numerous antibiotic-multiresistant Enterobacter aerogenes strains, we studied the in vitro antimicrobial activity of cefotaxime, ceftazidime, and cefepime alone or in association with sulbactam . For that, we selected 67 isolates according to their low level of susceptibility to cefotaxime . First, we deduced from a synergy test in presence of clavulanic acid and cloxacillin the production of an extended spectrum beta-lactamase (ESBL) and/or an overproduction of a chromosomal cephalosporinase . Three groups of strains were thus defined: one group of ESBL strains, another group of overproducing strains of chromosomal cephalosporinase, and a last group that produced the two types of enzymes . Minimal inhibitory concentrations (MICs) of each cephalosporin alone or in presence of 8 mg/L of sulbactam, gentamicin or amikacin were measured . Our results demonstrated the best activity of cefepime: MICs were low with a value inferior to 4 mg/L independently of the type of beta-lactamase . They were lower than 0.5 mg/L in presence of sulbactam against ESBL-producing strains . The cephalosporins could be used in association with aminoglycosides according to their susceptibility.

Z Naturforsch {C}, 2000 Nov-Dec, 55(11-12), 886 - 9
Antimicrobial activities of Ferulago essential oils; Demirci F et al.; Essential oils from Ferulago asparagifolia Boiss., F . galbanifera (Miller) W . Koch, F . humilis Boiss . (Endemic), F . trachycarpa Boiss . growing in Turkey were evaluated against 15 microorganisms for their antifungal and antibacterial activity using an agar tube dilution and microdilution broth susceptibility assay, respectively . The essential oil compositions were investigated by GC/MS . Inhibitory effects against Escherichia coli, Enterobacter aerogenes, Candida albicans, Gaeumannomyces graminis var . tritici, Sclerotium rolfsii and Fusarium moniliforme were remarkable . Results are discussed in comparison with the chemical composition of the essential oils.

Scand J Infect Dis, 2000, 32(6), 615 - 21
Increased incidence of bacteraemia due to viridans streptococci in an unselected population of patients with acute myeloid leukaemia; Persson L et al.; The aetiology, clinical characteristics and outcome of bacteraemia in patients with acute myeloid leukaemia were studied . All positive blood cultures collected at a haematological ward during 2 7-y periods were evaluated . Altogether, 274 episodes of bacteraemia in 152 patients were recorded, 80 episodes during 1980-86 and 194 during 1990-96 . During the 2 periods, trimethoprim-sulfamethoxazol in combination with amikacin was the first-line empirical therapy in patients with neutropaenia and fever . In 1990, antimicrobial prophylaxis with ciprofloxacin and fluconazole was introduced . The incidence of bacteraemia due to viridans streptococci or coagulase-negative staphylococci increased from the first period to the second, whereas the incidence of Enterobacteriaceae decreased . In granulocytopaenic patients during 1990-96, viridans streptococci accounted for 21% of the isolates and in patients treated prophylactically with fluoroquinolone, viridans streptococci accounted for 31% . All viridans streptococci were sensitive to penicillin . At the time of the positive blood cultures, the patients of the second period were granulocytopaenic in 83% of the episodes . The mortality related to septicaemia during the later period was 13% and only 1 of 33 (3%) of the patients with viridans streptococci died . Eight patients (9%) died in relation to septicaemia following curative antileukaemic therapy.

J Mol Microbiol Biotechnol, 2001 Jan, 3(1), 103 - 12
Phyloproteomics: species identification of Enterobacteriaceae using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; Conway GC et al.; To evaluate matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) as a tool for rapid identification of common clinical bacterial isolates, we analyzed 25 carefully selected isolates of pathogenic Escherichia coli (E . coli) and additional Enterobacteriaceae members . Organisms were prepared according to clinical microbiological protocols and analyzed with minimal additional processing . Spectra were reproducible from preparation to preparation and comprised 40-100 peaks primarily representing intracellular proteins with masses up to 25 kDa . Spectra of 14 genetically diverse bacteremic isolates of E . coli were compared with isolates representing other genera within the Enterobacteriaceae family . Using a new spectrum comparison algorithm, E . coli isolates were closely related to each other and were readily distinguishable from other Enterobacteriaceae, including Salmonella and Shigella . Presently, the methodology permits the analysis of 40 unknown isolates per hour per instrument . These results suggest that MALDI-ToF MS offers a rapid and reliable approach for performing phyloproteomics i.e., identification of unknown bacterial isolates based on similarities within protein biomarker databases.

J Basic Microbiol, 2000, 40(5-6), 343 - 9
Bacterial counts associated with poultry processing at different sampling times; Geornaras I et al.; Aerobic plate counts, Enterobacteriaceae counts and Pseudomonas counts were performed on neck skin samples from six processing steps in a poultry abattoir at three different sampling times . Sampling time 1 was shortly after start-up of processing operations, time 2 after a tea break which was preceded by a cold water rinse-down of equipment surfaces, and time 3 before shut-down . No significant differences (P > 0.05) in microbial numbers of neck skin samples were observed between the three sampling times at the six sampling sites . At this particular processing plant, therefore, sampling at any time of the processing shift would thus not lead to significantly different bacterial counts of neck skins . The lowest aerobic plate counts, over all three sampling times, were obtained for neck skins sampled after spray washing, and the highest for neck skins sampled after packaging . This indicated the efficacy of the washing step in reducing microbial contamination but subsequent re-contamination of carcasses . Despite the Pseudomonas counts of neck skins being lower than the Enterobacteriaceae counts at the beginning of processing, packaging of carcasses resulted in Pseudomonas counts that were higher than the Enterobacteriaceae counts.

J Food Prot, 2001 Jan, 64(1), 72 - 80
Quantification and variability analysis of bacterial cross-contamination rates in common food service tasks; Chen Y et al.; This study investigated bacterial transfer rates between hands and other common surfaces involved in food preparation in the kitchen . Nalidixic acid-resistant Enterobacter aerogenes B199A was used as a surrogate microorganism to follow the cross-contamination events . Samples from at least 30 different participants were collected to determine the statistical distribution of each cross-contamination rate and to quantify the natural variability associated with that rate . The transfer rates among hands, foods, and kitchen surfaces were highly variable, being as low as 0.0005% and as high as 100% . A normal distribution was used to describe the variability in the logarithm of the transfer rates . The mean +/- SD of the normal distributions were, in log percent transfer rate, chicken to hand (0.94 +/- 0.68), cutting board to lettuce (0.90 +/- 0.59), spigot to hand (0.36 +/- 0.90), hand to lettuce (-0.12 +/- 1.07), prewashed hand to postwashed hand (i.e., hand washing efficiency) (-0.20 +/- 1.42), and hand to spigot (-0.80 +/- 1.09) . Quantifying the cross-contamination risk associated with various steps in the food preparation process can provide a scientific basis for risk management efforts in both home and food service kitchens.

Enferm Infecc Microbiol Clin, 2000 Dec, 18(10), 500 - 5
{False resistance to imipenem in gram negative bacilli with and automatized system}; Fernandez F et al.; BACKGROUND: The aim of this study was to evaluate the reliability of MIC values of imipenem against gramnegative rods obtained with the automated system WalkAway-98 (MicroScan, Dade, USA) . MATERIAL AND METHODS: One-hundred and seventy three consecutive clinical isolates of Gram-negative rods for which the MIC of imipenem were > or = 4 mg/l (Urine-Combo 6I panels, U6I) or > or = 8 mg/l (Neg-Combo 6I panels, N6I) were evaluated, including 104 non-fermenting gram-negative rods (NFGNR) and 69 enterobacteria . Panels were inoculated and read according to manufacturer's instructions . Microdilution, according to NCCLS guidelines, was used as the method of reference . MIC of imipenem determined by WalllAway-96 and microdilution differing > or = 2 dilution steps from those obtained with mirodilution were considered as discrepant results . Discrepancies in clinical categories were also evaluated by calculating three types of errors: very major (false susceptibility), major (false resistance) and minor (either susceptible or resistant by one method and intermediate by the other one) . RESULTS: The percentages of discrepancies in the MIC of imipenem determined with U6I panels were 74% and 84% for NFGNR and enterobacteria, respectively . No very major errors were detected . Major errors were observed for 6% and 12% of the strains with U6I panels in NFGNR and enterobacteria, respectively, and in 12% (NFGNR) and 50% (enterobacteria) with N61 panels . With U61 panels minor errors were observed in 11% and 25% of NFGNR and enterobacteria, respectively, while with N61 panels minor error were observed in 39% and 45% of both groups, respectively . CONCLUSIONS: MIC of imipenem > or = 4 mg/l obtained with the WalkAway-96 system against gramnegative rods, particularly in the case of enterobacteria, should be confirmed with a reference susceptibility method.

Mol Plant Microbe Interact, 2001 Jan, 14(1), 10 - 20
Role of the nucleoid-associated protein H-NS in the synthesis of virulence factors in the phytopathogenic bacterium Erwinia chrysanthemi; Nasser W et al.; The ability of the enterobacterium Erwinia chrysanthemi to induce pathogenesis in plant tissue is strongly related to the massive production of plant-cell-wall-degrading enzymes (pectinases, cellulases, and proteases) . Additional factors, including flagellar proteins and exopolysaccharides (EPS), also are required for the efficient colonization of plants . Production of these virulence factors, particularly pectate lyases, the main virulence determinant, is tightly regulated by environmental conditions . The possible involvement of the protein H-NS in this process was investigated . The E . chrysanthemi hns gene was cloned by complementation of an Escherichia coli hns mutation . Its nucleotide sequence contains a 405-bp open reading frame that codes for a protein with 85% identity to the E . coli H-NS protein . An E . chrysanthemi hns mutant was constructed by reverse genetics . This mutant displays a reduced growth rate and motility but an increased EPS synthesis and sensitivity toward high osmolarity . Furthermore, pectate lyase production is dramatically reduced in this mutant . The hns mutation acts on at least two conditions affecting pectate lyase synthesis: induction of pectate lyase synthesis at low temperatures (25 degrees C) is no longer observed in the hns mutant and induction of pectate lyase production occurs in the late stationary growth phase in the hns background, instead of in the late exponential growth phase as it does in the parental strain . Moreover, the E . chrysanthemi hns mutant displays reduced virulence on plants . Taken together, these data suggest that H-NS plays a crucial role in the expression of the virulence genes and in the pathogenicity of E . chrysanthemi.

Aust Vet J, 2000 Dec, 78(12), 846 - 9
Application of ERIC-PCR for the comparison of isolates of Haemophilus parasuis; Rafiee M et al.; OBJECTIVE: To validate a polymerase chain reaction (PCR) based method . Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR), for the fingerprinting of Haemophilus parasuis strains and to use that method to differentiate isolates from apparently related outbreaks of Glasser's disease on three pig farms . DESIGN: ERIC-PCR was evaluated by comparing 15 different strains that represented all 15 recognised serovars in the Kielstein-Rapp-Gabrielson (KRG) scheme for serotyping H parasuis . Next, ERIC-PCR was used to examine 14 Australian field isolates of H parasuis; 12 collected from three farms suffering apparently related outbreaks of Glasser's disease and two from two other farms with no known connection . RESULTS: The 15 serovar reference strains all gave unique, reproducible ERIC-PCR fingerprints . The 12 isolates from the three apparently related outbreaks all gave a single fingerprint, which was distinct from any seen in the 15 serovar reference strains and the two other Australian field isolates in the studied farms . The confirmation that all 12 isolates were the same strain allowed the development of a prevention and control program that has prevented the emergence of any further outbreaks of Glasser's disease on the three farms . CONCLUSION: ERIC-PCR is a suitable technique for the differentiation of unrelated strains of H parasuis . The finding that the 12 field isolates of H parasuis all shared the same fingerprint is strong evidence that there was a common source of infection on all three farms . This study has shown, for the first time, that ERIC-PCR is a suitable technique for the sub-typing of H parasuis and useful for studying the epidemiology of outbreaks of Glasser's disease.

World J Surg, 2000 Dec, 24(12), 1537 - 41
Remaining small bowel length: association with catheter sepsis in patients receiving home total parenteral nutrition: evidence of bacterial translocation; Terra RM et al.; Patients with short bowel syndrome (SBS) receiving total parenteral nutrition (TPN) have a high incidence of catheter-related sepsis, one of its major complications . The aim of this study was to correlate the length of remaining small bowel (RSB) with septic episodes related to the central venous catheter in a group of patients with severe SBS with home TPN . The length of the RSB (<50 cm or > or = 50 cm) was related to the frequency of catheter sepsis, time until the first episode, and the agents responsible in eight SBS patients receiving home TPN . There were 13 episodes of catheter infection (0.88 per patient-year) . The group with a shorter RSB length (five patients) presented 1.3 to 2.76 infections/year and 2 to 9 months until the first episode, compared to 0 to 0.75 infections/ year (p = 0.0357) and 11 to 65 months until the first episode (p = 0.0332) in the group with the longer RSB . In the first group, the agents isolated were Enterobacteriae (Enterobacter sp., Klebsiella sp., Pseudomonas sp., and Proteus sp.) in eight episodes and Candida sp . in one . In the latter sepsis was caused by Staphylococcus sp . in three episodes and Pseudomonas sp . in one . Therefore patients with remaining small bowel shorter than 50 cm have a higher frequency of catheter-related sepsis, particularly by enteric microorganisms . This might be an evidence of the occurrence of bacterial translocation and its role in the pathogenesis of catheter-related sepsis in patients with an extremely short RSB receiving home TPN.

J Med Microbiol, 2001 Jan, 50(1), 29 - 34
Molecular analysis of clinical isolates of Providencia alcalifaciens; Sobreira M et al.; In an attempt to elucidate the virulence factors and the pathogenic mechanisms of Providencia alcalifaciens, 36 isolates identified in 1994-1995 in Recife city, Brazil were analysed by PCR to investigate the presence of DNA sequences homologous to virulence genes described in other invasive enterobacteria, as well as their ability to invade HeLa cells, their plasmid profiles and antibiotic resistance patterns . The genetic diversity of the isolates was also analysed by RAPD-PCR . No homologous sequences of virulence genes were observed with any of the P . alcalifaciens isolates studied . Ten isolates had no plasmid and 26 harboured one-to-five plasmids of 147-<6.9 kb . Invasion of HeLa cells was observed in only 10 isolates . No correlation between the plasmid content of the strains, their invasion of HeLa cells or their resistance to antimicrobial drugs could be established . The isolates could be distributed into 10 genotypic groups by RAPD-PCR . Considering the genotypic profile and ability to invade HeLa cells, 7 of the 10 invasive isolates belonged to the same genotypic group . The presence of invasive isolates in the same or a related genotypic group suggests the existence of a clonal lineage responsible for the invasiveness.

Akush Ginekol (Sofiia), 2000, 39(3), 19 - 22
{Nosocomial enterobacter - sepsis in neonatal intensive care unit in Pleven}; Rosmanova R et al.; At the recent years considerably increased the role of Enterobacter spp as causes of nosocomial sepsis in different intensive units . It is determined of their possibilities to change quick antibiotic resistance especially to third generation cephalosporins and wide insemination of the environment . During the period from 29.10.1997 to 30.12.1997 in Neonatal intensive care unit--Pleven have been registered 9 cases of nosocomial sepsis caused by Enterobacter aerogenes . The clinic picture run with shock, temperature instability, hyperbilirubinemia, mottling respiratory insufficiency, I/T ratio > 0.2 . Thrombocytopenia . Detection of the pathogen organisms present wide antibiotics resistance to cephalosporins . The microbiological control of the environment have been isolated Enterobacter spp from neonatal intensive unit, delivery room, unit for healthy newborn . The persistence of Enterobacter infections is a result of low supply of household linen, detergents, single-used products and widely used of cephalosporins, insufficient staff and overpopulation with patients.

Urologiia, 2000 Mar-Apr, (2), 8 - 15
{Practical approaches of antibiotics choice in uncomplicated urinary tract infections}; Strachunskii LS et al.; Infections of the urinary tract (IUT) belong to the most prevalent infectious diseases . Acute cystitis is the most frequent symptom of uncomplicated IUT . The main agents of IUT are gram-negative enterobacteria, mainly Escherichia coli (80%) . The agents of uncomplicated IUT are the least resistant (5%) to fluoroquinolones (norfloxacin and ciprofloxacin) . The duration of antibiotic therapy for acute cystitis is determined predominantly by risk factors: a 7-day course is recommended for cases with risk factors and a 3-day one for cases without risk factors . In acute pyelonephritis antibiotic therapy should be longer (10-14 days) . Preventive therapy is recommended for patients with frequent relapses of IUT.

Int J Antimicrob Agents, 2000 Sep, 16(1), 5 - 15
The fluoroquinolone antibacterials: past, present and future perspectives; Appelbaum PC et al.; The history of the development of the quinolones is described from the first quinolone, nalidixic acid, via the first 6-fluorinated quinolone norfloxacin, to the latest extended-spectrum fluoroquinolones . The structural modifications made to the basic quinolone and naphthyridone nucleus and to the side chains have allowed improvements to be made such that the next group of fluoroquinolones after norfloxacin, exemplified by ciprofloxacin, had high activity against gram-negative species and a number of atypical pathogens, good-to-moderate activity against gram-positive species and were well absorbed and distributed . These compounds have been successfully used in the clinic for a decade and the size of the market has risen in recent years to only a little less than that for penicillins and macrolides . Notwithstanding the broad spectrum of these compounds, defects became evident . The growth in understanding of structure activity relationships with fluoroquinolones has enabled the development of even better compounds . The targets in fluoroquinolone research during the last few years include: improvements in pharmacokinetic properties, greater activity against gram-positive cocci and anaerobes, activity against fluoroquinolone-resistant strains, and improvements in activity against non-fermentative gram-negative species . The compounds developed in the recent years have fulfilled some but not all of these goals; improved bioavailability is one target achieved with most of the more recent compounds allowing for once-daily dosing . Gatifloxacin, moxifoxacin and trovafloxacin have all greatly improved the activity against gram-positive cocci, particularly pneumococci, and against anaerobes . They are not quite as active as ciprofloxacin against Enterobacteriaceae, and show no substantial improvements in activity against non-fermentative species . Clinafloxacin, gemifloxacin and sitafloxacin have even better activity against gram-positive cocci and are as active as ciprofloxacin against most gram-negatives, though gemifloxacin is less active than the other new compounds against gram-negative anaerobes . These three compounds do retain some activity against a number of ciprofloxacin-resistant species (gram-positive and gram-negative), but whether this activity will be adequate for clinical use is at present unclear . Both clinafloxacin and sitafloxacin contain a chloro substituent at position 8 of the quinolone nucleus . A halogen at this position in a number of compounds, though giving good activity, has also been associated with phototoxicity . Several fluoroquinolones have had to be withdrawn or strictly limited in their use post-marketing and in some cases no obvious relationship can be seen between the adverse effects and structural features, making this an area for urgent research.

Med Sci Monit, 2000 Mar-Apr, 6(2), 285 - 90
Comparison of bacterial flora found in the peritoneal cavity and drains after intraabdominal surgery; Chylak J et al.; The aim of this study was to evaluate bacterial flora infecting during the surgical procedures the peritoneal cavity and drains which were used after the surgery in 40 patients who underwent surgery for colon and rectum tumors . Smears from the peritoneal cavity, liquid removed from the drain taken at 3-4 days after the surgery and smears from the drain taken at the end of drainage of each patient were examined for bacterial content . The comparison of bacterial flora found in the peritoneal cavity with bacteria found in drains showed that the frequency of isolation of anaerobes decreased in contrast to aerobes which were more often cultured over the time of drainage (p < 0.05) . Bacteroides spp, enterococci, and strains of Enterobacteriaceae were most often isolated from the peritoneal cavity, but over the time of drainage the frequency of isolation of coagulase-negative staphylococci including MRCNS increased as well as the number of patients infected with enterococci, whereas anaerobes and strains of Enterobacteriaceae were rarely isolated.

Antimicrob Agents Chemother, 2001 Mar, 45(3), 883 - 92
Phenotypic resistance of Staphylococcus aureus, selected Enterobacteriaceae, and Pseudomonas aeruginosa after single and multiple in vitro exposures to ciprofloxacin, levofloxacin, and trovafloxacin; Gilbert DN et al.; The phenotypic resistance of selected organisms to ciprofloxacin, levofloxacin, and trovafloxacin was defined as a MIC of > or =4 microg/ml . The dynamics of resistance were studied after single and sequential drug exposures: clinical isolates of methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA), Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa were utilized . After a single 48-h exposure of a large inoculum to four times the initial MIC for the organism, the frequency of selection of resistant mutants of MSSA was greater for trovafloxacin than levofloxacin (P = 0.008); for E . cloacae, the frequency was highest for ciprofloxacin and lowest for levofloxacin and trovafloxacin; for S . marcescens, the frequency was highest for trovafloxacin and lowest for ciprofloxacin (P = 0.003) . The results of serial passage experiments were analyzed both by the Kaplan-Meier product-limited method as well as by analysis of variance of mean inhibitory values . By both methods, MSSA and MRSA expressed mutants resistant to ciprofloxacin after fewer passages than were required for either levofloxacin or trovafloxacin . For the aerobic gram-negative bacilli, two general patterns emerged . Mutants resistant to trovafloxacin appeared sooner and reached higher mean MICs than did mutants resistant to levofloxacin or ciprofloxacin . Mutants resistant to ciprofloxacin appeared later and reached mean MICs lower than the MICs of the other two drugs studied . Even though individual strain variation occurred, the mean MICs were reproduced when the serial passage experiment was repeated using an identical panel of E . coli isolates . In summary, the dynamic selection of fluoroquinolone-resistant bacteria can be demonstrated in experiments that employ serial passage of bacteria in vitro.

Antimicrob Agents Chemother, 2001 Mar, 45(3), 825 - 36
In vitro and in vivo properties of Ro 63-9141, a novel broad-spectrum cephalosporin with activity against methicillin-resistant staphylococci; Hebeisen P et al.; Ro 63-9141 is a new member of the pyrrolidinone-3-ylidenemethyl cephem series of cephalosporins . Its antibacterial spectrum was evaluated against significant gram-positive and gram-negative pathogens in comparison with those of reference drugs, including cefotaxime, cefepime, meropenem, and ciprofloxacin . Ro 63-9141 showed high antibacterial in vitro activity against gram-positive bacteria except ampicillin-resistant enterococci, particularly vancomycin-resistant strains of Enterococcus faecium . Its MIC at which 90% of the isolates tested were inhibited (MIC(90)) for methicillin-resistant Staphylococcus aureus (MRSA) was 4 microg/ml . Ro 63-9141 was bactericidal against MRSA . Development of resistance to the new compound in MRSA was not observed . Ro 63-9141 was more potent than cefotaxime against penicillin-resistant Streptococcus pneumoniae (MIC(90) = 2 microg/ml) . It was active against ceftazidime-susceptible strains of Pseudomonas aeruginosa and against Enterobacteriaceae except Proteus vulgaris and some isolates producing extended-spectrum beta-lactamases . The basis for the antibacterial spectrum of Ro 63-9141 lies in its affinity to essential penicillin-binding proteins, including PBP 2' of MRSA, and its stability towards beta-lactamases . The in vivo findings were in accordance with the in vitro susceptibilities of the pathogens . These data suggest the potential utility of Ro 63-9141 for the therapy of infections caused by susceptible pathogens, including MRSA . Since insufficient solubility of Ro 63-9141 itself precludes parenteral administration in humans, a water-soluble prodrug, Ro 65-5788, is considered for development.

Antimicrob Agents Chemother, 2001 Mar, 45(3), 723 - 6
Incidence of class 1 and 2 integrases in clinical and commensal bacteria from livestock, companion animals, and exotics; Goldstein C et al.; Many pathogenic and commensal organisms are multidrug resistant due to exposure to various antibiotics . Often, this antimicrobial resistance is encoded by integrons that occur on plasmids or that are integrated into the bacterial chromosome . Integrons are commonly associated with bacterial genera in the family Enterobacteriaceae . We determined that class 1 integrases were present in approximately 46% of the isolates from the family Enterobacteriaceae; class 2 integrases were present only among Escherichia coli and Salmonella isolates . Seven percent of veterinary isolates were positive for class 3 integrase by DNA-DNA hybridization but could not be confirmed to be positive by PCR . None of the veterinary isolates possessed the class 4 integrase gene . The distribution of these integrase genes was variable within the members of the family Enterobacteriaceae when some or all integrase classes were absent from a particular genus . There was also considerable variability in the distribution of these integrases within a species, depending on the animal host . Unlike the class 1 integrases, the other integrase class, intI2, appears to be more restricted in its distribution among the members of the family Enterobacteriaceae . There is also considerable variability in the distribution of the class 1 integrases within E . coli strains isolated from different food animals . The class 1 integrases are the most widely disseminated of the four classes among the members of the family Enterobacteriaceae from both the clinical and normal flora of animals . This is the first report to closely examine the distribution of class 2 integrases in members of the family Enterobacteriaceae isolated in the United States.

Luminescence, 2001 Jan-Feb, 16(1), 33 - 8
Enterobacter cloacae leukotoxin: modulation of reactive oxidant species generated by neutrophils; Barnes AI et al.; A leukotoxin purified from Enterobacter cloacae culture by saline precipitation, gel chromatography and HPLC was studied as a modulator of reactive oxidant species (ROS) produced by human neutrophils . Chemiluminescence showed that stimulation of ROS was achieved at a low leukotoxin concentration, but ROS production decreased when the toxin was applied at concentrations above 30 microg/mL . Also, the addition of 100 microg toxin/mL significantly reduced the activating effect of phorbol myristate acetate (PMA) and low doses of toxin did not produce an opposite effect toward the stimulation produced by PMA . Normal neutrophils showed a linear correlation between the inverse of ROS production and time, but the kinetic reaction changed when toxins were added to the cells and the ROS formation increased directly with time .

FEMS Microbiol Lett, 2001 Feb 20, 195(2), 185 - 90
Extension of resistance to cefepime and cefpirome associated to a six amino acid deletion in the H-10 helix of the cephalosporinase of an Enterobacter cloacae clinical isolate; Barnaud G et al.; Enterobacter cloacae CHE, a clinical strain with overproduced cephalosporinase was found to be highly resistant to the new cephalosporins, cefepime and cefpirome (MICs> or =128 microg ml(-1)) . The strain was isolated from a child previously treated with cefepime . The catalytic efficiency of the purified enzyme with the third-generation cephalosporins, cefepime and cefpirome, was 10 times higher than that with the E . cloacae P99 enzyme . This was mostly due to a decrease in K(m) for these beta-lactams . The clinical isolate produced large amounts of the cephalosporinase because introduction of the ampD gene decreased ampC expression and partially restored the wild-type phenotype . Indeed, MICs of cefepime and cefpirome remained 10 times higher than those for a stable derepressed clinical isolate (OUDhyp) transformed with an ampD gene . Sequencing of the ampC gene showed that 18 nucleotides had been deleted, corresponding to the six amino acids SKVALA (residues 289--294) . According to the crystal structure of P99 beta-lactamase, this deletion was located in the H-10 helix . The ampR-ampC genes from the clinical isolates CHE and OUDhyp were cloned and expressed in Escherichia coli JM101 . The MICs of cefpirome and cefepime of E . coli harboring ampC and ampR genes from CHE were 100--200 times higher than those of E . coli harboring ampC and ampR genes from OUDhyp . This suggests that the deletion, confirmed by sequencing of the ampC gene, is involved in resistance to cefepime and cefpirome . However, the high level of resistance to cefepime and cefpirome observed in the E . cloacae clinical isolate was due to a combination of hyperproduction of the AmpC beta-lactamase and structural modification of the enzyme . This is the first example of an AmpC variant conferring resistance to cefepime and cefpirome, isolated as a clinical strain.

Infect Immun, 2001 Mar, 69(3), 1477 - 82
Signaling by toll-like receptor 2 and 4 agonists results in differential gene expression in murine macrophages; Hirschfeld M et al.; Lipopolysaccharide (LPS) derived from the periodontal pathogen Porphyromonas gingivalis has been reported to differ structurally and functionally from enterobacterial LPS . These studies demonstrate that in contrast to protein-free enterobacterial LPS, a similarly purified preparation of P . gingivalis LPS exhibited potent Toll-like receptor 2 (TLR2), rather than TLR4, agonist activity to elicit gene expression and cytokine secretion in murine macrophages and transfectants . More importantly, TLR2 stimulation by this P . gingivalis LPS preparation resulted in differential expression of a panel of genes that are normally induced in murine macrophages by Escherichia coli LPS . These data suggest that (i) P . gingivalis LPS does not signal through TLR4 and (ii) signaling through TLR2 and through TLR4 differs quantitatively and qualitatively . Our data support the hypothesis that the shared signaling pathways elicited by TLR2 and by TLR4 agonists must diverge in order to account for the distinct patterns of inflammatory gene expression.

Curr Microbiol, 2001 Apr, 42(4), 252 - 6
Microbiological and biochemical study of coffee fermentation; Avallone S et al.; The coffee fermentation microflora were rich and mainly constituted of aerobic Gram-negative bacilli, with Erwinia and Klebsiella genuses at the highest frequencies . The best population increase was observed with lactic acid bacteria and yeasts, whereas those microorganisms that counted on a pectin medium remained constant during the fermentation step . Qualitatively, lactic acid bacteria belonged mainly to Leuconostoc mesenteroides species but the others microflora were relatively heterogeneous . The microorganisms isolated on pectin medium were Enterobacteriaceae, identified as Erwinia herbicola and Klebsiella pneumoniae, not reported as strong pectolytic strains . Throughout coffee fermentation, 60% of the simple sugars were degraded by the total microflora and not specifically by pectolytic microorganisms.

Pediatr Infect Dis J, 2001 Jan, 20(1), 102 - 3; discussion 120-2
In vitro and in vivo antimicrobial activity of topical ofloxacin and other ototopical agents; Klein JO; BACKGROUND: Ototopical agents are extensively used for otitis externa (OE), acute otitis media identified by otorrhea in patients who have tympanostomy tubes (AOM-TT) and chronic suppurative otitis media (CSOM) . The quinolones have particular value as ototopical agents because of the broad spectrum of antibacterial activity of importance in otic diseases and the high concentrations of antibacterial activity at the site of infection . METHODS: A survey of literature on in vitro activity and microbiologic efficacy in clinical trials of quinolone otic products for OE, AOM-TT and CSOM . RESULTS: OE: Floxin otic and Cortisporin TC otic suspension were equally effective in eradicating the three major pathogens Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus . CSOM: Ofloxacin otic was effective in an open label trial in uniform eradication of S . aureus, P . aeruginosa, Proteus mirabilis and Enterobacter spp . AOM-TT: Ofloxacin otic and amoxicillin/clavulanate (by mouth) were equivalent clinically; rates of eradication of initial pathogens were similar for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, but ofloxacin otic was superior in eradication of S . aureus and P . aeruginosa CONCLUSIONS: In each of the studies of OE, CSOM and AOM-TT, ofloxacin otic solution was effective in eradicating the bacterial pathogen from the site of infection: equivalent to Cortisporin for children with OE; superior to amoxicillin/clavulanate for patients with AOM-TT who had acute drainage; and effective in eradicating bacterial pathogens from the external canal of patients with CSOM.

Proc Natl Acad Sci U S A, 2001 Feb 13, 98(4), 1883 - 8 Epub 2001 Jan 30.
The insect endosymbiont Sodalis glossinidius utilizes a type III secretion system for cell invasion; Dale C et al.; Sodalis glossinidius is a maternally transmitted secondary endosymbiont residing intracellularly in tissues of the tsetse flies, Glossina spp . In this study, we have used Tn5 mutagenesis and a negative selection procedure to derive a S . glossinidius mutant that is incapable of invading insect cells in vitro and is aposymbiotic when microinjected into tsetse . This mutant strain harbors Tn5 integrated into a chromosomal gene sharing high sequence identity with a type III secretion system invasion gene (invC) previously identified in Salmonella enterica . With the use of degenerate PCR, we have amplified a further six Sodalis inv/spa genes sharing high sequence identity with type III secretion system genes encoded by Salmonella pathogenicity island 1 . Phylogenetic reconstructions based on the inv/spa genes of Sodalis and other members of the family Enterobacteriaceae have consistently identified a well-supported clade containing Sodalis and the enteric pathogens Shigella and Salmonella . These results suggest that Sodalis may have evolved from an ancestor with a parasitic intracellular lifestyle, possibly a latter-day entomopathogen . These observations lend credence to a hypothesis suggesting that vertically transmitted mutualistic endosymbionts evolve from horizontally transmitted parasites through a parasitism-mutualism continuum.

J Hosp Infect, 2001 Feb, 47(2), 116 - 24
Evaluation of the contribution of isolation precautions in prevention and control of multi-resistant bacteria in a teaching hospital; Eveillard M et al.; From February 1999 to January 2000, a control programme to prevent the spread multi-resistant bacteria (MRB) was implemented in a French teaching hospital . This programme focused on methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBL), and was based on the application of barrier precautions (washing hands with antiseptic soaps, wearing disposable gloves and gowns, identifying MRB carriers) . No changes in antibiotic policy occurred during the year . Our aim was to conduct an evaluation of this programme by measuring incidence rates . Concurrently, the effect of barrier precautions was estimated in an indirect way, by documenting the availability of barrier precautions in MRB carriers' rooms and by analysing the monthly correlation between the supply of such material and the theoretical cumulated length of MRB carriers' isolation in six randomized wards . All MRB isolated in hospitalized patients were recorded, and differentiated between acquisition in our hospital or from elsewhere . For the analysis of trends, the year was divided in three periods of four months . Over the year, the global MRB incidence was 1.26 per 1000 patient-days (PD) {95% confidence interval (95%CI)=1.16-1.36} . The MRSA incidence was 0.89 per 1000 PD (95%CI=0.81- 0.97) and the ESBL incidence was 0.38 per 1000 PD (95% CI=0.33-0.43) . The MRB incidence decreased significantly in all types of specialties except for surgical wards . The incidence decreased by 17.9% for MRSA, 54.9% for ESBL and 34.8% for both MRB . Concurrently, the proportion of strains acquired in our hospital decreased for MRSA (P for trend > or = 0.05) and ESBL (P for trend > or = 0.01), whereas the incidence of imported strains increased slightly . The proportion of multiresistant strains in S . aureus (36.8%) and Enterobacter aerogenes (37.0%) remained similar throughout the year . Thus, the decrease of the incidence concerned both resistant and susceptible strains . The availability of antiseptic soaps increased significantly (P for trend > or = 0.01) . The amount of antiseptic soap ordered and the theoretical lengths of isolation were correlated on a monthly basis (Spearman coefficient = 0.72; P > or = 0.02) . These results shows the efficacy of such a programme of MRB containment in a large hospital, provided barrier nursing is instigated, together with the availability of such material as antiseptic soap, to allow implementation .

Mol Microbiol, 2001 Feb, 39(3), 781 - 91
Substrate complexes and domain organization of the Salmonella flagellar export chaperones FlgN and FliT; Bennett JC et al.; The flagellar proteins FlgN and FliT have been proposed to act as substrate-specific export chaperones, facilitating incorporation of the enterobacterial hook-associated axial proteins (HAPs) FlgK/FlgL and FliD into the growing flagellum . In Salmonella typhimurium flgN and fliT mutants, the export of target HAPs was reduced, concomitant with loss of unincorporated flagellin into the surrounding medium . Gel filtration chromatography of wild-type S . typhimurium cell extracts identified stable pools of FlgN and FliT homodimers in the cytosol, but no chaperone-substrate complexes were evident . Nevertheless, stable unique complexes were assembled efficiently in vitro by co-incubation of FlgN and FliT with target HAPs purified from recombinant Escherichia coli . The sizes of the chaperone-substrate complexes indicated that, in each case, a chaperone homodimer binds to a substrate monomer . FlgN prevented in vitro aggregation of FlgK monomers, generating a soluble form of the HAP . Recombinant polypeptides spanning the potentially amphipathic C-terminal regions of FlgN or FliT could not complement in trans the chaperone deficiency of the respective flgN and fliT mutants, but efficient flagellar assembly was restored by homodimeric translational fusions of these domains to glutathione S-transferase, which bound FlgK and FlgL like the wild-type FlgN . These data provide further evidence for the substrate-specific chaperone function of FlgN and FliT and indicate that these chaperones comprise common N- and C-terminal domains mediating homodimerization and HAP substrate binding respectively . In support of this view, the flgN mutation was specifically complemented by a hybrid chaperone comprising the N-terminal half of FliT and the C-terminal half of FlgN.

Clin Microbiol Infect, 2000 Sep, 6(9), 460 - 3
Recommendation for treatment of severe infections caused by Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs); Paterson DL; Extended-spectrum beta-lactamase (ESBL)-producing organisms are a global problem . No randomized controlled trials have ever been performed to guide optimal treatment . However, in vitro studies and observational studies strongly suggest that carbapenems (imipenem or meropenem) should be regarded as drugs of choice for serious infections due to ESBL-producing organisms . Other beta-lactam antibiotics (cefepime, beta-lactam/beta-lactamase inhibitor combinations) are not suitable as first-line therapy . The increasing frequency of the association between quinolone resistance and ESBL production have greatly limited the role of this class of antibiotic against ESBL producers.

Clin Microbiol Infect, 2000 Jul, 6(7), 376 - 84
Clinical and molecular epidemiology of chromosome-mediated resistance to third-generation cephalosporins in Enterobacter isolates in eastern France; Talon D et al.; OBJECTIVE: To determine both the prevalence of group I beta-lactamase-related resistance and the clinical setting in which resistance to expanded-spectrum cephalosporins occurs . METHODS: Isolates of Enterobacter spp . were sensitivity tested to a range of antibiotics, and selected isolates were DNA fingerprinted by pulsed-field gel electrophoresis . The medical records of all patients with positive cultures for Enterobacter spp . were reviewed to determine the effect of previous antibiotic treatment on the susceptibility profile of these organisms . RESULTS: The crude incidence of colonization/infection (n = 315) was 0.51 per 100 patients and 0.73 per 1000 days of hospitalization . The 4-day and 7-day Kaplan-Meier rates of colonization/infection with Enterobacter were estimated to be 7.57% (standard deviation (SD = 3.26%) and 4.16% (SD = 2.88%)), respectively . The time lag to colonization/infection with isolates producing large amounts of Bush group 1 beta-lactamase (HLBL) (27.35 +/- 27.30 days) was significantly different from that to colonization/infection with wild-type isolates (13.59 +/- 17.93 days) (P = 0.036) . Ninety-six isolates (30.5%) demonstrated acquired resistance to expanded-spectrum cephalosporins: 34 isolates (10.8%) produced extended-spectrum beta-lactamase, and 62 isolates (19.7%) produced HLBL . The 89 Enterobacter isolates susceptible to third-generation cephalosporins yielded 84 major DNA patterns, and the 45 HLBL isolates yielded 38 major DNA patterns . The risk of colonization/infection with HLBL-producing Enterobacter was higher in cases of antimicrobial treatment with third-generation cephalosporins or a fluoroquinolone, and in cases of urinary tract colonization/infection . CONCLUSIONS: The judicious use in hospitals of both expanded-spectrum cephalosporins and other antibiotics such as fluoroquinolones is necessary to curtail the emergence of resistance in Enterobacter spp.

Clin Microbiol Infect, 2000 Jun, 6(6), 316 - 23
TEM-24 extended-spectrum beta-lactamase-producing Enterobacter aerogenes: long-term clonal dissemination in French hospitals; Galdbart JO et al.; OBJECTIVE: To investigate interstrain relatedness of TEM-24-producing Enterobacter aerogenes clinical strains isolated between 1993 and 1998 in 10 French hospitals from nine areas by pulsed-field gel electrophoresis (PFGE) and plasmid patterns . METHODS: Fifteen TEM-24-producing strains and a set of 16 control strains having various other antibiotic resistance phenotypes were genotyped by PFGE . Plasmid DNA from TEM-24-producing strains and transconjugants was analyzed . RESULTS: Analysis of XbaI macrorestriction patterns revealed only minor variations, and showed that all 15 TEM-24-producing strains were closely related . Some isolates originating from distant areas had indistinguishable patterns . According to their clustering correlation coefficients, they were also genomically distant from the control strains . Two plasmid patterns were observed in TEM-24-producing strains, one of them in 13 of the strains . Large plasmids of 85 kb encoding TEM-24 beta-lactamase were present in all isolates and, in all except one strain, could be transferred with high frequency by conjugation . CONCLUSIONS: These results confirm that the spread of the TEM-24 extended-spectrum beta-lactamase in France was essentially due to the dissemination of a single clone.

Clin Microbiol Infect, 2000 Jun, 6(6), 294 - 302
Meropenem versus imipenem/cilastatin as empirical monotherapy for serious bacterial infections in the intensive care unit; Verwaest C; Belgian Multicenter Study Group; OBJECTIVE: To compare the efficacy and tolerability of meropenem and imipenem/cilastatin as empirical monotherapy in intensive care unit (ICU) patients with serious bacterial infections . METHODS: A multicenter, open-label, randomized, parallel-group trial was conducted in Belgium, evaluating empirical monotherapy with meropenem or imipenem/cilastatin (both 1 g/8 h intravenously) in ICU patients with one or more of the following infections caused by sensitive pathogens: lower respiratory tract infection (LRTI) in ventilated patients, intra-abdominal infection or sepsis . RESULTS: The overall satisfactory clinical response rate at the end of randomized treatment was 77.0% (67/87) with meropenem and 68.1% (62/91) with imipenem/cilastatin (difference 8.9%; 95% confidence interval -4.2% to 21.9%; P = 0.185) . The two drugs produced similar satisfactory clinical response rates against LRTIs: 68.3% (41/60) with meropenem versus 68.6% (35/51) with imipenem/cilastatin . Meropenem appeared to be slightly more effective against intra-abdominal infections: 95.5% (21/22) versus 76.7% (23/30), respectively . All five meropenem recipients with sepsis had a satisfactory clinical response, compared to 40.0% (4/10) of those who received imipenem/cilastatin . The overall satisfactory bacteriologic response rate was 67.1% (49/73) with meropenem and 60.3% (44/73) with imipenem/cilastatin (difference 6.9%; 95% confidence interval -8.7% to 22.4%; P = 0.389) . The predominant pathogens were Escherichia coli, Enterobacter spp . and Pseudomonas aeruginosa . No incidences of drug-related nausea and vomiting were reported, but one probable drug-related seizure occurred in the imipenem/cilastatin group . CONCLUSIONS: Meropenem is at least as efficacious (clinically and bacteriologically) as imipenem/cilastatin for the empirical monotherapy of serious bacterial infections in ICU patients, and it can therefore be considered a useful option in this setting . Moreover, meropenem is well tolerated and offers several potential advantages, including greater in vitro activity against Gram-negative pathogens and the option of bolus administration.

Int J Antimicrob Agents, 2001 Feb, 17(2), 123 - 9
Intra- and inter-generic plasmid-mediated spread of cephalosporin and aminoglycoside resistance amongst Klebsiella aerogenes K41 and other enterobacteria; Verma A et al.; Klebsiella aerogenes K41, resistant to third generation cephalosporins and aminoglycosides, was isolated from clinical samples of 153 in-patients . Blood cultures accounted for 24 (15.7%) of isolates . The MIC(90) of ceftazidime for the isolates of 84 patients was >512 mg/l and was reduced to 2.0 by 4 mg/l of clavulanic acid, but only to 64 by 4 mg/l of sulbactam . Isolates of K . aerogenes K41 produced extended-spectrum beta-lactamase (ESBL) SHV-5 and TEM-1, identified by isoelectric focusing . Plasmid profiles showed that co-dissemination of cephalosporin and aminoglycoside resistance, plus ESBL production, coincided with the acquisition of a 116-kb plasmid . This plasmid was transferable in vitro from K . aerogenes K41 to other serotypes and genera of the Enterobacteriaceae.

Microbiology, 2001 Jan, 147(Pt 1), 203 - 13
Cloning and characterization of the gene encoding periplasmic 2',3'-cyclic phosphodiesterase of Yersinia enterocolitica O:8; Trulzsch K et al.; The gene encoding periplasmic 2',3'-cyclic phosphodiesterase in Yersinia enterocolitica O:8 (designated cpdB), was cloned and expressed in Escherichia coli . This enzyme enables Y . enterocolitica to grow on 2',3'-cAMP as a sole source of carbon and energy . Sequencing and analysis of a 3 kb ECO:RI fragment containing the cpdB gene revealed an open reading frame of 1179 bp, corresponding to a protein with a molecular mass of 71 kDa . The first 25 amino acid residues show features of a typical prokaryotic signal sequence . The predicted molecular mass of the mature peptide is therefore in agreement with the molecular mass estimated by SDS gel electrophoresis (68 kDa) . The putative cpdB promoter region contains two possible -10 and -35 regions . Furthermore, the 5' untranslated region contains sequences with significant homology to the cyclic AMP-cyclic AMP receptor protein binding site and the sigma(28) consensus . This region is interrupted by an enterobacterial repetitive intergenic consensus (ERIC) sequence . Deletion of the ERIC element from the cpdB promoter region had no effect on cpdB expression . In the 3' untranslated region, a possible rho-independent transcriptional terminator was identified . The deduced amino acid sequence of the Y . enterocolitica CpdB protein shows 76% identity with CpdB of Salmonella typhimurium and E . coli . CpdB of Y . enterocolitica is exported to the periplasmic space . An isogenic Y . enterocolitica cpdB mutant strain, constructed by allelic exchange, was no longer able to grow on 2',3'-cAMP as sole source of carbon and energy . The CpdB mutant showed no significant change in virulence in an oral and intravenous mouse infection model.

J Immunol, 2001 Feb 15, 166(4), 2342 - 7
Bacterial lipopolysaccharide activates HIV long terminal repeat through Toll-like receptor 4; Equils O et al.; In HIV-infected patients, concurrent infections with bacteria and viruses are known to induce HIV replication as assessed by increases in plasma HIV RNA levels . In the present study, we determined the cell surface receptor and molecular mechanisms of enterobacterial LPS-induced HIV transcription . Human dermal microvessel endothelial cells (HMEC) were transfected with an HIV-long terminal repeat (LTR)-luciferase construct and subsequently stimulated with purified bacterial LPS . Our studies demonstrate that human Toll-like receptor 4 (TLR4) mediates LPS-induced NF-kappaB and HIV-LTR activation in HMEC through IL-1 signaling molecules, namely myeloid differentiation protein, IL-1R-associated kinase, TNFR-associated factor, and NF-kappaB-inducing kinase . Cotransfection of HMEC with HIV-LTR-luciferase and TLR4 cDNA from LPS-hyporesponsive C3H/HeJ mice abrogates LPS-induced HIV transcription as does the use of dominant-negative mutants of the IL-1 signaling molecules . Transfection of HMEC with an HIV-LTR-mutant that lacks the NF-kappaB binding site or pretreatment of cells with chemical inhibitors of the NF-kappaB pathway also blocked LPS-induced HIV-LTR transactivation . These data support the conclusion that TLR4 mediates enterobacterial LPS-induced HIV transcription via IL-1 signaling molecules and NF-kappaB activation plays an important role in HIV-LTR transactivation.

J Immunol, 2001 Feb 1, 166(3), 1871 - 6
Conventional alpha beta T cells are sufficient for innate and adaptive immunity against enteric Listeria monocytogenes; Bregenholt S et al.; We have begun to dissect the cellular requirements for generation of immunity against enteric infection by Listeria monocytogenes using a novel T(-) B(-) NK(-) mouse strain (mice double deficient for the common cytokine receptor gamma-chain (gamma(c)) and the recombinase-activating gene-2 (RAG2/gamma(c) mice) . Initial experiments showed that C57BL/6 mice and alymphoid RAG2/gamma(c) mice had similar kinetics of bacterial accumulation in the spleen, liver, and brain early after intragastric L . monocytogenes infection (up to day 3), calling into question the physiologic role of gut-associated lymphoid cells during the passage of this enterobacterium into the host . However, in contrast to C57BL/6 mice, RAG2/gamma(c) mice rapidly succumbed to disseminated infection by day 7 . Polyclonal lymph node CD4(+) and CD8(+) alphabeta T cells were able to confer RAG2/gamma(c) mice with long-lasting protection against enteric L . monocytogenes infection in the absence of gammadelta T, NK, and NK-T cells . Moreover, these alphabeta T-reconstituted RAG2/gamma(c) mice produced IFN-gamma at levels comparable to C57BL/6 mice in response to L . monocytogenes both in vitro and in vivo . Protection was IFN-gamma dependent, as RAG2/gamma(c) mice reconstituted with IFN-gamma-deficient alphabeta T cells were unable to control enteric L . monocytogenes infection . Furthermore, alphabeta T cell-reconstituted RAG2/gamma(c) mice were able to mount memory responses when challenged with lethal doses of L . monocytogenes . These data suggest that NK, NK-T, gammadelta T, and B cells are functionally redundant in the immunity against oral L . monocytogenes infection, and that in their absence alphabeta T cells are able to mediate the early IFN-gamma production required for both innate and adaptive immunity.

Antimicrob Agents Chemother, 2001 Feb, 45(2), 532 - 9
Antimicrobial properties and mode of action of the pyrrothine holomycin; Oliva B et al.; Holomycin, a member of the pyrrothine class of antibiotics, displayed broad-spectrum antibacterial activity, inhibiting a variety of gram-positive and gram-negative bacteria, with the exception of Enterobacter cloacae, Morganella morganii, and Pseudomonas aeruginosa . The antibiotic lacked activity against the eukaryotic microorganisms Saccharomyces cerevisiae and Candida kefyr . Holomycin exhibited a bacteriostatic response against Escherichia coli that was associated with rapid inhibition of RNA synthesis in whole cells . Inhibition of RNA synthesis could have been a secondary consequence of inhibiting tRNA aminoacylation, thereby inducing the stringent response . However, the levels of inhibition of RNA synthesis by holomycin were similar in a stringent and relaxed pair of E . coli strains that were isogenic except for the deletion of the relA gene . This suggests that inhibition of RNA synthesis by holomycin could reflect direct inhibition of DNA-dependent RNA polymerase . Examination of the effects of holomycin on the kinetics of the appearance of beta-galactosidase in induced E . coli cells was also consistent with inhibition of RNA polymerase at the level of RNA chain elongation . However, holomycin only weakly inhibited E . coli RNA polymerase in assays using synthetic poly(dA-dT) and plasmid templates . Furthermore, inhibition of RNA polymerase was observed only at holomycin concentrations in excess of those required to inhibit the growth of E . coli . It is possible that holomycin is a prodrug, requiring conversion in the cell to an active species that inhibits RNA polymerase.

Pediatrics . 2001 Feb;107(2):E26.
Two cases of diskitis attributable to anaerobic bacteria in children; Brook I; Diskitis, an inflammation of the intervertebral disk, is generally attributable to Staphylococcus aureus and rarely Staphylococcus epidermidis, Kingella kingae, Enterobacteriaciae, and Streptococcus pneumoniae . In many cases, no bacterial growth is obtained from infected intervertebral discs . Although anaerobic bacteria were recovered from adults with spondylodiscitis, these organisms were not reported before from children . The recovery of anaerobic bacteria in 2 children with diskitis is reported . Patient 1 . A 10-year-old male presented with 6 weeks of low back pain and 2 weeks of low-grade fever and abdominal pain . Physical examination was normal except for tenderness to percussion over the spine between thoracic vertebra 11 and lumbar vertebra 2 . The patient had a temperature of 104 degrees F . Laboratory tests were within normal limits, except for erythrocyte sedimentation rate (ESR), which was 58 mm/hour . Blood culture showed no growth . Magnetic resonance imaging with gadolinium contrast revealed minimal inflammatory changes in the 12th thoracic vertebra/first lumbar vertebra disk . There was no other abnormality . A computed tomography (CT)-guided aspiration of the disk space yielded bloody material, which was sent for aerobic and anaerobic cultures . Gram stain showed numerous white blood cells and Gram-positive cocci in chains . Cultures for anaerobic bacteria yielded heavy growth of Peptostreptococcus magnus, which was susceptible to penicillin, clindamycin, and vancomycin . The patient was treated with intravenous penicillin 600 000 units every 6 hours for 3 weeks, and then oral amoxicillin, 500 mg every 6 hours for 3 weeks . The back pain resolved within 2 weeks, and the ESR returned to normal at the end of therapy . Follow-up for 3 years showed complete resolution of the infection . Patient 2 . An 8-year-old boy presented with low back pain and low-grade fever, irritability, and general malaise for 10 days . He had had an upper respiratory tract infection with sore throat 27 days earlier, for which he received no therapy . The patient had a temperature of 102 degrees F, and physical examination was normal except for tenderness to percussion over the spine between the second and fourth lumbar vertebrae . Laboratory tests were normal, except for the ESR (42 mm/hour) . Radiographs of the spine showed narrowing of the third to fourth lumbar vertebra disk space and irregularity of the margins of the vertebral endplates . A CT scan revealed a lytic bone lesion at lumbar vertebra 4, and bone scan showed an increase uptake of (99m)technetium at the third to fourth lumbar vertebra disk space . CT-guided aspiration of the disk space yielded cloudy nonfoul-smelling material, which was sent for aerobic and anaerobic cultures . Gram stain showed numerous white blood cells and fusiform Gram-negative bacilli . Anaerobic culture grew light growth of Fusobacterium nucleatum . The organism produced beta-lactamase and was susceptible to ticarcillin-clavulanate, clindamycin, metronidazole, and imipenem . Therapy with clindamycin 450 mg every 8 hours was given parenterally for 3 weeks and orally for 3 weeks . Back pain resolved within 2 weeks . A 2-year follow-up showed complete resolution and no recurrence . This report describes, for the first time, the isolation of anaerobic bacteria from children with diskitis . The lack of their recovery in previous reports and the absence of bacterial growth in over two third of these studies may be caused by the use of improper methods for their collection, transportation, and cultivation . Proper choice of antimicrobial therapy for diskitis can be accomplished only by identification of the causative organisms and its antimicrobial susceptibility . This is of particular importance in infections caused by anaerobic bacteria that are often resistant to antimicrobials used to empirically treat diskitis . This was the case in our second patient, who was infected by F nucleatum, which was resistant to beta-lactam antibiotics . The origin of the anaerobic bacteria causing the infection in our patient is probably of endogenous nature . The presence of abdominal pain in the first child may have been attributable to a subclinical abdominal pathothology . The preceding pharyngitis in the second patient may have been associated with a potential hematogenous spread of F nucleatum . P magnus has been associated with bone and joint infections . This report highlights the importance of obtaining disk space culture for aerobic and anaerobic bacteria from all children with diskitis . Future prospective studies are warranted to elucidate the role of anaerobic bacteria in diskitis in children.

J Clin Microbiol, 2001 Feb, 39(2), 430 - 7
Use of rpoB gene analysis for detection and identification of Bartonella species; Renesto P et al.; Identification of Bartonella species is of increasing importance as the number of infections in which these bacteria are involved increases . To date, these gram-negative bacilli have been identified by various serological, biochemical, and genotypic methods . However, the development of alternative tools is required, principally to circumvent a major risk of contamination during sample manipulation . The aim of our study was to investigate the possible identification of various Bartonella species by comparison of RNA polymerase beta-subunit gene (rpoB) sequences . This approach has previously been shown to be useful for the identification of members of the family Enterobacteriaceae (C . M . Mollet, M . Drancourt, and D . Raoult, Mol . Microbiol . 26:1005-1011, 1997) . Following PCR amplification with specific oligonucleotides, a 825-bp region of the rpoB gene was sequenced from 13 distinct Bartonella strains . Analysis of these sequences allowed selection of three restriction enzymes (ApoI, AluI, and AflIII) useful for discerning the different strains by PCR-restriction fragment length polymorphism (PCR-RFLP) analysis . To confirm the potential value of such an approach for identification of Bartonella, the rpoB PCR was then applied to 94 clinical samples, and the results obtained were identical to those obtained by our reference PCR method . Twenty-four isolates were also adequately identified by PCR-RFLP analysis . In all cases, our results were in accordance with those of the reference method . Moreover, conserved regions of DNA were chosen as suitable primer targets for PCR amplification of a 439-bp fragment which can be easily sequenced.

Appl Environ Microbiol, 2001 Feb, 67(2), 986 - 90
Characterization of acetic acid bacteria in traditional acetic acid fermentation of rice vinegar (komesu) and unpolished rice vinegar (kurosu) produced in Japan; Nanda K et al.; Bacterial strains were isolated from samples of Japanese rice vinegar (komesu) and unpolished rice vinegar (kurosu) fermented by the traditional static method . Fermentations have never been inoculated with a pure culture since they were started in 1907 . A total of 178 isolates were divided into groups A and B on the basis of enterobacterial repetitive intergenic consensus-PCR and random amplified polymorphic DNA fingerprinting analyses . The 16S ribosomal DNA sequences of strains belonging to each group showed similarities of more than 99% with Acetobacter pasteurianus . Group A strains overwhelmingly dominated all stages of fermentation of both types of vinegar . Our results indicate that appropriate strains of acetic acid bacteria have spontaneously established almost pure cultures during nearly a century of komesu and kurosu fermentation.

Appl Environ Microbiol, 2001 Feb, 67(2), 910 - 21
Molecular analysis of Vibrio cholerae O1, O139, non-O1, and non-O139 strains: clonal relationships between clinical and environmental isolates; Singh DV et al.; A total of 26 strains of Vibrio cholerae, including members of the O1, O139, and non-O1, non-O139 serogroups from both clinical and environmental sources, were examined for the presence of genes encoding cholera toxin (ctxA), zonula occludens toxin (zot), accessory cholera enterotoxin (ace), hemolysin (hlyA), NAG-specific heat-stable toxin (st), toxin-coregulated pilus (tcpA), and outer membrane protein (ompU), for genomic organization, and for the presence of the regulatory protein genes tcpI and toxR in order to determine relationships between epidemic serotypes and sources of isolation . While 22 of the 26 strains were hemolytic on 5% sheep blood nutrient agar, all strains were PCR positive for hlyA, the hemolysin gene . When multiplex PCR was used, all serogroup O1 and O139 strains were positive for tcpA, ompU, and tcpI . All O1 and O139 strains except one O1 strain and one O139 strain were positive for the ctxA, zot, and ace genes . Also, O1 strain VO3 was negative for the zot gene . All of the non-O1, non-O139 strains were negative for the ctxA, zot, ace, tcpA, and tcpI genes, and all of the non-O1, non-O139 strains except strain VO26 were negative for ompU . All of the strains except non-O1, non-O139 strain VO22 were PCR positive for the gene encoding the central regulatory protein, toxR . All V . cholerae strains were negative for the NAG-specific st gene . Of the nine non-ctx-producing strains of V . cholerae, only one, non-O1, non-O139 strain VO24, caused fluid accumulation in the rabbit ileal loop assay . The other eight strains, including an O1 strain, an O139 strain, and six non-O1, non-O139 strains, regardless of the source of isolation, caused fluid accumulation after two to five serial passages through the rabbit gut . Culture filtrates of all non-cholera-toxigenic strains grown in AKI media also caused fluid accumulation, suggesting that a new toxin was produced in AKI medium by these strains . Studies of clonality performed by using enterobacterial repetitive intergenic consensus sequence PCR, Box element PCR, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE) collectively indicated that the V . cholerae O1 and O139 strains had a clonal origin, whereas the non-O1, non-O139 strains belonged to different clones . The clinical isolates closely resembled environmental isolates in their genomic patterns . Overall, there was an excellent correlation among the results of the PCR, AFLP, and PFGE analyses, and individual strains derived from clinical and environmental sources produced similar fingerprint patterns . From the results of this study, we concluded that the non-cholera-toxin-producing strains of V . cholerae, whether of clinical or environmental origin, possess the ability to produce a new secretogenic toxin that is entirely different from the toxin produced by toxigenic V . cholerae O1 and O139 strains . We also concluded that the aquatic environment is a reservoir for V . cholerae O1, O139, non-O1, and non-O139 serogroup strains.

Appl Environ Microbiol, 2001 Feb, 67(2), 895 - 903
Genetic diversity of Pierce's disease strains and other pathotypes of Xylella fastidiosa; Hendson M et al.; Strains of Xylella fastidiosa isolated from grape, almond, maple, and oleander were characterized by enterobacterial repetitive intergenic consensus sequence-, repetitive extragenic palindromic element (REP)-, and random amplified polymorphic DNA (RAPD)-PCR; contour-clamped homogeneous electric field (CHEF) gel electrophoresis; plasmid content; and sequencing of the 16S-23S rRNA spacer region . Combining methods gave greater resolution of strain groupings than any single method . Strains isolated from grape with Pierce's disease (PD) from California, Florida, and Georgia showed greater than previously reported genetic variability, including plasmid contents, but formed a cluster based on analysis of RAPD-PCR products, NotI and SpeI genomic DNA fingerprints, and 16S-23S rRNA spacer region sequence . Two groupings of almond leaf scorch (ALS) strains were distinguished by RAPD-PCR and CHEF gel electrophoresis, but some ALS isolates were clustered within the PD group . RAPD-PCR, CHEF gel electrophoresis, and 16S-23S rRNA sequence analysis produced the same groupings of strains, with RAPD-PCR resolving the greatest genetic differences . Oleander strains, phony peach disease (PP), and oak leaf scorch (OLS) strains were distinct from other strains . DNA profiles constructed by REP-PCR analysis were the same or very similar among all grape strains and most almond strains but different among some almond strains and all other strains tested . Eight of 12 ALS strains and 4 of 14 PD strains of X . fastidiosa isolated in California contained plasmids . All oleander strains carried the same-sized plasmid; all OLS strains carried the same-sized plasmid . A plum leaf scald strain contained three plasmids, two of which were the same sizes as those found in PP strains . These findings support a division of X . fastidiosa at the subspecies or pathovar level.

Folia Biol (Krakow), 1999, 47(3-4), 135 - 41
Exoproteinases of the type A in pathogenesis of insect bacterial diseases; Andrejko M; Immune inhibitors produced in infected larvae of Galleria mellonella by such entomopathogens as Pseudomonas aeruginosa, Serratia marcescens and Heterorhabditis bacteriophora effectively blocked in vitro bactericidal activity of insect haemolymph against Escherichia coli D31, both in Galleria mellonella and Pieris brassicae pupae previously vaccinated with Enterobacter cloacae . Even at a trace concentration, the extracellular proteinases, by proteolytic degradation, totally destroyed the activity of cecropin peptides from Galleria and cecropin-like and attacin-family proteins from Pieris, but no ability to destroy antibacterial activity was shown by extracts obtained from Galleria larvae killed by massive doses of bacterial saprophytes . It is suggested that by blocking antibacterial immune response of the host, the proteinases help the bacteria to multiply in the haemolymph, thus they could be considered an important factor in the pathogenesis of bacterial diseases of insects.

Rev Med Chil, 1999 Sep, 127(9), 1049 - 55
{Microbiological study of gallbladder bile in a high risk zone for gallbladder cancer}; Roa I et al.; BACKGROUND: Gallbladder cancer is frequent in Chile and there is sparse information about the association between this type of cancer and the presence of bacteria in the gallbladder bile . AIM: To determine the presence of aerobic bacteria in gallbladder bile in patients with and without gallbladder cancer . MATERIAL AND METHODS: A microbiological analysis of bile and pathological study was performed in 608 gallbladders, obtained during to cholecystectomies performed to 513 women and 95 men aged 44 years old as a mean . RESULTS: Pathological study showed a chronic cholecystitis in 468 cases (77%), an acute cholecystitis in 140 (33%), cancer in 24 (3.9%) and dysplasia in 5 cases (0.8%) . A positive culture was obtained in 22.5% of women and 28.5% of males . Twenty seven percent of women over 30 years old had positive cultures compared with 10% of younger women (p < 0.001) . Thirty two percent of acute cholecystitis had positive cultures, compared with 24% of chronic cholecystitis (p = 0.03) . E Coli was isolated in 51% of positive cases, Streptococci-Enterococci in 24%, Enterobacter sp in 9%, Klebsiella and Proteus in lower proportions . Salmonella sp was isolated in 4 cases, being all women with chronic cholecystitis . Thirteen of 29 cases with cancer or dysplasia had positive cultures (45%), compared with 25% of patients with inflammatory gallbladder diseases (p = 0.02) . Streptococci-Enterococci were isolated in 7 cases and Enterobacter sp in three . CONCLUSIONS: The presence of Salmonella sp in gallbladder bile was not frequent in the studied patients . Its role in the pathogenesis of gallbladder cancer must be reassessed.

Rev Med Chil, 1999 Sep, 127(9), 1033 - 40
{Antimicrobial resistance of agents causing urinary tract infections in 11 Chilean hospitals . PRONARES project}; Valdivieso F et al.; BACKGROUND: The computer program WHONET generates a common database to analyze local or general antimicrobial resistance of bacteria . A surveillance of agents causing urinary tract infections in Chile has been performed using this program . AIM: To report the results after 12 months of urinary tract infection agent surveillance . MATERIAL AND METHODS: Since November, 1997, a surveillance of in vitro antimicrobial resistance, using agar diffusion techniques, has been performed in 20 to 40 bacterial strains per month, isolated from 11 hospitals in the country . Results have been analyzed using WHONET program . RESULTS: In first 12 months, 3144 strains, 1625 coming from outpatients, have been studied . Seventy four percent of isolated strains were E coli, 19% were other enterobacteria, 4.1% were non fermenting bacilli and 2.1% were Gram (+) cocci . Sixty five percent of E coli strains were resistant to ampicillin, 11% to cefazolin, 2.5% to cefuroxime, 19% to ceftriaxone, 9% to ceftazidime, 4.2% to gentamicin 1.3% to amikacin, 5.6% to ciprofloxacin, 8.4% to grepafloxacin, 4.3% to nitrofurantoin and 43% to trimeproprim/sulphamethoxazole . Eighty two percent of other enterobacteria strains were resistant to ampicillin, 45.5% to cefazolin, 33.5% to cefuroxime, 26.6% to ceftriaxone, 21.5% to ceftazidime, 30.3% to gentamicin 17.2% to amikacin, 21% to ciprofloxacin, 16.3% to grepafloxacin, 48.2% to nitrofurantoin and 44.6% to trimeproprim/sulphamethoxazole . There were differences in betalactamic resistance among hospitals . CONCLUSIONS: Noteworthy is the high resistance rates to third generation cephalosporins, evidenced when the new cutoff values for E coli and Klebsiella spp are used . This national surveillance provides updated information on antimicrobial resistance of agents causing urinary tract infections.

J Agric Food Chem, 2000 Dec, 48(12), 5975 - 80
Comparative study on chemical changes in olive juice and brine during green olive fermentation; Sanchez AH et al.; Changes in physicochemical characteristics, substrate depletion, and product formation during fermentation were followed in both brine and olive juice in order to achieve a complete knowledge of fermentation chemistry in Spanish-type green olives . Both spontaneous and controlled fermentations were investigated . Fermentation rate, irrespective of the type of fermentation, was lower in olive juice than in brine, but the main acid products eventually reached equilibrium . Final free acidity remained significantly (p < 0.05) higher, and combined acidity remained lower, in brine than in olive juice in both fermentations, but differences in final pH were not significant in controlled fermentation . Final concentrations of lactic and formic acids were significantly (p < 0 . 05) higher, and those of ethanol and succinic acid were lower, in controlled fermentation than in spontaneous fermentation . Butanediol, attributable to Enterobacteriaceae growth, was formed only in the latter case . Calculated carbon recoveries were not significantly (p < 0.05) different in any case, giving a mean of some 78%.

Tunis Med, 2000 Nov, 78(11), 628 - 33
{Study of the incidence and cost of nosocomial infections in general surgery}; Ennigrou S et al.; Nosocomial infection incidence and its cost were study . We have identified 61 infected patients and 75 infectious episodes, is an incidence of 9.4% infected for 100 hospitalized by trimester . Operative site infections are the most frequent (60%), operative site infection (9.1%), inferior respiratory ways infections (2.2%) . Incriminated germs are represented essentially by negative gram Bacillus (77.3%) with predominance of enterobacterias (59%) . Invasive technique usage, surgery types and contamination classes have been identified as risk factors of nosocomial infection occurrence . The supplementary stay duration estimated by simple comparison between infected group and no-infected one is 9.3% days, responsible of an over cost of 336 TD by infected patient and 273 TD by infectious episode . The curative antibiotic costs have been estimated at 70 TD by infected patient being equivalent to two hospitalization days and to 57 TD by infectious episode.

Oral Microbiol Immunol, 2000 Jun, 15(3), 203 - 10
The oral microbiota of children undergoing liver transplantation; Sheehy EC et al.; This study investigated the oral microbiota of children undergoing liver transplantation . Oral swabs were taken using a standardized procedure from 27 children before liver transplantation and at 3 and 100 days post-transplantation and from 27 healthy controls at baseline and 90 days . Viridans streptococci, yeasts, staphylococci, enterococci and Enterobacteriaceae were enumerated and identified using conventional techniques . The oral microbiota of the patients changed significantly immediately post-transplantation, but by the final examination, it had returned to baseline levels . The oral microbiota of the controls did not change significantly . The numbers and proportions of Streptococcus salivarius, Streptococcus sanguis and Streptococcus gordonii as percentages of the total streptococcal counts and of the total anaerobic counts decreased significantly 3 days post-transplantation (P < or = 0.006) . There were no significant changes in the numbers and proportions of Streptococcus oralis and Streptococcus mitis isolated pre- and post-transplantation . The isolation frequencies and numbers of yeasts were significantly higher in patients than controls . Staphylococci were isolated in low numbers from all children . Enterococci and Enterobacteriaceae were isolated infrequently from patients.

Eur J Clin Microbiol Infect Dis, 2000 Nov, 19(11), 881 - 5
Clinical comparison of two commercial blood culture systems; Spanjaard L et al.; A prospective, volume-controlled comparison of the BacT/Alert FAN (Organon Teknika, USA) and Vital (bioMerieux, France) blood culture systems was performed in a university hospital during a period of 11 months . Twenty to 40 ml of blood drawn from an adult patient was distributed equally between a BacT/Alert FAN and a Vital blood culture set, both consisting of an aerobic and an anaerobic bottle . Bottles were weighed prior to use and after incubation to calculate the blood volume . A compliant pair of aerobic, or anaerobic, bottles of a blood culture was defined as follows: blood volumes were 4-11 ml and the blood volumes in the two bottles differed by < or =20% . From 120 compliant pairs of aerobic bottles, 135 organisms were recovered, of which 78 were isolated in both bottles, 44 in the BacT/Alert FAN bottle only and 13 in the Vital bottle only (P<0.0005) . In particular, aerobic BacT/Alert FAN bottles yielded more members of the family Enterobacteriaceae (P<0.01) . The BacT/Alert FAN system also performed significantly better when comparing anaerobic bottles, and the yield was greater during septic episodes . Both culture systems were similar regarding detection time, recovery during antimicrobial therapy, and the occurrence of false-positive and false-negative bottles . The overall performance of the BacT/Alert FAN system was better than that of the Vital system.

FEMS Microbiol Lett, 2001 Jan 1, 194(1), 19 - 25
Genotyping of clinical Serratia marcescens isolates: a comparison of PCR-based methods; Patton TG et al.; The polymerase chain reaction (PCR)-based procedures of randomly amplified polymorphic DNA (RAPD) and repetitive element (RE)-based PCR were used to amplify total DNA prepared from each of 62 clinical Serratia marcescens isolates . Three different random primers, designated 1060, 1254 and 1283, were used individually in RAPD-PCR . Primers representing enterobacterial repetitive intergenic consensus (ERIC) sequences, extragenic palindromic (REP) elements, and polymorphic GC-rich repetitive sequences (PGRS) constituted the repetitive element-PCR . We were able to generate 40, 40 and 58 genotypic groupings using the 1060, 1254 and 1283 RAPD primers, respectively . Using the ERIC, REP and PGRS primers, 19, 54 and 60 unique genotypic profiles were yielded, respectively . The PGRS primers, which were developed to amplify GC-rich repetitive sequences in the genome of Mycobacteria, were the most discriminatory . These data indicate that both of these PCR-based approaches are a valid means of discriminating strain differences among isolates of S . marcescens and the amount of differentiation depends on the primer used . These techniques should prove useful for routine surveillance or in examining outbreaks of S . marcescens in clinical settings.

J Pediatr Surg, 2001 Jan, 36(1), 56 - 62
Acidification of formula reduces bacterial translocation and gut colonization in a neonatal rabbit model; Mehall JR et al.; BACKGROUND/PURPOSE: The authors hypothesized that gastric acidity is protective because it is bactericidal . They tested acidified formula for protection against gut colonization and bacterial translocation . METHODS: In vitro: Formula was acidified to pH of 2, 3, 4, 5 and innoculated with Enterobacter . Growth over time was quantitatively assessed . In vivo: 442 premature rabbit pups were sorted randomly and fed formula of pH 2, 3, 4, or 7, with ranitidine . Two models were utilized: (1) with bacterial challenge using a known acid sensitive organism, (2) without bacterial challenge to simulate natural gut colonization and to test against organisms of unknown acid sensitivity . Normal acid animals received pH 7 formula, no ranitidine . On day 3, the mesenteric lymph nodes (MLN), spleen, liver, and cecum were harvested and cultured . RESULTS: Bacterial growth was inhibited at pH 2 and 3, growth was logarithmic above pH 4 (P<.001) . Total and organ-specific translocation was reduced at pH 3 and below in both models (P<.05) . Translocation with formula pH 3 equaled normal acid animals . Quantitative cecal colonization was reduced in pups receiving pH 3 and below in both models (P<.05) . CONCLUSION: Acidification of formula below pH 4 is bactericidal to enteric organisms . Acidified formula decreases bacterial translocation and gut colonization.

Liver Transpl, 2001 Jan, 7(1), 22 - 6
Evolving trends in multiple-antibiotic-resistant bacteria in liver transplant recipients: a longitudinal study of antimicrobial susceptibility patterns; Singh N et al.; The incidence, sources, impact on outcome, and temporal trends in multiple-antibiotic-resistant bacteria in liver transplant recipients over the last decade (from 1990 through 1999) were assessed . Of 165 consecutive patients who underwent transplantation, 31% (51 of 165 patients) had at least 1 infection caused by multiple-antibiotic-resistant bacteria . Overall, 69% (66 of 96 infections) of all bacterial infections were multiple-antibiotic resistant . Ninety-one percent (45 of 49 isolates) of the Staphylococcus aureus isolates, 50% (6 of 12 isolates) of the enterococci, and 54% of the gram-negative bacteria (47%; 7 of 15 Pseudomonas aeruginosa, and 60%; 12 of 20 Enterobacteriaceae) were multiple-antibiotic resistant . A significant trend toward an increase in infections caused by multiple-antibiotic-resistant bacteria (P =.003), largely caused by an increase in gram-positive infections, was documented through the decade . There was a significant increase in infections caused by methicillin-resistant S aureus (P =.0001) and vancomycin-resistant enterococci (P =.04) over time . The proportion of gram-negative isolates that were multiple-antibiotic resistant (P =.447) did not increase significantly over time . However, a strikingly high frequency of resistance to piperacillin or ceftazidime suggests that extended-spectrum beta-lactamase production in our Enterobacteriaceae may have been more prevalent than realized . Mortality at 1 year was significantly greater in patients with multiple-antibiotic resistant bacteria compared with all other patients (P =.001) . These longitudinal trends have implications not only for guiding therapeutic practices, but ultimately for devising strategies to curtail multiple-antibiotic resistance in liver transplant recipients.

Wiad Lek, 2000, 53(9-10), 493 - 8
{Susceptibility to antibiotics of some species of Enterobacter isolated from various clinical materials}; Janicka G et al.; We investigated 185 strains of Enterobacter spp . (E . cloacae--143 strains, E . agglomerans--15 strains, E . sakazakii--14 strains and E . aerogenes--13 strains) isolated from several clinical materials . An agar diffusion assay on Mueller-Hinton Agar was performed (according to NCCLS procedure and National Reference Center of Microorganisms' Drug-sensitiveness at Central Laboratory of Sera and Vaccinations in Warsaw Poland) . E . cloacae: about 90% of the strains were sensitive to carbapenems . 85.3% of the isolates were susceptible to piperacillin + tazobactam . About 80% of the strains were susceptible to cotrimoxazole and ciprofloxacin . E . agglomerans: all strains were susceptible to imipenem, and 86.7%--to meropenem . 86.7% of the strains were susceptible to ureidopenicillins + inhibitors of beta-lactamases . About 80% of the isolates were susceptible to cotrimoxazole and ciprofloxacin . E . sakazakii: all isolates were susceptible to carbapenems . About 90% of the strains were susceptible to cotrimoxazole and 50%--to ciprofloxacin . E . aerogenes: all of the strains were susceptible to carbapenems and ciprofloxacin, 92.3%--to cotrimoxazole.

Aliment Pharmacol Ther, 2001 Feb, 15(2), 257 - 67
Lack of small intestinal ulcerogenecity of nitric oxide-releasing indomethacin, NCX-530, in rats; Mizoguchi H et al.; AIM: To evaluate the intestinal ulcerogenic property of nitric oxide-releasing indomethacin (NCX-530) in the rat, in comparison with indomethacin . METHODS: Animals were given indomethacin or NCX-530 subcutaneously and killed 24 h later for macroscopic examination of the small intestine . RESULTS: A single administration of indomethacin (10 mg/kg) provoked damage, mainly in the jejunum and ileum, accompanied by an increase in myeloperoxidase and inducible nitric oxide synthase activities as well as bacterial translocation . NCX-530 at an equimolar dose (14.2 mg/kg) caused no gross damage in the small intestine, nor any significant change in inducible nitric oxide synthase and myeloperoxidase activities or bacterial translocation . NOR-3, the nitric oxide donor (6.0 mg/kg), when administered subcutaneously together with indomethacin, significantly prevented the occurrence of intestinal lesions and other mucosal changes . Indomethacin reduced mucus and fluid secretions in the small intestine, while both NCX-530 and NOR-3 enhanced these secretions . NCX-530 reduced the mucosal prostaglandin E2 contents and exhibited an anti-inflammatory action against carrageenan-induced paw oedema, with equal effectiveness to indomethacin . CONCLUSION: NCX-530 does not cause intestinal damage, despite inhibiting cyclooxygenase activity . The reduced intestinal toxicity of NCX-530 may be attributable to inhibition of enterobacterial translocation, partly by increasing the mucus and fluid secretions mediated by nitric oxide released from this compound.

Can J Microbiol, 2000 Dec, 46(12), 1159 - 65
Identification of DNA sequences that regulate the expression of the Enterobacter cloacae UW4 1-aminocyclopropane-1-carboxylic acid deaminase gene; Grichko VP et al.; Analysis of the DNA sequence upstream of the previously isolated Enterobacter cloacae UW4 ACC deaminase gene (Shah et al . 1998) suggests that this segment contains several features that are thought to be involved in the transcriptional regulation of this gene . These features include half of a CRP (cAMP receptor protein) binding site, an FNR (fumarate-nitrate reduction) regulatory protein binding site, an LRP (leucine responsive regulatory protein) binding site, and an LRP-like protein coding region . ACC deaminase activity was measured following growth of either various Escherichia coli strains carrying a plasmid that contained the Enterobacter cloacae UW4 ACC deaminase gene, or of Enterobacter cloacae UW4 . Variables that were compared include aerobic versus anaerobic conditions, the presence and absence of ACC in the growth medium, addition of leucine to the medium, and bacterial strains that did or did not contain either lrp or fnr genes . The data reported are consistent with the involvement of most, if not all, of the above mentioned potential regulatory regions in the expression of ACC deaminase.

Infection, 2000 Nov-Dec, 28(6), 384 - 7
Influence of an infectious disease service on antibiotic prescription behavior and selection of multiresistant pathogens; Lemmen SW et al.; BACKGROUND: A routine infectious disease service was established in January 1998 in order to optimize the antibiotic usage and prescription pattern of a neurologic intensive care unit (NICU) . METHODS: Treatment guidelines for the most prevalent infections were implemented and individual antibiotic regimes were discussed at the bedside with infectious disease experts . RESULTS: This interdisciplinary cooperation reduced the total number of antibiotics prescribed by 38.1%, from 7,789 in 1997 to 4,822 in 1998, without compromising patient outcomes (mortality rate: 22/313 patients in 1997 vs . 32/328 patients in 1998) . Total patient days (2,254 days vs . 2,296 days) and average length of stay in the NICU (7.2 days vs . 7.0 days) were comparable . Antimicrobial expenditure decreased by 44.8% (71,680 Euros in 1997 vs 39,567 Euros in 1998) . Taking into account the costs for the infectious disease service (approximately 8,000 Euros in 1998), a total saving of 24,113 Euros was made . The dramatic reduction in antibiotic usage (mainly of carbapenems) resulted in a statistically significant decreased isolation of Stenotrophomonas maltophilia (p<0.05), Enterobacter cloacae (p<0.05), multiresistant Pseudomonas aeruginosa (p<0.05) and Candida spp . (p<0.05), without any change in the infection control guidelines . CONCLUSION: These data show that an infectious disease service can optimize and reduce antibiotic usage . This results in a decrease in the occurence of multiresistant gram-negative pathogens and Candida spp . in intensive care units and, at the same time, saves costs.

Int J Food Microbiol, 2000 Dec 5, 62(1-2), 139 - 48
Inhibition of surface spoilage bacteria in processed meats by application of antimicrobial films prepared with chitosan; Ouattar B et al.; A study was undertaken to evaluate the feasibility of using antimicrobial films, designed to slowly release bacterial inhibitors, to improve the preservation of vacuum-packaged processed meats during refrigerated storage . The antimicrobial films were prepared by incorporating acetic or propionic acid into a chitosan matrix, with or without addition of lauric acid or cinnamaldehyde, and were applied onto bologna, regular cooked ham, or pastrami . At various times during storage, packages were opened and the amounts of antimicrobial agents remaining in the chitosan matrix were measured . Regardless of film composition or meat product type, propionic acid was nearly completely released from the chitosan matrix within 48 h of application, whereas release of acetic acid was more limited, with 2-22% of the acid remaining in chitosan after 168 h of storage . Addition of lauric acid, but not cinnamaldehyde, to the chitosan matrix generally reduced the release of acetic acid significantly (P < or = 0.05) and the release was more limited onto bologna than onto ham or pastrami . In addition, the efficacies of the various films for inhibiting bacterial growth were tested against indigenous lactic acid bacteria and Enterobacteriaceae, and against Lactobacillus sakei or Serratia liqueficiens, surface-inoculated onto the meat products . Whereas lactic acid bacteria were not affected by the antimicrobial films under study, the growth of Enterobacteriaceae and S . liquefaciens was delayed or completely inhibited as a result of film application . Strongest inhibition was observed on drier surfaces (bologna), onto which acid release was slower, and with films containing cinnamaldehyde, as a result of its greater antimicrobial activity under these conditions.

J Clin Microbiol, 2001 Jan, 39(1), 293 - 7
Outbreak of necrotizing enterocolitis associated with Enterobacter sakazakii in powdered milk formula; van Acker J et al.; We describe an outbreak of necrotizing enterocolitis (NEC) that occurred in the neonatal intensive care unit of our hospital . A total of 12 neonates developed NEC in June-July 1998 . For two of them, twin brothers, the NEC turned out to be fatal . Enterobacter sakazakii, a known contaminant of powdered milk formula, was isolated from a stomach aspirate, anal swab, and/or blood sample for 6 of the 12 neonates . A review of feeding procedures revealed that 10 of the 12 patients were fed orally with the same brand of powdered milk formula . E . sakazakii was isolated from the implicated prepared formula milk as well as from several unopened cans of a single batch . Molecular typing by arbitrarily primed PCR (AP-PCR) confirmed, although partially, strain similarity between milk and patient isolates . No further cases of NEC were observed after the use of the contaminated milk formula was stopped . With this outbreak we show that intrinsic microbiological contamination of powdered milk formula can be a possible contributive factor in the development of NEC, a condition encountered almost exclusively in formula-fed premature infants . The use of sterilized liquid milk formula in neonatal care could prevent problems with intrinsic and extrinsic contamination of powdered milk formula.

J Clin Microbiol, 2001 Jan, 39(1), 241 - 50
Ability of laboratories to detect emerging antimicrobial resistance: proficiency testing and quality control results from the World Health Organization's external quality assurance system for antimicrobial susceptibility testing; Tenover FC et al.; The accuracy of antimicrobial susceptibility data submitted by microbiology laboratories to national and international surveillance systems has been debated for a number of years . To assess the accuracy of data submitted to the World Health Organization by users of the WHONET software, the Centers for Disease Control and Prevention distributed six bacterial isolates representing key antimicrobial-resistance phenotypes to approximately 130 laboratories, all but one of which were outside of the United States, for antimicrobial susceptibility testing as part of the World Health Organization's External Quality Assurance System for Antimicrobial Susceptibility Testing . Each laboratory also was asked to submit 10 consecutive quality control values for several key organism-drug combinations . Most laboratories were able to detect methicillin (oxacillin) resistance in Staphylococcus aureus, high-level vancomycin resistance in Enterococcus faecium, and resistance to extended-spectrum cephalosporins in Klebsiella pneumoniae . Many laboratories, particularly those using disk diffusion tests, had difficulty in recognizing reduced susceptibility to penicillin in an isolate of Streptococcus pneumoniae . The most difficult phenotype for laboratories to detect was reduced susceptibility to vancomycin in an isolate of Staphylococcus epidermidis . The proficiency testing challenge also included a request for biochemical identification of a gram-negative bacillus, which most laboratories recognized as Enterobacter cloacae . Although only a small subset of laboratories have submitted their quality control data, it is clear that many of these laboratories generate disk diffusion results for oxacillin when testing S . aureus ATCC 25923 and S . pneumoniae ATCC 49619 that are outside of the acceptable quality control range . The narrow quality control range for vancomycin also proved to be a challenge for many of the laboratories submitting data; approximately 27% of results were out of range . Thus, it is important to establish the proficiency of laboratories submitting data to surveillance systems in which the organisms are tested locally, particularly for penicillin resistance in pneumococci and glycopeptide resistance in staphylococci.

J Clin Microbiol, 2001 Jan, 39(1), 175 - 82
Molecular epidemiology of the integron-located VEB-1 extended-spectrum beta-lactamase in nosocomial enterobacterial isolates in Bangkok, Thailand; Girlich D et al.; Over a 21/2-month period in 1999, 37 ceftazidime-resistant nonrepetitive enterobacterial isolates were collected from 37 patients in a Bangkok hospital, Thailand . Eighty-one percent of these strains expressed a clavulanic acid-inhibited extended-cephalosporin resistance profile . An identical extended-spectrum beta-lactamase (ESBL), VEB-1, was found in 16 unrelated enterobacterial isolates (Escherichia coli, n = 10; Enterobacter cloacae, n = 2; Enterobacter sakazakii, n = 1; and Klebsiella pneumoniae, n = 3) and in two clonally related E . cloacae isolates . The bla(VEB-1) gene was located on mostly self-conjugative plasmids (ca . 24 to 200 kb) that conferred additional non-beta-lactam antibiotic resistance patterns . Additionally, the bla(VEB-1) gene cassette was part of class 1 integrons varying in size and structure . The bla(VEB-1)-containing integrons were mostly associated with bla(OXA-10)-like and arr-2-like gene cassettes, the latter conferring resistance to rifampin . These data indicated the spread of bla(VEB-1) in Bangkok due to frequent transfer of different plasmids and class 1 integrons and rarely to clonally related strains . Plasmid- and integron-mediated resistance to rifampin was also found in enterobacterial isolates.

Acta Crystallogr D Biol Crystallogr, 2001 Jan, 57(Pt 1), 162 - 4
Expression, purification, crystallization and preliminary X-ray analysis of the native class C beta-lactamase from Enterobacter cloacae 908R and two mutants; Wouters J et al.; Crystals have been obtained of the Enterobacter cloacae 908R beta-lactamase and two point mutants by the vapour-diffusion method using similar conditions {pH 9.0, polyethylene glycol (M(r) = 6000) as precipitant} . The three crystal forms belong to the orthorhombic space group P2(1)2(1)2, with roughly the same unit-cell parameters; i.e . for the wild-type crystals a = 46.46, b = 82.96, c = 95.31 A . In the best cases, the crystals diffract to about 2.1 A resolution on a rotating-anode X-ray source at room temperature . Co-crystallization experiments of poor substrates with the wild-type protein and the active-site serine mutant (S64C) are planned and should lead to a better understanding of the catalytic mechanism of class C beta-lactamases.

Pediatrics . 2001 Jan;107(1):E11.
Peptostreptococcus asaccharolyticus renal abscess: a rare cause of fever of unknown origin; Casullo VA et al.; Renal abscess is uncommon in pediatrics and is rarely a cause of fever of unknown origin . We recently cared for a patient who presented with a 3-week history of fever . An indium scan ultimately led to the diagnosis of a renal abscess . Aspiration yielded Peptostreptococcus asaccharolyticus . This unusual case prompted a review of the clinical and microbiologic features of renal abscess in pediatric patients at our hospital over the past 10 years . Seven additional patients with a discharge diagnosis of renal abscess were identified . Only 2 of the patients had identifiable risk factors (diabetes mellitus and polycystic kidneys) . Staphylococcus aureus or Enterobacteriaceae were responsible for most infections, consistent with hematogenous and urinary tract sources, respectively . No other cases of anaerobic abscess were identified . This case highlights the importance of considering a renal abscess in the differential diagnosis of fever of unknown origin and of processing specimens for both aerobic and anaerobic organisms.

J Bacteriol, 2001 Jan, 183(2), 435 - 42
FimW is a negative regulator affecting type 1 fimbrial expression in Salmonella enterica serovar typhimurium; Tinker JK et al.; Type 1 fimbriae are proteinaceous surface appendages that carry adhesins specific for mannosylated glycoproteins . These fimbriae are found on most members of the family Enterobacteriaceae and are known to facilitate binding to a variety of eukaryotic cells, including those found on the mucosal surfaces of the alimentary tract . We have shown that the regulation of type 1 fimbrial expression in Salmonella enterica serovar Typhimurium is controlled, in part, by the products of four genes found within the fim gene cluster: fimZ, fimY, fimW, and fimU . To better understand the specific role of FimW in fimbrial expression, a mutation was constructed in this gene by the insertion of a kanamycin resistance DNA cassette into the chromosome . The resulting fimW mutation was characterized by mannose-sensitive hemagglutination and agglutination with fimbria-specific antiserum . Assays suggested that this mutant was more strongly fimbriate than the parental strain, exhibiting a four- to eightfold increase in fimbrial production . The fimW mutation was introduced into a second strain of Salmonella enterica serovar Typhimurium, and this mutant was also found to be strongly fimbriate compared to the parental strain . Consistent with the role of this protein as a negative regulator, fimA-lacZ expression in serovar Typhimurium, as well as in Escherichia coli, was increased twofold in the absence of functional FimW . Primer extension analysis determined that fimW transcription is initiated from its own promoter 31 bp upstream of the translation start site . Analysis using a fimW-lacZ reporter indicated that fimW expression in serovar Typhimurium was increased under conditions that select for poorly fimbriate bacteria and low fimA expression . FimW also appears to act as an autoregulator, since expression from the fimW-lacZ reporter was increased in a fimW mutant . FimW was partially purified by fusion with the E . coli maltose-binding protein . Use of this FimW protein extract, as well as others, in DNA-binding assays was unable to identify a specific binding site for FimW in the fimA, fimZ, fimY, or fimW promoter regions . To analyze protein-protein interactions, FimW was expressed in a LexA-based two-hybrid system in E . coli . A significant interaction between FimW and the DNA-binding activator protein, FimZ, was detected using this system . These results indicate that FimW is a negative regulator of serovar Typhimurium type 1 fimbrial expression and may function by interfering with FimZ-mediated activation of fimA expression.

Appl Environ Microbiol, 2001 Jan, 67(1), 475 - 80
Antimicrobial properties of garlic oil against human enteric bacteria: evaluation of methodologies and comparisons with garlic oil sulfides and garlic powder; Ross ZM et al.; The antimicrobial effects of aqueous garlic extracts are well established but those of garlic oil (GO) are little known . Methodologies for estimating the antimicrobial activity of GO were assessed and GO, GO sulfide constituents, and garlic powder (GP) were compared in tests against human enteric bacteria . Test methodologies were identified as capable of producing underestimates of GO activity . Antimicrobial activity was greater in media lacking tryptone or cysteine, suggesting that, as for allicin, GO effects may involve sulfhydryl reactivity . All bacteria tested, which included both gram-negative and -positive bacteria and pathogenic forms, were susceptible to garlic materials . On a weight-of-product basis, 24 h MICs for GO (0.02 to 5.5 mg/ml, 62 enteric isolates) and dimethyl trisulfide (0.02 to 0.31 mg/ml, 6 enteric isolates) were lower than those for a mixture of diallyl sulfides (0.63 to 25 mg/ml, 6 enteric isolates) and for GP, which also exhibited a smaller MIC range (6.25 to 12.5 mg/ml, 29 enteric isolates) . Viability time studies of GO and GP against Enterobacter aerogenes showed time- and dose-dependent effects . Based upon its thiosulfinate content, GP was more active than GO against most bacteria, although some properties of GO are identified as offering greater therapeutic potential . Further exploration of the potential of GP and GO in enteric disease control appears warranted.

J Antibiot (Tokyo), 2000 Oct, 53(10), 1086 - 95
Synthesis and biological activity of the penem antibiotic MEN 10700 and its orally absorbed ester MEN 11505; Arcamone FM et al.; The synthesis and biological properties of the new penem antibiotic MEN 10700 (6) and of its selected oral prodrug MEN 11505 (8f) are described . MEN 10700 showed a broad spectrum of activity, with high potency both on Gram-positive and Gram-negative strains . It also exhibited good antibacterial activity toward anaerobes and on strains selected for their resistance to other antibacterial agents (cefotaxime- or ceftazidime-resistant Gram-negative strains, ciprofloxacin-resistant E . coli, extended spectrum beta-lactamase producing and cephalosporinase inducible enterobacteria) . MEN 10700 showed a very high stability to enzymatic degradation by renal dehydropeptidase DHP-I . After oral administration in rats of the pivaloyloxymethyl ester prodrug MEN 11505, the relative bioavailability of MEN 10700 was calculated as F=43%.

Immunobiology, 2000 Nov, 202(4), 408 - 20
Cytokine inducing activities of rhizobial and mesorhizobial lipopolysaccharides of different lethal toxicity; Urbanik-Sypniewska T et al.; The lethality and cytokines-inducing activity of lipopolysaccharides (LPS) obtained from nodulating bacteria, Rhizobium leguminosarum and Mesorhizobium loti, were compared to those of Salmonella typhimurium LPS . The activity of R . leguminosarum LPS was almost comparable to Salmonella endotoxin in terms of lethality, Limulus lysate gelating activity and in vivo tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and interferon-gamma (IFN-gamma) induction capacity . In contrast to high lethal toxicity of Rhizobium LPS, the lethality of LPS isolated from Mesorhizobium loti was more than 10(3)-fold lower . Weak lethality of LPS from Mesorhizobium correlated with low capacity of this LPS to induce TNF-alpha, IL-1beta, IL-6 and IFN-gamma both in vivo and in vitro in murine splenocytes . The examined overall chemical composition of LPS indicates a considerable distinction in their lipid A regions . Lipid A's obtained from R . leguminosarum and M . loti differed from their enterobacterial counterpart with respect to lipid A sugar backbone, its phosphate content as well as the type and distribution of hydrophobic acyl residues . The relation of lipid A chemotype and bioactivity of LPS from the two Rhizobiaceae genera is discussed.

J Chemother, 2000 Oct, 12(5), 390 - 5
In vitro antimicrobial activity of propolis dry extract; Drago L et al.; In this study the antibacterial and antifungal properties of propolis, a natural product of bees, have been investigated against different pathogens . Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined according to NCCLS standards on 320 strains including Staphylococcus aureus, Group A beta-hemolytic streptococci, Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Candida albicans . Time-kill curves were assessed for susceptible microorganisms, testing 0, 0.5, 1, 2, 4 x MIC for propolis, by counting viable bacteria after 0, 3, 6, 24 hours and viable yeasts after 0, 3, 6, 24 and 48 hours . Propolis showed good antimicrobial activity against most of the isolates, particularly S . pneumoniae, H . influenzae and M . catarrhalis, but not against Enterobacteriaceae . Time-kill curves demonstrated bacteriostatic rather than bactericidal activity of propolis, the latter being evident only at high concentrations.

Gynecol Obstet Fertil, 2000 Nov, 28(11), 832 - 4
{Septic shock complicating amniocentesis}; Thabet NP et al.; Amniocentesis is a routine technique for prenatal diagnosis . The incidence of severe intra-amniotic infection is very low . We report a case of septic shock following an amniocentesis in a 34-year-old women . Patient admitted in intensive care unit and need mechanical ventilation and vasoactives drugs to control hemodynamic pertubation . Bacteriological data showed positive polymicrobial blood cultures to Klebsiella pneumoniae and Enterobacter . The patient gradually improved, however her renal function was still impaired and she was discharged three months after admission.

J Pak Med Assoc, 2000 Nov, 50(11), 369 - 73
Changing pattern of antimicrobial susceptibility of organisms causing community acquired urinary tract infections; Farooqi BJ et al.; OBJECTIVE: To assess common organisms causing Urinary Treat Infection (UTI) in this community and to see antimicrobial susceptibility pattern of these isolates . DESIGN: Prospective study on urine samples . SETTING: Tertiary care hospital in Karachi . METHODS: Over a period of 8 years (1990-97) 9,892 urine samples grew significant bacteriuria for various organisms . All Gram negative rods and entercocci was identified by using API 20E and API 32 strips respectively . Staphylococci were identified by catalase, coagulase and D'Nase tests . Antimicrobial sensitivity testing of all isolates was performed on Diagnostic Sensitivity Test plates by Kerby Bauer method . The discs used were ampicillin, trimethoprim-sulfamethoxazole, cefotaxime, ceftriaxone, aztreonam, ofloxacin, carbenicillin, amikacin, gentamicin, penicillin, clindamycin, methicillin, vancomycin, ceftazidime, cefuroxime, Nalidixic acid, pipemedic acid and Nitrofurantoin . RESULTS: Our results indicate that E . coli and Klebsiella aerogenes are the most common organisms causing UTI in this community . Other organisms involved are Pseudomonas aeroginosa, Enterobacter species, Enterococcus, Proteus mirabillus, Staphylococcus aureus and Staphylococcus saprophyticus . Organisms resistant to various antimicrobial agents such as gentamicin, Amikacin, Ofloxacin, Cefotaxime and Ceftazidime are increasing . CONCLUSION: In conclusion, E . coli and Klebsiella aerogenes are the most common organisms causing UTI in this community . Pattern of antibiotic susceptibility to first line antibiotics is changing . Antimicrobial susceptibility testing of all isolates is crucial for the treatment of UTI.

J Appl Microbiol, 2000 Dec, 89(6), 1018 - 26
A survey on the microbiological changes during the manufacture of dry-cured lacón, a Spanish traditional meat product; Vilar I et al.; This article describes a microbiological study carried out on lacon, a dry-cured meat product made in the north-west of Spain from the fore extremity of pig . Using classical methods, aerobic mesophilic flora, salt-tolerant flora, lactic acid bacteria, Enterobacteriaceae, enterococci, moulds and yeasts were enumerated, some physicochemical parameters (pH, aw and moisture and NaCl contents) were determined and a representative number of isolates of the salt-tolerant flora (the main microbial group) were identified during the manufacture of five batches . All the microbial groups, with the exception of Enterobacteriaceae and enterococci, reached maximum counts both on the surface and in the interior of the pieces at the end of the post-salting stage and afterwards progressively dropped during the drying-ripening stage . Staphylococcus xylosus, Staph . saprophyticus, Staph . simulans, Staph . sciuri and Micrococcus luteus were the main species isolated throughout manufacturing . This study will significantly increase knowledge of the microbiology of cured meat products made from entire pieces.

Nat Toxins, 1999, 7(6), 221 - 32
Silage and animal health; Wilkinson JM; The process of preserving crops by fermentation in silos is under the control of the farmer to a much lesser degree compared to the level of control by the manufacturer over the production of other fermented foods, such as cheese and yoghurt . Additives designed to direct the extent and pattern of the fermentation are relatively unpopular in most countries, and their use is not guaranteed to remove the risk of undesirable components in silage . Hazards to animal health associated with silage fall into three categories: (1) undesirable micro-organisms e.g . Listeria, enterobacteria, clostridia and moulds; (2) undesirable chemicals, e.g . mycotoxins, and (3) excess acidity and other metabolic disorders . In some regions of Europe, the production of silage is discouraged or prohibited because of the risk of undesirable microbes . The princIpal risk in these areas is that of the secondary fermentation of cheese made from milk contaminated by bacterial spores, rather than a direct hazard of contaminated silage to animal health . With the possible exception of high dry matter silage conserved in large bales, respiratory hazards to animals from moulds and their spores generally are less from silage than hay . Mycotoxins and phytoestrogens may survive the ensiling period and constitute risks to animal health . Relatively little is known about the epidemiology of diseases that may be linked to undesirable chemicals and excess acidity in silage . Therefore, research is needed to define epidemiologically and mechanistically the risks to animal health and to the human food chain from silages contaminated with pathogenic bacteria and mycotoxins, and to understand more completely the relationships between the physical and chemical compositions of silage and metabolic disorders in animals.

Antimicrob Agents Chemother, 2001 Jan, 45(1), 275 - 9
Clinical isolation and resistance patterns of and superinfection with 10 nosocomial pathogens after treatment with ceftriaxone versus ampicillin-sulbactam; Carmeli Y et al.; Isolation of pathogens from clinical cultures and their resistance patterns may be altered by antecedent antibiotic treatment . The objective of this study was to assess the influence of treatment with ceftriaxone versus that with ampicillin-sulbactam on recovery and superinfections with 10 nosocomial pathogens . The study was designed as a historical cohort study, using a propensity score to adjust for confounding by indication and multivariate survival analyses to adjust for other confounding . Two thousand four hundred forty-five patients were treated with ampicillin-sulbactam, and 1, 308 were treated with ceftriaxone . The study analyzed two outcomes: (i) recovery of pathogens from clinical cultures and (ii) microbiologically documented infections . Data were obtained from administrative, pharmacy, clinical, and laboratory databases and by chart extraction . Following treatment, new isolation of at least 1 of the 10 target pathogens occurred for 244 patients . After adjustment, more infections occurred in the ampicillin-sulbactam group (hazard ratio {HR}, 1.55; P = 0.009) . This was observed with all gram-negative rods combined (HR, 3.6; P < 0.001) and with each genus of the family Enterobacteriaceae . No differences in isolation of gram-positive bacteria were evident (P = 0.33) . Microbiologically documented superinfections occurred in 172 patients and were less frequent in the ceftriaxone group (3.8% versus 5%; HR, 1.6; P = 0 . 015) . All the Escherichia coli and Klebsiella spp . isolates were susceptible to ceftriaxone, but half were resistant to ampicillin-sulbactam . The prevalence of oxacillin resistance among Staphylococcus aureus isolates was higher in the ceftriaxone group (63% versus 31%; odds ratio, 3.8; P = 0.08) . Differences in the rates of superinfections and the likely causative organisms following treatment with ceftriaxone or ampicillin-sulbactam were evident . This may guide clinicians in empirical choices of antibiotics to treat superinfection.

Infect Immun, 2001 Jan, 69(1), 15 - 23
Shigella flexneri LuxS quorum-sensing system modulates virB expression but is not essential for virulence; Day WA Jr et al.; Quorum-sensing systems regulate the expression of virulence factors in a wide variety of plant and animal pathogens, including members of the Enterobacteriaceae . Studies of Shigella virulence gene expression have demonstrated that maximal expression of genes encoding the type III secretion system and its substrates and maximal activity of this virulence organelle occur at high cell density . In these studies, we demonstrate that the expression of ipa, mxi, and spa invasion operons is maximal in stationary-phase bacteria and that conditioned media derived from stationary-phase cultures enhance the expression of these loci . In contrast, expression of virB, a transcription factor essential for the expression of invasion loci, peaks in late log phase; accordingly, virB expression is enhanced by a signal(s) present in conditioned media derived from late-log-phase cultures . Autoinducer 2 (AI-2), a quorum signaling molecule active in late log phase, was synthesized by Shigella species and enteroinvasive Escherichia coli and shown to be responsible for the observed peak of virB expression . However, AI-2 does not influence invasion operon expression and is not required for Shigella virulence, as mutants deficient in AI-2 synthesis are fully virulent . The implications of these findings with regard to both virB and invasion operon expression and the evolution of circuitries governing virulence gene expression are discussed.

Int J Antimicrob Agents, 2000 Dec, 16(4), 483 - 7
Resistance of bacteria in urinary tract infections; Chomarat M; Bacterial infection of the urinary tract is a common health problem in young women but also the most common nosocomial infection (>33%) contributing to the mortality of patients, and increasing the duration and cost of hospitalization . Escherichia coli is the most predominant organism and its prevalence varies in different studies . The high consumption of inappropriately prescribed antibiotics, combined with multiple pathology and frequent use of invasive devices, is a major factor contributing to high levels of resistance . There is a serious decrease in susceptibility of E . coli strains to amoxycillin, due to the presence of R-TEM enzymes, to cotrimoxazole and trimethoprim . Nitrofurantoin and fosfomycin-trometamol remain highly active against urinary Enterobacteriaceae, with over 90% of E . coli being susceptible . Knowledge of the most likely causative organisms and the prevalence of resistance pathogens to antimicrobial agents is essential to select antibiotics and to establish guidelines for the empirical treatment of urinary tract infections.

Int J Antimicrob Agents, 2000 Dec, 16(4), 467 - 71
Bacterial agents of lower respiratory tract infections (LRTIs), beta-lactamase production, and resistance to antibiotics in elderly people . DEDALO Study Group; Sanguinetti CM et al.; This study determined the etiology of lower respiratory tract infections in the elderly and assessed whether the growth of beta-lactamase producing bacteria is particularly favoured in these patients . Between December 1998 and May 1999, 187 patients with community-acquired pneumonia (CAP), and 887 patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) were enrolled . The mean age was 74 years (range of 65-94 year) . Sputum and bronchial aspirate for microbiological investigation were obtained . Besides organisms commonly involved in bacterial infections of the lower respiratory tract (i.e . Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis), Enterobacteriaceae and Pseudomonas spp . were also found . A high percentage of these bacteria were beta-lactamase producers . These data along with the clinical presentation, severity of infection, and epidemiological knowledge, might represent a guide for the choice of empiric antimicrobial treatment.

Int J Antimicrob Agents, 2000 Dec, 16(4), 395 - 400
beta-Lactam susceptibility patterns and investigation of cephalosporin hydrolysing beta-lactamases of Gram-negative extraintestinal clinical isolates; Gal Z et al.; Of more than 3500 isolates of enterobacteriaceae, 48-69% were resistant to aminopenicillins and 11-45% to amoxycillin+clavulanic acid . Resistance to second and third generation cephalosporins was present in 11-17 and 3-8% of Escherichia coli, 47-56 and 15-52% of Klebsiella-Enterobacter, 36-57 and 16-27% of Proteus, Providencia and Morganella isolates . Pseudomonas aeruginosa strains varied in their resistance to antipseudomonal beta-lactams . Isoelectric points, inhibitor profiles and substrate profiles of beta-lactamases extracted from representatives of the resistant strains indicated that the resistance was mainly due to the hyperproduction of chromosomally encoded AmpC beta-lactamases . This was confirmed by plasmid profile and PCR investigations . Extended-spectrum beta-lactamase and metallo-penicillinase producing strains were not found . One Pseudomonas maltophilia strain produced an oxacillinase.

Am J Infect Control, 2000 Dec, 28(6), 465 - 71
Computer keyboards and faucet handles as reservoirs of nosocomial pathogens in the intensive care unit; Bures S et al.; PURPOSE: We postulate that computer keyboards and faucet handles are significant reservoirs of nosocomial pathogens in the intensive care unit (ICU) setting . METHODS: Sterile swab samples were obtained from 10 keyboards and 8 pairs of faucet handles in the medical ICU at Tripler Army Medical Center during a period of 2 months . Methicillin-resistant Staphylococcus aureus (MRSA) obtained from the environmental and patient specimens were sent for DNA identification by using pulsed-field gel electrophoresis . RESULTS: A total of 144 samples were obtained (80 keyboards and 64 faucet handles), yielding 33 isolates . The colonization rate for keyboards was 24% for all rooms and 26% in occupied rooms . Rates for faucet handles in all rooms and occupied rooms were 11% and 15%, respectively . The environmental isolates annd their prevalence were: MRS, 49%; Enterococcus, 18%; Enterobacter, 12%; and all other gram-negative rods, 21% . Fourteen individual patient isolates were recorded: MRSA, 43%; Enterobacter, 21%; other gram-negative rods, 36%; and Enterococcus, 0% . By using pulsed-field gel electrophoresis, an indistinguishable strain of MRSA was identified in two patients, the keyboards and faucet handles in their respective rooms, and on other keyboards throughout the ICU, including the doctors' station . CONCLUSIONS: The colonization rate for keyboards and faucet handles, novel and unrecognized fomites, is greater than that of other well-studied ICU surfaces in rooms with patients positive for MRSA . Our findings suggest an associated pattern of environmental contamination and patient infection, not limited to the patient's room . Pulsed-field gel electrophoresis results have documented an indistinguishable strain of MRSA present as an environmental contaminant on these two fomites and in two patients with clinical infections patients during the same period . We believe these findings add evidence to support the hypothesis that these particular surfaces may serve as reservoirs of nosocomial pathogens and vectors for cross-transmission in the ICU setting . New infection control policies and engineering plans were initiated on the basis of our results.

Curr Biol, 2000 Nov 30, 10(23), 1543 - 5
Caenorhabditis elegans is a model host for Salmonella typhimurium; Labrousse A et al.; The idea of using simple, genetically tractable host organisms to study the virulence mechanisms of pathogens dates back at least to the work of Darmon and Depraitere {1} . They proposed using the predatory amoeba Dictyostelium discoideum as a model host, an approach that has proved to be valid in the case of the intracellular pathogen Legionella pneumophila {2} . Research from the Ausubel laboratory has clearly established the nematode Caenorhabditis elegans as an attractive model host for the study of Pseudomonas aeruginosa pathogenesis {3} . P . aeruginosa is a bacterium that is capable of infecting plants, insects and mammals . Other pathogens with a similarly broad host range have also been shown to infect C . elegans {3,4} . Nevertheless, the need to determine the universality of C . elegans as a model host, especially with regards pathogens that have a naturally restricted host specificity, has rightly been expressed {5} . We report here that the enterobacterium Salmonella typhimurium, generally considered to be a highly adapted pathogen with a narrow range of target hosts {6}, is capable of infecting and killing C . elegans . Furthermore, mutant strains that exhibit a reduced virulence in mammals were also attenuated for their virulence in C . elegans, showing that the nematode may constitute a useful model system for the study of this important human pathogen.

J Invertebr Pathol, 2000 Nov, 76(4), 285 - 92
Interaction of Xenorhabdus nematophilus (Enterobacteriaceae) with the antimicrobial defenses of the house cricket, Acheta domesticus; da Silva CC et al.; Fifth instar Acheta domesticus nymphs exhibited a decline in total hemocyte counts during the first hour of exposure to dead Xenorhabdus nematophilus; the bacterial level in the hemolymph also declined during this time . Thereafter bacterial numbers in the hemolymph increased as the level of damaged hemocytes increased . The bacteria lowered phenoloxidase activity in vivo by initially reducing the number of hemocytes containing prophenoloxidase and later by inhibiting enzyme activation . Preincubating X . nematophilus in hemolymph with active phenoloxidase in vitro accelerated the removal of the bacteria from the hemolymph in vivo which may be due to modification of the bacterial surface by serine proteases . Lysozyme activity increased in bacteria-injected insects in parallel with an increase in counts of damaged hemocytes; most of the enzyme was located in hemocytes . Lipopolysaccharides of X . nematophilus caused changes in hemocyte counts and phenoloxidase and lysozyme levels comparable to whole bacteria . Lipopolysaccharides also slowed the removal rate of the bacteria from, and accelerated bacterial emergence into, the hemolymph.

Gene, 2000 Nov 27, 258(1-2), 193 - 9
Albicidin antibiotic and phytotoxin biosynthesis in Xanthomonas albilineans requires a phosphopantetheinyl transferase gene; Huang G et al.; Xanthomonas albilineans produces a family of highly potent antibiotics and phytotoxins called albicidins, which are key pathogenesis factors in the systemic development of leaf scald disease of sugarcane . A gene (xabA) required for albicidin biosynthesis encodes a peptide of 278 amino acids, including the signature sequence motifs for phosphopantetheinyl transferases (PPTases) that activate polyketide and non-ribosomal peptide synthetases . The Escherichia coli entD gene, which encodes a PPTase involved in biosynthesis of enterobactin (a siderophore), restored biosynthesis of albicidin (a DNA replication inhibitor) in X . albilineans Tox- LS156 (xabA::Tn5) . We conclude that XabA is a PPTase required for post-translational activation of synthetases in the albicidin biosynthetic pathway . This is the first antibiotic or toxin biosynthesis gene characterized from the genus Xanthomonas, and the first demonstration that antibiotic synthetases in the Pseudomonadaceae, like those in the Enterobacteriaceae and in Gram-positive bacteria, can require activation by a PPTase . Coupled with the recent demonstration of a separate albicidin biosynthetic gene cluster, the results indicate the possibility for overproduction of albicidins,which allows better understanding and application of these potent inhibitors of prokaryote DNA replication.

Int Microbiol, 2000 Mar, 3(1), 31 - 8
Rapid identification of Salmonella typhimurium, S . enteritidis and S . virchow isolates by polymerase chain reaction based fingerprinting methods; Bennasar A et al.; In this study we used and evaluated three rapid molecular typing methods for the identification of three frequent, clinically significant Salmonella serovars on the basis of the ease, simplicity and reproducibility of the chosen methods . We determined the genetic diversity among several isolates of Salmonella enteritidis, S . typhimiurium and S . virchow, and compared them with other enterobacteria by using the repetitive extragenic palindromic (REP) sequences, the enterobacterial repetitive intergenic consensus (ERIC) sequences, and the 16S-23S rDNA intergenic spacer region (ITS 1) . The objective was to evaluate their potential application to discriminate among members of the species Salmonella enterica subspecies enterica using the genetic diversity of the group found by genomic fingerprinting . The three different serovars of Salmonella studied gave reproducible and distinguishable profiles using whichever of the above mentioned polymerase chain reaction (PCR) methods assayed . The conserved patterns in each serovar allowed for easy differentiation from other serovars of Salmonella.

Med Dosw Mikrobiol, 2000, 52(1), 35 - 49
{Evaluation of the usefulness of selected virulence markers for identification of virulent Yersinia enterocolitica strains . II . Genotypic markers associated with the pYV plasmid}; Gierczynski R; Pathogenic strains of Yersinia enterocolitica bear virulence associated plasmid pYV . Unfortunately plasmid pYV is easily lost by these bacteria incubated at elevated temperatures (37 degrees C) or long stored at room temperatures . This sometimes makes difficult the detection of the virulence plasmid, especially by its isolation or biochemical tests . On the other hand, observations done by some authors suggest that polymerase chain reaction (PCR) could be useful for demonstration of the pYV plasmid of Yersinia strains . Accordingly to this observation the aim of the presented study was to check the usefulness of plasmid-localised genes virF and yadA, detected by PCR, for the identification of the virulent strains of Y . enterocolitica . In the presented study one hundred and fifty two clinical strains of Y . enterocolitica belonging to serogroup O3 were investigated by the PCR for the presence of genes virF and yadA . Bacterial strains were first tested for the presence of pYV plasmid . In addition the phenotypic features: calcium dependence, Congo red binding and autoagglutination were determined . In this way the virulence plasmid was found in 130 of 152 examined strains . For PCR studies also forty plasmid-cured strains of Y . enterocolitica and 32 non-Y . enterocolitica, Enterobacteriaceae strains were included . The obtained results show that the tested genes were present only in Yersinia strains possessing the pYV plasmid and no one non-specific PCR product was observed . The detection level of these genes in nested PCR permits to detect pathogenic Y . enterocolitica in suspension composed of 1 x 10(3) CFU/ml of pYV+ bacilli and 3 x 10(9) CFU/ml plasmid-cured, isogenic bacteria . In the study it was shown that genes virF and yadA were useful virulence markers, which could be helpful in clinical studies for the detection of the virulence plasmid in Y . enterocolitica strains long stored or incubated at elevated temperatures.

PDA J Pharm Sci Technol, 2000 Nov, 54(6), 470 - 7
Alternative microbial testing: a novel DNA-based detection system for specified microorganisms in pharmaceutical preparations
Merker P, Grohmann L, Petersen R, Ladewig J, Gerbling KP, Lauter FR.
Fluorescence-coupled PCR technology was employed to quantify DNA segments specific for Staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacteriaceae . The PCR procedure is put forward as an alternative method for detecting microbial contaminations in pharmaceutical preparations and is compared to the tests for specified microorganisms described in European Pharmacopoeia (EP) 2, 2.6.13 and the USP, chapter 61 . Data presented here describe the validation of this analytical method when used for proof of absence of specified microorganisms . The detection systems were specific for the microorganisms analyzed, and led to linear results over a wide range (more than 6-7 log intervals) . The correlation coefficients lay above 0.99 . The precision of replicate determinations within a single test was observed to be high, the relative standard deviation being between 0.39% and 1.53% . The precision between different tests was also high, with a relative standard deviation between 0.76% and 1.91% . The sensitivity without pre-enrichment amounted to 1-10 CFU . Since determination of the specified bacteria was performed following pre-enrichment, the limit of detection amounted to 1 CFU . Equivalent results were obtained in a study on nine batches of a milky hydrophilic cream (SH-No . M 440 A) with the conventional test for microbial contamination and the PCR procedure . The data presented here strongly indicate that the use of fluorescence-coupled PCR techniques can prove the absence of specified bacteria faster and more efficiently than conventional methods.

Braz J Infect Dis, 1998 Dec, 2(6), 291 - 299
Drug Resistance in Bacteria Isolated From a Brazilian Hospital; Garcia Franco Do Nascimento G et al.; Bacteria commonly associated with cases of hospital infection were isolated from samples of food, from food handless, and from objects and surfaces from different places of a hospital in Piracicaba, Sao Paulo, Brazil, and the resistance patterns to antibiotic of these strains of bacteria were evaluated . The resistance patterns of these bacteria showed a large variation, and a high frequency of resistance to ampicillin (60.9%), cephalothin (58.7%) and carbenicillin (52.2%) was observed . The frequency of resistance to cephalosporins of 3rd and 4th-generations was 26.1% and 17.4% of the samples, respectively . Resistance to more than two drugs was observed in 27 samples (56.5%), and in four strains multiple resistance to 17 or more tested drugs was recorded . Five bacteria which were multi-resistant to antibiotics (Enterobacter aerogenes, Escherichia coli, Proteus sp, Pseudomonas sp and Staphylococcus aureus) were studied to determine the chromosomal or plasmidial genetic basis of the resistance, using plasmid curing and agarose gel electrophoresis of plasmidial DNA . It was possible to verify that for the antibiotics chloramphenicol and kanamycin, the resistance seems to be of plasmidial origin.

Braz J Infect Dis, 1998 Oct, 2(5), 241 - 255
Piperacillin/Tazobactam: Evaluation of Its In vitro Activity against Bacteria Isolated in Two Brazilian Hospitals and an Overview of Its Antibacterial Activity, Pharmacokinetic Properties and Therapeutic Potential; Sader HS et al.; Piperacillin/tazobactam is a highly active antibiotic against most clinically important species of Gram-negative and positive bacteria, including anaerobes . It has never been used or tested against bacteria isolated in Brazil . In this article we report the in vitro activity of piperacillin/tazobactam against clinical isolates from two tertiary hospitals in Sao Paulo and Rio de Janeiro and review the evolving clinical literature . The study was performed before its commercialization in Brazil . Its activity was compared to that of several broad-spectrum antimicrobial agents commercially available in Brazil . Piperacillin/tazobactam was active against 83% of the isolates tested, while imipenem was active against 91%, cefepime 77%, and ciprofloxacin 73% . Against Enterobacteriaceae (n=398), cefepime was more active than piperacillin/tazobactam (92% versus 88%) . Klebsiella pneumoniae strains (n=95) presented low susceptibility to piperacillin/tazobactam (79%), ceftazidime (67%), and to cefepime (82%) indicating a high percentage of ESBL-producing strains . The most active compounds against this species were imipenem (100%) and ciprofloxacin (93%) . Piperacillin/tazobactam was the most active compound against Gram-positive cocci (n=238; percentage of susceptibility rank order: piperacillin/tazobactam = imipenem > ciprofloxacin > cefepime) and the second most active against nonenteric Gram-negative bacilli (n=250, rank order: imipenem {72%} > piperacillin/tazobactam {60%} > cefepime {56%} > ceftazidime {52%} > gentamicin {45%} > ciprofloxacin = aztreonam {42%}) . Cefepime was the most active compound against P . aeruginosa (n=128, only 67%), followed by ceftazidime (64%), piperacillin/tazobactam (63%) and imipenem (59%) . Only imipenem (91%) was active against more than 50% of the A . baumannii isolates (n=79) tested . Piperacillin/tazobactam was the second most active compound against A . baumannii (49%) and the most active against B . cepacia (91%) . Our results demonstrated a high level of antimicrobial resistance in the hospitals evaluated, especially among nonenteric Gram-negative bacilli; and clonal dissemination of multiresistant strains . Piperacillin/tazobactam may contribute to the treatment of nosocomial infections in Brazil, however, some degree of resistance was detected in some species in the instance of frequent multiresistant bacteria in the tertiary level hospitals where the drug was evaluated.

Microbiology, 2000 Dec, 146 Pt 12, 3171 - 82
A method for direct cloning of fur-regulated genes: identification of seven new fur-regulated loci in Escherichia coli; Vassinova N et al.; A strain that allows the cloning of Fur-regulated loci was constructed . The strain, named FUR-SEL1, contains a chromosomal fhuA'-'cat transcriptional fusion that is expressed from the Fur-regulated promoter, fhuA(p) . Therefore, Fur boxes introduced on a multicopy plasmid can cause derepression of the fusion by titrating the Fur repressor and thereby confer chloramphenicol resistance, which can be used as a selectable phenotype for cloning Fur-regulated loci . However, a number of additional mutations had to be introduced before FUR-SEL1 could be used for cloning Fur-regulated genes . The principal approach consisted of introducing a leaky fur mutation that ensures a more than 10(6)-fold increase in chloramphenicol resistance for FUR-SEL1 transformants carrying FUR-box-containing plasmids . To verify that the cloning procedure selects Fur-regulated genes, 10 recombinant plasmids chosen at random among the ones selected with FUR-SEL1 were analysed by FURTA (Fur-titration assay), a method for identification of Fur-regulated genes . In addition, the nucleotide sequences of their chromosomal inserts were determined . Besides known Fur-regulated genes, seven Escherichia coli loci which have not previously been shown to be Fur regulated were found, including the pgmA and nrdHIEF genes, predicted ORF yhhY and four promoters identified first in this study . Three of the promoters preceded the nohA gene, and ORFs ygaC and yhhX . The fourth was located upstream of orf78 predicted in this work . The regulation of the promoter activities by iron and the involvement of Fur in this regulation were shown . Employing FUR-SEL1 for cloning Fur-regulated loci from other enterobacteria is discussed.

J Clin Microbiol, 2000 Dec, 38(12), 4646 - 8
Comparison of the Rodac imprint method to selective enrichment broth for recovery of vancomycin-resistant enterococci and drug-resistant Enterobacteriaceae from environmental surfaces; Hacek DM et al.; We compared the Rodac imprint technique to selective enrichment broth for detecting vancomycin-resistant enterococci (VRE) and multidrug-resistant Enterobacteriaceae (MDRE) on surfaces . Rodac plates contained tryptic soy agar with 5% sheep blood, vancomycin (6 microg/ml), ceftazidime (2 microg/ml), amphotericin B (2 microg/ml), and clindamycin (1 microg/ml) . Two types of broth were used: brain heart infusion (BHI) and BHI plus vancomycin (6 microg/ml) and ceftazidime (2 microg/ml) (BHIVC) . Of the 46 surfaces cultured for VRE, 12 (26%) were positive . Of the 12 VRE-positive surfaces, 11 (92%) grew from Rodac, 8 (67%) grew from BHIVC, and 7 (58%) grew from BHI . A larger study is needed for MDRE, as only 4 of 43 surfaces were MDRE positive . The Rodac imprint technique successfully recovered VRE from environmental surfaces.

J Clin Microbiol, 2000 Dec, 38(12), 4539 - 47
Duodenal microflora in very-low-birth-weight neonates and relation to necrotizing enterocolitis; Hoy CM et al.; Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in the neonatal period . Small-bowel overgrowth with aerobic gram-negative bacteria has previously been implicated in the development of NEC . This prospective study performed quantitative bacteriology on 422 duodenal aspirates collected from 122 very-low-birth-weight (<1,500-g) newborns, at the time of routine changing of nasogastric tubes . Isolates of Enterobacteriaceae were typed by repetitive extragenic, palindromic PCR and pulsed-field gel electrophoresis . One or more samples from 50% of these infants yielded gram-negative bacteria, predominantly Escherichia coli, Klebsiella spp., and Enterobacter spp., with counts up to 10(8) CFU/g . The proportion of samples with gram-negative bacteria increased with postnatal age, while the percentage of sterile samples declined . Molecular typing revealed marked temporal clustering of indistinguishable strains . All infants had been fed prior to isolation of gram-negative organisms . Antibiotic use had no obvious effect on colonization with Enterobacteriaceae . There were 15 episodes of suspected NEC (stage I) and 8 confirmed cases of NEC (2 stage II and 6 stage III) during the study period . Duodenal aspirates were collected prior to clinical onset in 13 episodes of NEC . Seven of these yielded Enterobacteriaceae, of which five strains were also isolated from infants without NEC . Very-low-birth-weight infants have high levels of duodenal colonization with Enterobacteriaceae, with evidence of considerable cross-colonization with indistinguishable strains . There was no association between duodenal colonization with particular strains of Enterobacteriaceae and development of NEC.

Braz J Infect Dis, 1998 Feb, 2(1), 18 - 24
Evaluation of the Antimicrobial Activity of Sparfloxacin, Relative to Other Oral Antibiotics Against 1,125 Bacterial Isolates from 10 Medical Centers in Brazil; Mendes C et al.; A multicenter study was carried out in order to compare the in vitro activity of sparfloxacin to ciprofloxacin, amoxicillin/clavulanic acid, cephalexin, cefuroxine and azithromycin, against 1,125 microorganisms recently isolated from clinical specimens, most of them representative of respiratory tract infections . Sparfloxacin demonstrated potent action and was more active than the beta-lactam agents and azithromycin against most of the bacterial strains tested . Sparfloxacin was more potent (96% and 95% sensitivity, with MIC(90) of 0.19microg/mL and 0.5microg/mL, respectively)than the other antimicrobial agents tested against the Enterobacteriaceae family (Escherichia coli and Elebsiella pneumoniae) . It was found to be equivalent in activity to ciprofloxacin (96% and 91% sensitivity and MIC(90) of 0.25 and 0.75microg/mL, respectively) . Sparfloxacin was also found to be very active against the most fastidious microorganisms commonly associated to respiratory tract infections such as the penicillin-susceptible and resistant Streptococcus pneumoniae (MIC(90) 0.5microg/mL and 0.38microg/mL, respectively), ampicillin-susceptible and -resistant Haemophilus influenzae (MIC(90) 0.016microg/mL and 0.38microg/mL, respectively), beta-lactamase producing Moraxella catarrhalis (MIC(90) 0.032microg/mL) and non beta-lactamase producing M.catarrhalis (MIC(90) 0.5microg/mL).

Presse Med, 2000 Oct 28, 29(32), 1745 - 51
{Effectiveness of combined vancomycin and pefloxacine in gastrointestinal decontamination for preventing infections after chemotherapy-induced bone marrow aplasia . A randomized double-blind study}; Thomas X et al.; OBJECTIVE: To test the value of the combination of pefloxacin and vancomycin as gastro-intestinal tract decontamination for the prevention of infections in patients with chemotherapy-induced neutropenia . PATIENTS AND METHODS: Oral pefloxacin plus vancomycin (48 patients), pefloxacin alone (51 patients), or placebo (52 patients) were administered in a randomized double-blind study . Evaluation was done by determining site and documentation of infections, organisms responsible for bacteriologically documented infections, organisms acquired in surveillance cultures and number of days with fever during aplasia . RESULTS: Patients receiving pefloxacin had significantly fewer episodes of bacteremia with enterobacteriacae . No differences were noted between patients treated by pefloxacin and those who received a combination of pefloxacin with vancomycin regarding gram-positive (Gram+) infections and infections with gram-negative (Gram-) organisms usually resistant to pefloxacin . However, placebo gave similar results . There was no induction of resistance to pefloxacin during the study . Tolerance of treatment was excellent . Only a prolonged aplasia has been observed in patients receiving pefloxacin . CONCLUSION: Thus, the combination of vancomycin with pefloxacin was not more efficacious than pefloxacin only for the prevention of Gram+ infections in the neutropenic patient . The systematic use of antibiotics as gastrointestinal tract decontamination for the prevention of infections in patients with aplasia may be questionable.

Appl Environ Microbiol, 2000 Dec, 66(12), 5521 - 3
Evaluation of p-naphtholbenzein-beta-D-galactoside as a substrate for bacterial beta-galactosidase; James AL et al.; We describe the synthesis of a new substrate for the detection of beta-galactosidase and evaluate its performance in comparison with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) and cyclohexenoesculetinbeta-D-galactoside (CHE-Gal) . Of 206 Enterobacteriaceae strains able to hydrolyze X-Gal, 194 (94.2%) hydrolyzed CHE-Gal and 192 (93.2%) hydrolyzed p-naphtholbenzein-beta-D-galactoside (PNB-Gal) . We conclude that PNB-Gal is an effective substrate for the detection of beta-galactosidase.

Appl Environ Microbiol, 2000 Dec, 66(12), 5340 - 7
Fatty acid competition as a mechanism by which Enterobacter cloacae suppresses Pythium ultimum sporangium germination and damping-off; van Dijk K et al.; Interactions between plant-associated microorganisms play important roles in suppressing plant diseases and enhancing plant growth and development . While competition between plant-associated bacteria and plant pathogens has long been thought to be an important means of suppressing plant diseases microbiologically, unequivocal evidence supporting such a mechanism has been lacking . We present evidence here that competition for plant-derived unsaturated long-chain fatty acids between the biological control bacterium Enterobacter cloacae and the seed-rotting oomycete, Pythium ultimum, results in disease suppression . Since fatty acids from seeds and roots are required to elicit germination responses of P . ultimum, we generated mutants of E . cloacae to evaluate the role of E . cloacae fatty acid metabolism on the suppression of Pythium sporangium germination and subsequent plant infection . Two mutants of E . cloacae EcCT-501R3, Ec31 (fadB) and EcL1 (fadL), were reduced in beta-oxidation and fatty acid uptake, respectively . Both strains failed to metabolize linoleic acid, to inactivate the germination-stimulating activity of cottonseed exudate and linoleic acid, and to suppress Pythium seed rot in cotton seedling bioassays . Subclones containing fadBA or fadL complemented each of these phenotypes in Ec31 and EcL1, respectively . These data provide strong evidence for a competitive exclusion mechanism for the biological control of P . ultimum-incited seed infections by E . cloacae where E . cloacae prevents the germination of P . ultimum sporangia by the efficient metabolism of fatty acid components of seed exudate and thus prevents seed infections.

FEMS Microbiol Ecol, 2000 Sep 1, 33(3), 209 - 218
Isolation and characterisation of ethoprophos-degrading bacteria; Karpouzas DG et al.; An enrichment culture technique was used to isolate bacteria responsible for the enhanced biodegradation of ethoprophos in a soil from Northern Greece . Restriction fragment length polymorphism patterns of the 16S rRNA gene, partial 16S rRNA sequence analysis, and sodium dodecylsulfate-polyacrylamide gel electrophoresis total protein profile analysis were used to characterise the isolated bacteria . Two of the three ethoprophos-degrading cultures were pure and both isolates were classified as strains of Pseudomonas putida (epI and epII) . The third culture comprised three distinct components, a strain identical to P . putida epI and two strains with 16S rRNA sequence similarity to Enterobacter strains . Isolate epI effectively removed a fresh ethoprophos addition from both fumigated and non-fumigated soil when introduced at high inoculum density, but removed it only from fumigated soil at low inoculum density . Isolates epI and epII degraded cadusafos, isazofos, isofenphos and fenamiphos, but only at a slow rate . This high substrate specificity was attributed to minor (cadusafos), or major (isazofos, isofenphos, fenamiphos) structural differences from ethoprophos . Studies with (14)C-labelled ethoprophos indicated that isolates epI and epII degraded the nematicide by removing the S-propyl moiety.

Folia Microbiol (Praha), 1999, 44(6), 629 - 34
Selective medium for primary isolation of members of the tribe Proteeae; Urbanova E; A selective Proteeae medium (SPM) for isolation and preliminary detection of species of genera Proteus, Morganella, and Providencia was evaluated . The SPM contains tryptose phosphate agar with phenolphthalein monophosphate (as substrate for phosphatase activity), bile salts and polymyxin B (as inhibitors) . The selectivity of the SPM was tested by the ecometric method of quality assurance of culture media . Fourteen reference cultures of enterobacteria and fifty-four strains of Proteeae were tested for their absolute growth index (AGI) . Ninety-five percent of tested Proteeae strains display an AGI above 2.5 . The detected phosphatase activity proved to be able to discriminate colonies of members of the tribe Proteeae . The ability of SPM for primary isolation of members of Proteeae was tested on food and clinical material and 94 strains were isolated . In addition, the SPM was employed in routine practice of clinical microbiology . From 1016 clinical samples (stool, urine, vaginal and urethral swabs), 57 strains of Proteeae were detected by the SPM in contrast to 35 strains by the routine procedure . The difference amounts to nearly 40%.

Curr Infect Dis Rep, 2000 Oct, 2(5), 391 - 398
Multidrug-resistant Pathogens: Mechanisms of Resistance and Epidemiology; Kaye KS et al.; Resistance to antimicrobial agents among bacteria and fungi is a persistent problem complicating the management of critically ill patients . To understand the issues involved in resistance in critical care, it is essential to understand the epidemiology and mechanisms of resistance . beta-lactam resistance in pneumococci, and penicillin and chloramphenicol resistance in Neisseria meningitidis, have complicated the management of meningitis . Vancomycin resistance in enterococci and methicillin resistance in Staphylococcus aureus have disseminated among hospitals, nursing homes and, in some cases, community patients . Glycopeptide resistance in S . aureus has recently been described in clinical isolates; the potential for spread of this resistance trait is concerning . Resistance to broad-spectrum cephalosporins is a persistent challenge in the management of infections caused by Pseudomonas areuginosa, and Enterobacter species, as well as other Enterobacteriaceae . Azole resistance in Candida species . has also complicated the treatment of nosocomial infections . Resistance to antimicrobial drugs is a persistent and emerging problem and presents major therapeutic challenges.

Poult Sci, 2000 Nov, 79(11), 1566 - 70
Reduction of Salmonella in the crop of broiler chickens subjected to feed withdrawal; Hinton A Jr et al.; Broilers were challenged with 10(9) Salmonella typhimurium and then were provided a glucose-based cocktail supplemented with 0 to 15% glucose during feed withdrawal in battery cages or in pens on litter . After feed withdrawal, broilers were processed, and their crops were aseptically removed and weighed . Crops were then stomached in distilled water, and the pH of the suspension was measured electronically . Salmonella typhimurium, Enterobacteriaceae, and lactic acid bacteria in the crop suspensions were enumerated on the appropriate bacteriological medium . Findings indicated that fewer S . typhimurium and other Enterobacteriaceae were recovered from the crops of broilers provided the cocktail supplemented with 7.5% glucose than from the crops of broilers provided either water or cocktails supplemented with lower or higher concentrations of glucose . Inhibition of the growth of S . typhimurium and other Enterobacteriaceae in the crops of broilers provided the cocktail supplemented with 7.5% glucose was generally associated with increased growth of lactic acid bacteria and decreased crop pH . Providing the cocktail to broilers before shipping to processing plants may reduce the number of food-borne pathogens that poultry carry into processing plants.

Microbios, 2000, 103(405), 107 - 17
The spectrum of pathogenic bacteria in positive blood cultures; Bahar MA et al.; There is compelling evidence to suggest that the profiles of pathogenic bacteria which cause septicaemia shock vary from one region to another due to differences in the source of contamination . Blood cultures were prepared from 3,481 patients with symptoms of systemic bacterial contamination . The blood cultures of 558 (16.02%) patients showed at least one kind of bacterial infection . This rate was markedly higher than that reported in Germany (12.8%) and Japan (12.3%) . Systemic bacterial infection was significantly higher in males than in females (82% versus 18%) . Most of the patients surveyed (62%) were adults and the rest were either infants (19%) or neonates (19%) . When blood samples of these patients were cultured, and isolated bacteria were characterized by a variety of diagnostic tests, over twenty different strains of bacteria were identified and characterized . More than 29% of positive cultures were Enterobacter spp . while Staphylococcus aureus (20%) and Brucella spp . (8%) ranked second and third highest among the infections . The results suggest that agents which cause infections vary with respect to region and that knowledge of local risk factors may aid in patient diagnosis and treatment.

Int J Antimicrob Agents, 2000 Nov, 16(3), 239 - 43
In vitro activity of gatifloxacin compared with gemifloxacin, moxifloxacin, trovafloxacin, ciprofloxacin and ofloxacin against uropathogens cultured from patients with complicated urinary tract infections; Naber KG et al.; Minimum inhibitory concentrations (MICs) of gatifloxacin were compared with those of gemifloxacin, moxifloxacin, trovafloxacin, ciprofloxacin and ofloxacin using an agar dilution method for 400 uropathogens cultured from the urine of urological patients with complicated and/or hospital-acquired urinary tract infections (UTI) . The collection of strains was made up of Enterobacteriaceae (34.5%), enterococci (31.5%), staphylococci (21.2%) and non-fermenting bacteria (12.8%) . The antibacterial activity of the three newer fluoroquinolones, gatifloxacin, gemifloxacin, and moxifloxacin, were similar, but showed some drug specific differences . Gemifloxacin was most active against Escherichia coli, but less so against Proteus mirabilis . In this series all isolates of E . coli were inhibited at a MIC of 0.25 mg/l gatifloxacin and moxifloxacin and by 0.125 mg/l gemifloxacin . The MIC distribution of all fluoroquinolones showed a bimodal distribution for staphylococci, enterococci and Pseudomonas aeruginosa . The two modes for P . aeruginosa were 1 and 64 mg/l for gemifloxacin and moxifloxacin and 0.5 and 64 mg/l for gatifloxacin . For staphylococci the two modes were 0.125 and 2 mg/l for gatifloxacin, 0.03 and 4 mg/l for gemifloxacin, and 0.03 and 2 mg/l for moxifloxacin; for enterococci, 0.25 and 16 mg/l for gatifloxacin, 0.06 and 2 mg/l for gemifloxacin, and 0.25 and 8 mg/l for moxifloxacin . Compared with trovafloxacin the MICs were similar, but the newer fluoroquinolones were more active than ciprofloxacin and ofloxacin against Gram-positive bacteria . Of the newer fluoroquinolones gatifloxacin had the highest rate of renal excretion and could be considered a promising alternative fluoroquinolone agent for the treatment of UTI.

J Wildl Dis, 2000 Oct, 36(4), 783 - 7
Bacteria and nematodes in the conjunctiva of mule deer from Wyoming and Utah; Dubay SA et al.; Swabs of conjunctiva were collected from 44 live and 226 hunter-harvested mule deer (Odocoileus hemionus) from Wyoming and Utah (USA) . We identified 29 gram negative and 22 gram positive bacterial taxonomic categories, but many isolates from hunter-harvested animals were environmental contaminants . Staphylococcus spp . and Micrococcus spp . were the most common gram positive bacteria isolated, and Enterobacter spp., Escherichia coli, and Pseudomonas spp . were common gram negative bacteria isolated . Thelazia californiensis were found in 15% of hunter-harvested deer in Utah in 1994 and in 8% in 1995 . Nematodes were found in 40% of live deer in 1995 and 66% in 1996 . Three live animals showed clinical signs of infectious keratoconjunctivitis (IKC) in 1996, but pathogenic bacteria were not isolated from these individuals . Hemolytic, non-piliated Moraxella ovis was isolated from two clinically normal live deer in 1996 and isolates were similar to those cultured from IKC cases from Wyoming and Utah.

Infect Control Hosp Epidemiol, 2000 Oct, 21(10), 651 - 3
Outbreak of nosocomial multidrug-resistant Enterobacter aerogenes in a geriatric unit: failure of isolation contact, analysis of risk factors, and use of pulsed-field gel electrophoresis; Piagnerelli M et al.; We describe herein an outbreak of Enterobacter aerogenes in a geriatric acute unit with failure of contact isolation that necessitated the temporary closure of the department . We emphasize the need for guidelines for the management of multiresistant bacteria.

Curr Microbiol, 2000 Dec, 41(6), 417 - 20
Enterobacter cowaniisp . nov., a new species of the family Enterobacteriaceae; Inoue K et al.; The name Enterobacter cowanii sp . nov . is proposed for a group of organisms referred to as NIH Group 42 . Members of this species are Gram-negative, motile rods conforming to the definition of the family Enterobacteriaceae . The DNA relatedness of nine strains of NIH Group 42 to the proposed type strain of this species averaged 85% at 70 degrees C, whereas the relatedness to other species within the family Enterobacteriaceae was less than 38% . Because the DNA relatedness (5-38%) is closer to species of the genus Enterobacter than to other species of the family, the members of NIH Group 42 were placed in the genus Enterobacter . The majority of strains of E . cowanii were isolated from clinical specimens . A culture of the type strain (888-76) has been deposited in the Japan Collection of Microorganisms as JCM 10956.

J Food Prot, 2000 Nov, 63(11), 1483 - 6
Enrichment procedures and plating media for isolation of Yersinia enterocolitica; Jiang GC et al.; A shortened enrichment procedure (25 degrees C for 24 h) was compared with cold enrichment procedures (4 degrees C for 1 to 3 weeks) and direct plating for isolation of Yersinia enterocolitica from commercial ground meat samples . The combined data of all recovery procedures showed that this organism was isolated from 34% of the ground beef samples . The highest isolation rate was 32% for the 4 degrees C/3-week enrichment, followed by 28% for the 4 degrees C/2-week enrichment, 26% for the 25 degrees C/24-h enrichment, 22% for the 4 degrees C/1-week enrichment, and 10% for direct plating . No significant differences (P > 0.05) in isolation rate occurred between the 4 degrees C/3-week, 4 degrees C/2-week, 25 degrees C/24-h, and 4 degrees C/1-week enrichments . The combined data of all recovery procedures showed that Y . enterocolitica was isolated from 64% of ground pork samples . The highest isolation rate was 48% for the 4 degrees C/3-week enrichment, followed by 40% for the 25 degrees C/24-h enrichment, 34% for the 4 degrees C/2-week enrichment, 24% for the 4 degrees C/1-week enrichment, and 24% for direct plating . No significant differences (P > 0.05) in isolation rate occurred between the 4 degrees C/3-week, 25 degrees C/24-h, and 4 degrees C/2-week enrichments . During the plating phase of the experiment, the efficiency of a dye-containing, Yersinia-selective medium (KV202) was compared with that of a commercially available cefsulodin-irgasan-novobiocin medium . Recovery rates were similar for both media . However, KV202 agar differentiated Y . enterocolitica from such contaminating bacteria as Enterobacter, Serratia, and Salmonella by colony morphologic characteristics and color.

J Mol Microbiol Biotechnol, 2000 Oct, 2(4), 375 - 80
Lipopolysaccharide biosynthesis in Leptospira; Bulach DM et al.; Lipopolysaccharide is the major surface antigen of Leptospira . Variation in LPS structure is the basis for the more than 200 serovars that have been identified . Despite the importance of this antigen in immunity and diagnostics, there is relatively little known about the genetics and chemistry of leptospiral LPS, as compared to some members of the Enterobacteriaceae . The nucleotide sequence of the locus encoding enzymes for the biosynthesis of the O-antigen component of leptospiral LPS (rfb locus) has been determined for three serovars namely, L . interrogans serovar Pomona, L . interrogans serovar Hardjo subtype Hardjoprajitno and L . borgpetersenii serovar Hardjo subtype Hardjobovis . In the absence of data relating to the chemical structure or genetic tools to construct isogenic mutants in Leptospira, similarity analysis has been used to provide insight into the mechanisms by which the leptospiral O-antigen is assembled by comparison with characterized systems from other bacteria . In addition, comparison of the gene layout in each of the serovars provides an indication of the genetic basis for serovar diversity.

Lett Appl Microbiol, 2000 Oct, 31(4), 307 - 12
Discriminatory detection of extended-spectrum beta-lactamases by restriction fragment length dimorphism-polymerase chain reaction; Lee SH et al.; Plasmid-mediated resistance mechanisms to beta-lactams, comprising mostly extended-spectrum beta-lactamase (ESBL) production, lead to resistance against even the most recently developed beta-lactams in enterobacteria, which is now a serious threat to antibiotic therapy . In this work, the diagnostic ability of the restriction fragment length dimorphism (RFLD)-polymerase chain reaction (PCR) method in clinical samples was evaluated . Nine newly designed primer pairs were used to differentiate the genes encoding TEM-1a, SHV-12, MOX-1, MIR-1 and Toho-1 beta-lactamases . The RFLD-PCR was carried out successfully and these genes were differentiated by the sizes of their PCR product . This discriminatory detection of the genes was also confirmed by digestion with unique restriction enzyme sites and sequencing of the PCR products . The fragment sizes of PCR products digested with the enzymes were identical to the sizes calculated from nucleotide sequences of five beta-lactamase genes deposited in EMBL, GenBank and/or DDBJ databases and the sequences were also identical . In conclusion, the method and newly designed primers applied in this work can differentiate the ESBLs rapidly and effectively.

Can J Microbiol, 2000 Oct, 46(10), 867 - 77
A review of antimicrobial resistance in Canada; Blondeau JM et al.; Antimicrobial resistance is a global concern . Over the past 10 years, considerable efforts and resources have been expended to detect, monitor, and understand at the basic level the many different facets of emerging and increasing resistance . This review summarizes our current understanding of bacterial antimicrobial resistance issues in Canada with particular emphasis given to the Enterobacteriaceae, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus, Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Streptococcus pyogenes . In addition, future concerns and programs for ongoing surveillance are discussed.

Dan Med Bull, 2000 Sep, 47(4), 296 - 300
Community-acquired bacteraemia and antibiotic resistance . Trends during a 17-year period in a Danish county; Pedersen G et al.; INTRODUCTION: The aim was to ascertain the prevalence of antibiotic resistance among blood isolates from patients with community-acquired bacteraemia and to relate it to antibiotic consumption . METHODOLOGY: Cases of community-acquired bacteraemia were identified in a regional bacteraemia register in the County of Northern Jutland . The study included 3974 episodes in 3805 patients during a 17-year period . Total regional consumption of antibiotics was expressed in Defined Daily Doses (DDD) . RESULTS: The prevalence of antibiotic resistance was stable with few exceptions . The most notable time trend was noted for Escherichia coli for which the prevalence of resistance to ampicillin increased from 17% (95% confidence limits (CL) 12-23%) to 28% (95% CL 23-33%); for other Enterobacteriaceae the increase was from 73% (95% CL 61-83%) to 86% (95% CL 77-92%) . The prevalence of resistance to aminoglycosides, fluoroquinolones and third-generation cephalosporins remained low among all isolates of Enterobacteriaceae . Regional antibiotic consumption ranged from 10.2 to 13.6 DDD/1000 inhabitants/day . Consumption of penicillins with Gram-negative spectrum reached a maximum of 4.6 DDD/1000 inhabitants/day in 1993 and decreased towards the end of the study period . The prevalence of ampicillin-resistant E . coli was positively correlated with consumption of penicillins with Gram-negative spectrum; the correlation was stronger when adjustment was made for co-selection by tetracyclines and sulphonamides . CONCLUSION: Therapeutic options for community-acquired bacteraemia have not yet become seriously limited by prevalence of acquired antibiotic resistance . Still we found some evidence that consumption of penicillins with Gram-negative spectrum, sulphonamides and tetracyclines promotes antibiotic resistance among Enterobacteriaceae.

J Antimicrob Chemother, 2000 Nov, 46(5), 703 - 11
Integron-located VEB-1 extended-spectrum beta-lactamase gene in a Proteus mirabilis clinical isolate from Vietnam; Naas T et al.; A clinical isolate of Proteus mirabilis Lil-1 was obtained from a Vietnamese patient hospitalized in Paris, France . This isolate was resistant to cephalosporins, and there was marked synergy between cephalosporins and clavulanic acid together with unusual synergy between cefoxitin and cefuroxime . PCR analysis revealed the presence of blaVEB-1, an integron-located gene coding for an extended-spectrum beta-lactamase (ESBL) identified previously in an Escherichia coli isolate MG-1 from Vietnam . Using class 1 integron primers and blaVEB-1 intragenic primers, the insert region of the blaVEB-1-containing integron along with flanking sequences were amplified from P . mirabilis Lil-1 whole-cell DNA . A novel class 1 integron, In55, was identified that contained, in addition to intI1, qacEDelta1, sul1 and Orf5 genes, an 8 kb variable region . This region was comparable in size to that found previously in E . coli MG-1, but different from those previously identified in two Pseudomonas aeruginosa isolates from Thailand . In55 was located on a 190 kb self-transferable plasmid, which was different in size and structure from that found in E . coli MG-1 . The finding of blaVEB-1 on different plasmids and integrons in enterobacterial isolates underlines the interspecies spread of this novel ESBL gene.

J Clin Microbiol, 2000 Nov, 38(11), 4180 - 5
Evaluation of PCR-based methods for discrimination of Francisella species and subspecies and development of a specific PCR that distinguishes the two major subspecies of Francisella tularensis; Johansson A et al.; Previous studies have demonstrated that the four subspecies of the human pathogen Francisella tularensis, despite showing marked variations in their virulence for mammals and originating from different regions in the Northern Hemisphere, display a very close phylogenetic relationship . This property has hampered the development of generally applicable typing methods . To overcome this problem, we evaluated the use of PCR for discrimination of the subspecies using various forms of long arbitrary primers or primers specific for repetitive extragenic palindromic sequences (REP) or enterobacterial repetitive intragenic consensus (ERIC) sequences . Patterns generated by use of REP, ERIC, or long arbitrary primers allowed differentiation at the species level and of the four subspecies of F . tularensis . With each of these three methods, similar or identical clustering of strains was found, and groups of strains of different geographical origins or differing in virulence showed distinct patterns . The discriminatory indices of the methods varied from 0.57 to 0.65; thus, the patterns were not sufficiently discriminatory to distinguish individual strains . The sequence of a fragment generated by amplification with an arbitrary primer was determined, and a region showing interstrain heterogeneity was identified . Specific primers were designed, and a PCR was developed that distinguished strains of F . tularensis subsp . holarctica from strains of other F . tularensis subspecies, including strains of the highly virulent F . tularensis subsp . tularensis . Notably, one European isolate showed the genetic pattern typical of the highly virulent F . tularensis subsp . tularensis, generally believed to exist only in North America . It is proposed that a combination of the specific PCR together with one method generating subspecies-specific patterns is suitable as a rapid and relatively simple strategy for discrimination of Francisella species and subspecies.

Crit Care Med, 2000 Oct, 28(10), 3530 - 3
Nosocomial pneumonia in the pediatric trauma patient: a single center's experience; Patel JC et al.; OBJECTIVES: To evaluate a single center's experience with the frequency rate, patterns of occurrence, and impact on outcome of nosocomial pneumonia in the critically injured child . DESIGN: Retrospective review of prospectively collected data . SETTING: Level I university trauma center with a pediatric trauma intensive care unit . PATIENTS: A total of 523 consecutive critically injured children admitted to the pediatric intensive care unit during an 80-month interval . MEASUREMENTS AND RESULTS: Thirty-five episodes of nosocomial pneumonia were identified in 29 children (frequency rate of 5.5%) . The mean age of the children was 9.2 yrs, and the mean Injury Severity Score was 27 +/- 9 . In 91% of patients (26 children), nosocomial pneumonia was associated with mechanical ventilation . This represented a 13% frequency rate in injured children who were ventilated during the study period . The most common organisms recovered were Staphylococcus aureus (21%), Haemophilus influenzae (19%), Pseudomonas (11%), and Enterobacter (11%) . Early pneumonia (diagnosed < or = 7 days after injury) was predominantly caused by Haemophilus species . In contrast, Enterobacter and/or Pseudomonas were isolated primarily in late pneumonia (diagnosed >7 days after injury) . Staphylococcus was prominent throughout the hospitalization . Overall, children with nosocomial pneumonia were more severely injured (Injury Severity Score 27 vs . 17, p < .001) and had a longer hospital stay (26 vs . 7 days, p < .001) . Despite this, mortality (6.9% vs . 7.9%, p = NS) was not significantly different from injured children without pneumonia . CONCLUSIONS: In this study of a single pediatric trauma center, nosocomial pneumonia occurred in a small but significant percentage of injured children . The frequency rate increased two- to three-fold with mechanical ventilation . Microbiology varied with day of onset . In contrast to the adult, mortality did not seem to be significantly altered by this complication . Analysis of additional pediatric trauma centers is encouraged to confirm these characteristics of nosocomial pneumonia in the injured child.

Acta Microbiol Immunol Hung, 2000, 47(4), 457 - 70
Proteus virulence: involvement of the pore forming alpha-hemolysin (a short review); Toth V et al.; The genus Proteus belongs to the tribe of Proteae in the family of Enterobacteriaceae, and consists of five species: P . mirabilis, P . vulgaris, P . morganii, P . penneri and P . myxofaciens . They are distinguished from the rest of Enterobacteriaceae by their ability to deaminate phenylalanine and tryptophane . They hydrolyze urea and gelatin and fail to ferment lactose, mannose, dulcitol and malonate; and do not form lysine and arginine decarboxylase or beta-galactosidase {1} . Colonies produce distinct "burned chocolate" odor and frequently show the characteristics of swarming motility on solid media . P . mirabilis, P . vulgaris and P . morganii are widely recognized human pathogens . They have been isolated from urinary tract infections, wounds, ear, and nosocomial bacteremic infections, often in immuncompromised patients {2-6} . P . myxofaciens has no clinical interest to this time . P . penneri as species nova was nominated by the recommendation of Hickman and co-workers {7} . Formerly it was recognized as P . vulgaris biogroup 1 or indole negative P . vulgaris {8, 9} . Although it has been less commonly isolated from clinical samples than the other three human pathogenic Proteus species, it has nevertheless been connected with infections of the urinary tract, wounds and has been isolated from the feces of both healthy and diarrheic individuals {10-12} . Potential virulence factors responsible for virulence of Proteae are: IgA protease, urease, type3 fimbriae associated with MR/K haemagglutinins of at least two antigenic types, endotoxin, swarming motility and HlyA and/or HpmA type hemolysins {for review see ref . 13} . In the followings we give a survey of accumulated concepts about the position and characteristics of HlyA type alpha-hemolysins both in general and with emphasis on virulence functions in the tribe of Proteae.

Scand J Infect Dis, 2000, 32(5), 521 - 5
Risk and patterns of bacteraemia after splenectomy: a population-based study; Ejstrud P et al.; During a period in which vaccination of splenectomized patients has been recommended, we analysed the patterns of severe post-splenectomy infections (i.e . bacteraemia or meningitis) in a defined population-based cohort . A total of 561 patients undergoing splenectomy were identified during 1984-93 in a Danish county, and the 538 eligible patients were followed for 1731 person-years . After splenectomy, 38 patients contracted a bacteraemia, of which 45% occurred within 30 d (i.e . during the postoperative period) . No cases of meningitis were found . Among splenectomized patients the incidence rate of bacteraemia was 2.3 per 100 person-years at risk . Beyond the postoperative period we found an 8-fold increased risk of bacteraemia . Enterobacteria were the predominant cause (45%), and only 1 case due to Streptococcus pneumoniae was recorded . 89 (17%) died during the postoperative period, and the overall mortality rate was 18.4 per 100 person-years at risk . In all, 60% of the patients had been given a pneumococcal vaccination, and a Cox proportional hazard regression model showed that vaccination significantly reduced the risk of bacteraemia of any cause beyond the postoperative period . We conclude that splenectomy increases the risk of severe infections, and that vaccinated patients carry a lower risk of infection than non-vaccinated ones.

J Mol Biol, 2000 Nov 3, 303(4), 467 - 78
Functions of the subunits in the FlhD(2)C(2) transcriptional master regulator of bacterial flagellum biogenesis and swarming; Claret L et al.; In enterobacteria like Salmonella, biogenesis of cell surface flagella needed for motility is dependent upon the master operon flhDC at the apex of the flagellar gene hierarchy . The operon products FlhD and FlhC act together in a FlhD(2)C(2 )heterotetramer to induce flagellar gene transcription, while FlhD also represses cell septation . The flhDC operon is pivotal to differentiation into elongated hyperflagellated swarm cells that undergo multicellular migration, most strikingly in Proteus . We set out to establish the mechanism of action of the FlhD(2)C(2) multimer . In Proteus swarm cell extracts, all the FlhC was assembled into the FlhD(2)C(2 )transcription activator, but FlhD additionally formed approximately equimolar amounts of a FlhD(2) homodimer . Both FlhD and FlhC subunits homodimerised in vivo and in vitro, suggesting that self-interactions stabilise the FlhD(2)C(2 )complex . The FlhC and FlhD subunit proteins were separately expressed and purified, and the FlhD(2)C(2)heterotetramer was reconstituted in vitro . Purified FlhC bound specifically and cooperatively to the promoter region of the flhDC-regulated flhB flagellar gene in the absence of FlhD . Purified FlhD was unable to bind this target DNA, but binding by the FlhD(2)C(2)complex was approximately tenfold greater than the FlhC subunit alone, suggesting that FlhD potentiated the FlhC/DNA interaction . In support of this possibility, pre-incubation of FlhC with FlhD reduced the apparent dissociation constant, K(D), for the FlhC/DNA complex from 100 nM to 13 nM . Furthermore, in competition assays, FlhD substantially increased the specificity of DNA recognition by FlhC, and also stabilised the resultant labile protein/DNA complex, prolonging its half-life from around two minutes to more than 40 minutes . FlhD(2)C(2)is therefore an atypical prokaryotic transcription activator in which interaction of the FlhC subunit with DNA target sequences is enhanced by the coexpressed helper subunit FlhD .

Br J Biomed Sci, 2000, 57(3), 226 - 33
Extended-spectrum beta-lactamase-producing Klebsiella spp; West PW; Extended-spectrum beta-lactamases (ESBLs) are associated particularly with Klebsiella spp . These enzymes have arisen by mutation of the genes coding for clavulanate-sensitive, plasmid-mediated beta-lactamases such as TEM-1, TEM-2 and SHV-1 . Amino acid changes in ESBLs confer enhanced hydrolysis of oxyimino-aminothiazolyl beta-lactams and aztreonam . Enzyme hyperproduction and loss of porins contribute to hydrolytic efficiency . ESBLs are highly susceptible to inhibition by clavulanate, and their presence can be detected by the disc-approximation test, using amoxycillin/clavulanate and an ESBL-susceptible antibiotic . Other manual procedures have been used and commercial tests to detect the enzymes include Etest, Vitek and Dade Microscan products . The epidemiology of ESBLs is complex, and epidemic and sporadic strains may be encountered in the same hospital . Spread between hospitals--even countries--has been documented . ESBL activity is carried on large plasmids that often carry determinants for resistance to aminoglycosides and other antibiotics, and this is transmissible to Escherichia coli and other species of Enterobacteriaceae in which ESBLs have been detected.

Int J Med Microbiol, 2000 May, 290(2), 153 - 65
Genome plasticity in Enterobacteriaceae; Brunder W et al.; The comparative analysis of multiple representatives of the genomes of particular species are leading us away from a view of bacterial genomes as static, monolithic structures towards the view that they are relatively variable, fluid structures . This plasticity is mainly the result of the rearrangement of genes within the genome and the acquisition of novel genes by horizontal transfer systems, e . g . plasmids, bacteriophages, transposons or gene cassettes . These mechanisms often act in concert thus generating a complex genetic structure . Genomic variations are not a phenomenon at the DNA level alone, they influence the phenotype of a bacterium as well and can render a formerly harmless organism into a hazardous pathogen . This review deals not only with the mechanisms of genome rearrangements and the horizontal transfer of genes in Enterobacteriaceae but also points out that mobile genetic elements themselves are subjected to variation.

Presse Med, 2000 Sep 23, 29(27), 1497 - 503
{Sensitivity to antibiotics of bacteria from nosocomial infections . Evolution in resuscitation services of military hospitals}; Garrabe E et al.; OBJECTIVE: The aim of this study, conducted in the French Military hospitals, was to monitor the course of the antimicrobial sensibility of bacteria isolated from nosocomial infection in intensive care units . PATIENTS AND METHODS: A prospective study has been conducted from January to December 1998 in all the intensive care units of the French Army . All the non-repetitive strains isolated from nosocomial infection were collected and sent to a reference centre . Antimicrobial susceptibility was determined by the agar dilution method . Beta-lactamase were identified by iso-electro-focalisation . Antibiotics choice and interpretative criteria were those of the "Comite Francais de l'Antibiogramme de la Societe Francaise de Microbiologie" . RESULTS: A total of 849 strains are included in this study . Pseudomonas aeruginosa was the most frequently isolated bacterium (20%) followed by Escherichia coli (19%) Staphylococcus aureus (15%), coagulase-negative Staphylococci (CoNS) (11%) and Enterococci (7%) . Imipenem was the most effective antibiotic against enterobacteriaceae (336 isolates; 100% susceptibility) . Gentamicin (92%), amikacin (92%) third generation cephalosporins (83%), aztreonam (83%) and ciprofloxacin (78%) were also very effective . Resistance to III generation cephalosporins was correlated with an extended spectrum beta-lactamase (BLSE) in 36% of cases . This BLSE could be associated with an over production of the constitutive cephalosporinase . The most frequent species producing BLSE were Enterobacter aerogenes (75% of BLSE) and Klebsiella pneumoniae (17%) . Among the 172 P . aeruginosa isolated, antimicrobial susceptibility were respectively: 71% for imipenem, 62%: tobramycin, 60%: amikacin 59%: ciprofloxacin 59% piperacillin + tazobactam, 55% piperacillin, 53%: ceftazidime and 44% for ticarcillin . Seventy per cent of the 96 CoNS and 50.2% of the 126 S . aureus isolated were resistant to methicillin . A strain of S . aureus and 2 CoNS strains had intermediate resistance to teicoplanin . Twenty per cent of the 59 Enterococci strains isolated were resistant to aminopenicillins (10/11 strains of E . faecium), and 9% presented a high level of resistance to gentamicine . One strain of E . faecium was resistant to vancomycin . CONCLUSION: The evolution of the susceptibility to antibiotics in intensive care units reflects the antibiotic pressure and level of cross-transmission . High rates of meticillin-resistance among staphylococci, of resistance to beta-lactams antibiotics among P . aeruginosa and of ciprofloxacin among Enterobacteriaceae are shown in this study . The implementation of appropriate strategies for surveillance and prevention is necessary.

Mol Pathol, 2000 Aug, 53(4), 211 - 5
Identification by 16S ribosomal RNA gene sequencing of an Enterobacteriaceae species from a bone marrow transplant recipient; Woo PC et al.; AIMS: To ascertain the clinical relevance of a strain of Enterobacteriaceae isolated from the stool of a bone marrow transplant recipient with diarrhoea . The isolate could not be identified to the genus level by conventional phenotypic methods and required 16S ribosomal RNA (rRNA) gene sequencing for full identification . METHODS: The isolate was investigated phenotypically by standard biochemical methods using conventional biochemical tests and two commercially available systems, the Vitek (GNI+) and API (20E) systems . Genotypically, the 16S bacterial rRNA gene was amplified by the polymerase chain reaction (PCR) and sequenced . The sequence of the PCR product was compared with known 16S rRNA gene sequences in the GenBank database by multiple sequence alignment . RESULTS: Conventional biochemical tests did not reveal a pattern resembling any known member of the Enterobacteriaceae family . The isolate was identified as Salmonella arizonae (73%) and Escherichia coli (76%) by the Vitek (GNI+) and API (20E) systems, respectively . 16S rRNA sequencing showed that there was only one base difference between the isolate and E coli K-12, but 48 and 47 base differences between the isolate and S typhimurium (NCTC 8391) and S typhi (St111), respectively, showing that it was an E coli strain . The patient did not require any specific treatment and the diarrhoea subsided spontaneously . CONCLUSIONS: 16S rRNA gene sequencing was useful in ascertaining the clinical relevance of the strain of Enterobacteriaceae isolated from the stool of the bone marrow transplant recipient with diarrhoea.

Res Microbiol, 2000 Sep, 151(7), 521 - 33
Oligonucleotide probe for the visualization of Escherichia coli/Escherichia fergusonii cells by in situ hybridization: specificity and potential applications; Regnault B et al.; There are several occasions when enumeration of Escherichia coli cells is needed . These include examination of urine specimens and water or food samples . Present methods rely on growth in more or less selective media (colony-forming units on agar or the most probable number method using liquid media) . Unfortunately, no really selective medium with 100% efficiency of plating is available for E . coli . A 24-mer oligonucleotide probe (Colinsitu), complementary to a piece of 16S ribosomal ribonucleic acid, has been tested for specifically visualizing E . coli cells by in situ hybridization and epifluorescence microscopy . The fluorescent dye-labeled probe was able to stain cells of E . coli, Shigella spp . and E . fergusonii . Shigella spp . are known to belong to the E . coli genomospecies and E . fergusonii is the nomenspecies closest to E . coli by DNA-DNA hybridization . The probe did not stain any strain of 169 other genomospecies of the family Enterobacteriaceae or of a few other species frequently encountered in the environment . Revivification without cell division allowed the visualization of E . coli cells in contaminated water . In situ hybridization using the Colinsitu probe is a potential tool for the confirmation of (atypical) E . coli in reference centers and the rapid (3-6 h) detection and enumeration of E . coli in urine specimens, contaminated water and food . More work is needed to include in situ hybridization in laboratory routine.

Mycoses, 2000 Sep, 43(7-8), 303 - 8
Oral yeasts and coliforms in HIV-infected individuals in Hong Kong; Tsang CS et al.; The objective was to determine the oral carriage patterns of yeasts and coliforms and their relationships, if any, with age, risk group, CDC classification, CD4+ count and medications in a predominantly Chinese, HIV-infected cohort in Hong Kong . A prospective longitudinal study was carried out over a 12-month period, of 32 predominantly Chinese male HIV-infected cohort in a hospital setting in Hong Kong . Oral carriage rates were determined by the concentrated rinse culture method and correlated with other clinical parameters using regression analysis . A total of 73 oral rinse samples were collected and the weighted mean carriage rates of oral yeasts and coliforms were 54.8% and 28.8%, respectively . The most common yeast and the Enterobacteriaceae isolated were Candida albicans and Enterobacter cloacae, respectively . An increased carriage rate of yeasts was associated with zidovudine usage and Centres for Disease Control (CDC) stage IV of the HIV infection whereas the opposite was associated with the usage of antiparasitics and multivitamins . Although the oral carriage rate of coliforms was significantly lower in individuals taking antibacterials and multivitamins, it was not significantly influenced by age, CD4+ lymphocyte count and the intake of antivirals, antifungals or folates . These data imply that oral yeast carriage in HIV infection is related to the severity of the disease as opposed to oral coliform carriage which appears to be unusually transient in the study cohort.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3220 - 3
Heterogeneity of AmpC cephalosporinases of Hafnia alvei clinical isolates expressing inducible or constitutive ceftazidime resistance phenotypes; Girlich D et al.; Ten unrelated Hafnia alvei clinical isolates were grouped according to either their low-level and inducible cephalosporinase production or their high-level and constitutive cephalosporinase production phenotype . Their AmpC sequences shared 85 to 100% amino acid identity . The immediate genetic environment of ampC genes was conserved in H . alvei isolates but was different from that found in other ampC-possessing enterobacterial species.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3177 - 9
A 1998 survey of extended-spectrum beta-lactamases in Enterobacteriaceae in France . The French Study Group; De Champs C et al.; In a 3-month period in 1998, 79 consecutive isolates of Enterobacteriaceae producing an extended-spectrum beta-lactamase (ESBL) were collected . ESBLs were predominantly TEM derivatives (74 of 79): TEM-24-like (40 isolates), TEM-3-like (29 isolates), TEM-21 (3 isolates), and TEM-4 and TEM-52 (1 isolate each) . Four isolates produced SHV derivatives SHV-4 (three isolates) and SHV-5 (one isolate), and one strain produced a CTX-M-3 enzyme . The high proportion of TEM-24-like-producing Enterobacter aerogenes isolates (36 of 79) suggests the occurrence of an epidemic strain in France.

Antimicrob Agents Chemother, 2000 Nov, 44(11), 3158 - 62
Nucleotide sequence of the chromosomal ampC gene of Enterobacter aerogenes; Preston KE et al.; The AmpC beta-lactamase gene and a small portion of the regulatory ampR sequence of Enterobacter aerogenes 97B were cloned and sequenced . The beta-lactamase had an isoelectric point of 8 and conferred cephalosporin and cephamycin resistance on the host . The sequence of the cloned gene is most closely related to those of the ampC genes of E . cloacae and C . freundii.

FEMS Microbiol Lett, 2000 Sep 15, 190(2), 181 - 4
Treatment options for extended-spectrum beta-lactamase-producers; Essack SY; A review of antibiotic options for the treatment of infections caused by extended-spectrum beta-lactamase-producing isolates is presented . The use of the third-generation cephalosporin, cefotaxime, for infections caused by isolates producing ceftazidimase-type extended-spectrum beta-lactamases is controversial, despite in vitro susceptibility to the antibiotic in many instances . The fourth-generation cephalosporin, cefipime, although active against most extended-spectrum beta-lactamases, is reported to show a marked inoculum effect . The cephamycins, such as cefoxitin . are generally effective against Enterobacteriaceae producing TEM- and SHV-derived extended-spectrum beta-lactamases, but Klebsella pneumoniae strains are prone to cephamycin resistance as a result of porin loss . The use of beta-lactamase inhibitor combinations is variable . Sulbactam is less effective than clavulanate for the inhibition of SHV-derived extended-spectrum beta-lactamases and a marked inoculum effect has been noted, while the efficacy of tazobactam against SHV-derived extended-spectrum beta-lactamase producers is controversial . Furthermore, extended-spectrum beta-lactamases are often encoded by multi-resistant plasmids carrying genes conferring resistance to aminoglycosides, chloramphenicol, sulfonamides, trimethoprim and other antimicrobials, severely limiting even alternative therapies . Extensive susceptibility testing before the institution of antibiotic therapy is thus vital.

J Agric Food Chem, 2000 Jul, 48(7), 2943 - 7
Soybean vegetable protein (Tofu) preserved with high pressure; Prestamo G et al.; Tofu is a soybean vegetable protein that Asians have long consumed; its intake is increasing in other countries . Tofu was purchased at a local shop . The tofu samples were already preserved in plastic bags subjected to vacuum and storage (5 C) . Tofu samples were subjected to high pressure (HP) of 400 MPa at 5 C for 5, 30, and 45 mm . Microbial analysis, sensorial evaluation, and structure were determined . HP treatment in tofu reduces the microbial population . Most of the microorganisms found in the initial population belonged to the Enterobacteriaceae family, bacteria Gram-negative (no Enterobacteriaceae), and bacteria Gram-positive . Alter HP treatment, Hafnia alvei and Bacillus cereus were found . After HP treatment, tofu is a pasteurized product, which is safer in terms of secondary pathogenic microbial contamination . Sensorial test results revealed that treated tofu was acceptable to consumers . The micrographs on the cryofracture observed with a cryoscanning electron microscope revealed a more compact structure after pressure compared with that of untreated samples, but the aggregates in the treated samples were more disperse.

Biochemistry, 2000 Oct 17, 39(41), 12671 - 7
Determination of the pKa value of C115 in MurA (UDP-N-acetylglucosamine enolpyruvyltransferase) from Enterobacter cloacae; Krekel F et al.; The enzyme UDP-N-acetylglucosamine (UDP-NAG) enolpyruvyltransferase (MurA) catalyzes the formation of enolpyruvyl-UDP-NAG, a precursor in peptidoglycan biosynthesis . The residue at position 115 in MurA has been proposed to act as a general acid in the enzymatic reaction . This is also the primary site of action of the antibiotic fosfomycin . In this paper, the pK(a) of Cys-115 has been determined to be 8.3, by titration of Enterobacter cloacae MurA with the alkylating agent iodoacetamide as a function of pH . Use of site-directed mutagenesis has established that only C115 is essential for catalysis, and the three other cysteine residues (C251, C354, and C381) are nonessential . Mass spectrometric analysis demonstrated that C115 is not alkylated at pH <7, but is alkylated significantly at pH >7 . Measurement of the enzymatic inhibition by iodoacetamide as a function of pH showed maximum inhibition at pH >9, with a second-order rate constant of inhibition of 44 M(-)(1) s(-)(1) at pH 10 . The presence of either one of the substrates did not influence the inactivation behavior, while the presence of both substrates resulted in a 5-fold reduction in the extent of alkylation . The covalent species that results from PEP bound to C115 of MurA exhibited 50-100-fold increased resistance against alkylation by iodoacetamide . These results imply that C115 is appreciably protonated at physiological pH and, therefore, is capable of acting as a proton donor in the enzyme-catalyzed reaction . However, it also implies that C115 is appreciably deprotonated at physiological pH also, whereupon the resultant thiolate nucleophile may play an important role in the formation of the covalent O-phosphothioketal species, whose role in catalysis is yet to be established.

Int J Food Microbiol, 2000 Sep 25, 60(2-3), 171 - 84
Application of a systematic experimental procedure to develop a microbial model for rapid fish shelf life predictions; Koutsoumanis K et al.; A systematic experimental procedure for fish shelf-life modelling was used to develop a model for predicting the quality of fish in the chill chain . For this, the growth of the naturally occurring bacteria pseudomonads, Shewanella putrefaciens, Enterobacteriaceae, lactic acid bacteria and yeasts, on gilt-head seabream (Sparus aurata), was studied at temperatures from 0 to 15 degrees C . The results from the microbiological, organoleptical and chemical analysis conducted on naturally contaminated fish as well as on inoculated sterile fish blocks identified pseudomonads as a good spoilage index . Growth of pseudomonads was modelled as a function of storage temperature and correlated to organoleptical shelf life . To reduce the time required for the enumeration of the initial pseudomonads number, which is crucial information for shelf life prediction, a conductance assay was established . Compared with the conventional microbiological tests, this method gave results in one-fourth of the time.

J Exp Med, 2000 Oct 2, 192(7), 1035 - 46
Salmonella-induced caspase-2 activation in macrophages: a novel mechanism in pathogen-mediated apoptosis; Jesenberger V et al.; The enterobacterial pathogen Salmonella induces phagocyte apoptosis in vitro and in vivo . These bacteria use a specialized type III secretion system to export a virulence factor, SipB, which directly activates the host's apoptotic machinery by targeting caspase-1 . Caspase-1 is not involved in most apoptotic processes but plays a major role in cytokine maturation . We show that caspase-1-deficient macrophages undergo apoptosis within 4-6 h of infection with invasive bacteria . This process requires SipB, implying that this protein can initiate the apoptotic machinery by regulating components distinct from caspase-1 . Invasive Salmonella typhimurium targets caspase-2 simultaneously with, but independently of, caspase-1 . Besides caspase-2, the caspase-1-independent pathway involves the activation of caspase-3, -6, and -8 and the release of cytochrome c from mitochondria, none of which occurs during caspase-1-dependent apoptosis . By using caspase-2 knockout macrophages and chemical inhibition, we establish a role for caspase-2 in both caspase-1-dependent and -independent apoptosis . Particularly, activation of caspase-1 during fast Salmonella-induced apoptosis partially relies on caspase-2 . The ability of Salmonella to induce caspase-1-independent macrophage apoptosis may play a role in situations in which activation of this protease is either prevented or uncoupled from the induction of apoptosis.

J Clin Microbiol, 2000 Oct, 38(10), 3623 - 30
16S ribosomal DNA sequence analysis of a large collection of environmental and clinical unidentifiable bacterial isolates; Drancourt M et al.; Some bacteria are difficult to identify with phenotypic identification schemes commonly used outside reference laboratories . 16S ribosomal DNA (rDNA)-based identification of bacteria potentially offers a useful alternative when phenotypic characterization methods fail . However, as yet, the usefulness of 16S rDNA sequence analysis in the identification of conventionally unidentifiable isolates has not been evaluated with a large collection of isolates . In this study, we evaluated the utility of 16S rDNA sequencing as a means to identify a collection of 177 such isolates obtained from environmental, veterinary, and clinical sources . For 159 isolates (89.8%) there was at least one sequence in GenBank that yielded a similarity score of > or =97%, and for 139 isolates (78.5%) there was at least one sequence in GenBank that yielded a similarity score of > or =99% . These similarity score values were used to defined identification at the genus and species levels, respectively . For isolates identified to the species level, conventional identification failed to produce accurate results because of inappropriate biochemical profile determination in 76 isolates (58.7%), Gram staining in 16 isolates (11.6%), oxidase and catalase activity determination in 5 isolates (3.6%) and growth requirement determination in 2 isolates (1.5%) . Eighteen isolates (10.2%) remained unidentifiable by 16S rDNA sequence analysis but were probably prototype isolates of new species . These isolates originated mainly from environmental sources (P = 0.07) . The 16S rDNA approach failed to identify Enterobacter and Pantoea isolates to the species level (P = 0.04; odds ratio = 0.32 {95% confidence interval, 0.10 to 1.14}) . Elsewhere, the usefulness of 16S rDNA sequencing was compromised by the presence of 16S rDNA sequences with >1% undetermined positions in the databases . Unlike phenotypic identification, which can be modified by the variability of expression of characters, 16S rDNA sequencing provides unambiguous data even for rare isolates, which are reproducible in and between laboratories . The increase in accurate new 16S rDNA sequences and the development of alternative genes for molecular identification of certain taxa should further improve the usefulness of molecular identification of bacteria.

J Clin Microbiol, 2000 Oct, 38(10), 3577 - 80
Evaluation of the MicroScan rapid neg ID3 panel for identification of Enterobacteriaceae and some common gram-negative nonfermenters; O'Hara CM et al.; The MicroScan Rapid Neg ID3 panel (Dade Behring, Inc., West Sacramento, Calif.) is designed for the identification of gram-negative bacilli . We evaluated its ability to accurately identify Enterobacteriaceae that are routinely encountered in a clinical laboratory and glucose nonfermenting gram-negative bacilli . Using 511 stock cultures that were maintained at -70 degrees C and passaged three times before use, we inoculated panels according to the manufacturer's instructions and processed them in a Walk/Away instrument using version 22.01 software . The time to identification was 2 h and 30 min . All panel identifications were compared to reference identifications previously determined by conventional tube biochemicals . At the end of the initial 2.5-h incubation period, 405 (79.3%) identifications were correct . An additional 49 (9.6%) isolates were correctly identified after required additional off-line biochemical tests were performed . Thus, at 24 h, 88.8% of the 511 strains tested were correctly identified . Twenty-two (4.3%) were identified to the genus level only . Twenty-six (5.1%) strains were misidentified . Because the system is based on fluorogenics, there are no conventional tests readily available with which to compare possibly incorrect reactions . Of the 28 Salmonella strains that were tested, 5 were incorrectly reported . The 21 remaining errors were scattered among the genera tested . Testing on nine strains gave a result of "no identification" (very rare biotype) . The Rapid Neg ID3 panel in this study approached 89% accuracy for the identification of gram-negative organisms encountered in the hospital laboratory.

Int J Food Microbiol, 2000 Sep 15, 60(1), 15 - 24
Microbial species associated with different sections of broccoli harvested from three regions in Australia; Padaga M et al.; The microbial populations associated with the different sections of broccoli harvested from three locations in Australia were studied during storage at 5, 15 and 20 degrees C . Bacterial and yeast populations associated with the outer florets and cut surfaces of the stem were generally 10-fold or more higher than those associated with inner florets or non-cut stems, respectively . The predominating bacterial species varied with the origin of the broccoli . Pseudomonas fluorescens, Ps . corrugata and Ps . viridiflava predominated at populations of 10(5)-10(7) cfu/g on broccoli harvested from Victoria, Ps . fluorescens, Ps . mendocina and Ps . fragii and Arthrobacter spp . (10(-3) 10(6) cfu/g) were prevalent on broccoli harvested from Queensland . Broccoli harvested from New South Wales exhibited a predominance of Ps . fluorescens, Arthrobacter spp . and Enterobacteragglomerans (10(3)-10(5) cfu/g) . Most species grew on broccoli during storage . Similar species were found at the different sections of broccoli, although, for some species there was evidence of strain variation at the different locations and for different temperature of storage.

Spine, 2000 Oct 1, 25(19), 2461 - 6
Deep wound infections after neuromuscular scoliosis surgery: a multicenter study of risk factors and treatment outcomes; Sponseller PD et al.; STUDY DESIGN: A retrospective case-control study evaluating risk factors for infection, causative organisms, and results of treatment in patients with cerebral palsy or myelomeningocele who underwent fusion for scoliosis was performed . OBJECTIVES: To identify risk factors for infection, and to characterize the infections in terms of infecting organisms and response to treatment . SUMMARY OF BACKGROUND DATA: No previous studies have analyzed risk factors or causative organisms, nor have they indicated results of treatment for infections in this group of patients . METHODS: After a 10-year retrospective review of 210 surgically treated patients, deep wound infections developed in 16 patients with myelomeningocele and 9 patients with cerebral palsy . These patients were studied extensively for possible risk factors, along with 50 uninfected patients matched for age, diagnosis, and year of surgery . Statistical testing was performed to identify risk factors . The courses of the infections were characterized in terms of organisms isolated and response to treatment . Treatment was performed in a stepwise fashion and classified in terms of the most successful step: debridement and closure, granulation over rods, or instrumentation removal . RESULTS: Of the 10 risk factors tested, 2 were found to be significant: degree of cognitive impairment and use of allograft . Findings showed that 52% of the infections were polymicrobial . Gram-negative organisms were isolated as commonly as gram-positive organisms . The most common organisms were coagulase-negative Staphylococcus, Enterobacter, Enterococcus, and Escherichia coli.- Debridement and closure were successful in 11 of 25 patients with deep wound infection . Of the 14 patients with infection not resolved by serial debridements and closure, 2 were managed successfully by allowing the wound to granulate over rods, and 7 required rod removal for persistent wound drainage . There were three symptomatic pseudarthroses . Infections resulting from gram-positive organisms were most often managed successfully with debridement and closure (P = 0.012) . CONCLUSIONS: Patients with cerebral palsy or myelomeningocele who have severe cognitive impairment, and those who received allograft may be at increased risk for infection . Infections are more often polymicrobial and caused by gram-negative organisms than is typical for elective orthopedic procedures . This suggests an enteric source . Treatment with debridement and closure was not always successful . Patients in whom infection develops are then at increased risk for pseudarthrosis.

Immunology, 2000 Oct, 101(2), 262 - 70
The lipid A region of lipopolysaccharides from Rhizobiaceae activates bone marrow granulocytes from lipopolysaccharide-hyporesponsive C3H/HeJ and C57BL/10ScCr mice; Pedron T et al.; We established in previous studies that the binding of Salmonella lipopolysaccharide (LPS) to constitutive receptors of low affinity triggers the expression of the inducible LPS-binding molecule CD14 in bone marrow cells (BMC) of C3H/HeOU mice, but not in BMC from C3H/HeJ mice . We show in this study that BMC from C3H/HeJ and C57BL/10ScCr mice do not express CD14 after exposure to LPSs from Salmonella enterica and Bordetella pertussis, but do express this marker when treated with several LPSs from Rhizobiaceae, or their lipid A fragments . This shows that the constitutive LPS receptor in BMC from C3H/HeJ and C57BL/10ScCr mice is fully able to trigger a complete signalling cascade . Results of cross-inhibition of the binding of radiolabelled LPS indicated that active LPSs (from R . species Sin-1 and R . galegae) and inactive LPSs (from S . enterica and B . pertussis) bind to the same site of the constitutive LPS receptor of C3H/HeJ cells . Furthermore, binding of R . species Sin-1 LPS, and signalling induced by this LPS, were both inhibited by pre-exposure of C3H/HeJ cells to B . pertussis lipid A . This correlation between binding and signalling suggests that in C3H/HeJ cells, the constitutive receptor, which recognizes a large panel of LPSs from different origins, appears selectively unable to be activated by some particular LPSs, such as those of Enterobacteria and Bordetella.

Appl Environ Microbiol, 2000 Oct, 66(10), 4340 - 4
Molecular characterization of Yarrowia lipolytica and Candida zeylanoides isolated from poultry; Deak T et al.; Yeast isolates from raw and processed poultry products were characterized using PCR amplification of the internally transcribed spacer (ITS) 5.8S ribosomal DNA region (ITS-PCR), restriction analysis of amplified products, randomly amplified polymorphic DNA (RAPD) analysis, and pulsed-field gel electrophoresis (PFGE) . ITS-PCR resulted in single fragments of 350 and 650 bp, respectively, from eight strains of Yarrowia lipolytica and seven strains of Candida zeylanoides . Digestion of amplicons with HinfI and HaeIII produced two fragments of 200 and 150 bp from Y . lipolytica and three fragments of 350, 150, and 100 bp from C . zeylanoides, respectively . Although these fragments showed species-specific patterns and confirmed species identification, characterization did not enable intraspecies typing . Contour-clamped heterogeneous electric field PFGE separated chromosomal DNA of Y . lipolytica into three to five bands, most larger than 2 Mbp, whereas six to eight bands in the range of 750 to 2,200 bp were obtained from C . zeylanoides . Karyotypes of both yeasts showed different polymorphic patterns among strains . RAPD analysis, using enterobacterial repetitive intergenic sequences as primers, discriminated between strains within the same species . Cluster analysis of patterns formed groups that correlated with the source of isolation . For ITS-PCR, extraction of DNA by boiling yeast cells was successfully used.

Rev Argent Microbiol, 2000 Jul-Sep, 32(3), 149 - 52
{Blood cultures: use of presumptive antiobiograms}; Soloaga R et al.; Mortality associated to bacteremia varies between 20 and 40% depending upon several factors, such as focus of infection, microorganism, host conditions, etc . It has also been documented that mortality may double when the patient does not receive antibiotic treatment to which the microorganism is susceptible . The objective of our work has been to determine the correlation between disk diffusion antibiogram according to NCCLS guidelines, from isolated colonies, and the one performed directly from the blood culture flask . During 1996, in the Institute of Cardiology and Cardiovascular Surgery (ICYCC) in Buenos Aires City, 81 episodes of bacteremia were studied . In every case, an antibiogram was carried out: 1) from the bottle: a- Directly (D), harvesting 20 microliters in Mueller Hinton agar, b- Diluted (d), previous centrifugation and Gram staining to adjust turbidity equivalent to 0.5 Mc Farland; 2) from isolated colonies, according to NCCLS guidelines . There were almost no major errors, except with two strains of Enterobacter cloacae versus cephalotin . The diluted method was not so convenient to read inhibition zones, especially with staphylococci . With gram-positive bacteria, the main problems appeared in the direct method with erythromycin, oxacillin and ciprofloxacin because of minor errors . With gram-negative bacteria, major errors were observed in the direct method, mainly with piperacillin (7%) and to a lesser extent with piperacillin tazobactam (2%) . Except for imipenem, trimethoprim sulfamethoxazoie and cefotaxime, all antimicrobial agents presented minor errors with both methodologies . Based upon the high rate of minor errors, we consider it is important to confirm results obtained with the standard technique (NCCLS), considering as presumptive those results from the blood culture bottles (D and d).

FEMS Microbiol Lett, 2000 Oct 1, 191(1), 145 - 9
Detection and characterisation of integrons in Salmonella enterica serotype enteritidis; Brown AW et al.; Integrons have been widely described among the Enterobacteriaceae including strains of multi-resistant Salmonella enterica serotype Typhimurium DT104; however, information with respect to the presence of integrons among S . enterica serotype Enteritidis strains is limited . Multi-resistant isolates of Enteritidis were screened for the presence of integrons using a PCR protocol . One integron was detected in all isolates that were resistant to sulfonamide and streptomycin . Characterisation of these isolates indicated an integron which ranged in size between 1000 and 2000 bp and which harboured a gene cassette encoding the ant(3")-Ia gene specifying streptomycin and spectinomycin resistance . Further studies revealed the integrons to be located on large conjugative plasmids . This appears to be the first report of plasmid-borne integrons in Enteritidis.

J Bacteriol, 2000 Oct, 182(20), 5749 - 56
Identification of RpoS (sigma(S))-regulated genes in Salmonella enterica serovar typhimurium; Ibanez-Ruiz M et al.; The rpoS gene encodes the alternative sigma factor sigma(S) (RpoS) and is required for survival of bacteria under starvation and stress conditions . It is also essential for Salmonella virulence in mice . Most work on the RpoS regulon has been in the closely related enterobacterial species Escherichia coli . To characterize the RpoS regulon in Salmonella, we isolated 38 unique RpoS-activated lacZ gene fusions from a bank of Salmonella enterica serovar Typhimurium mutants harboring random Tn5B21 mutations . Dependence on RpoS varied from 3-fold to over 95-fold, and all gene fusions isolated were regulated by growth phase . The identities of 21 RpoS-dependent fusions were determined by DNA sequence analysis . Seven of the fusions mapped to DNA regions in Salmonella serovar Typhimurium that do not match any known E . coli sequence, suggesting that the composition of the RpoS regulon differs markedly in the two species . The other 14 fusions mapped to 13 DNA regions very similar to E . coli sequences . None of the insertion mutations in DNA regions common to both species appeared to affect Salmonella virulence in BALB/c mice . Of these, only three (otsA, katE, and poxB) are located in known members of the RpoS regulon . Ten insertions mapped in nine open reading frames of unknown function (yciF, yehY, yhjY, yncC, yjgB, yahO, ygaU, ycgB, and yeaG) appear to be novel members of the RpoS regulon . One insertion, that in mutant C52::H87, was in the noncoding region upstream from ogt, encoding a O(6)-methylguanine DNA methyltransferase involved in repairing alkylation damage in DNA . The ogt coding sequence is very similar to the E . coli homolog, but the ogt 5' flanking regions were found to be markedly different in the two species, suggesting genetic rearrangements . Using primer extension assays, a specific ogt mRNA start site was detected in RNAs of the Salmonella serovar Typhimurium wild-type strains C52 and SL1344 but not in RNAs of the mutant strains C52K (rpoS), SL1344K (rpoS), and C52::H87 . In mutant C52::H87, Tn5B21 is inserted at the ogt mRNA start site, with lacZ presumably transcribed from the identified RpoS-regulated promoter . These results indicate that ogt gene expression in Salmonella is regulated by RpoS in stationary phase of growth in rich medium, a finding that suggests a novel role for RpoS in DNA repair functions.

J Dairy Sci, 2000 Sep, 83(9), 1957 - 65
A study of the incidence and significance of intramammary enterobacterial infections acquired during the dry period; Bradley AJ et al.; We assessed the incidence of enterobacterial infection of the mammary glands of 629 cows, from six commercial herds in Somerset, during the nonlactating period; samples were collected from all clinical quarters of these cows during the subsequent lactation . A rise in the incidence of intramammary enterobacterial infection was detected between drying off and before calving . Quarters infected with an enterobacterial organism during the dry period were more likely to develop mastitis due to that pathogen than were uninfected quarters . Of all enterobacterial mastitis occurring in the first 100 d of lactation, 52.6% arose in quarters previously infected, during the dry period, with the same strain of bacteria, as identified by DNA fingerprinting using enterobacterial repetitive intergenic consensus primers . When compared with unsampled controls, quarters sampled during the dry period did not show a higher incidence of infection at calving or of subsequent clinical mastitis . These findings suggest that chronic infections are important in the epidemiology of enterobacterial mastitis and that environmental management during the dry period may greatly impact the incidence of enterobacterial mastitis in the subsequent lactation.

Pharmacotherapy, 2000 Sep, 20(9 Pt 2), 213S - 218S; discussion 224S-228S
Beta-lactamase inhibitor combinations with extended-spectrum penicillins: factors influencing antibacterial activity against enterobacteriaceae and Pseudomonas aeruginosa; Lister PD; Production of beta-lactamases is the most common mechanism by which gram-negative bacteria express resistance to beta-lactam antibiotics . One successful method of circumventing the threat of plasmid-encoded beta-lactamases is to combine inhibitors of these enzymes with a penicillin . Currently, four inhibitor-penicillin combinations are in clinical use: ampicillin-sulbactam, amoxicillin-clavulanate, ticarcillin-clavulanate, and piperacillin-tazobactam . Of these, ticarcillin-clavulanate and piperacillin-tazobactam have the broadest spectra of activity that includes Pseudomonas aeruginosa . Many factors influence the activity and pharmacodynamics of these combinations, including potency of both agents, pharmacokinetics of the inhibitor, type and quantity of beta-lactamase produced by the target bacterium, and potential for the inhibitor to induce expression of chromosomal cephalosporinases in the target bacterium . Although ticarcillin-clavulanate and piperacillin-tazobactam have similar spectra of activity, they have many differences . Most notable are increased potency of piperacillin against Enterobacteriaceae and P aeruginosa, increased activity of piperacillin-tazobactam against gram-negative pathogens producing penicillin-sensitive enzyme (PSE)-class beta-lactamase or hyperproducing other plasmid-encoded beta-lactamases, and the more favorable pharmacokinetics of tazobactam . In the treatment of P . aeruginosa infections, the potential for clavulanate to induce expression of chromosomal cephalosporinase and antagonize antibacterial activity of ticarcillin is a concern, especially in patients who lack protective host defenses . These are not concerns with piperacillin-tazobactam.

Berl Munch Tierarztl Wochenschr, 2000 Jul-Aug, 113(7-8), 276 - 8
Bacteriological quality of raw cow's milk from four dairy farms and a milk collection centre in and around Addis Ababa; Godefay B et al.; Bacteriological quality of raw cow's milk taken at different sampling points from four dairy farms and a milk collection centre in and around Addis Ababa was evaluated . Milk samples were aseptically collected from udder, bucket, storage container before and after cooling and upon arrival at the processing plant . A high increase in the mean total aerobic plate count was observed in milk samples taken from the bucket (1.1 x 10(5) cfu/ml), storage container before cooling (4 x 10(6) cfu/ml) and upon arrival at the processing plant (1.9 x 10(8) cfu/ml) . The mean coliform counts ranged from 1.3 x 10(4) cfu/ml (storage container before cooling) to 7.1 x 10(4) cfu/ml (upon arrival at the processing plant) . The hygienic quality of raw milk from the collection centre was poor with a mean total bacterial count of 1.3 x 10(7) cfu/ml . Milk sampled from the udder contained mainly staphylococci and micrococci as udder-specific bacteria, while samples taken at later stages were additionally contaminated with bacteria of environmental origin (especially Enterobacteriaceae) . Lack of knowledge about clean milk production, use of unclean milking equipment and lack of potable water for cleaning purposes were some of the factors which contributed to the poor hygienic quality of raw milk in the study farms.

J Vet Med Sci, 2000 Aug, 62(8), 893 - 5
Antibacterial activity of chaff vinegar and its practical application; Makino SI et al.; Since enterohemorrhagic Escherichia coli O157, Salmonella, etc., sometimes contaminate animal feces and may cause infectious diseases to humans, it is important to remove pathogenic bacteria from domestic animal waste . For the purpose, we examined the antibacterial activity of chaff vinegar . We found that the chaff vinegar inhibited the growth of pathogenic bacteria immediately in vitro but not efficiently spores and lactic acid bacteria . Further, it removes bacteria, especially Enterobacteriaceae, from animal feces and the surface of the concrete-floor in the cattle barn . Chaff vinegar is advertised as a natural chemical substance for a soil conditioner, to promote the composting and to deodorize their smell . Chaff vinegar may be useful for organic agriculture without enteric pathogenic bacteria.

J Pak Med Assoc, 2000 Aug, 50(8), 250 - 2
In-vitro antimicrobial activity of Cefpirome: a new fourth-generation cephalosporin against clinically significant bacteria; Hafeez S et al.; OBJECTIVE: To study the in-vitro antimicrobial activity of Cefpirome: A new fourth generation Cephalosporin in comparison with other agents against clinically significant Gram-negative and Gram-positive bacteria . SETTING: A multi-center in-vitro study was conducted in 13 centers . MATERIALS AND METHODS: Bacterial isolates--A total of 1300 isolates were collected from different clinical laboratories and hospitals at 13 centers . Organisms were identified by the API identification systems (API systems, SA Vericeu, France) . The age and sex of each patient, type of hospital unit, source of the isolate and genus and species of the bacteria were recorded on standardized report forms . The sensitivity testing was carried out by the "NCCLS (modified Kirby-Bauer) method"--using Mueller-Hinton agar . RESULTS: The results suggest that Cefpirome has a potential clinical advantage against gram-positive and gram-negative bacteria resistant to other third generation cephalosporins . CONCLUSION: Cefpirome was active against both gram-negative and gram-positive organisms . Cefpirome was more active than ceftazidime, cefoperazone, ceftizoxime and ceftriaxone against E . coli, Klebsiella spp, Enterobacter spp, Proteus spp, Salmonella typhi, Enterococci, methicillin sensitive Staphylococci and Betahemolytic Streptococci . The activity of Cefpirome was comparable with ceftazidime against pseudomonas aeruginosa . Cefpirome had the smallest numbers of resistant isolates . Cefpirome was more active than other third generation cephalosporins compared in this study against E . coli (87% vs 61%), Klebsiella spp (84% vs 56%), Enterobacter spp (88% vs 59%), Proteus spp (97% vs 92%), Salmonella typhi (98% vs 96%), methicillin sensitive Staphylococci (86% vs 59%) and Enterococci spp (82% vs 72%).

Antimicrob Agents Chemother, 2000 Oct, 44(10), 2728 - 32
Distribution and antimicrobial activity of fosfomycin in the interstitial fluid of human soft tissues; Frossard M et al.; Fosfomycin is a broad-spectrum antibiotic which is established as therapy for uncomplicated lower urinary tract infections . In addition, preliminary data indicate that fosfomycin has a potential role in the treatment of soft tissue infections . However, the use of fosfomycin has not been established for this condition, and it is unclear whether the level of fosfomycin penetration into human soft tissues is high enough to eradicate relevant pathogens . To better characterize the antibiotic potential of fosfomycin, we applied a combined in vivo pharmacokinetic-in vitro pharmacodynamic model to human volunteers . For this purpose fosfomycin concentrations in vivo in the fluid of the interstitial space of human soft tissues were measured by microdialysis following intravenous infusion of 4 or 8 g of fosfomycin (n = 6) . Subsequently, bacterial isolates with relevance for soft tissue infections were exposed to concentrations according to the in vivo pharmacokinetic profile in the interstitial space fluid obtained by microdialysis . Our experiments indicated a high degree of soft tissue penetration for fosfomycin, with ratios of the area under the concentration-time curve from 0 to 8 h for muscle (AUC(0-8(muscle)))/AUC(0-8(serum)) of 0.48+/-0.08 and 0.53+/-0.04 and ratios of AUC(0-8(adipose tissue))/AUC(0-8(serum)) of 0.74+/-0.12 and 0.71+/-0.11 following administration of 4 and 8 g, respectively . In corresponding in vitro simulation experiments with selected isolates of Staphylococcus aureus, Enterobacter cloacae, and Serratia marcescens for which MICs were 16 microg/ml, organisms were undetectable after a single dosing interval . Fosfomycin exhibits a strong ability to penetrate into the fluid of the interstitial space of soft tissues and reaches levels sufficient to substantially inhibit the growth of relevant bacteria at the target site . We therefore conclude that fosfomycin might qualify as an alternative candidate for the therapy of soft tissue infections.

J Rheumatol, 2000 Sep, 27(9), 2185 - 92
On the difficulties of establishing a consensus on the definition of and diagnostic investigations for reactive arthritis . Results and discussion of a questionnaire prepared for the 4th International Workshop on Reactive Arthritis, Berlin, Germany, July 3-6, 1999; Braun J et al.; OBJECTIVE: There is no agreement on how to classify and diagnose reactive arthritis (ReA) and it is also unclear what kind of specific clinical and laboratory investigations are appropriate . We define relevant points of agreement and identify points of disagreement among an international group of experts in the field . METHODS: Prior to the 4th International Workshop on Reactive Arthritis, Berlin, July 1999, we sent questionnaires to 42 experts identified by personal knowledge and recent publications . RESULTS: The response rate was 81% (n = 34) . There was agreement on the nomenclature and recommendation to use the term "reactive arthritis" only if the clinical picture and the microbes involved are HLA-B27 and spondyloarthropathy (SpA) associated, whereas the term "infection related arthritis" is used for all other arthritides related to or associated with infections . A differentiation between acute and chronic ReA with a cutoff of 6 months is recommended . The history of a preceding symptomatic infection is thought to be most relevant for a diagnosis of ReA . The minimal interval between preceding symptoms and arthritis is proposed to be 1-7 days, maximally 4 weeks . The joint pattern in ReA is asymmetrical, with predominance of the lower limbs . SpA related symptoms may contribute to the diagnosis . A search for chlamydia in urine/urethra/cervix is recommended, while in the case of diarrhea enterobacteria should be searched for in stool and antibodies against them in serum . There were also areas of disagreement, such as: Is arthritis essential for the diagnosis of ReA?, Is it oligoarthritis or any arthritis?, What are the role and value of polymerase chain reaction investigation?, The role and value of serology?, Is the diagnostic sensitivity of microbiological tests for ReA increased by HLA-B27 determination? CONCLUSION: The points of agreement will support better communication in this area, and clarification of the disagreements will lead to further studies and discussion.

Glycobiology, 2000 Sep, 10(9), 875 - 81
Preparative synthesis of GDP-beta-L-fucose by recombinant enzymes from enterobacterial sources; Albermann C et al.; The 6-deoxyhexose L-fucose is an important and characteristic element in glycoconjugates of bacteria (e.g., lipopolysaccharides), plants (e.g., xyloglucans) and animals (e.g., glycolipids, glycoproteins, and oligosaccharides) . The biosynthetic pathway of GDP-L-fucose starts with a dehydration of GDP-D-mannose catalyzed by GDP-D-mannose 4,6-dehydratase (Gmd) creating GDP-4-keto-6-deoxymannose which is subsequently converted by the GDP-4-keto-6-deoxy-D-mannose 3,5-epimerase-4-reductase (WcaG; GDP-beta-L-fucose synthetase) to GDP-beta-L-fucose . Both biosynthetic genes gmd and wcaG were cloned from Escherichia coli K12 and the enzymes overexpressed under control of the T7 promoter in the expression vectors pET11a and pET16b, yielding both native and N-terminal His-tag fusion proteins, respectively . The activities of the Gmd and WcaG were analyzed . The enzymatic conversion from GDP-D-mannose to GDP-beta-L-fucose was optimized and the final product was purified . The formation of GDP-beta-L-fucose by the recombinant enzymes was verified by HPLC and NMR analyses . The His-tag fusion variants of the Gmd and WcaG proteins were purified to near homogeneity . The His-tag Gmd recombinant enzyme was inactive, whereas His-tag WcaG showed very similar enzymatic properties relative to the native GDP-beta-L-fucose synthetase . With the purified His-tag WcaG Km and Vmax values, respectively, of 40 microM and 23 nkat/mg protein for the substrate GDP-4-keto-6-deoxy-D-mannose and of 21 microM and 10 nkat/mg protein for the cosubstrate NADPH were obtained; a pH optimum of 7.5 was determined and the enzyme was stimulated to equal extend by the divalent cations Mg2+ and Ca2+ . The Gmd enzyme showed a strong feedback inhibition by GDP-beta-L-fucose.

Clin Infect Dis, 2000 Aug, 31 Suppl 2, S16 - 23
In vitro activity of newer fluoroquinolones for respiratory tract infections and emerging patterns of antimicrobial resistance: data from the SENTRY antimicrobial surveillance program; Jones RN et al.; In 1997, an international surveillance program, SENTRY Antimicrobial Surveillance Program, was initiated with the aim of tracking the emergence of antimicrobial resistance worldwide . Results from reference antimicrobial susceptibility testing of bacterial pathogens (from bloodstream, inpatient and outpatient lower respiratory tract, urinary tract, and skin and soft-tissue infections) were included in an extensive database used to define antimicrobial resistance patterns throughout the world . On the basis of 1997-1999 test results from the Americas, fluoroquinolones continue to demonstrate potent in vitro activity against Enterobacteriaceae and important pathogens (Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and atypicals) that cause community-acquired respiratory tract infections . At published breakpoint concentrations, gatifloxacin, levofloxacin, sparfloxacin, grepafloxacin, trovafloxacin, and ciprofloxacin inhibited approximately 100% of H . influenzae isolates, including those that demonstrated resistance to beta-lactams and macrolides . Fluoroquinolones were also active against numerous other gram-negative bacilli and demonstrated high activity against S . pneumoniae and beta-hemolytic or viridans group streptococci . New fluoroquinolones maintain activity against penicillin-resistant strains of S . pneumoniae, with a low overall resistance in this species, even among the most recent (1999) clinical isolates . The SENTRY Antimicrobial Surveillance Program will continue to monitor the antibacterial activity of these newer agents throughout the world, to identify emerging resistant strains and to facilitate possible intervention strategies as these newer compounds are used in the clinic setting.

Nucleic Acids Res, 2000 Sep 15, 28(18), 3486 - 96
Web-based visualization tools for bacterial genome alignments; Florea L et al.; With the increase in the flow of sequence data, both in contigs and whole genomes, visual aids for comparison and analysis studies are becoming imperative . We describe three web-based tools for visualizing alignments of bacterial genomes . The first, called Enteric, produces a graphical, hypertext view of pairwise alignments between a reference genome and sequences from each of several related organisms, covering 20 kb around a user-specified position . Insertions, deletions and rearrangements relative to the reference genome are color-coded, which reveals many intriguing differences among genomes . The second, Menteric, computes and displays nucleotide-level multiple alignments of the same sequences, together with annotations of ORFs and regulatory sites, in a 1 kb region surrounding a given address . The third, a Java-based viewer called Maj, combines some features of the previous tools, and adds a zoom-in mechanism . We compare the Escherichia coli K-12 genome with the partially sequenced genomes of Klebsiella pneumoniae, Yersinia pestis, Vibrio cholerae, and the Salmonella enterica serovars Typhimurium, Typhi and Paratyphi A . Examination of the pairwise and multiple alignments in a region allows one to draw inferences about regulatory patterns and functional assignments . For example, these tools revealed that rffH, a gene involved in enterobacterial common antigen (ECA) biosynthesis, is partly deleted in one of the genomes . We used PCR to show that this deletion occurs sporadically in some strains of some serovars of S.enterica subspecies I but not in any strains tested from six other subspecies . The resulting cell surface diversity may be associated with selection by the host immune response.

J Antimicrob Chemother, 2000 Sep, 46(3), 369 - 76
Comparison of cation-adjusted Mueller-Hinton broth with Iso-Sensitest broth for the NCCLS broth microdilution method; Koeth LM et al.; Comparison of MIC results obtained in different parts of the world is currently difficult because of variations in methods . In this study, cation-adjusted Mueller-Hinton broth, the NCCLS-recommended medium, was compared with Iso-Sensitest broth, which is widely used in Europe . Microbroth dilution testing, using the NCCLS procedure, was performed on 124 Gram-positive (staphylococci and enterococci) and Gram-negative (Enterobacteriaceae and Pseudomonas aeruginosa) isolates from the CDC reference set, with the only variable being the medium used . Twelve antimicrobial agents were tested: amoxycillin-clavulanic acid, ampicillin, ciprofloxacin, erythromycin, gentamicin, imipenem, levofloxacin, oxacillin, gemifloxacin, trimethoprim- sulphamethoxazole, tetracycline and vancomycin . Vancomycin, erythromycin and oxacillin were only evaluated for the Gram-positive organisms . Trimethoprim-sulphamethoxazole was only evaluated for a subset of Gram-negative organisms because of off-scale results . The 124 isolates were tested in one American and one UK laboratory with two batches of cation-adjusted Mueller-Hinton broth and two of Iso-Sensitest broth . A statistical evaluation of the data used a 24 fully specified factorial analysis to determine if there were significant differences in results owing to Gram reaction, site of testing and type and/or batch of broth . In addition, the cumulative results for each antimicrobial agent in each broth were plotted against the range of MIC dilutions tested . MICs of ciprofloxacin, levofloxacin, gemifloxacin, gentamicin and tetracycline were slightly higher (half a doubling dilution) with Iso-Sensitest broth than with Mueller-Hinton broth . MIC results for the other antimicrobial agents were equivalent . Essential and category agreement rates were comparable for all agents (88.4-100% and 88.2-99.0%, respectively).

J Biol Chem, 2000 Dec 15, 275(50), 39032 - 8
Characterization of a beta -N-acetylglucosaminidase of Escherichia coli and elucidation of its role in muropeptide recycling and beta -lactamase induction; Votsch W et al.; Using the known mapping position the gene encoding a beta-1, 4-N-acetylglucosaminidase needed for the degradation of muropeptides could be identified . nagZ encodes a cytosolic enzyme active on N-actylglucosamyl-beta-1,4-(1,6)-anhydromuramic acid containing muropeptides . These degradation products of the peptidoglycan are formed during the enlargement of the murein sacculus as a consequence of a growth mechanism, which couples the controlled degradation of the cell wall polymer with the insertion of new material . NagZ is needed for the formation of monosaccharides from the released disaccharides during the cytosolic steps of the muropeptide-recycling pathway . The formation of intracellular 1, 6-anhydro-N-acetylmuramyl-peptides is important for the expression control of the inducible beta-lactamases of the AmpC type . A mutant lacking active NagZ cannot establish AmpC mediated beta-lactam resistance . The biochemical characterization of the enzyme showed its activity on different muropeptides and inhibitors of enzyme activity could be identified . This observation might be important for designing inhibitors of NagZ that could prevent the establishment of beta-lactam resistance of Enterobacteria possessing inducible beta-lactamases.

Curr Microbiol, 2000 Oct, 41(4), 300 - 4
Secondary endosymbionts of psyllids have been acquired multiple times; Thao ML et al.; Previous studies have established that psyllids (Hemiptera, Psylloidea) contain primary endosymbionts, designated as Carsonella ruddii, which cospeciate with the psyllid host . This association appears to be the consequence of a single infection of a psyllid ancestor with a bacterium . Some psyllids may have additional secondary (S-) endosymbionts . We have cloned and sequenced the 16S-23S ribosomal RNA genes of seven representative psyllid S-endosymbionts . Comparison of the S-endosymbiont phylogenetic trees with those of C . ruddii indicates a lack of congruence, a finding consistent with multiple infections of psyllids with different precursors of the S-endosymbionts and/or possible horizontal transmission . Additional comparisons indicate that the S-endosymbionts are related to members of the Enterobacteriaceae as well as to several other endosymbionts and insect-associated bacteria.

Mol Gen Mikrobiol Virusol, 2000, (3), 17 - 21
{Construction of an expression plasmid vector for accomplishing in vivo delivery of recombinant biologically active proteins . 2 . Synthesis of HBcAG in a vaccine strain of Salmonella choleraesuis}; Beliavskaia VA et al.; The capacity of a previously described plasmid vector pAZ to deliver bioactive proteins to targets in vivo has been studied . This vector molecule has a strong constitutive promoter, is extremely stable in cells of vaccinal S . choleraesuis strain, and encodes the synthesis of marker protein beta-galactosidase which helps monitor the vector's fate in the host . The gene encoding hepatitis B virus core antigen (HBcAg) has been inserted into pAZ under its constitutive promoter . The resultant recombinant plasmid p19-24 has been used to transform Enterobacteriaceae (E . coli and S . choleraesuis) cells . Transformed cells produce immunologically active HBcAg . p19-24 was stable in S . choleraesuis cells during their culturing and during this strain persistence in mice . Triple oral immunization of rabbits in a dose of 1 x 10(9) S . choleraesuis cells TC177 induced the production of virus-specific antibodies . Successful transformation of cells of another vaccinal strain S . abortus ovis by this plasmid extends the potentialities of the vector . The results demonstrate good prospects of using pAZ vector for the construction of live oral vaccines.

Mol Gen Mikrobiol Virusol, 2000, (3), 3 - 7
{Transketolase mutation in riboflavin-synthesizing strains of Bacillus subtilis}; Gershanovich VN et al.; Unlike its predecessors B . subtilis rosR and 41, riboflavin producing B . subtilis 24 strain does not utilize pentose and gluconate and poorly assimilates glucose . Simultaneous addition of glutamic and shikimic acid restored its capacity to grow and produce riboflavin in medium with pentose and gluconate . This strain lacks the activity of transketolase, the key enzyme of the pentose phosphate cycle, and possesses normal ribulose-5-phosphate-epimerase and glucose phosphate isomerase activities . Like enterobacteria, B . subtilis has two different transport systems for glucose and mannose . The data are discussed from the viewpoint of increasing riboflavin production by transketolase mutants . Probable consequences of cell wall and cytoplasmatic membrane damage in B . subtilis with this mutation are discussed.

Microbiology, 2000 Sep, 146 ( Pt 9), 2249 - 58
The replication and stable-inheritance functions of IncP-9 plasmid pM3; Greated A et al.; Little is known of the transfer and maintenance machinery of the IncP-9 plasmids, which are found in Pseudomonas spp . and include both degradative and resistance plasmids . One such plasmid, pM3, which confers resistance to streptomycin and tetracycline, was found repeatedly in Pseudomonas species from numerous locations in Belarus . pM3 has a broad host range, but is unable to replicate in enterobacteria at 37 degrees C and above . A mini derivative, pMT2, was constructed by partial PstI digestion and ligation with a fragment encoding Km(R) . The complete sequence of pMT2 was determined . Analysis of its 8526 bp of pM3 DNA revealed several ORFs whose predicted polypeptide products were found to have similarity to previously analysed proteins involved in plasmid replication (rep gene), transfer (mpf; mating-pair formation gene) and stable maintenance (par, mrs genes) . The organization of these genes showed similarity to several plasmid systems including the Ti and pSYM plasmids as well as IncP-1 plasmids . Subcloning narrowed down the region required for replication, and identified the putative rep gene and putative par promoter region as able to express incompatibility . rep deletion mutants were lost from the cell line, and expression of the rep gene was shown to be controlled by negative autoregulation . A pMT2 derivative with an insertion between the rep and par genes showed very weak, if any, ability to replicate autonomously, suggesting that plasmid maintenance may depend on a close interaction of rep and par functions.

Mol Microbiol, 2000 Sep, 37(5), 1106 - 15
The spvB gene-product of the Salmonella enterica virulence plasmid is a mono(ADP-ribosyl)transferase; Otto H et al.; A number of well-known bacterial toxins ADP-ribosylate and thereby inactivate target proteins in their animal hosts . Recently, several vertebrate ecto-enzymes (ART1-ART7) with activities similar to bacterial toxins have also been cloned . We show here that PSIBLAST, a position-specific-iterative database search program, faithfully connects all known vertebrate ecto-mono(ADP-ribosyl)transferases (mADPRTs) with most of the known bacterial mADPRTs . Intriguingly, no matches were found in the available public genome sequences of archaeabacteria, the yeast Saccharomyces cerevisiae or the nematode Caenorhabditis elegans . Significant new matches detected by PSIBLAST from the public sequence data bases included only one open reading frame (ORF) of previously unknown function: the spvB gene contained in the virulence plasmids of Salmonella enterica . Structure predictions of SpvB indicated that it is composed of a C-terminal ADP-ribosyltransferase domain fused via a poly proline stretch to a N-domain resembling the N-domain of the secretory toxin TcaC from nematode-infecting enterobacteria . We produced the predicted catalytic domain of SpvB as a recombinant fusion protein and demonstrate that it, indeed, acts as an ADP-ribosyltransferase . Our findings underscore the power of the PSIBLAST program for the discovery of new family members in genome databases . Moreover, they open a new avenue of investigation regarding salmonella pathogenesis.

Lett Appl Microbiol, 2000 Sep, 31(3), 259 - 64
Effect of a water extract of Moringa oleifera seeds on the hydrolytic microbial species diversity of a UASB reactor treating domestic wastewater; Kalogo Y et al.; The effect of a continuous supply of a water extract of Moringa oleifera seeds (WEMOS) on the hydrolytic microbial population of biomass grown in mesophilic upflow anaerobic sludge blanket reactors treating domestic wastewater was investigated . The WEMOS-treated sludge had seemingly a wider diversity, with enterobacter and klebsiella as dominant hydrolytic bacteria, compared with the control sludge . Additional tests indicated that various hydrolytic bacteria could degrade WEMOS . It appeared that a continuous supply of WEMOS to an anaerobic digester, treating domestic wastewater, increased the diversity of hydrolytic bacteria and therefore enhanced the biological start-up of the reactor.

Lett Appl Microbiol, 2000 Sep, 31(3), 251 - 4
Vaginal bacterial microflora modifications during the growth of healthy cows; Otero C et al.; The aim of this work was first, to determine the predominant groups capable of colonizing the vagina and maintaining high numbers with time . The normal microbial flora of the cow's vagina and its evolution from weaning to service was then studied using standard microbiological methods . The results show that the most dominant bacteria belong to the streptococci, followed by the staphylococci, with similar levels during the whole study period . Enterobacteriaceae and lactobacilli were present at very low levels, the latter increasing during the cow's growth, suggesting some kind of hormonal influence . The results will allow the selection of micro-organisms with probiotic characteristics, classified as GRAS (Generally Regarded as Safe), to be used in the prevention of infections in the vaginal tract of cows, such as metritis, which produces delayed periods between partum and conception, and consequent economic losses.

Infect Control Hosp Epidemiol, 2000 Aug, 21(8), 534 - 6
Nosocomial infections in a new medical center, Turkey; Durmaz B et al.; Nosocomial infection was found in 255 (2.5%) of 10,164 inpatients in a new medical center with a 310-bed capacity . The infection rate was 12.5% in the intensive care unit, 9.5% in neurology, 5.5% in general surgery, and 4.0% in orthopedics . Rates in the other services were lower . Hospital-acquired infections in our medical center frequently involved multiply resistant Enterobacteriaceae and staphylococci.

Biosystems, 2000 Jun, 57(1), 37 - 48
Minimizing stochastic complexity using local search and GLA with applications to classification of bacteria; Franti P et al.; In this paper, we compare the performance of two iterative clustering methods when applied to an extensive data set describing strains of the bacterial family Enterobacteriaceae . In both methods, the classification (i.e . the number of classes and the partitioning) is determined by minimizing stochastic complexity . The first method performs the minimization by repeated application of the generalized Lloyd algorithm (GLA) . The second method uses an optimization technique known as local search (LS) . The method modifies the current solution by making global changes to the class structure and it, then, performs local fine-tuning to find a local optimum . It is observed that if we fix the number of classes, the LS finds a classification with a lower stochastic complexity value than GLA . In addition, the variance of the solutions is much smaller for the LS due to its more systematic method of searching . Overall, the two algorithms produce similar classifications but they merge certain natural classes with microbiological relevance in different ways.

Int J Antimicrob Agents, 2000 Sep, 16(1), 31 - 6
Spectrum and transferability of beta-lactam resistance in hospital strains of Enterobacter isolated in Bratislava and Innsbruck; Bujdakova H et al.; The transferability and expression of beta-lactam resistance were compared in multiresistant clinical isolates of Enterobacter spp . collected from different hospitals in Bratislava, Slovakia (n = 15) and Innsbruck, Austria (n = 19) during 1996-1997 . The strains from Bratislava were resistant to ampicillin, cefoxitin, cefotaxime, ceftazidime and ceftriaxone . All strains from Innsbruck were resistant to ampicillin and cefoxitin; 17 were also resistant to ceftazidime and aztreonam but the majority remained susceptible to cefotaxime and ceftriaxone . All strains were susceptible to cefepime and imipenem . The majority of the tested strains transferred resistance determinants to E . coli recipient by conjugation . Production of beta-lactamase including ESBL was the major mechanism of beta-lactam resistance . Large plasmids of 77-88 and 91 kb were confirmed in clinical isolates from Bratislava and Innsbruck.

J Bacteriol, 2000 Sep, 182(18), 5256 - 61
The Escherichia coli O111 and Salmonella enterica O35 gene clusters: gene clusters encoding the same colitose-containing O antigen are highly conserved; Wang L et al.; O antigen is part of the lipopolysaccharide present in the outer membrane of gram-negative bacteria . Escherichia coli and Salmonella enterica each have many forms of O antigen, but only three are common to the two species . It has been found that, in general, O-antigen genes are of low GC content . This deviation in GC content from that of typical S . enterica or E . coli genes (51%) is thought to indicate that the O-antigen DNA originated in species other than S . enterica or E . coli and was captured by lateral transfer . The O-antigen structure of Salmonella enterica O35 is identical to that of E . coli O111, commonly found in enteropathogenic E . coli strains . This O antigen, which has been shown to be a virulence factor in E . coli, contains colitose, a 3,6-dideoxyhexose found only rarely in the Enterobacteriaceae . Sequencing of the O35-antigen gene cluster of S . enterica serovar Adelaide revealed the same gene order and flanking genes as in E . coli O111 . The divergence between corresponding genes of these two gene clusters at the nucleotide level ranges from 21.8 to 11.7%, within the normal range of divergence between S . enterica and E . coli . We conclude that the ancestor of E . coli and S . enterica had an O antigen identical to the O111 and O35 antigens, respectively, of these species and that the gene cluster encoding it has survived in both species.

Jpn J Antibiot, 2000 Jun, 53(6), 387 - 408
{Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan . Levofloxacin--Surveillance Group}; Yamaguchi K et al.; The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan . The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI . However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones . About 90% of P . aeruginosa isolates from RTI were susceptible to fluoroquinolones . In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

Antimicrob Agents Chemother, 2000 Sep, 44(9), 2247 - 53
IBC-1, a novel integron-associated class A beta-lactamase with extended-spectrum properties produced by an Enterobacter cloacae clinical strain; Giakkoupi P et al.; A transferable beta-lactamase produced by a multidrug-resistant clinical isolate of Enterobacter cloacae was studied . The bla gene was carried by a large (>80-kb) transmissible plasmid . Nucleotide sequence analysis of cloned fragments revealed that it was part of a gene cassette carried by a class 1 integron along with other resistance genes, including aac(6')-Ib . The encoded beta-lactamase, designated IBC-1, was a novel class A enzyme that hydrolyzed ceftazidime and cefotaxime and was inhibited by tazobactam and, to a lesser extent, by clavulanate . Also, imipenem exhibited potent inhibitory activity against IBC-1 . The enzyme consisted of 287 amino acid residues, including Ser-237, cysteines at positions 69 and 237a, and Arg-244, which may be implicated in its interaction with beta-lactams . In amino acid sequence comparisons, IBC-1 displayed the highest similarity with the chromosomal penicillinase of Yersinia enterocolitica, a carbenicillinase from Proteus mirabilis GN79, the species-specific beta-lactamases of Klebsiella oxytoca, and the carbapenemase Sme-1 . However, a phylogenetic association with established beta-lactamase clusters could not be conclusively shown.

Pathol Biol (Paris), 2000 Jun, 48(5), 470 - 1
{Nitrofurans: a modern treatment for uncomplicated urinary infections?}; Cahen P et al.; From January 1995 to December 1998, 2,912 strains of enteric bacilli were isolated from the urinary tract . Increasing antibiotic resistance in Enterobacteriaceae as a cause of urinary tract infection (UTI) led us to reevaluate first- and second-line therapies . We studied antimicrobial susceptibilities of these strains to norfloxacin (NOR), nalidixic acid (NAL), trimethoprim sulfamethoxazole (TS) and nitrofurantoin (FT) using the disk diffusion method . These results show no significant superiority of the activity of nitrofurantoin against Enterobacteriaceae compared with the other antibiotics with sustained concentration in urine . However, if we consider only multiresistant Enterobacteriaceae (cefotaxime resistant), this molecule appears to be very active . These results show a significant superiority of nitrofurantoin in vitro against these multiresistant Enterobacteriaceae . Thus, this molecule could once again become a good choice for the treatment of uncomplicated UTI.

J Immunol, 2000 Sep 1, 165(5), 2335 - 40
Outer membrane protein A (OmpA) binds to and activates human macrophages; Soulas C et al.; Outer membrane protein (Omp)A is highly represented and conserved in the Enterobacteriaceae family . Using a recombinant OmpA from Klebsiella pneumoniae (P40), we have analyzed the interaction between OmpA and macrophages . We report that Alexa488-labeled P40 binds (at 4 degrees C) to murine and human macrophages in a dose-dependent manner and is rapidly internalized (at 37 degrees C) . No binding or internalization of the Alexa488-labeled glycophorin A control protein is observed under the same conditions . Furthermore, P40 up-regulates the production of IL-1beta, IL-8, IL-10, IL-12, and TNF-alpha by human macrophages and of NO by the RAW 264.7 murine macrophage cell line . P40 also synergizes with IFN-gamma and suboptimal concentrations of LPS to up-regulate the production of these mediators . In conclusion, P40 binds to and activates macrophages . These data suggest that recognition of OmpA by macrophages may be an initiating event in the antibacterial host response.

J Food Prot, 2000 Aug, 63(8), 1093 - 9
High-pressure processing applied to cooked sausages: bacterial populations during chilled storage; Yuste J et al.; Vacuum-packaged cooked sausages were pressurized at 500 MPa for 5 or 15 min at mild temperature (65 degrees C) and later stored at 2 and 8 degrees C for 18 weeks . Counts of aerobic mesophiles and psychrotrophs, lactic acid bacteria, enterobacteria, Baird-Parker microbiota, and Listeria spp . were determined 1 day and 3, 6, 9, 12, 15, and 18 weeks after treatment and compared with those of cooked sausages treated at 80 to 85 degrees C for 40 min . Pressurization generated reductions of about 4 log CFU/g in psychrotrophs and lactic acid bacteria . Enterobacteria and Listeria proved the most pressure sensitive; insignificant or no growth was detected throughout the study . Heat treatment inactivated psychrotrophs and enterobacteria similarly to pressure treatment . Listeria monocytogenes and enterotoxigenic Staphylococcus aureus were not found in treated samples . In general, there was no significant difference in counts of any bacterial populations either among treatments or between storage temperatures . High-pressure processing at mild temperature is an effective preservation method that can replace heat pasteurization applied to some cooked meat and poultry products after packaging.

Rev Latinoam Microbiol, 1999 Jan-Mar, 41(1), 11 - 6
{Application of gas chromatography in the identification of Enterobacter cloacae, Enterobacter aerogenes, and Enterobacter agglomerans}; Robles Valderrama E et al.; Enterobacter cloacae, Enterobacter aerogenes and Enterobacter agglomerans were identified using gas chromatography as a substitution of the traditional techniques . Their acid methyl esters profiles were determined using a gas chromatograph Hewlett Packard 5890A and a RSL-150 heliflex capillary column . A total of 120 samples were analyzed from reference strains (ATCC 13047, 13048, 27155) and environmental isolations, eleven fatty acids were included in the profiles from which cis-9, 10-methyleneoctadecanoic acid (peak 24), cis-9-hexadecenoic acid (peak 14), octadecanoic acid (peak 23) and dodecanoic acid (peak 3), were the most important for the differentiation of the three species analyzed.

J Membr Biol, 2000 Aug 1, 176(3), 223 - 36
Mechanisms of action of rabbit CAP18 on monolayers and liposomes made from endotoxins or phospholipids; Gutsmann T et al.; We have investigated the mechanism of action of the cationic antimicrobial protein (18 kDa) CAP18 on liposomes and monolayers made from phospholipids and enterobacterial lipopolysaccharides (LPS) . CAP18 intercalates into lipid matrices composed of LPS from sensitive strains, weaker into those made of LPS from a resistant strain (Proteus mirabilis strain R45) or negatively charged phospholipids, but not into those composed of neutral phosphatidylcholine . From the combination of data obtained with fluorescence resonance energy transfer and Fourier-transform infrared spectroscopy and film balance measurements, it can be concluded that structural differences in the LPS determine the depth of intercalation of CAP18 into the respective lipid matrices . Thus, we identified the L-Arap4N linked to the first Kdo of the LPS of P . mirabilis strain R45 to be responsible for the CAP18 resistance of this strain . These data provide insight into CAP18-mediated effects on the integrity of the outer membrane of Gram-negative bacteria and led to an improved model for rabbit CAP18 membrane interaction.

Microbiology, 2000 Aug, 146 ( Pt 8), 2051 - 8
Characterization of a tonB mutation in Erwinia chrysanthemi 3937: TonB(Ech) is a member of the enterobacterial TonB family; Enard C et al.; The pectinolytic enterobacterium Erwinia chrysanthemi 3937 causes a systemic disease in its natural host, the African violet (Saintpaulia: ionantha) . It produces two structurally unrelated siderophores, chrysobactin and achromobactin . Chrysobactin makes a large contribution to invasive growth of the bacterium in its host . Insertion mutants of a chrysobactin-defective strain were constructed and screened on the universal CAS-agar medium used for siderophore detection . A set of mutants affected in the production of achromobactin were identified . This paper describes a mutant affected in the transport of all the ferrisiderophores used by the bacterium as iron sources . Molecular analysis revealed that the insertion mutation disrupts the tonB gene . The predicted Er . chrysanthemi TonB protein has a molecular mass of 27600 Da and shares 20-58% identity with the TonB proteins from 20 other bacterial species . The pathogenicity of the tonB mutant was assessed by inoculation of African violets . The impairment in the spread of symptoms was similar in the tonB mutant to that in chrysobactin-defective mutants . However, the pectinolytic activity, the major pathogenicity determinant in Er . chrysanthemi, appeared to be stimulated twofold in the tonB mutant.

FEMS Microbiol Lett, 2000 Aug 15, 189(2), 135 - 41
Pseudomonas aeruginosa B-band lipopolysaccharide genes wbpA and wbpI and their Escherichia coli homologues wecC and wecB are not functionally interchangeable; Burrows LL et al.; The O antigen unit of Pseudomonas aeruginosa serotype O5 is a complex trisaccharide containing 2-acetamido-3-acetiminido-2, 3-dideoxy-beta-D-mannuronic acid, 2-acetimido-3-acetimido-2, 3-dideoxy-beta-D-mannuronic acid, and 2-acetimido-2, 6-deoxy-beta-D-galactosamine . Specific knockout mutations in the putative UDP-D-N-acetylglucosamine (UDP-D-GlcNAc) epimerase gene, wbpI, or the putative UDP-D-N-acetylmannosamine dehydrogenase gene, wbpA, resulted in strains that no longer produced B-band lipopolysaccharide, confirming the essential roles of these genes in B-band O antigen synthesis . Despite approximately 50% similarity of wbpI and wbpA to the Escherichia coli genes wecB (rffE) and wecC (rffD) involved in enterobacterial common antigen synthesis, cross-complementation experiments were not successful . These results imply that the P . aeruginosa UDP-D-GlcNAc precursor may be di-N-acetylated prior to further modification, preventing the E . coli enzymes from recognizing it as a substrate.

Int J Antimicrob Agents, 2000 Aug, 15(4), 271 - 5
In vitro activity of ceftiofur tested against clinical isolates of Escherichia coli and Klebsiella pneumoniae including extended spectrum beta-lactamase producing strains; Deshpande L et al.; In vitro activity of ceftiofur, a cephalosporin used in veterinary practice was compared using ceftriaxone-resistant (producing extended spectrum beta-lactamase (ESBL)) and -susceptible clinical isolates of Esherichia coli and Klebsiella pneumoniae . The ceftriaxone-susceptible isolates exhibited a lower range of ceftiofur MICs (MIC50, 0.5 mg/l, MIC90 1.0 mg/l) . Those isolates known to produce an ESBL were also resistant to ceftiofur (MIC50, > or = 32 mg/l) . The latter isolates were also less susceptible to other comparator drugs (cefquinome, gentamicin and trimethoprim/sulphamethoxazole) in contrast to the ceftriaxone-susceptible strains . The clinical isolates showed high correlation between ceftriaxone and ceftiofur MICs (y = 2.6 + 0.89x, r = 0.95) . Using the current ceftiofur susceptible breakpoint (< or = 2 mg/l) used for veterinary practice (respiratory tract pathogens), the ESBL-producing strains of E . coli and K . pneumoniae could be accurately separated from susceptible strains . This ceftiofur breakpoint MIC corresponds to the National Committee for Clinical Laboratory Standards ESBL screening concentration for ceftriaxone set at < or = 1 mg/l = negative for ESBL production . Ceftiofur was also observed to be very active in vitro against ampicillin-resistant, non-ESBL producing enteric isolates . This new cephem appears to be very potent against the tested Enterobacteriaceae and of potential wide clinical veterinary utility.

Anal Biochem, 2000 Jul 15, 283(1), 64 - 70
Purification of integral outer-membrane protein OmpC, a surface antigen from Salmonella typhi for structure-function studies: a method applicable to enterobacterial major outer-membrane protein; Arockiasamy A et al.; Extraction of the outer-membrane porin, OmpC, from Salmonella typhi Ty21a was done by using a modified salt-extraction procedure . It was possible to extract only the major outer-membrane protein (OMP) from the crude membrane using this method . Aberrant lipopolysaccharide (LPS) production in the galE mutant Ty21a has resulted in more isoforms of OmpC and subsequently led to anomalous mobility in SDS-PAGE . The purity of the preparation was confirmed by denaturing urea SDS-PAGE and N-terminal sequencing . The major OMP extracts had LPS of both bound and free forms . The free form of LPS could be removed by gel filtration and the bound form, largely, was removed using ion-exchange chromatography and by passing through ultrafiltration devices . This method has been used to extract the native trimer of OmpC, the major OMP, in a large scale, for structure-function studies . S . typhi Ty21a OmpC preparation yielded reproducible diffraction-quality crystals . Extracts of porin from wild-type Escherichia coli HB101, grown under high osmolarity conditions, showed a single species of OMP on SDS-PAGE . This suggests the possible application of the method to other gram-negative bacterial porins.

Am J Perinatol, 2000, 17(1), 19 - 22
Maternal risk factors for perinatal septicemia due to the Enterobacteriaceae; Monif GR; Cases of perinatal septicemia due to the Enterobactericeae, which manifest in the first 24 hr of life were analyzed for the presence or absence of the maternal risk factors defined in the CDC group B streptococcus (GBS) risk-factor protocol . Microbiological data involving blood culture isolates were reviewed for the recovery of an Enterobacteriaceae from January 1975 through June 1995 . Enterobacteriaceae perinatal septicemia was defined as the recovery an Enterobacteriaceae from one or more set of blood cultures in the first 24-36 hr of life in conjuncture with clinical evidence of neonatal stress in the first 24 hr . A case would also be considered of perinatal origin for cultures obtained up to 36 hr provided that evidence of clinical disease was present in the first 24 hr of life . Fifteen cases of perinatal septicemia due to the Enterobacteriaceae were analyzed . All but four shared one or more maternal risk factors . The maternal risk criteria established to avert early-onset GBS disease are commonly encountered in women destined to have newborns with perinatal septicemia due to the Enterobacteriaceae . Antibiotic selection for risk-driven protocols for GBS avoidance may need to be broadened to address the issue of coverage for penicillin-sensitive and penicillin-resistant Enterobacteriaceae.

Southeast Asian J Trop Med Public Health, 1999 Dec, 30(4), 770 - 5
Bacterial contamination of bottle milk in infants under 6 months in Children's Hospital, Bangkok, Thailand; Suthienkul O et al.; The bacterial contamination of bottle milk samples obtained randomly from 500 infants under 6 months of age who came to the Out-patient Department of Children's Hospital Bangkok was determined by collecting bottle milk samples prepared at home following interview of their caretakers after obtaining their consent . Bacterial contamination was found in 91.8% (459/500) of bottle milk samples . Among the positive samples, 82.8% (380/459) contained enteric bacteria, another 17.2% were unidentified bacteria . The dominant enteric bacteria isolated from bottle milk were Klebsiella spp (56.6%), Enterobacter spp (41.3%), Aeromonas spp (14.4%), E . coli (13.4 %) and Vibrio cholerae non 0-1 (1.8%) . Isolated E . coli were further identified as enteropathogenic E . coli (7.8%, 4/51) and enterotoxigenic E . coli (3.9%, 2/51) . About 74% of the contaminated bottle milk contained one type of bacteria, 23.7% had two types and 2.3 % had 3 or more types of bacteria . A level of bacterial contamination greater than the US government limited number (USGLN 2x10(4) CFU/ml) was found in 86.4% of total examined samples (432/500) {geometric mean (GM) of 2.9 x 10(6) CFU/ml} . About 66% (333/500) of bottle milk samples had coliforms greater than the USGLN (1 x l0(2) CFU/ml) with GM of 1.3 x 10(4) CFU/ml . Therefore, in the preparation of bottle milk, feeding practice should be emphasized in every setting of maternal-child health care and promotion of breast-feeding should be encouraged by the health personnel.

Infect Control Hosp Epidemiol, 2000 Jul, 21(7), 465 - 9
A heterogeneous outbreak of Enterobacter cloacae and Serratia marcescens infections in a surgical intensive care unit; Dorsey G et al.; OBJECTIVE: To investigate an outbreak of invasive disease due to Enterobacter cloacae and Serratia marcescens in a surgical intensive care unit (ICU) . DESIGN: Pulsed-field gel electrophoresis (PFGE) analysis of restriction fragments was used to characterize the outbreak isolate genotypes . A retrospective cohort study of surgical ICU patients was conducted to identify risk factors associated with invasive disease . Unit staffing data were analyzed to compare staffing levels during the outbreak to those prior to and following the outbreak . SETTING: An urban hospital in San Francisco, California . PATIENTS: During the outbreak period, December 1997 through January 1998, there were 52 patients with a minimum ICU stay of > or = 72 hours . Of these, 10 patients fit our case definition of recovery of E . cloacae or S . marcescens from a sterile site . RESULTS: PFGE analysis revealed a highly heterogeneous population of isolates . Bivariate analysis of patient-related risk factors revealed duration of central lines, respiratory colonization, being a burn patient, and the use of gentamicin or nafcillin to be significantly associated with invasive disease . Both respiratory colonization and duration of central lines remained statistically significant in a multivariate analysis . Staffing data suggested a temporal correlation between understaffing and the outbreak period . CONCLUSIONS: Molecular epidemiological techniques provided a rapid means of ruling out a point source or significant cross-contamination as modes of transmission . In this setting, patient-related risk factors, such as respiratory colonization and duration of central lines, may provide a focus for heightened surveillance, infection control measures, and empirical therapy during outbreaks caused by common nosocomial pathogens . In addition, understaffing of nurses may have played a role in this outbreak, highlighting the importance of monitoring staffing levels.

Lakartidningen, 2000 Jun 28, 97(26-27), 3174 - 6
{Peroral antibiotic prophylaxis in upper gastrointestinal surgery . A study of biological availability}; Rasmussen IC et al.; Sixteen patients undergoing elective upper gastrointestinal surgery with presumed normal gastrointestinal function received peroral trimethoprim-sulfamethoxazole (TMP/SMZ 160/800 mg) and metronidazole (2 g) in the morning regardless of what time the operation was to be started . The concentration of SMZ in plasma was measured before and after the operation . Only 37 per cent of the patients were found to have adequate levels of SMZ concentration . Patients with grave obesity or malignant disease of the liver, biliary tract or pancreas had concentrations below the minimal inhibitory concentrations for species of Enterobacteriacae . Peroral antibiotic prophylaxis is therefore not suitable in all types of upper gastrointestinal surgery.

Gene, 2000 Jul 25, 253(1), 55 - 66
Sequence diversity of intervening sequences (IVSs) in the 23S ribosomal RNA in Salmonella spp; Pabbaraju K et al.; Intervening sequences (IVSs) occur sporadically in the rrl (ribosomal RNA large) genes for 23S ribosomal RNA (rRNA) at helix-25 (base pair 550) and helix 45 (base pair 1170) in several bacterial genera, including Salmonella, Yersinia, Proteus, and Providencia, representing the Enterobacteriaceae, but are missing from other genera such as Escherichia . These sequences are transcribed, but later excised without re-ligation during RNaseIII processing of the rRNA, resulting in fragmented 23S rRNA . The IVSs from 22 strains of the SARB (Salmonella Reference Collection B) set were amplified by PCR and sequenced.IVSs with 90% or more sequence identity were placed in the same family; Salmonella has three families of IVSs in helix-25 (A, B, and C) and two in helix-45 (M and O) . The rRNA secondary structure for the IVSs predicted from the mfold program reveals a primary stem of about 14bp, which is the postulated RNaseIII cleavage site, and a secondary region of stems and loops . The primary stem is considerably well conserved, with a high rate of compensatory mutations (positional covariants), confirming the reality of the secondary structure and indicating that removal of the IVSs exerts a positive selective pressure to retain the secondary structure . The pattern of possession and presence of families of IVSs was diverse and could not be related to the proposed ancestry of the strains as revealed by the multi-locus enzyme electrophoresis pattern of the strains, suggesting that the IVSs are transferred between strains by lateral transfer . Helix-25 IVSs from families A, B, and C of Salmonella and D of Proteus, which share almost identical primary stems, are placed in superfamily I, while the primary stems of other IVSs from Proteus and Providencia are unrelated to superfamily I and are thus placed into superfamily II; this indicates lateral transfer of members of superfamily I between Proteus and Salmonella, but an independent origin of IVSs of superfamily II in Proteus and Providencia.

Biochem Biophys Res Commun, 2000 Aug 11, 274(3), 649 - 54
Induction of oxidative stress in leukocytes by an Enterobacter cloacae toxin able to form oligomers and binding to proteins; Albesa I et al.; A leukotoxic and hemolytic toxin was purified from cultures of Enterobacter cloacae . Stimulation of oxidative stress was observed and the production of reactive oxidant species was measured in leukocytes treated with toxin by means of nitroblue tetrazolium and chemiluminescence assays . Molecular weight of toxin was estimated by chromatography and SDS-PAGE . Two protean peaks with toxic activity were found in Sephadex G-100 (P1, 42.0 kDa; and P2, 13.3 kDa) . The relative amounts between the peaks (P1/P2 = 0.36) changed when 2-mercaptoethanol was employed (P1/P2 = 0.59) . When Sephadex G-200 chromatography was performed, a protean peak of Ve = 113 mL (100 kDa) was found; its was dissociated with 3 M urea in toxic proteins of lower mass: 42, 27, and 13.3 kDa . SDS-PAGE (15%) showed a single toxin band of purified monomer (13.3 kDa), but electrophoresis of a 42-kDa toxin with urea presented three bands of trimer, dimer, and monomer . An increase of casein hydrolysate and albumin molecular weight was observed by chromatography after incubation with toxin due to the binding of both proteins with toxin .

Appl Environ Microbiol, 2000 Aug, 66(8), 3330 - 6
Genotypic heterogeneity of Streptococcus oralis and distinct aciduric subpopulations in human dental plaque; Alam S et al.; The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR . Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual . S . oralis is the predominant aciduric bacterium isolated from noncarious tooth sites . Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (chi(2) = 13.09; P = 0.0031) . Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects . The basis of this instability is unknown but is similar to that reported for Streptococcus mitis . Examination of S . oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing . These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci . The demonstration of distinct aciduric populations of S . oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.

J Microbiol Immunol Infect, 2000 Jun, 33(2), 100 - 4
Characteristics of neonatal bacterial meningitis in a teaching hospital in Taiwan from 1984-1997; Chang Chien HY et al.; During the period from 1984 to 1997, 85 bacterial meningitis neonates with positive cerebrospinal fluid cultures were treated . The ages of these patients ranged from 1 to 28 days . The male to female ratio was 1.7 to 1 . The most common causative agent was group B beta-hemolytic streptococci (GBS, 31.8%), followed by Escherichia coli (20%), Proteus mirabilis (7.1%), Enterobacter cloacae (5.9%), other streptococci excluding Streptococcus pneumoniae (5.9%), Chryseobacterium meningosepticum (5.9%), enterococci (4.7%), and Klebsiella pneumoniae (3.5%) . Among the 85 patients treated, 51 (60%) were younger than 7 days old . Among them, dyspnea was the most common clinical manifestation . In contrast, fever and diarrhea were seen more frequently in neonates with late onset of disease (after seven days of age) . Ampicillin and cefotaxime were the most commonly used antibiotics . The most frequently encountered complications were hydrocephalus and seizures . Since 1991, GBS has overtaken E . coli as the leading cause of neonatal bacterial meningitis . This was accompanied by a fall in the mortality rate, but a sustained high incidence of complications and sequelae . The results of this study highlight the importance of developing strategies to prevent group B streptococcal infection.

Med Microbiol Immunol (Berl), 2000 Jun, 188(4), 191 - 6
Infection of dendritic cells by enterobacteriaceae; Schoppet M et al.; Dendritic cells (DC) are potent antigen-presenting cells that play a crucial role in initiation and modulation of specific immune responses . Various pathogens like viruses or bacteria are able to persist inside DC . In this study we investigated the ability of the Gram-negative bacteria Salmonella typhimurium and Escherichia coli to infect DC . DC isolated from peripheral blood of healthy donors were infected with wild-type S . typhimurium and a nonpathogenic E . coli stool isolate . Association of bacteria with DC was assessed by labeling of the bacteria with green fluorescent protein . Both Gram-negative bacteria were associated with DC as evidenced by microscopy and flow cytometry . The intracellular location could be confirmed by lysis of DC and subsequent determination of colony-forming units on agar plates, which showed a rapid decline in viable Gram-negative bacteria 6 h after infection, being by far more pronounced for E . coli than for S . typhimurium . Testing the stimulation of T cells by infected versus uninfected but otherwise identically treated human immature DC in a mitogen-dependent T cell proliferation assay, we found that S . typhimurium . but not E . coli exhibited a suppressive effect on T cell stimulation, being most significant on days 3-5 after infection . Thus, suppression of dendritic cell function was associated with an enteropathogenic bacterium, S . typhimurium, which can cause severe forms of enteritis . The bacteria with normally mild or no gastric symptoms, E . coli, had no influence on stimulation of T cells by DC.

J Hosp Infect, 2000 May, 45(1), 29 - 34
Enterobacter cloacae outbreak in the NICU related to disinfected thermometers; van den Berg RW et al.; In the first week ot December 1997, an increasing incidence of neonates colonized with multi-drug resistant Enterobacter cloacae (MR-E . cloacae) was observed in the neonatal Intensive care unit of our 950-bed university hospital . Initially, re-enforcement of infection control practices including hand disinfection and cohort isolation seemed to be sufficient to control the outbreak . Nevertheless, an increasing number of newly admitted patients was paralleled by another rise in the incidence of colonized neonates . Since E . cloacae was initially found in urine specimens of the patients, surveillance and environmental cultures were aimed at procedures and instruments that might colonize the gastro-intestinal and/or urinary tract . E, cloacae was isolated from a single cap of an electronic digital thermometer . Despite banning of this possible source, newly admitted neonates still became colonized . The unit was closed for further admissions and a second round of extensive screening was started; this time including all available thermometers and continuous rectal temperature probes . Ready-to-use 'disinfected thermometers and probes were found to be colonized with MR-E . cloacae . Observation of disinfection procedures and a laboratory investigation revealed that 'rushed disinfection with alcohol 80% led to a 1 in 10 chance of thermometers still being contaminated . Furthermore, alcoholic hand rub used for convenience disinfection failed to disinfect thermometers in 40% and 20% of the cases when done in a 'rushed' or 'careful' fashion, respectively . Adequate disinfection of the thermometers led to the control of the outbreak, with no new occurrence of MR-E . cloacae in the following months.

Zhonghua Yi Xue Za Zhi, 1998 Jun, 78(6), 416 - 9
{Analysis of critically ill patients with bacteremia}; Du B et al.; OBJECTIVE: To study the epidemiology of bacteremia of critically ill patients and the mortality associated with bacteremia and risk factors for death in an intensive care unit . METHOD: 75 patients with 116 episodes of bacteremia were retrospectively studied . RESULTS: The mortality rate of the patients was 43% . Staphylococci (29%), Enterococci (12%), Class I inducible beta-lactamase-producing Enterobacter (12%), extensive spectrum beta-lactamase-producing Enterobacter (10%) were the most common pathogens, among which gram-positive organisms constitute a major part . The most commonly affected organs were respiratory (77%), hepatic (53%), circulatory (53%), gastrointestinal (50%), renal (47%), central nervous (36%), and hemopoietic systems (27%) . Multiple organ failure accounted for 76% . Univariate analysis revealed that the severity of underlying illness, multiple organ failure (MOF), septic shock, hepatic failure, renal failure and infection focus were the risk factors for in-hospital death (P < 0.05) . Cox proportional hazard model analysis suggested central nervous system failure, septic shock, hemopoietic failure, hepatic failure and respiratory manipulation significantly affected the survival time of patients with bacteremia (P < 0.05) . CONCLUSION: Gram-positive organisms are major pathogens of bacteremia in critically ill patients . Antibiotic therapy can not prevent the occurence of bacteremia, nor can it improve the prognosis.

Arch Pathol Lab Med, 2000 Aug, 124(8), 1157 - 64
Concordance of endotoxemia with gram-negative bacteremia . A meta-analysis using receiver operating characteristic curves; Hurley JC; OBJECTIVE: To apply meta-analysis to compare the concordance between the results of 2 types of limulus amebocyte lysate (LAL) assay, gelation (GLAL) and chromogenic (CLAL), with the detection of gram-negative bacteremia in patients with suspected bacteremia . DESIGN: Meta-analysis using receiver operating characteristic-based analytical method . DATA SOURCES: MEDLINE literature search and manual reviews of article bibliographies together with direct approaches to authors of potentially eligible studies . STUDY SELECTION: The studies that were selected had all included at least 10 patients, of whom at least 2 patients were diagnosed with gram-negative bacteremia, and all had data available for extraction into a contingency table format . RESULTS: Fifty-six studies (28 GLAL and 28 CLAL studies) met the inclusion criteria . Studies were stratified by type of test (GLAL vs CLAL) . Each analysis was repeated with smaller studies excluded . There was no difference between the 2 types of LAL assays . Among the CLAL studies, there was no difference between studies that did versus those that did not use the sepsis syndrome criteria as a basis for patient inclusion . Among 45 studies for which data on the proportion of non-Enterobacteriaceae were available, there was a trend toward higher concordance as this proportion increased . CONCLUSIONS: The concordance between the LAL test and the detection of gram-negative bacteremia in patients with suspected bacteremia is no higher with the CLAL assay than with the original GLAL version . However, the concordance is higher among studies with a higher proportion of non-Enterobacteriaceae among the gram-negative bacteremia isolates.

J Clin Microbiol, 2000 Aug, 38(8), 3036 - 8
Clinical significance and antibiotic resistance patterns of Leminorella spp., an emerging nosocomial pathogen; Blekher L et al.; Although Leminorella spp., members of the family Enterobacteriaceae, were previously isolated from feces and urine specimens, clinical correlates have not been studied . We conducted a retrospective study to investigate the clinical significance and disease spectrum of these organisms, as well as their antibiotic susceptibility patterns . Identification and susceptibility testing were performed by an automated system . Eighteen cases were identified retrospectively during a 28-month period (1/97 to 4/99), representing an incidence of 11 cases per 100,000 patient admissions . The medical records of 14 patients were reviewed . The average patient age was 67 years, and 78% were males . Patients had multiple and diverse underlying conditions which might have predisposed them to infection . Leminorella spp . were classified as definite pathogens in 43% of the cases, probable pathogens in 29%, and possible pathogens in 21% . In one case of asymptomatic bacteriuria, the isolate had no clinical significance . All infections but one were nosocomial . Clinical syndromes included urinary tract infection in six patients, surgical site infection in three patients, and primary bacteremia, peritonitis, respiratory tract infection, and soft tissue infection in one patient each . Isolates were uniformly susceptible to imipenem . Other beta-lactam agents had poor activity against the isolates . We conclude that Leminorella spp . are significant nosocomial pathogens that are capable of causing a variety of clinical syndromes and are resistant to multiple antibiotic agents.

Pediatrics, 2000 Aug, 106(2 Pt 1), 251 - 5
Outpatient pediatric blood cultures: time to positivity; McGowan KL et al.; OBJECTIVE: Using a continuously monitoring blood culture system, we determined the time to positivity of blood cultures performed on immunocompetent infants and children who were not receiving antibiotics at the time of culture . STUDY DESIGN: This study was conducted prospectively using blood cultures taken in the emergency department and outpatient clinics of an urban pediatric teaching hospital from February 1, 1993, through December 31, 1996 . Cultures were excluded if obtained from patients receiving antibiotics, patients with a central line, patients with prosthetic devices, or those being followed by the oncology division . Our measures included: 1) recording the time to positive culture obtained by using a continuously monitoring blood culture instrument, 2) patient information derived from the hospital computer system concerning antibiotic use and the presence of indwelling central venous catheters and prosthetic devices, and 3) a chart review of 10% of patients from whom positive cultures were obtained . RESULTS: During the 47-month study period, 10 200 single bottle blood cultures were obtained, 711 (6.97%) of which became positive . Patients ranged in age from <1 week to 24 years (mean: 2.00 years) . Two hundred fifty-eight cultures (36.3%) contained only pathogens, 370 (52%) contained only skin contaminants, and 83 (11.7%) contained a mixture of contaminant and pathogen . Of the 258 cultures containing only pathogens, 14% were positive by 12 hours, 87% by 24 hours, 92% by 36 hours, 95% by 48 hours, 98% by 60 hours, and 99.7% by 72 hours . Ninety-five percent of critical pediatric pathogens including Streptococcus pneumoniae, Salmonella and other Enterobacteriaceae, Neisseria meningitidis, and groups A and B streptococci were detected in <24 hours . CONCLUSION: Because 87% of all cultures containing pathogens were detected within the first 24 hours of incubation, this study can assist emergency department, clinic, and primary care clinicians when making critical decisions concerning patients on whom blood cultures were obtained . Data on time to positivity of blood cultures can be used in conjunction with clinical status to support clinicians in making patient management decisions . Use of short stay (</=24 hours) or extended care units requiring less patient supervision may be easier to justify when a continuously monitoring blood culture instrument is used in the microbiology laboratory.bacteremia, sepsis.

Br J Biomed Sci, 2000, 57(2), 119 - 25
Bacteraemia among patients attending a cancer hospital in Lahore, Pakistan; Mortlock S; Bacteraemia can be life-threatening, particularly in the neutropenic cancer patient, and any episode of pyrexia is treated empirically with antibiotics, and a blood culture taken . Over an 18-month period, 3025 (934 patients) blood culture sets were received by the microbiology department of the Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan . The blood culture sets used a blood/tryptone soya broth (1:5 ratio) mixture and were manually subcultured onto appropriate media following incubation at 37 degrees C . Of these, 406 (13.4%) were positive for bacteria or yeasts, the most common organisms being coagulase-negative staphylococci (16%), Escherichia coli (15.1%), other Enterobacteriaceae (11.8%), Staphylococcus aureus (9.1%) and Pseudomonas aeruginosa (8.6%) . In addition, a number of unusual organisms were isolated which could have been peculiar to this institution or to patients with neoplastic disease . Sensitivity patterns for the major groups of organisms were compared with the previous year's figures (where available), to identify any change.

J Dairy Sci, 2000 Jul, 83(7), 1479 - 86
Microbial populations, fermentation end-products, and aerobic stability of corn silage treated with ammonia or a propionic acid-based preservative; Kung L Jr et al.; We studied the effects of ammonia treatment on microbial populations during the fermentation of corn silage . We also compared the effects of ammonia to a preservative containing buffered propionic acid and other antifungal compounds on the fermentation and aerobic stability of corn silage . In the first experiment, whole-plant corn was ensiled without treatment or treated with ammonia-N to supply an additional 0.3% N (fresh-forage basis) . The addition of ammonia immediately increased silage pH and had no effect on numbers of lactic acid bacteria, but delayed their growth compared with untreated silage . Numbers of enterobacteria declined more slowly, but numbers of yeasts and molds declined more quickly in silage treated with ammonia . During the early stages of ensiling, lactic acid increased more rapidly in untreated than in treated silage . The reverse was true for acetic acid concentrations . When exposed to air, growth of yeasts and molds was delayed in ammonia-treated silage . In a second experiment, various levels (0.1 to 0.3%, fresh weight) of ammonium-N or a preservative with buffered propionic acid were added to whole-plant corn and allowed to ensile for 106 d . Silage treated with ammonia had a greater ratio of L- to D-lactic acid than did other silages . Untreated silage was aerobically stable for 32.3 h, whereas the low (42 h) and moderate (52.7 h) concentrations of both additives numerically improved aerobic stability . High concentrations of ammonia-N (0.3%) or a buffered propionic acid preservative (0.3%), markedly improved the aerobic stability of corn silage (82 and 69 h for ammonia and propionic acid-treated silage, respectively).

Antimicrob Agents Chemother, 2000 Aug, 44(8), 2046 - 51
A population pharmacokinetic analysis of the penetration of the prostate by levofloxacin; Drusano GL et al.; Prostatitis has remained a pathological entity that is difficult to treat . Part of the difficulty revolves about the putative offending pathogens . For acute prostatitis, members of the Enterobacteriaceae, particularly Escherichia coli, play a central role, while intracellular pathogens such as Chlamydia are more frequently seen in chronic prostatitis . Consequently, a drug needs to be able to penetrate to this specialized site in both the acute and chronic infection forms of the disease and also have potent activity against the most common causative pathogens, both intracellular and extracellular . Levofloxacin has such an activity profile . We wished to document its ability to penetrate to the site of infection . Patients undergoing prostatectomies were administered 500 mg of levofloxacin orally every 24 h for 2 days prior to surgery, and then on the day of surgery, 500 mg was administered as an hour-long, constant-rate intravenous (i.v.) infusion . A set of blood samples was obtained as guided by stochastic optimal design theory . Prostate biopsy times were determined by randomizing subjects into one of four groups, based on the interval after the i.v . dose . All plasma and prostate drug concentrations were comodeled by a population modeling program, BigNPEM, implemented on the Cray T3E Supercomputer housed at the Supercomputer Center at the University of California at San Diego . Penetration was determined as the ratio of the area under the concentration-time curve (AUC) of levofloxacin in the prostate to the plasma levofloxacin AUC . When calculated from the mean population parameters, this penetration ratio was 2.96 . We also performed a 1,000-subject Monte Carlo simulation from the mean parameter vector and covariance matrix . The mean penetration ratio here was 4.14 with a 95% confidence interval of 0.20 to 19.6 . Over 70% of the population had a penetration ratio in excess of 1.0 . Levofloxacin adequately penetrates a noninflamed prostate and should be evaluated for the therapy of prostatitis.

J Agric Food Chem, 2000 Jun, 48(6), 2489 - 94
Evaluation of gamma-irradiation in cocoa husk; Bonvehi JS et al.; gamma-Irradiation was investigated as a technique to improve the hygienic quality of cocoa husk . Cocoa husk is a byproduct of cocoa bean processing industry . It contains approximately 57.5% (w/w) dietary fiber (nonstarch polysaccharides plus lignin), 15% (w/w) crude protein, 10.7% (w/w) mineral elements, 2.32% (w/w) cocoa butter, and 2.8% (w/w) carbohydrates (free sugars plus starch) . The effect of irradiation on the growth rates of microorganisms are reported . Total counts, enterobacteriaceae, coliforms, Staphylococcus aureus, Streptococcus "D" of Lancefield, and yeast and mold counts before and after irradiation at 5, 8, and 10 kGy were determined . Cocoa husk was irradiated in open containers . An irradiation dose of 5 kGy was already sufficient to decrease the microbial counts to a very low level . No alteration in dietary fiber was measured in the irradiated product and no significant differences were detected between irradiated and nonirradiated cocoa husk.

J Nutr Sci Vitaminol (Tokyo), 2000 Apr, 46(2), 55 - 7
Biosynthesis of pyridoxine: origin of the nitrogen atom of pyridoxine in microorganisms; Tanaka K et al.; The amide nitrogen atom of glutamine was incorporated into pyridoxine in four eukaryotes, Emericella nidulans, Mucor racemosus, Neurospora crassa and Saccharomyces cerevisiae, and two prokaryotes, Staphylococcus aureus and Bacillus subtilis, but not in the following prokaryotes, Pseudomonas putida, Enterobacter aerogenes and Escherichia coli . On the other hand, the nitrogen atom of glutamate was incorporated into pyridoxine in P . putida, E . aerogenes and E . coli, but not in S . aureus and B . subtilis . These results suggest that there are at least two different biosynthetic routes for pyridoxine and the difference does not depend on prokaryotes and eukaryotes.

Infection, 1999, 27 Suppl 2, S35 - 8
Selective pressure by antibiotics as feed additives; Witte W et al.; Antibacterial substances are used in considerable amounts as growth promoters in animal husbandry . There are, however, incalculable risks for human health resulting from the use of particular feed additives . Even 30 years ago the detection of transferable antibiotic resistance in Enterobacteriaceae led to the demand that antibiotics used in human chemotherapy, or for which cross-resistance against human therapeutics has been demonstrated, should be prohibited as growth promoters . The application of molecular methods to typing and characterization of bacteria and their resistance genes has provided more concise evidence for the transfer of antibiotic resistance among animal husbandry and humans as to resistance to glycopeptides (vanA gene cluster) and to streptogramins (satA).

Infection, 1999, 27 Suppl 2, S2 - 8
Drug resistance among clinical isolates of frequently encountered bacterial species in central Europe during 1975-1995 . Study Group Bacterial Resistance of the Paul-Ehrlich-Society for Chemotherapy; Kresken M et al.; A multicenter study for monitoring antimicrobial drug resistance in clinical isolates of the family Enterobacteriaceae, Pseudomonas aeruginosa, Staphylococcus and Enterococcus species in central Europa conducted by the Study Group Bacterial Resistance of the Paul-Ehrlich-Society for Chemotherapy has been ongoing since 1975 . Between 1975 and 1995 susceptibility data on almost 60,000 bacteria, which were isolated and sampled under a common protocol by laboratories from Austria, Germany and Switzerland, were collected . These bacterial isolates were known by the respective investigators to have caused infections . From 1975 to the mid-80s none of the bacterial species examined showed an increase in resistance . The frequency of resistance in klebsiellae and Staphylococcus aureus to some antibiotics even declined . In 1990 and particularly in 1995, a clear increase in resistance for a number of antibiotic-organism pairs was observed . Resistance rates to fluoroquinolones increased in all species under investigation . In Escherichia coli the increase of resistance to ampicillin, co-trimoxazole and gentamicin was remarkable . Resistance to imipenem increased in P . aeruginosa . Resistance to cephalosporins, on the other hand, remained largely unchanged in gram-negative bacilli . Between 1990 and 1995, the prevalence of oxacillin resistance increased from 1.7 to 12.9% in S . aureus and from 15.8 to 55.8% in coagulase-negative staphylococci, whereas staphylococcal and enterococcal resistance to glycopeptides was still rare.

Diabetes Metab, 2000 May, 26(3), 219 - 24
{Role of antibiotic therapy in diabetic foot management}; Hartemann-Heurtier A et al.; Antibiotic therapy is not the most important component in diabetic foot ulcer management which should be based on weight bearing avoidance and arterial revascularization . However antibiotic therapy is necessary in presence of extensive deep involvement or systemic signs of infection . Initial antimicrobial treatment depends on bacteria supposed origin . For patients not coming from hospital, the initial choice antibiotic is an amoxicillin/clavulanate agent because it offers optimal coverage for most pathogens involved in those diabetic foot lesions (gram positive cocci, gram negative and anaerobic organisms) . For patients at high risk to be infected with nosocomially acquired pathogens, the initial antibiotic therapy must cover methicillin-resistant staphylococci, resistant pseudomonas aeruginosa or enterobacteriae . In all cases, when definitive reliable cultures are reported, initial antibiotic regimens should be revised to narrow the coverage to specific pathogens . In presence of osteomyelitis, a temporary combination of two agents which are known to reach high bone concentrations is necessary, and antibiotic therapy should be continued for at least two months . In other cases, antibiotic treatment duration depends on clinical out come.

Avian Dis, 2000 Apr-Jun, 44(2), 460 - 4
Bacterial cholecystitis with cardiac and pulmonary dissemination in a blue-naped mousebird (Urocolius macrourus); Ferrell ST et al.; A blue-naped mousebird (Urocolius macrourus) was diagnosed by gross necropsy and histopathology as having a chronic, fibrosing bacterial cholecystitis . Acute, severe, necrotizing pneumonia and myocarditis also were present with intralesional gram-negative bacteria . The bacteria within the lungs and heart were suspected to have spread from the biliary tract because of the pattern of distribution and similar gram-staining characteristics . Enterobacter sp . and Escherichia coli were cultured from the pulmonary lesions . Cloacal cultures in clinically normal blue-naped mousebirds and speckled mousebirds (Colius striatus) yielded both Enterobacter sp . and E . coli . We hypothesize a pathogenesis in this bird consisting of biliary stasis of unknown etiology and eventual infection of the biliary tract by the normal gram-negative gastrointestinal flora . Death was believed to be a result of cardiac and respiratory dysfunction secondary to the bacterial dissemination from the biliary tree and endotoxemia.

Scand J Infect Dis, 2000, 32(3), 293 - 8
Outbreak investigation of nosocomial enterobacter cloacae bacteraemia in a neonatal intensive care unit; Yu WL et al.; Over a period of 7 months, 23 patients hospitalized in a neonatal intensive care unit (NICU) developed nosocomial Enterobacter cloacae bacteraemia . Contaminated saline for preparing heparin solution was initially identified as the common source of E . cloacae bacteraemia . Although environmental sanitation was enforced, the outbreak continued . E . cloacae has always been isolated from various cultures of the environmental specimens, from the hands of personnel and from the faeces of patients . All of the 23 bacteraemic isolates and 8 stool isolates from infected infants, as well as the 17 isolates from environmental specimens were found to be of the same genotype using the polymerase chain reaction-based DNA fingerprinting method . After various infection control methods were instituted, the outbreak eventually came under control . For epidemiological investigation, 23 neonates without E . cloacae bacteraemia were matched for case-control study . Nineteen (83%) of the case-patients were premature . The significant risk factors leading to E . cloacae bacteraemia in the NICU included small gestation age, low birthweight, exposure to personnel with contaminated hands and the presence of E . cloacae in the stool carriage (p=0.003, 0.007, 0.018 and 0.040, respectively) . The gastrointestinal tracts of the patients and environmental surfaces appeared to be the principal sites of bacterial reservoir . In conclusion, the outbreak of E . cloacae bacteraemia was caused by a particular strain and possibly via multiple modes of transmission, including a bottle of contaminated saline as an initial common source, endogenous spread from the gastrointestinal tract and successive cross-infections between patients, hands of personnel and the environment . Effective infection control requires a multidisciplinary approach and reinforcement of infection control procedures, including aseptic technique, hand washing, proper isolation and disinfection of environmental surfaces.

Klin Lab Diagn, 2000 Mar, (3), 51 - 4
{The use of improved commercial micro-LA-tests for the identification of different groups of microorganisms in clinical microbiology}; Nekhorosheva AG et al.; Lachema kits ENTEROtest 24, ENTERO-Rapid 24, ENTERO-Screen, NEFERMtest 24, STAPHYtest 16, STREPTOtest 16, En-COCCUS test were used in identification of 871 strains of microorganisms isolated from clinical material . The kits proved to be highly reliable: they identified 88.8-97.5% cultures and permitted rapid (within 4 h) identification of enterobacteria most often occurring in clinical practice . The advantages of these kits are stripped plates allowing identification of cultures in individual stripes, a wide spectrum of biochemical tests, modern composition of biosubstrates in suspension media, and rational disposition of the tests, allowing technologically simpler identification of a wider spectrum of cultures in one stage without difficult accessory tests . Comparison of the above kits with kits manufactured by bioMerieux (France) showed a 84.6-100% correlation of the results.

J Clin Microbiol, 2000 Jul, 38(7), 2504 - 11
Genomic variability of Haemophilus influenzae isolated from Mexican children determined by using enterobacterial repetitive intergenic consensus sequences and PCR; Gomez-De-Leon P et al.; Genomic fingerprints from 92 capsulated and noncapsulated strains of Haemophilus influenzae from Mexican children with different diseases and healthy carriers were generated by PCR using the enterobacterial repetitive intergenic consensus (ERIC) sequences . A cluster analysis by the unweighted pair-group method with arithmetic averages based on the overall similarity as estimated from the characteristics of the genomic fingerprints, was conducted to group the strains . A total of 69 fingerprint patterns were detected in the H . influenzae strains . Isolates from patients with different diseases were represented by a variety of patterns, which clustered into two major groups . Of the 37 strains isolated from cases of meningitis, 24 shared patterns and were clustered into five groups within a similarity level of 1.0 . One fragment of 1.25 kb was common to all meningitis strains . H . influenzae strains from healthy carriers presented fingerprint patterns different from those found in strains from sick children . Isolates from healthy individuals were more variable and were distributed differently from those from patients . The results show that ERIC-PCR provides a powerful tool for the determination of the distinctive pathogenicity potentials of H . influenzae strains and encourage its use for molecular epidemiology investigations.

J Chemother, 2000 Jun, 12(3), 199 - 203
Host range variability in the transfer of antibiotic resistance determinants from Pseudomonas aeruginosa strains; Blahova J et al.; Twelve multiply drug-resistant strains of Pseudomonas aeruginosa, isolated in Frankfurt University Clinics during the year 1998, transferred determinants of antibiotic resistance with remarkable variability in the host range of transferred plasmids . As a new phenomenon, two of them transferred resistance genes to both groups of recipients, i.e . to Enterobacteriaceae as well as to a strain of P . aeruginosa . Six strains had more restrictive activity and transferred resistance determinants to Enterobacteriaceae only, while four additional strains demonstrated transferability only to P . aeruginosa . Two isolates transferred imipenem resistance and one cefepime resistance . Differences in selection pressure occurring during therapy of individual patients seems to be one of the possible factors influencing the spectrum of antibiotic resistance genes present in P . aeruginosa and their transfer to susceptible strains.

Zh Mikrobiol Epidemiol Immunobiol, 2000 Jan-Feb, (1), 79 - 80
{The effect of inulin on the biological properties of enterobacteria}; Valyshev AV et al.; The influence of inulin on some biological properties of Enterobacteriaceae, both pathogenic (Salmonella) and opportunistic (Klebsiella, Escherichia coli) was experimentally determined in vitro . The study revealed that inulin stimulated the production of colicin and suppressed the hemolytic activity in E . coli . The effect produced by inulin on the antilysozyme activity (ALA) of Enterobacteriaceae was different: in S . typhimurium ALA was decreased and in most K . pneumoniae strains the expression of this sign was enhanced.

Hinyokika Kiyo, 2000 May, 46(5), 335 - 8
{A case of emphysematous pyelonephritis improved with conservative therapy--indication for conservative therapy}; Kondo T et al.; A 51-year-old female patient was hospitalized in our department with high fever and left flank pain . Laboratory examination showed leukocytosis, increase of C-reactive protein (CRP), hyperglycemia and renal insufficiency . Enterobacter aerogenes grew out of the cultured urine . The radiograph and computerized tomographic (CT) scan revealed streaky gas in the destroyed left renal parenchyma with perirenal gas . She was diagnosed with left emphysematous pyelonephritis . Antibiotics therapy, treatment for sepsis and disseminated intravesicular coagulation was initiated resulting in mitigation of inflammation . High blood glucose initially required insulin therapy, but finally returned to normal levels through administration of oral antidiabetics . Although leukocytosis and low grade fever continued, the patient was discharged on day 53 with a negative CRP . CT scan indicated that the emphysematous change was localized after three months and almost resolved after four months . Renal scintigram indicated the residual function of the affected kidney . Because of the possibility of residual renal function and the cure by conservative therapy alone, the conservative therapy is preferred when the initial treatment is effective.

Symp Ser Soc Appl Microbiol, 2000, (29), 61S - 70S
Survival of Escherichia coli in foods; McClure PJ et al.; Studies describing the survival of Escherichia coli in foods, more often than not use the O157:H7 serovar as the target organism . Whilst E . coli O157:H7 is undoubtedly the predominant agent of concern for foodborne disease caused by enterohaemorrhagic E . coli (EHEC), a consequence of this concern is the commonly held view that this one serovar is 'atypical' in its response to stress conditions and therefore better able to survive adverse environments . Many of the studies published do not make comparisons with other E . coli (either commensal organisms or other pathogenic types) or other members of the Enterobacteriaceae, that would justify this view . Nevertheless, there has been a great deal of valuable data and information generated describing the fate of E . coli O157:H7 in a range of foods stored under various conditions . In many respects, the results of these studies are not surprising considering the survivability of other closely related pathogens, such as Shigella spp . This ability to survive in foods for long periods of time confirms the need for reliable control measures where contamination is possible or likely, e.g . proper handling and thorough cooking of beefburgers . The factors that may influence survival in different foods are described, with the intention of providing an insight in this area of food safety . Key considerations for carrying out survival studies are identified, with particular reference to methodologies used.

Malays J Pathol, 1996 Jun, 18(1), 31 - 4
Evaluation of the use of Bactec anaerobic blood cultures in the detection of bacteraemia and fungaemia in children; Riley PA et al.; In an attempt to reduce costs, the role of Bactec anaerobic blood culture in the detection of bacteraemia and fungaemia in children was evaluated . Results from 3167 sets of aerobic and anaerobic blood cultures from children admitted to the University Hospital, Kuala Lumpur during a one year period, were analysed . Four hundred and eight (12.9%) sets of blood cultures were positive, of which 348 sets (11.0%) from 201 patients were clinically significant . Of the 348 significant positive sets, organisms were isolated on 177 (50.9%) occasions from both aerobic and anaerobic bottles, on 136 (39.1%) occasions from the aerobic bottle only and 35 (10.0%) occasions from the anaerobic bottle only . No strict anaerobes were isolated, but clinically significant isolates recovered from the anaerobic bottle only included Klebsiella pneumoniae, Salmonella species, Enterobacter cloacae, Staphylococcus aureus, coagulase negative staphylococci, Streptococcus pneumoniae and Group B streptococcus . Patients with bacteraemia diagnosed solely by anaerobic culture were distributed evenly across the various paediatric subspecialities . When results from the anaerobic bottles were excluded, the overall isolation rate was reduced from 11% to 9.9% . Potential financial savings resulting from omission of anaerobic cultures must be balanced against the small number of bacteraemic episodes that could be missed . Undiagnosed bacteraemia may result in increased morbidity and mortality with its own attendant financial implications.

Zh Mikrobiol Epidemiol Immunobiol, 1999 Nov-Dec, (6), 21 - 4
{The production of inflammation mediators by mouse peritoneal cells under conditions of combined exposure to staphylococcal enterotoxin and lipopolysaccharide}; Riabichenko EV et al.; The influence of staphylococcal enterotoxin of type A (SEA) and enterobacterial lipopolysaccharide (LPS) on the production of tumor necrosis factor alpha (TNF alpha), gamma-interferon and active forms of oxygen by mouse peritoneal cells was studied . Both SEA and LPS, when injected to animals, produced stimulating influence on the oxygen metabolism of phagocytizing cells . The highest toxic doses of LPS induced the maximal generation of oxygen radicals . Under the conditions of the development of lethal toxic shock, i.e . after the combined injection of SEA and LPS, the synergic activation of oxygen metabolism was observed, which was also manifested by the pronounced production of TNF alpha and the increased synthesis of gamma-interferon.

Res Microbiol, 2000 May, 151(4), 255 - 61
The presence of intragenically located REP-like elements in Bacillus sporothermodurans is sufficient for REP-PCR typing; Herman L et al.; The technique of repetitive extragenic palindromic polymerase chain reaction (REP-PCR) enables the identification and discrimination of clonally related Bacillus sporothermodurans isolates from ultra-high temperature and sterilized milk . The aim of this study was to investigate the genetic basis for the generation of these highly informative REP-PCR patterns . The major 947-bp REP-PCR fragment of B . sporothermodurans was cloned, together with its 5' and 3' flanking sequences . Only partial homology with the REP consensus sequence was established at the borders of the REP-PCR fragment . Moreover, these border sequences were located within two distinct open reading frames, with great homology to the uvrA and uvrB genes of Escherichia coli . The presence of these REP-like elements in B . sporothermodurans was thus sufficient for high resolution REP-PCR typing of this Gram-positive organism . In some cases (and especially with Gram-positives), REP-PCR could thus be considered more as an arbitrary primed PCR, albeit at a somewhat higher annealing temperature and using conserved primers . The random priming effect at the less stringent annealing conditions of REP-PCR was also demonstrated for enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) on another Gram-positive organism, Listeria monocytogenes.

Ann Fr Anesth Reanim, 2000 May, 19(5), 424 - 9
{Pharmaceutical use and antibiotic therapy in intensive care units}; Gauzit R; The present study has involved a sample of 750 medical or medical/surgical intensive care units . The aim was to identify the variations of antibiotic (AB) use, measured in monetary terms, and to sort out explicative variables accounting for the corresponding expense . Activity and expense data have been recorded for 1997 . "Second intention" antibiotics have been defined as follows: imipenem, ceftazidime, cefpirome, cefepime, piperacillin/tazobactam, amikacin, isepamicin, vancomycin and teicoplanin . Only 60 evaluable sheets have been sent back . They include data about 28,000 admissions and 183,960 hospital days . The results are presented as means +/- standard deviation (SD) and the variability has been considered to be important if the ratio SD/mean was > 1 . Nosocomial infections (NI) surveillance, antibiotic advisory board and restriction of use for some molecules were present in 95%, 67% and 78% of units, respectively . The units usually had 10 beds (range: 6-24) and the mean activity was 468 +/- 184 admissions/year and 3,066 +/- 1,454 hospital days/year . Mean duration of hospitalisation (MDH) was 6.9 +/- 2.7 days and mean omega score 114 +/- 61 . Mean age of patients was 56.5 years, IGS II score 35.7 +/- 7; 29 +/- 16% of patients were mechanically ventilated for more than 48 hours and mortality rate was 17 +/- 7% . The mean number of bacterial isolates per unit was 369 +/- 323: Staphylococcus sp . 30% {including 25% of meticillin-resistant Staphylococcus aureus (MRSA)}; enterobacteria 30% (including 14% of cefotaxime-resistant isolates); Pseudomonas sp . 14% (including 40% of ticarcillin R isolates); other 26% . Pharmaceutical expense was 834 +/- 364 FF per day of hospitalisation, including 536 +/- 273 FF for drugs . Antibiotics accounted for 32% of the expense and second intention molecules for nearly 50% of antibiotic expense . More than 80% of antibiotic expense was accounted for by only 10 molecules . The mean cost/hospital day for the most expensive antibiotic, whatever the molecule ranking first, was 27 FF, for the second and third ones 18 and 14 FF . The expense for the tenth molecule was only 3 FF . There was a correlation between antibiotic expense and number of beds, number of hospital days, MDH, omega score, number of patients mechanically ventilated for more than 48 hours, mortality, number of bacterial isolates and incidence of NI . Molecules thought to be active against MRSA and ticarcillin-resistant Pseudomonas sp . accounted for 7 and 20% of total antibiotic expense, as compared to 7.5 and 4.6%, respectively, of bacterial isolates . As a conclusion, in this sample of 60 intensive care units, differences were shown for the cost of antibiotics, but the variability was low, without major discrepancies . Ten molecules accounted for 83% of total antibiotic expense . The financial impact of molecules against ticarcillin-resistant Pseudomonas sp is high.

Plasmid, 2000 Jul, 44(1), 54 - 65
pUB2380: characterization of a ColD-like resistance plasmid; Albiger B et al.; A detailed analysis of the mobilizable, ColE1-like resistance plasmid, pUB2380, is reported . The 8.5-kb genome encodes six (possibly seven) major functions: (1) a ColD-like origin of replication, oriV, with associated replication functions, RNAI and RNAII; (2) a set of active mobilization functions highly homologous to that of ColE1, including the origin of transfer, oriT; (3) a ColE1-like multimer resolution site (cer); (4) a kanamycin-resistance determinant, aph, encoding an aminoglycoside-3'-phosphotransferase type 1; (5) an insertion sequence, IS1294; and (6) two genes, probably cotranscribed, of unknown function(s) . The GC content of the various parts of the genome indicates that the plasmid is a hybrid structure assembled from DNA from at least three different sources, of which the replication region, the mobilization functions, and the resistance gene are likely to have originated in the enterobacteriaceae .

Circulation, 2000 Jun 27, 101(25), 2916 - 21
Prolonged antibiotic prophylaxis after cardiovascular surgery and its effect on surgical site infections and antimicrobial resistance; Harbarth S et al.; BACKGROUND: Despite evidence supporting short antibiotic prophylaxis (ABP), it is still common practice to continue ABP for more than 48 hours after coronary artery bypass graft (CABG) surgery . METHODS AND RESULTS: To compare the effect of short (<48 hours) versus prolonged (>48 hours) ABP on surgical site infections (SSIs) and acquired antimicrobial resistance, we conducted an observational 4-year cohort study at a tertiary-care center . An experienced infection control nurse performed prospective surveillance of 2641 patients undergoing CABG surgery . The main exposure was the duration of ABP, and main outcomes were the adjusted rate of SSI and the isolation of cephalosporin-resistant enterobacteriaceae and vancomycin-resistant enterococci (acquired antibiotic resistance) . Adjustment for confounding was performed by multivariable modeling . A total of 231 SSIs (8.7%) occurred after a median of 16 days, including 93 chest-wound infections (3.5%) and 13 deep-organ-space infections (0 . 5%) . After 1502 procedures using short ABP, 131 SSIs were recorded, compared with 100 SSIs after 1139 operations with prolonged ABP (crude OR, 1.0; CI, 0.8 to 1.3) . After adjustment for possible confounding, prolonged ABP was not associated with a decreased risk of SSI (adjusted OR, 1.2; CI, 0.8 to 1.6) and was correlated with an increased risk of acquired antibiotic resistance (adjusted OR, 1.6; CI, 1.1 to 2.6) . CONCLUSIONS: Our findings confirm that continuing ABP beyond 48 hours after CABG surgery is still widespread; however, this practice is ineffective in reducing SSI, increases antimicrobial resistance, and should therefore be avoided.

J Bacteriol, 2000 Jul, 182(14), 3920 - 3
A promoter region binding protein and DNA gyrase regulate anaerobic transcription of nifLA in Enterobacter cloacae; Hu B et al.; Our work provides evidence that a sequence characteristic of FNR binding sites, when interacted with by a trans-acting factor, activates anaerobic transcription of the nifLA operon in Enterobacter cloacae . DNA gyrase activity has been found to be important for the anaerobic transcription of the nifLA promoter . Our results suggest that anaerobic regulation of the nifLA operon is mediated through the control of the promoter region-binding trans-acting factor at the transcriptional level, while DNA supercoiling functions in providing a topological requirement for the activation of transcription.

Med Dosw Mikrobiol, 1999, 51(1-2), 81 - 90
{Occurrence of Escherichia coli O157 in feces of healthy persons, from selected groups, in the country}; Szych J et al.; The purpose of the study was determination of the occurrence of E . coli O157 in faeces samples of healthy subjects and characterization of the isolated strains with respect to their potential pathogenicity . The study was carried out in two stages . In the first one in 5 sanitary-epidemiological stations samples were tested from healthy subjects after inoculation onto McConkey (MC) or/and McConkey with sorbitol (SMC) media and isolating from each culture 10 lactose-positive (on MC medium) or sorbitol-negative (on SMC) colonies . Then latex test was done with each isolate for E . coli O157 presence . In all, 1005 samples were studied, including 260 taken from children aged 0-2 years, 180 samples from children aged 3-10 years, and 565 samples from older children and adults . E . coli O157 rods were cultured from 6 adults (0.6%) . In the second stage carried out at the Laboratory of Enterobacteriaceae, Bacteriology Department, National Institute of Hygiene strains obtained from territorial laboratories were studied determining their phenotypic and genotypic traits regarded as virulence markers of verotoxic E . coli O157 strains, such as inability to ferment sorbitol and MUG breakdown, and production of verotoxins and enterohaemolysin . By the PCR method fragments were sought of genes coding for production of verotoxins, intimin and enterohaemolysin . The results showed that no E . coli O157 strain obtained from healthy individuals produced verotoxins, but three studied strains contained the eae gene determining intimin production and they were regarded as enteropathogenic.

Zh Obshch Biol, 2000 May-Jun, 61(3), 229 - 57
{The population genetics of nodule bacteria}; Provorov NA; The data are reviewed on the population structure and evolutionary dynamics of the nodule bacteria (rhizobia) which are among the most intensively studied microorganisms . High level of the population polymorphism was demonstrated for the rhizobia populations using the enzyme electrophoresis (MLEE profiles) . The average value of Nei's coefficient of heterogeneity (H = 1 - sigma pi2 {n/(n - 1)}) were: 0.590 for rhizobia (Rhizobium, Bradyrhizobium), 0.368 for enterobacteria (Escherichia, Salmonella, Shigella) and 0.452 for pathogenic bacteria (Bordetella, Borrelia, Erysipelothrix, Haemophilus, Helicobacter, Listeria, Mycobacterium, Neisseria, Staphylococcus) populations . In spite of being devoid of the effective systems for the gene conjugative transfer, many rhizobia populations possess an essentially panmictic structure . However, the enterobacteria populations in which the gene transfer may be facilitated due to the conjugative F- and R-factors, usually display the clonal population structure . The legume host plant is proved to be a key factor that determines the high levels of polymorphism and of panmixis as well as high evolutionary rates of the symbiotic bacteria populations . The host may ensure: a) an increase in mutation and gene transfer frequencies; b) stimulation of the competitive (selective) processes in both symbiotic and free-living rhizobia populations . A "cyclic" model of the rhizobia microevolution is presented which allows to assess the inputs the interstrain competition for the saprophytic growth and for the host nodulation into evolution of a plant-associated rhizobia population . The nodulation competitiveness in the rhizobia populations is responsible for the frequency-dependent selection of the rare genotypes which may arise in the soil bacterial communities as a result of the transfer of symbiotic (sym) genes from virulent rhizobia strains to either avirulent rhizobia or to the other (saprophytic, phytopathogenic) bacteria . Therefore, the nodulation competitiveness may ensure: a) panmictic structure of the natural rhizobia populations; b) high taxonomic diversity of rhizobia which was apparently caused by a broad sym gene expansion in the soil bacterial communities . The kin selection models are presented which explain evolution of the "altruistic" (essential for the host plant, but not for the bacteria themselves) symbiotic traits (e.g., the ability for symbiotic nitrogen fixation and for differentiation into non-viable bacteroids) in the rhizobia populations . These models are based on preferential multiplication of the nitrogen-fixing clones either in planta (due to an elevated supply of the nitrogen-fixing nodules with photosynthates) or ex planta (due to a release of the rhizopines from the nitrogen-fixing nodules) . Speaking generally, interactions with the host plants provide a range of mechanisms increasing a genetic heterogeneity and an evolutionary potential in the associated rhizobia populations.

Diagn Microbiol Infect Dis, 2000 Jun, 37(2), 115 - 25
Respiratory tract pathogens isolated from patients hospitalized with suspected pneumonia: frequency of occurrence and antimicrobial susceptibility patterns from the SENTRY Antimicrobial Surveillance Program (United States and Canada, 1997); Jones RN et al.; Thirty-seven sentinel hospitals (29 in the United States {US}; eight in Canada) collected bacterial isolates from hospitalized patients with a diagnosis of pneumonia . The antimicrobial susceptibility patterns of these pathogens were determined to more than 60 agents (40 reported) using the reference broth microdilution method described by the National Committee for Clinical Laboratory Standards . The five most frequently recorded species among the 2757 isolates collected during the study were (no . tested/%): Staphylococcus aureus (632/22.9%), Pseudomonas aeruginosa (498/18 . 1%), Haemophilus influenzae (284/10.3%), Klebsiella spp . (240/8.7%), and Streptococcus pneumoniae (213/7.7%) . There was a significant difference in the susceptibility to antimicrobials between the US and Canada for S . aureus to oxacillin (50.1% versus 93.8% susceptible, respectively), gentamicin (78.7% versus 97.8%), and fluoroquinolones (49.5 to 53.0% versus 89.8 to 94.9%) . Amikacin (92 . 8% susceptible) was the most active antimicrobial agent against P . aeruginosa, and meropenem was the most potent beta-lactam . Against H . influenzae, most drugs retained a high level of activity, whilst against the S . pneumoniae, only the newer fluoroquinolones (gatifloxacin, levofloxacin, sparfloxacin) remained highly effective in vitro . Only two antimicrobial agents (imipenem and meropenem) were >99% active against the Klebsiella spp . and Enterobacter spp . isolated in this survey (possess extended spectrum beta-lactamases or hyperproduction of Amp C cephalosporins); cefepime (95.6-100.0% susceptible) was significantly more active than other cephalosporins tested . Clonal, epidemic outbreaks of multiply resistant strains were very rare in monitored hospitals . In conclusion, important differences exist between the US and Canada in the susceptibility patterns of some respiratory tract pathogens to commonly used antimicrobial agents with Canadian strains generally being more susceptible to currently available antimicrobial agents.

Zhonghua Yi Xue Za Zhi (Taipei), 2000 May, 63(5), 361 - 7
Meropenem versus imipenem/cilastatin in the treatment of sepsis in Chinese patients; Kuo BI et al.; BACKGROUND: Meropenem and imipenem are beta-lactam antibiotics of the carbapenem group . Carbapenems have bactericidal activity against a broad spectrum of bacteria, including most gram-positive cocci, gram-negative bacilli and anaerobes . Experience in using meropenem in Chinese patients has not been previously reported . METHODS: Meropenem (2 g daily) and imipenem/cilastatin (2 g daily) were compared in an open, randomized, prospective study on the treatment of hospitalized Chinese septic patients . All participants (male or female) were hospitalized with a diagnosis of sepsis . All patients were randomly allocated to one of the two treatment groups: the meropenem group or the imipenem/cilastatin group . Clinical status was evaluated daily during treatment and at the end of therapy or when treatment was withdrawn . Patients were checked every day for potential side-effects, according to subjective and objective symptoms . RESULTS: Fifty-three patients were enrolled in the study; 50 were evaluated for clinical efficacy and 27 patients were evaluated for bacteriologic efficacy . The most frequent clinical diagnoses were pneumonia and urinary tract infection . The predominant pathogens were Pseudomonas aeruginosa, Escherichia coli and Enterobacter cloacae . There were 31 pathogens isolated from 27 patients . A single pathogen was identified in 23 patients, and two pathogens were isolated from four patients . Satisfactory clinical outcome (excellent and good) was 84% in the meropenem group and 76% in the imipenem/cilastatin group . Satisfactory bacteriologic response was 80% in the meropenem group and 75% in the imipenem/cilastatin group . Transiently elevated liver enzymes were the most common side-effect . One patient treated with imipenem/cilastatin experienced a seizure during the study, while another patient treated with meropenem withdrew due to urticaria . CONCLUSIONS: The efficacy and safety data presented in this report indicate that meropenem was well tolerated and appeared to be as effective as standard monotherapy with imipenem in bacteremic patients . Meropenem and imipenem/cilastatin were highly effective for the treatment of bacteremia in Chinese patients and only mild or negligible side-effects were noted.

J Hosp Infect, 2000 Jun, 45(2), 107 - 16
Role of infection control measures in limiting morbidity associated with multi-resistant organisms in critically ill patients; Souweine B et al.; A retrospective comparative study was performed to determine the impact of infection control measures (ICMs) on colonization and infections due to methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae (producing transferable extended-spectrum beta-lactamase, KPESBL), and multi-resistant Enterobacter aerogenes (MREA) in intensive care unit patients . Infection Control Measures included surveillance cultures, isolation procedures and mupirocin for MRSA nasal carriage . The numbers of patients infected and/or colonized by MRSA, KPESBL or MREA were compared during two consecutive one-year periods (Period 1 before ICMs, and Period 2 after ICMs) . The antibiotic consumption during the two periods was analysed . In Period 1 and Period 2, respectively, the rate of patients infected or colonized by at least one of the three organisms was 15% and 6.8% (P=0.001); by MRSA 7.7% and 2.6% (P=0 . 004); by KPESBL 1.7% and 0% (P=0.25); and by MREA 5.6% and 4.3% (P=0 . 47) . During Period 2, there was a clear-cut decrease in the percentage of patients infected by MRSA (P=0.018), a non-significant decrease in those infected by KPESBL (P=0.06), and no decrease in patients infected by MREA (P=0.22) . When calculated per 1000 patient-days, for Period 1 and Period 2, respectively, the rate of patients infected or colonized by at least one of the three organisms was 11.9 and 8.8; for MRSA it was 4 and 2.2; for KPESBL it was 1 and 0; and for MREA it was 4 and 4 . Antibiotic cost was pound98.7 in Period 1 and pound62.7 in Period 2 . ICMs contributed to the control of infections and colonizations due to MRSA and KPESBL but not those due to MREA .

Ugeskr Laeger, 2000 May 15, 162(20), 2886 - 91
{Two thousands seven hundred and thirty nine episodes of bacteremia in the county of Northern Jutland 1996-1998 . Presentation of a regional clinical database}; Schonheyder HC; A complete registration of bacteraemias has been undertaken in the County of Northern Jutland (population 493,000) since 1996, in the form of a bacteraemia register maintained by the Department of Clinical Microbiology, Aalborg Hospital, which serves the seven hospitals in the county . A follow-up is conducted on all patients with positive blood cultures . We registered 2,739 bacteraemias during 1996-1998 . Eighty-nine percent of bacteraemias were monomicrobial and 11% polymicrobial . Among monomicrobial bacteraemias the predominant bacteria were Staphylococcus aureus (17%), Streptococcus pneumoniae (12%), Escherichia coli (31%), and other enterobacteria (14%) . The source (focus) of infection was identified in 82% and the main foci were the urogenital tract (28%), the respiratory tract (14%), the digestive tract (13%), the hepato-biliary tract (8%), and intravascular devices (8%) . The overall 30 day case fatality rate (CFR) was 21.5% . At first notification antibiotic therapy was appropriate in 54% of bacteraemias (CFR 14.8%), antibiotic therapy was inappropriate or missing in 38% (CFR 21.0%), active therapy had been withdrawn in 0.3%, in 5% the patient had died, and in 2% therapy had been completed or the patient had been discharged alive . The register has thus created a platform for research projects regarding risk factors, therapy and prognosis of bacteraemia.

Antimicrob Agents Chemother, 2000 Jul, 44(7), 1860 - 4
Rapid discriminatory detection of genes coding for SHV beta-lactamases by ligase chain reaction; Kim J et al.; Ligase chain reaction (LCR) is a recently developed technique that employs a thermostable ligase and allows for the discrimination of DNA sequences differing in only a single base pair . The method has been adapted and applied to differentiation of bla(SHV) genes . We have developed an LCR typing method to characterize point mutations in genes for SHV-derived extended-spectrum beta-lactamases with four different sets of biotinylated LCR primers . To evaluate the applicability of the current technique, we tested seven Escherichia coli strains producing SHV-1, SHV-2, SHV-2a, SHV-3, SHV-4, SHV-5, and SHV-12 . With the LCR typing, seven SHV genes can be distinguished according to their incorporating point mutations . In an attempt to characterize SHV beta-lactamases by LCR typing in clinical isolates, 46 strains carrying bla(SHV) genes (32 Klebsiella pneumoniae, 10 Enterobacter cloacae, and 4 E . coli) were subjected to antibiotic susceptibility testing, isoelectric focusing, and LCR typing . LCR typing allowed the characterization of beta-lactamases, and genotypes obtained by LCR typing were in accordance with phenotypes such as antibiotic resistance profile and pI value of beta-lactamase . Therefore, we concluded that LCR typing may permit defining the SHV families with simplicity and reliability and can be applied to the detailed characterization and molecular epidemiology of SHV-type beta-lactamases.

Infect Immun, 2000 Jul, 68(7), 4145 - 54
Relationship between the Tsh autotransporter and pathogenicity of avian Escherichia coli and localization and analysis of the Tsh genetic region; Dozois CM et al.; The temperature-sensitive hemagglutinin Tsh is a member of the autotransporter group of proteins and was first identified in avian-pathogenic Escherichia coli (APEC) strain chi7122 . The prevalence of tsh was investigated in 300 E . coli isolates of avian origin and characterized for virulence in a 1-day-old chick lethality test . Results indicate that among the tsh-positive APEC isolates, 90.6% belonged to the highest virulence class . Experimental inoculation of chickens with chi7122 and an isogenic tsh mutant demonstrated that Tsh may contribute to the development of lesions within the air sacs of birds but is not required for subsequent generalized infection manifesting as perihepatitis, pericarditis, and septicemia . Conjugation and hybridization experiments revealed that the tsh gene is located on a ColV-type plasmid in many of the APEC strains studied, including strain chi7122, near the colicin V genes in most of these strains . DNA sequences flanking the tsh gene of strain chi7122 include complete and partial insertion sequences and phage-related DNA sequences, some of which were also found on virulence plasmids and pathogenicity islands present in various E . coli pathotypes and other pathogenic members of the Enterobacteriaceae . These results demonstrate that the tsh gene is frequently located on the ColV virulence plasmid in APEC and suggest a possible role of Tsh in the pathogenicity of E . coli for chickens in the early stages of infection.

Int J Food Microbiol, 2000 Jun 1, 56(2-3), 179 - 90
The use of a starter culture in the fermentation of cassava for the production of "kivunde", a traditional Tanzanian food product; Kimaryo VM et al.; Three cassava fermentation methods (spontaneous fermentation, back-slopping and the use of starter culture) for the production of kivunde, executed in three trials at 30 degrees C, were compared in terms of cyanide level reduction, microbiology and product quality improvement . Among the isolates from spontaneously fermented cassava batches, four strains were selected on the basis of their enzymatic activities and acid production . All were identified as Lactobacillus plantarum and were used as starters in this study . Lowest residual cyanide levels were detected after 120 h fermentation time in samples fermented with the starter culture and were below the maximum value of 10 mg/kg recommended by the Codex/FAO for cassava flour . This finding seems to be related to the alpha-glucosidase activity of the inoculated strains of which API-zyme (Bio-Merieux) tests showed activities of between 20 and > or = 40 nmol/4 h . The total residual cyanide levels of the spontaneous and back-slopping fermentations at 96 h were respectively 43.5 and 47.7 mg/kg dry weight of cassava . Extension of the fermentation period to 5 days, lead to further substantial reduction in the residual cyanide level in both these processes, but not below the recommended maximum value as in the case of starter culture fermented products . The spontaneous and back-slopping fermented cassava showed signs of deterioration after 3 days of fermentation . There was a sharp drop of pH and an increase of titratable acidity for all three batches during the first 48 h followed by a slow rise of pH and drop in titratable acidity towards the end of fermentation . The samples fermented with the starter culture had a smooth texture and pleasant fruity aroma, as opposed to the course and dull appearance and more complex flavour of the samples of spontaneous and back-slopping batches . During fermentation with starter culture, Enterobacteriaceae and yeasts and moulds could not be isolated throughout the period of fermentation (detection limit: 10 colony forming units/g) . The present findings indicate the suitability of these Lb . plantarum strains as starter cultures for cassava fermentation in the kivunde process . The paper highlights the potential for the improvement of a traditional African fermented food (kivunde) through the use of a starter culture.

Cent Eur J Public Health, 2000 May, 8(2), 80 - 2
Effect of new quaternary bisammonium compounds on the growth and cell surface hydrophobicity of Enterobacter cloacae; Majtan V et al.; The effect of new quaternary bisammonium salts (QBAS) of series A: 1, 10-{bis(alkyldimethyl-diammonium)}-4,7-dioxo-3,8-dioxoundecandi bromides and series B: alpha-omega{bis(dodecyldimethyl-diammonium)}-3,x-dioxo-4,y- dioxoalcandibromides on the growth and surface hydrophobicity of E . cloacae strain was studied . The compounds of series A possess changing side substituent and the inhibition of growth displayed evident dependence of effect on length of alkyl with optimum at C9-C11 (cut off effect) . In series B are compounds with changing joining chain between two ammonium cations where the mentioned effect was not observed . The cell surface hydrophobicity of tested strain was determined by the method of adhesion to hydrocarbon--xylene (BATH) and in salt aggregation test of ammonium sulphate (SAT) . The effect of 1/4 of the MIC compounds series A with nonyl, decyl and undecyl reduced the adhesion of E . cloacae cells below 50% against the control . These compounds at sub-MICs decreased salt-aggregative ability of E . cloacae cells . The influencing of cell surface hydrophobicity was not found after affecting of compounds at sub-MIC from series B with the exception of moderate decrease at compound with joining chain of C7 . The length of chain connecting two symmetrical parts of molecule has slight impact on the effect of bisammonium salts . The influence of QBAS at sub-MICs on cell surface hydrophobicity can interfere with pathogenic potential of E . cloacae.

FEMS Microbiol Lett, 2000 Jun 15, 187(2), 155 - 60
Prevalence of the multiple antibiotic resistance operon (marRAB) in the genus Salmonella; Kunonga NI et al.; The multiple antibiotic resistance operon (marRAB) is a member of the multidrug resistance (mdr) systems . Similar to other mdr systems, this operon when induced encodes resistance to structurally and functionally unrelated antibiotics . marRAB has been shown to be conserved in the family Enterobacteriaceae, but within the genus Salmonella certain species appeared to be lacking this operon . To investigate how conserved the marRAB operon was in Salmonella, 30 veterinary isolates were examined by PCR, Southern blot, and dot blot analysis . Using DNA primers based on the marRAB operon of S . typhimurium, a predicted 2.3-kb amplicon resulted after PCR in 16 of the 30 organisms . The 2.3-kb DNA band from S . enteritidis was cloned and sequenced and shown to possess 99% sequence homology to marRAB from S . typhimurium . Using a labeled marRAB gene probe from S . enteritidis, Southern blot and dot blot analysis confirmed the presence of the operon in all 30 Salmonella species examined . Furthermore, when these isolates were induced with low levels of either tetracycline or chloramphenicol, increased antimicrobial resistance was observed to structurally and functionally unrelated antibiotics . Thus, the widespread occurrence of the marRAB locus in this genus prescribes judicious use of antimicrobials to avoid induction of a mdr phenotype.

Curr Microbiol, 2000 Aug, 41(2), 101 - 5
An ACC deaminase minus mutant of Enterobacter cloacae UW4 no longer promotes root elongation; Li J et al.; The ACC deaminase gene (acdS) from Enterobacter cloacae UW4 was replaced by homologous recombination with the acdS gene with a tetracycline resistance gene inserted within the coding region . Upon characterization of this AcdS minus mutant, it was determined that both ACC deaminase activity and the ability to promote the elongation of canola roots under gnotobiotic conditions were greatly diminished . This result is consistent with a previously postulated model that suggests that a major mechanism utilized by plant growth-promoting bacteria involves the lowering of plant ethylene levels, and hence ethylene inhibition of root elongation, by bacterial ACC deaminase.

Int J Antimicrob Agents, 2000 Jul, 15(2), 143 - 7
Nosocomial bacterial and fungal meningitis in children; an eight year national survey reporting 101 cases . Pediatric Nosocomial Meningitis Study Group; Krcmery V et al.; One hundred and one cases of nosocomial meningitis in children from a national survey over 8 years have been analyzed for risk factors and outcome . From 101 cases, 115 organisms were isolated . Seventy six were Gram-positive bacteria, 29 were Gram-negative and there were ten fungal isolates . Major risk factors for acquisition of nosocomial meningitis were neurosurgery (70.2%), ventriculoperitoneal shunt (42.9%), prior therapy with broad spectrum antibiotics (64.1%), central venous catheter (94.5%), premature neonates with very low birth weight (32.8%) and total parenteral nutrition (68.8%) . Overall attributable mortality was 14 . 9%; in bacterial infection it was 13.2% and in fungal nosocomial meningitis, 30.0% . Higher mortality was significantly related to perinatal pathology with CNS abnormality, prematurity polymicrobial infection with Enterobacteriaceae and concomitant bacteraemia . Prematurity in neonates, very low birth weight and infection with Enterobacteriaceae were significantly associated with a worse outcome.

Bioorg Med Chem Lett, 2000 May 1, 10(9), 847 - 51
The synthesis and evaluation of 2-substituted-7-(alkylidene)cephalosporin sulfones as beta-lactamase inhibitors; Buynak JD et al.; A series of 2-substituted-7-(alkylidene)cephalosporin sulfones were prepared and evaluated as beta-lactamase inhibitors . Compound 11c showed excellent activity as an inhibitor of the class C beta-lactamase derived from Enterobacter cloacae, strain P99.

J Bacteriol, 2000 Jun, 182(12), 3482 - 9
The Brucella abortus CcrM DNA methyltransferase is essential for viability, and its overexpression attenuates intracellular replication in murine macrophages; Robertson GT et al.; The CcrM DNA methyltransferase of the alpha-proteobacteria catalyzes the methylation of the adenine in the sequence GAnTC . Like Dam in the enterobacteria, CcrM plays a regulatory role in Caulobacter crescentus and Rhizobium meliloti . CcrM is essential for viability in both of these organisms, and we show here that it is also essential in Brucella abortus . Further, increased copy number of the ccrM gene results in striking changes in B . abortus morphology, DNA replication, and growth in murine macrophages . We generated strains that carry ccrM either on a low-copy-number plasmid (strain GR131) or on a moderate-copy-number plasmid (strain GR132) . Strain GR131 has wild-type morphology and chromosome number, as assessed by flow cytometry . In contrast, strain GR132 has abnormal branched morphology, suggesting aberrant cell division, and increased chromosome number . Although these strains exhibit different morphologies and DNA content, the replication of both strains in macrophages is attenuated . These data imply that the reduction in survival in host cells is not due solely to a cell division defect but is due to additional functions of CcrM . Because CcrM is essential in B . abortus and increased ccrM copy number attenuates survival in host cells, we propose that CcrM is an appropriate target for new antibiotics.

Drugs, 2000 May, 59(5), 1137 - 47; discussion 1148
Gemifloxacin; Lowe MN et al.; Gemifloxacin is a fluoroquinolone antibacterial agent which has an enhanced affinity for topoisomerase i.v. . It has potent activity against most Gram-positive bacteria, particularly Streptococcus pneumoniae . Gemifloxacin is over 30-fold more active than ciprofloxacin and 4- to 8-fold more active than moxifloxacin against this pathogen . Gemifloxacin has excellent activity against Haemophilus influenzae and Moraxella catarrhalis, and is unaffected by beta-lactamase production . It is generally 2-fold less active than ciprofloxacin against most Enterobacteriaceae . Atypical respiratory pathogens (Legionella, Mycoplasma and Chlamydia spp.) are highly susceptible to gemifloxacin . Preliminary results from phase II trials show that oral gemifloxacin 320 mg/day produced bacteriological responses of 94.7% in patients with acute exacerbations of chronic bronchitis and 95% of patients with uncomplicated urinary tract infections . Adverse events included nausea, abdominal pain, headache and mild rash in patients and healthy volunteers treated with gemifloxacin 320 mg/day . Gemifloxacin has a low potential for mild phototoxicity (comparable to that of ciprofloxacin).

Zh Mikrobiol Epidemiol Immunobiol, 1999 Jul-Aug, (4), 65 - 7
{The microbiological characteristics of intestinal dysbacteriosis in children and adults in the city of Moscow}; Likhoded VG et al.; The bacteriological analysis of 302 children has revealed that dysbacteriosis with the increased content of hemolytic Escherichia in the intestine develops more frequently in the presence of the deficiency of bifido- and lactobacteria . The development of other kinds of dysbacteriosis with the increased content of different opportunistic enterobacteria, staphylococci, enterococci and fungi, as well as dysbacteriosis with the decreased content of Escherichia, does not practically depend on the deficiency of bifido- and lactobacteria . In patients with the increased content of Escherichia an increase in the content of opportunistic enterobacteria, staphylococci and fungi is observed more frequently than in patients with the low content of Escherichia.

Zh Mikrobiol Epidemiol Immunobiol, 1999 Jul-Aug, (4), 63 - 5
{The characteristics of the vaginal microflora in intrauterine contraception}; Bukharin OV et al.; The results of the study of vaginal microbiocenosis in women using intrauterine contraceptives are presented . Inflammatory complications in intrauterine contraception were shown to be linked with vaginal dysbiosis . Disturbances in vaginal microbiocenosis were characterized by the deficiency of lactoflora and the presence of enterobacteria, Staphylococcus aureus, Gardnerella of fungi of the genus Candida . The problem of the possibility of complications of microbial etiology in women using intrauterine contraceptives are discussed.

Zh Mikrobiol Epidemiol Immunobiol, 1999 Sep-Oct, (5), 81 - 5
{The genetic control of the F1-specific components of the capsular antigen in Yersinia pestis}; Kosse LV et al.; The preparation of Y . pestis capsular antigen F1, isolated from Y . pestis Fra-positive strain by Baker's method, has been shown to have a composition and contain three components: protein, glycoprotein and a lipid-containing component . Each of them equally reacts with antibodies to F1 and diagnostic preparations based on these antibodies . The synthesis of protein and glycoprotein is temperature-dependent and controlled by pYT (Caf) . The synthesis of glycoprotein is constitutive and determined by chromosomal genes . Protein and glycoprotein have almost identical mol . wt., 18 and 17 kD respectively, but their localization is different: protein is secreted on the surface of bacterial cells and into the environment, while glycoprotein can be found inside the cells and is similar to intracellular glycoprotein of different enterobacteria, described in our earlier works and exhibiting F1 specificity . Different biological role of these F1-specific components is suggested.

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