Mikrobiyol Bul, 1992 Jan, 26(1), 1 - 11 {Typing by isoelectric focusing of beta-lactamase enzymes in Klebsiella and Enterobacter strains resistant to the new beta-lactam antibiotics}; Gur D et al.; Resistance to new generation beta-lactam antibiotics in Gram-negative bacteria is increasing worldwide . This resistance is due to EBS enzymes in Klebsiella spp., and Type-I chromosomal enzymes in Enterobacter spp., Citrobacter, P . aeruginosa, Providencia, M . morganii and S . marcescens . In this study, the types of beta-lactamases in 16 Klebsiella spp . and 15 Enterobacter spp . which are resistant to newer beta-lactam antibiotics was investigated by isoelectric focusing . The results of the study showed that TEM-1 enzymes are prevalent in these isolates . pI (isoelectric point) values and antibiotic susceptibility test results suggest that there are EBS enzymes in Klebsiella spp., and Type-I enzymes in Enterobacter spp . These results have to be supported by further investigations. Chemotherapy, 1992, 38 Suppl 2, 10 - 7 The threat of resistance to the new oral cephalosporins; Cullmann W; Phenotypic resistance to beta-lactam antibiotics is mainly due to the prevalence of beta-lactamases . The most common enzymes responsible for resistance to aminopenicillins and older (1st generation) cephalosporins are the TEM-1, TEM-2, OXA-1 and SHV-1 enzymes, all of which are plasmid-mediated . The recent development of oral cephalosporins sharing structural features and an antimicrobial spectrum comparable to that of 3rd-generation cephalosporins has provided highly active compounds for the management of outpatient infections . Two principal mechanisms, however, may cause resistance to these new compounds: the overproduction of chromosomally encoded beta-lactamases with predominating cephalosporinase activity, and the recently observed extended-spectrum beta-lactamases . The overproduction of chromosomally mediated beta-lactamases has been observed only in some species (Enterobacter cloacae, Citrobacter freundii, Serratia spp.) which cause mainly nosocomial infections and are therefore of minor importance in outpatients . The extended-spectrum beta-lactamases TEM-3 to TEM-12 and SHV-2 to SHV-7 have been observed in various countries, they derived from the original enzymes by point mutations and occurred in intensive-care units . These enzymes may cause resistance to 3rd-generation cephalosporins including the recently developed orally active compounds . Moderate resistance to cefetamet is observed only in strains producing either the TEM-3 or the TEM-4 enzyme, whereas the prevalence of the other enzymes is of no consequence for the activity of cefetamet . Consequently, cefetamet will not exhibit a marked selection pressure favoring the spread of extended-spectrum beta-lactamase-producing strains. Arch Microbiol, 1992, 157(5), 471 - 4 Anaerobic malonate decarboxylation by Citrobacter diversus . Growth and metabolic studies, and evidence of ATP formation; Janssen PH et al.; Citrobacter diversus ATCC 27156 was able to grow by decarboxylation of malonate to acetate under strictly anaerobic conditions, in the presence of yeast extract . The growth yield, corrected for growth on yeast extract, was 2.03 g cell dry mass per mol malonate . The addition of malonate to ATP-depleted cell suspensions (less than 0.2 nmol ATP/mg cell protein) resulted in a rapid increase in cellular ATP levels to between 4.5 and 6.0 nmol/mg cell protein . Intact cells decarboxylated malonate at rates of up to 1.5 mumol/min.mg protein . Enzyme assays on malonate-grown cells indicated activation of malonate by an ATP-dependent ligase reaction and by CoA transfer from acetyl-CoA, followed by decarboxylation of malonyl-CoA to acetyl-CoA with subsequent recovery of the invested ATP by substrate level phosphorylation through the activity of acetate kinase . Net ATP synthesis is postulated to be mediated by gradient formation coupled to the decarboxylation of malonyl-CoA . The protonophore CCCP and H(+)-ATPase inhibitor DCCD significantly reduced cellular ATP levels, suggesting a role for proton gradients in the energy metabolism of this strain when growing an malonate . Inhibitors of sodium metabolism or ommission of sodium had no effect on ATP levels or malonate decarboxylation. Jpn J Antibiot, 1992 Jan, 45(1), 1 - 11 {Synergistic action of cefodizime with other antimicrobial agents on clinically isolated microorganisms . II . Synergistic action with sisomicin}; Deguchi K et al.; Cefodizime (CDZM) possesses a broad antimicrobial spectrum and a relatively long half life in the blood . In addition, it shows excellent therapeutic efficacies in the treatment of infections in leukopenic animal models, hence it is expected that CDZM may have good efficacies against various infections in immunocompromised hosts . In the meantime, sisomicin (SISO) not only has strong antibacterial activities against Gram-negative rods (GNR), but has relatively low nephrotoxicity and ototoxicity . Thus, we examined antibacterial effectiveness of the combination of CDZM and SISO against clinical isolates in vitro . 1 . Antibacterial effects of CDZM+SISO combination were examined using SISO susceptible strains of Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, Proteus vulgaris, Morganella morganii and Pseudomonas aeruginosa . Observations that the combination of the 2 drugs showed FIC indices between less than 0.5-less than 1.0 against most of these strains at SISO concentrations of 1 MIC or sub MIC levels strongly suggested the presence of a synergistic action between the 2 drugs against SISO susceptible strains of GNR . 2 . Of the strains tested, 10% of C . freundii, 6.7% of E . cloacae, 63.3% of S . marcescens, 23.3% of P . vulgaris and 18.0% of P . aeruginosa were found to be resistant to SISO, and little synergistic effect of the 2 drugs was observed against these strains . 3 . As the synergistic effect of the 2 drugs against GNR was observed against SISO susceptible strains including those which were resistant to CDZM, but not against those strains which were resistant to SISO, it seems reasonable to conclude that the appearance of the synergistic effect between the 2 drugs depends on the activity of SISO. Chemotherapy, 1992, 38(4), 218 - 24 Beta-lactamase stability and inhibitory activity of meropenem combined with a potent antibacterial activity; Nouda H et al.; The affinity of meropenem for various known types of beta-lactamases and its stability to them were tested in comparison with other beta-lactams, including imipenem . Meropenem exhibited a marked stability to all beta-lactamases tested and was only hydrolyzed by Xanthomonas maltophilia beta-lactamase, as were other beta-lactams . This was responsible for the potent antibacterial activities of meropenem against beta-lactamase-producing strains . Meropenem and imipenem had almost the same, relatively high affinity for beta-lactamases; however, they had a lower affinity than clavulanic acid for penicillin beta-lactamases and cefoxitin for cephalosporin beta-lactamases . Meropenem also had higher beta-lactamase inhibitory activity than imipenem . Meropenem inhibited type III (TEM-1), Ia Citrobacter freundii and Ic Proteus vulgaris beta-lactamases in a progressive manner . Meropenem was thought to be a potent inhibitor of various beta-lactamase because of its ability to form stable enzyme-meropenem acyl-complexes . Meropenem generally exhibited a lower induction potential than imipenem against five clinical isolates of C . freundii, Enterobacter cloacae and Pseudomonas aeruginosa, but its induction potential was higher than that of ceftazidime . Meropenem induced beta-lactamases at concentrations above the MIC. Zh Mikrobiol Epidemiol Immunobiol, 1992, (5-6), 43 - 5 {An increase in the immunogenicity of bacterial antigens under the influence of one of the derivatives of muramyl dipeptide}; Britsina MV et al.; As revealed in animal experiments, glucosaminylmuramyl dipeptide (GMDP), the synthetic analog of muramyl dipeptide, when introduced intraperitoneally in a single injection or orally, exhibits adjuvant activity with respect to Citrobacter 0-antigens, Shigella flexneri and enhances the protective properties of dysentery and pertussis vaccines . The stimulating properties of GMDP depend on its dose, the route of its administration, the time elapsed after its administration, its ratio to the concomitant doses of bacterial antigens and to the dose of the virulent culture used for challenge. Med Dosw Mikrobiol, 1992, 44(3-4), 97 - 107 {Occurrence of P.fimbrii in strains from selected genera of Enterobacteriaceae}; Jagielski M et al.; This study was aimed at recognition of frequency of occurrence of P fimbriae in strains of Escherichia coli isolated from samples of feces of children with symptoms of diarrhoea and at search of these adhesions in strains representing other than Escherichia genera of Enterobacteriaceae strains . One hundred forty laboratory strains were investigated . They belonged to genus Citrobacter, Enterobacter, Hafnia, Klebsiella, Morganella, Proteus, Providencia, Salmonella, Shigella, and Yersinia . Also were tested 1277 colonies of enteric rods isolated from the MacConkey's medium inoculated with samples of feces from 163 children with symptoms of diarrhoea . Mannose-resistant active hemagglutination test was performed with human group O erythrocytes and guinea pig erythrocytes stabilized with glutaraldehyde . Presence of P fimbriae was detected by the slide latex test with latex covered by P1 glycoprotein . Among 140 laboratory strains of Enterobacteriaceae in 21 strains (3-E . cloaceae, 2-Hafnia, 13-K . pneumoniae, 2-P . rettgeri and in one strains of Providencia) presence of MRHA adhesins was demonstrated . Nine of these strains (2-Hafnia, 5-K . pneumoniae and 2-P . rettgeri) reacted specifically in the latex test . Among 1142 colonies of E . coli isolated from children with symptoms of diarrhoea, 326 colonies belonged to 13 EPEC serotypes . With 118 (36.2%) of EPEC colonies a positive result of MRHA reaction was found with human erythrocytes and 34 (10.4%) with guinea pig erythrocytes . Positive latex test was obtained with 77 (23.6%) colonies . All these colonies possessed MRHA adhesins . Remaining 816 colonies of E . coli strains did not represent microorganisms belonging to serotypes accepted as enteropathogenic . From 112 (13.7%) colonies out of 816 not belonging to EPEC, positive results was obtained in the MRHA test with human erythrocytes and this was the case also with 41 (5.0%) colonies in MRHA reaction with application of guinea pig erythrocytes . The latex test was positive in 65 (7.9%) colonies of E . coli . From remaining 135 colonies other than E . coli, positive result of latex test of presence of P fimbriae was obtained with 54 (40.0%) colonies, including 14 colonies of E . cloacae, 23-K . pneumoniae and 17-K . oxytoca . In all these strains presence of MRHA adhesins was demonstrated . These investigations demonstrated that among EPEC strains significantly more frequently, than not belonging to these serotypes of E . coli, MRHA adhesins, including P fimbriae was observed.(ABSTRACT TRUNCATED AT 400 WORDS) J Hyg Epidemiol Microbiol Immunol, 1992, 36(4), 419 - 24 Pilot studies on the occurrence of some infectious diseases in two different areas in south Yemen (Aden) (part II . Microbiology); Kopecky K et al.; This paper is the second part of the article dealing with intestinal bacteria . The findings are relatively poor in comparing with the frequency of intestinal protozoa . Among 83 stool specimens taken for bacteriological examination 14 isolations of different bacteria were proved . One S . muenchen was isolated from a 3 year old boy with fever, diarrhoea . Five cases of Alkalescens dispar 05 manit negative and 05 manit positive were identified . Two of these cases were without clinical symptoms . All were males aged 10-17 years . One isolation of E . coli EPEC 086 K6 H11 was in a 10 year-old boy with diarrhoea, four watery stools daily and cramps . Six cases of other E . coli were of different types, all with clinical symptoms . Of them three were males and three females at the age from 3-46 years . One case had a mixed infection of Citrobacter, E . coli and Klebsiella with diarrhoea, about 5 watery stools daily and abdominal pain . The frequency of intestinal bacteria in males was nearly three times higher than in females . The occurrence in age groups 10-20 was almost equal 20.0-22.2%, in 0-4 it was 42.9% and surprisingly low in 5-9 years old--3.4% only. FEMS Microbiol Lett, 1991 Dec 15, 69(1), 53 - 6 Molecular cloning of the ViaB region of Salmonella typhi; Hashimoto Y et al.; The ViaB region required for Vi antigen production in Salmonella typhi was cloned . The plasmid pGBM124 containing a 14-kb S . typhi chromosomal DNA fragment conferred the ability to produce Vi antigen on Escherichia coli HB101 and ViaB-deleted S . typhi GIFU10007-3 . Tn5 insertion analysis showed that the 14-kb DNA was split into three regions . Region 1 and region 2 are involved in the biosynthesis of Vi polysaccharide . Region 3 is involved in translocation of the Vi polysaccharide to the cell surface . Southern blot hybridization showed that regions 2 and 3 but not region 1, were considerably homologous to the DNA of Vi-positive Citrobacter freundii. J Chemother, 1991 Dec, 3(6), 343 - 7 Beta-lactamase induction antagonizes beta-lactam susceptibilities in Citrobacter diversus and Enterobacter cloacae clinical isolates; Oliva B et al.; Inducible beta-lactamases were obtained after exposure to several beta-lactams in clinical isolates of Enterobacter cloacae and Citrobacter diversus . Enzyme production was related to the inducer and medium composition . beta-lactamase is able to inactivate only labile compounds, thus generating minimum inhibitory concentrations higher than in the absence of the inducer; imipenem susceptibilities usually were not changed. Antibiot Khimioter, 1991 Dec, 36(12), 24 - 6 {Microbial colonization and succession in the large intestine of newborn infants during their stay with mothers at the maternity hospital}; Bochkov IA et al.; Formation of microflora in the large intestine of 5-day old infants was studied in one of the Moscow maternity homes . The up-to-date procedures for isolation and identification of aerobic and anaerobic organisms were used in the study and the findings were processed on a computer . In the newborns of the maternity home of the "mother-infant" type there was observed colonization of the large intestine with aerobic and anaerobic organisms . A wave-like dynamics in the formation of the symbiotic microflora was revealed . It reflected the phenomenon of the microbial succession in the infants . The attempts to detect microbial interference between the species colonizing the large intestine showed that it was extremely rare in the 5-day old infants . This was likely the reason of the low intestine resistance to the colonization in the newborns which in its turn defined the frequent colonization of the intestine mucosa with S . aureus and the organisms of the Klebsiella, Enterobacter and Citrobacter group. Berl Munch Tierarztl Wochenschr, 1991 Dec 1, 104(12), 409 - 11 {Biochemical properties of avian Citrobacter amalonaticus strains}; Mutlu OF; A report is given on the biochemical properties of C . amalonaticus-strains of avian origin . Some strains show decisive deviations of the "norm", usually established from mammalian strains and details are given in a table . The results are discussed and the strains considered to be avian specific. Poult Sci, 1991 Dec, 70(12), 2429 - 32 Xylose-lysine-tergitol 4: an improved selective agar medium for the isolation of Salmonella; Miller RG et al.; A study was conducted to evaluate a new selective plating medium for isolating Salmonella using pure bacterial cultures, and poultry environmental specimens containing high numbers of competing enteric bacteria . Xylose-lysine-tergitol 4 (XLT4) agar was found to strongly inhibit Proteus, Pseudomonas, Providencia, and many other nonsalmonellae and to provide good differentiation between Salmonella and Citrobacter . The XLT4 medium significantly improved Salmonella isolation from chicken farm environmental drag-swab samples over the other selective plating media evaluated. Arch Intern Med, 1991 Dec, 151(12), 2419 - 24 A large nontypical outbreak of Norwalk virus . Gastroenteritis associated with exposing celery to nonpotable water and with Citrobacter freundii; Warner RD et al.; The US Air Force Academy experienced a point-source outbreak of gastroenteritis originally believed to be caused by Salmonella . The overall attack rate was 48% among approximately 3000 cadets and staff . Food-specific attack rates implicated chicken salad . The odds ratio for chicken salad consumption in ill cadets was 10.7 (95% confidence interval: 8.2; 13.8) . The celery component had been exposed to nonpotable water . Citrobacter freundii were statistically associated with consumption of the suspected vehicle and subsequent illness . Most aspects were consistent with the epidemiology of Norwalk gastroenteritis . However, the clinical presentation was not typical of reported outbreaks . One hundred five cadets required intravenous rehydration . Serum samples implicated Norwalk virus as the most probable cause of this outbreak . The Centers for Disease Control (Atlanta, Ga) recently began national surveillance for viral gastroenteritis . All outbreaks of gastroenteritis associated with nonpotable water should be investigated for evidence of viral cause. J Bacteriol, 1991 Dec, 173(23), 7692 - 4 Presence of 5-methylcytosine in CC(A/T)GG sequences (Dcm methylation) in DNAs from different bacteria; Gomez-Eichelmann MC et al.; The presence of CC(A/T)GG sequences with methylated internal cytosine (Dcm methylation) was determined in DNA from different genera of eubacteria . This methylation was studied by using restriction enzymes EcoRII and BstNI, which cleave unmethylated or methylated CC(A/T)GG sequences . Dcm methylation was only detected in genera of the family Enterobacteriaceae closely related to Escherichia: Shigella, Citrobacter, Salmonella, and Klebsiella. Antimicrob Agents Chemother, 1991 Nov, 35(11), 2359 - 65 Induction of a class I beta-lactamase from Citrobacter freundii in Escherichia coli requires active ftsZ but not ftsA or ftsQ products; Ottolenghi AC et al.; A possible connection between septation/division and induction of cloned ampC beta-lactamase was investigated . When a ftsZ84(Ts) mutant of Escherichia coli carrying ampR-ampC from Citrobacter freundii was grown at the restrictive temperature (42 degrees C), induction of beta-lactamase by cefoxitin was inhibited by about 80% . Inhibition was virtually complete when a ftsZ84(Ts) mutant of different genetic background was tested . Although somewhat delayed, the induction of beta-lactamase in transformed ftsA(Ts) and ftsQ(Ts) mutants was similar to that observed in wild-type transformants . These results imply that FtsZ is involved in the process of beta-lactamase induction. J Antimicrob Chemother, 1991 Nov, 28(5), 669 - 76 Selection and characterization of cefepime-resistant gram-negative bacteria; Piddock LJ et al.; The NCTC type strains and four clinical isolates of Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, Morganella morganii, Providencia stuartii and Pseudomonas aeruginosa were exposed, in agar, to cefepime at 3, 5, and 10 x MIC and a breakpoint concentration of 16 mg/L . Mutants were selected at a frequency of approximately 10(-8) that had decreased susceptibility to cefepime and cefpirome, and species-dependent resistance to other beta-lactams . Any putative mutant with a greater than four-fold increase in the MIC was examined to determine its beta-lactamase expression and outer membrane protein (Omp) profile . Mutant strains of P . stuartii and M . morganii lacked an Omp of molecular mass similar to that of OmpF, and were cross-resistant to nalidixic acid . Mutant strains of E . cloacae had derepressed class I beta-lactamase production and lacked an Omp corresponding to OmpF, suggesting that in this species both parameters are necessary for decreased susceptibility . Derepressed beta-lactamases purified from mutant strains of E . cloacae, C . freundii and P . stuartii was able to hydrolyse cefepime, but not as quickly as TEM-10. Int J Food Microbiol, 1991 Nov, 14(2), 127 - 34 A new plate medium for rapid presumptive identification and differentiation of Enterobacteriaceae; Manafi M et al.; A new selective differential agar medium for rapid presumptive identification of Enterobacteriaceae from water and food samples is described (EMX ID agar) . By a combination of fluorogenic and chromogenic substrates, the medium detects the presence of beta-D-glucuronidase, beta-D-galactosidase, beta-D-xylosidase, tryptophane deaminase and H2S; additionally, cytochrome-oxidase and indole production can be demonstrated . This medium provides an inexpensive means for simple and rapid presumptive identification of E . coli and coliforms and for the differentiation within the Klebsiella-Enterobacter and the Proteus-Providencia-Morganella group . Furthermore, it allows to distinguish between the H2S-positive Enterobacteriaceae Citrobacter freundii, Salmonella spp., S . arizonae, Edwardsiella, Proteus mirabilis, P . vulgaris and some oxidase-positive bacteria. J Clin Microbiol, 1991 Nov, 29(11), 2385 - 9 Rapid isolation and presumptive diagnosis of uropathogens by using membrane filtration and differential media; Friedman MP et al.; Random urine samples from hospitalized patients (n = 550) and seeded sterile filtered urine samples (n = 730) were used to test a membrane filtration technique, Qualture (Future Medical Technologies International, Inc., West Palm Beach, Fla.), for the detection and identification of uropathogens . Results for each sample were compared with those obtained by the calibrated loop (0.01 ml) method to demonstrate the sensitivity of the method as a screening tool and the specificity of the presumptive diagnosis obtained from the pattern of growth on differential media . The medium was supplied as dehydrated nutrient pads (Sartorius AG, Goettingen, Germany) and was activated by rehydration by the addition of the liquid specimen . With a threshold of 10(4) CFU/ml defining a positive culture, the sensitivity of the Qualture was 100% . At lower levels of bacteriuria, the Qualture was more sensitive than the calibrated loop method . Significant infections were presumptively diagnosed at 4 h by filtration rather than at 24 h on agar medium . The specificity of uropathogen identification ranged from 99% for Enterococcus spp . to 83% for Pseudomonas spp . Citrobacter spp . could not be differentiated from Escherichia coli and Providencia spp . could not be differentiated from Proteus spp., which does not create a therapeutic dilemma . Filtration, isolation, quantitation, and presumptive diagnosis are performed in one step, without subculture . Membrane filtration is a sensitive and rapid technique, with the advantage that it can be used as a collection and transport device without the use of growth inhibitors. J Bacteriol, 1991 Oct, 173(19), 5964 - 74 Evolution of the ferric enterobactin receptor in gram-negative bacteria; Rutz JM et al.; Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis of iron-deficient and replete cell envelopes, 59Fe-siderophore uptake studies, and Western immunoblots and cytofluorimetric analyses with monoclonal antibodies (MAbs), we surveyed a panel of gram-negative bacteria to identify outer membrane proteins that are structurally related to the Escherichia coli K-12 ferric enterobactin receptor, FepA . Antibodies within the panel identified FepA epitopes that are conserved among the majority of the bacteria tested, as well as epitopes present in only a few of the strains . In general, epitopes of FepA that are buried in the outer membrane bilayer were more conserved among gram-negative bacteria than epitopes that are exposed on the bacterial cell surface . The surface topology and tertiary structure of FepA are quite similar in E . coli and Shigella flexneri but differ in Salmonella typhimurium . Of the 18 different genera tested, 94% of the bacteria transported ferric enterobactin, including members of the previously unrecognized genera Citrobacter, Edwardsiella, Enterobacter, Haemophilus, Hafnia, Morganella, Neisseria, Proteus, Providencia, Serratia, and Yersinia . The ferric enterobactin receptor contains at least one buried epitope, recognized by MAb 2 (C . K . Murphy, V . I . Kalve, and P . E . Klebba, J . Bacteriol . 172:2736-2746, 1990), that is conserved within the structure of an iron-regulated cell envelope protein in all the bacteria that we have surveyed . With MAb 2, we identified and determined the Mr of cell envelope antigens that are immunologically related to E . coli FepA in all the gram-negative bacteria tested . Collectively, the library of anti-FepA MAbs showed unique patterns of reactivity with the different bacteria, allowing identification and discrimination of species within the following gram-negative genera: Aeromonas, Citrobacter, Edwardsiella, Enterobacter, Escherichia, Haemophilus, Hafnia, Klebsiella, Morganella, Neisseria, Proteus, Providencia, Pseudomonas, Salmonella, Serratia, Shigella, Vibrio, and Yersinia. FEMS Microbiol Lett, 1991 Sep 15, 67(1), 79 - 84 Cloning and nucleotide sequencing of the gene encoding the beta-lactamase from Citrobacter diversus; Perilli M et al.; The gene coding for the class A beta-lactamase of Citrobacter diversus has been cloned and sequenced . It contains the information for a 294-amino-acid precursor protein, including a 27-residue N-terminal signal peptide . The deduced sequence of the N-terminal portion of the mature protein is in excellent agreement with that determined by microsequencing of the protein and readily explains the pI differences observed between the naturally occurring forms I and II of the enzyme . The sequence of the mature protein exhibits a very high degree of similarity with that of the Klebsiella oxytoca class A beta-lactamase. J Gen Microbiol, 1991 Sep, 137 ( Pt 9), 2147 - 53 In vitro characterization of intra-generic inhibition of growth in Salmonella typhimurium; Berchieri A Jr et al.; The intra-generic inhibition of bacterial growth observed previously in vivo and in vitro with strains of Salmonella, Citrobacter and E . coli was studied in vitro using S . typhimurium strain F98 . There was complete inhibition of multiplication of S . typhimurium when it was added to stationary-phase broth cultures of different Salmonella serotypes, but only partial inhibition when added to broth cultures of E . coli . The degree of inhibition between different mutants of F98 was affected by the numbers of bacteria of the inhibiting strain, but this was not the only factor, since exponential-phase bacterial cells were less inhibitory than stationary-phase cells . The inhibitory effect was produced at temperatures between 20 degrees C and 40 degrees C . The complete inhibition of growth observed between F98 mutants was abolished by ampicillin, rifampicin and streptomycin, but not by nalidixic acid . Inhibition was also prevented by separating the two cultures by a dialysis membrane . A TnphoA insertion mutant of F98 was produced which did not show inhibition in vitro but was still inhibitory in vivo . It is suggested that this complete inhibition of bacterial multiplication between organisms of the same genus, which is greater than that produced between organisms from different genera, is mediated by a cell surface protein. J Antimicrob Chemother, 1991 Sep, 28(3), 369 - 75 Characterization of FCE 22101-resistant Enterobacteriaceae and the effect of FCE 22101 upon the activity of anti-pseudomonal beta-lactams for Pseudomonas aeruginosa; Piddock LJ et al.; Twenty-five strains of Enterobacteriaceae (five each of Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, Morganella morganii, and Providencia stuartii) were exposed to FCE 22101 in agar containing 3, 5, or 10 x the MIC . Any putative mutant with a greater than or equal to four-fold increase in the MIC was examined for beta-lactamase expression and outer membrane protein (OMP) profile . Mutant colonies were selected at a frequency of 10(-7)-10(-11) with decreased susceptibility to FCE 22101 and other beta-lactams, but after one subculture on antibiotic-free agar the mutants from 13 of the 25 strains reverted to wild-type . Only 19 stable mutants were selected from the other 12 wild-type strains, of which 15 lacked an OMP of similar molecular size to OmpF, and/or a low size OMP of approximately 18 kDa . None of the mutants had a significant alteration in expression of Richmond & Sykes class I beta-lactamase . In a separate section of the study in which 50 strains of Pseudomonas aeruginosa were examined, it was found that FCE 22101, at a concentration of 4 mg/L, induced beta-lactamase expression such that, after 24 h exposure, 24 of the 50 strains had a greater than or equal to four-fold rise in the MIC of several anti-pseudomonal beta-lactams. Antimicrob Agents Chemother, 1991 Sep, 35(9), 1748 - 52 Pharmacokinetic studies and renal dehydropeptidase stability of the new beta-lactamase inhibitor BRL 42715 in animals; Coleman K et al.; BRL 42715 is a novel, highly potent beta-lactamase inhibitor with good activity against a broad range of beta-lactamases, including the class I enzymes of Enterobacter and Citrobacter spp . (K . Coleman, D.R.J . Griffin, J.W.J . Page, and P.A . Upshon, Antimicrob . Agents Chemother . 33:1580-1587, 1989) . The pharmacokinetics of BRL 42715 were studied following oral and parenteral administration in mice, rats, rabbits, beagle dogs, and cynomolgus monkeys . The elimination half-life (t1/2) of BRL 42715 following intravenous administration was 7 min in rats, 6.2 min in rabbits, 11 min in dogs, and 18 min in cynomolgus monkeys; and interspecies scaling indicated a t1/2 of 31 min in humans . Urinary recovery was 24 to 43% in the three species studied . A linear relationship was observed between the dose and the theoretical concentration in blood at time zero and between the dose and area under the concentration-time curve following intravenous administration to mice . Extravascular dosing in mice, rats, and dogs resulted in an increase in t1/2, suggesting a depot effect . BRL 42715 was absorbed in mice following an oral dose (bioavailability of 0.2), but was not absorbed in rats, dogs, or cynomolgus monkeys to any significant extent . The binding of BRL 42715 in serum was 27 to 38% in mouse, rat, and dog sera but was somewhat higher (68 to 70%) in primate and human sera . BRL 42715 was not readily hydrolyzed by the renal dehydropeptidase enzymes of any of the five species studied. Infection, 1991 Sep-Oct, 19(5), 363 - 9 In vitro activity of cefpodoxime and ten other cephalosporins against gram-positive cocci, Enterobacteriaceae and Pseudomonas aeruginosa, including beta-lactamase producers; Wiedemann B et al.; Cefpodoxime, the deesterified part of the orally available cefpodoxime proxetil, is active against most Enterobacteriaceae with MIC50 of 0.06 to 2 mg/l . Only Enterobacter cloacae and Citrobacter freundii strains show MIC50 of 4 mg/l . Coagulase negative staphylococci have a MIC50 of 2, while Staphylococcus aureus strains have a MIC of 4 mg/l . In comparison to other orally available cephalosporins cefpodoxime is slightly less active than cefixime and cefotiam against gram-negative bacteria but more active than cefuroxime, cefaclor, and cephalexin . Against staphylococci the activity of cefpodoxime is comparable to that of cefotiam and cefuroxime and superior to cefaclor and cephalexin, while cefixime does not have sufficient activity against these species . Like all cephalosporins cefpodoxime has no activity against enterococci. Diagn Microbiol Infect Dis, 1991 Sep-Oct, 14(5), 435 - 41 Oral ofloxacin therapy of infections due to multiply-resistant bacteria; Scully BE et al.; We determined the efficacy and safety of orally administered ofloxacin, 400 mg twice daily, in the treatment of infections due to multiply-resistant bacteria . Patients (n = 99) were treated for 84 infections in 82 patients evaluable for efficacy with a bacteriologic response of 71% . Organisms treated included Pseudomonas aeruginosa (39), Staphylococcus aureus (11), Serratia marcescens (9), Enterobacter species (7), five each of Escherichia coli, Citrobacter, Salmonella, Klebsiella, and other organisms . The overall clinical responses was 89%: 28 (90%) of 16 osteomyelitis, 10 (83%) of 12 urinary tract infections, and three of three bacteremias . Insomnia occurred in 27% and responded to dose reduction . Resistance of P . aeruginosa to ofloxacin developed in 15% of isolates . No hepatic, renal, or hematologic toxicity developed in spite of long therapy, 283 days . Ofloxacin was an effective therapy for lower respiratory, urinary, bone, and soft tissue infections due to multiply-resistant Gram-negative bacteria and is effective for selected Staphylococcus aureus infections. Diagn Microbiol Infect Dis, 1991 Sep-Oct, 14(5), 425 - 34 In vitro activity evaluations of cefdinir (FK482, CI-983, and PD134393) . A novel orally administered cephalosporin; Briggs BM et al.; Cefdinir, a so-called third-generation oral cephalosporin was tested in vitro against over 700 pathogens from patients with bacteremia . Cefdinir was very active against the Enterobacteriaceae with a 50% minimum inhibitory concentration (MIC50) value range of less than or equal to 0.03-8 micrograms/ml . The enteric species having the highest MIC90S (greater than or equal to 16 micrograms/ml) were Citrobacter freundii, and the enterobacters, Morganella morganii, Proteus vulgaris, and Serratia marcescens . Cefdinir was generally two- to fourfold less active than cefixime, but markedly more potent with a wider spectrum compared with older oral cephalosporins, cefaclor or cefuroxime . In contrast to cefixime, cefdinir inhibited Staphylococcus aureus (MIC90, 1 micrograms/ml) and other staphylococci . Pneumococci, beta-hemolytic streptococci, Haemophilus influenzae, Moraxella catarrhalis, and pathogenic Neisseria spp . (MIC90S, 0.12-0.5 micrograms/ml) were cefdinir susceptible, but Pseudomonas aeruginosa, oxacillin-resistant staphylococci and Bacteroides fragilis gr . strains were resistant . Cefdinir was generally bactericidal with a minimal inoculum effect at 10(6) colony-forming units per spot . Cefdinir beta-lactamase hydrolysis by some recently described extended broad spectrum beta-lactamases was suspected . Cefdinir exhibited a wide, balanced spectrum for an oral cephalosporin indicating possible clinical use against susceptible pathogens in respiratory tract, urinary tract, genital and cutaneous infections. Diagn Microbiol Infect Dis, 1991 Sep-Oct, 14(5), 417 - 24 In vitro activity of a new cephalosporin ME-1206 compared with other agents; Chin NX et al.; The in vitro activity of ME-1206, a new aminothiazolyl cephalosporin that can be orally absorbed when converted to an ester, was compared with that of other beta-lactams . ME-1206 inhibited 50% of the Enterobacteriaceae at 2 micrograms/ml, similar to cefotaxime, ceftazidime, and cefixime . It did not inhibit, MIC greater than or equal to 32 micrograms/ml, Enterobacter species or Citrobacter freundii resistant to cefotaxime and ceftazidime, and it was less active than cefotaxime and ceftazidime against Serratia marcescens . Haemophilus influenzae, Neisseria gonorrhoeae, and Moraxella catarrhalis were inhibited by less than or equal to 0.25 micrograms/ml of ME-1206 inhibited hemolytic streptococci groups A, B, C, and G, MIC90 0.06 micrograms/ml, but it did not inhibit enterococci . Pseudomonas aeruginosa and other pseudomonads were resistant to ME-1206 . MICs and MBCs of ME-1206 for susceptible species were within a dilution . ME-1206 was not hydrolyzed by TEM-1 or TEM-2, but was hydrolyzed by TEM-3 and TEM-5 . ME-1206 was hydrolyzed by beta-lactamases of Morganella, Proteus vulgaris, and K1 of Klebsiella oxytoca, but minimally by the P99 beta-lactamase of Enterobacter cloacae . ME-1206 is comparable in in vitro activity and beta-lactamase stability to many of the current cephalosporins. Mol Biol Evol, 1991 Sep, 8(5), 654 - 68 Temporal and topological clustering of diverged residues among enterobacterial dihydrofolate reductases; Garvin LD et al.; The complete nucleotide and encoded amino acid sequences were determined for the dihydrofolate reductase (DHFR) from the bacteria Enterobacter aerogenes and Citrobacter freundii . These were compared with the closely related Escherichia coli DHFR sequence . The ancestral DHFR sequence common to these three species was reconstructed . Since that ancestor there have been seven, nine, and one amino acid replacements in E . coli, E . aerogenes, and C . freundii, respectively . In E . coli, five of its seven replacements were located in the beta-sheet portion of the protein, and all seven were located in a single restricted region of the protein . In E . aerogenes, all nine of its replacements were located within surface residues, with five clustered in a region topologically distinct from the E . coli cluster . The replaced side chains are sometimes in direct contact but more often are separated by an intervening side chain . It is argued that the temporal clustering of replacements is typical for the evolution of most proteins and that the associated topological clustering gives a picture of how evolutionary change is accommodated by protein structure. J Antimicrob Chemother, 1991 Aug, 28(2), 209 - 19 beta-Lactamase expression and outer membrane protein changes in cefpirome-resistant and ceftazidime-resistant gram-negative bacteria; Piddock LJ et al.; Twenty-five strains of Enterobacteriaceae (five each of Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, Morganella morganii, and Providencia stuartii) and five strains of Pseudomonas aeruginosa were exposed to various concentrations of cefpirome or ceftazidime in agar . Mutants with a greater than four-fold increase in the MIC were examined for changes in beta-lactamase expression and outer membrane protein (OMP) profile . Both agents selected mutants with decreased susceptibility to the selecting antibiotic and other beta-lactams at a frequency of 10(-7)-10(-8) . The MICs of all beta-lactams were higher for the resistant mutants of E . cloacae and P . aeruginosa than for the other species . Both agents selected mutants expressing derepressed class I beta-lactamase, but this was more common with ceftazidime . Only a few mutants of P . aeruginosa and E . cloacae had an MIC of cefpirome that was above the recommended breakpoint concentration . Some mutant strains of Enterobacteriaceae lacked an OMP of molecular size similar to OmpF, but the MIC of cefpirome was below the breakpoint concentration for all these strains. Eur J Clin Microbiol Infect Dis, 1991 Aug, 10(8), 676 - 82 In vitro activity of cefcanel versus other oral cephalosporins; Chin NX et al.; Cefcanel is a new orally absorbed cephalosporin . Its activity was compared with that of cefuroxime, cefaclor, cephalexin, and cefixime against gram-positive and negative aerobic and anaerobic bacteria . Cefcanel had excellent activity against methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis, MIC90 1 micrograms/ml, superior to the other oral cephalosporins . However, methicillin-resistant staphylococci were resistant, MIC greater than or equal to 16 micrograms/ml . Streptococcus pyogenes and Streptococcus pneumoniae were inhibited by 0.015-1 micrograms/ml, concentrations comparable to other cephalosporins . Clostridium spp . were inhibited by 0.25 micrograms/ml, 8- to 128-fold lower concentrations than were found for other agents, but the MICs were greater than 64 micrograms/ml for Bacteroides spp . The MIC90 for Moraxella catarrhalis was 1 micrograms/ml, similar to cefuroxime but 16-fold greater than the MICs of cefixime . Escherichia coli and Klebsiella pneumonia which were high beta-lactamase producers were resistant, MICs greater than 64 micrograms/ml, and 50% of Enterobacter cloacae and Citrobacter freundii were resistant . Cefcanel was hydrolyzed by TEM-1, TEM-3 and Moraxella Bro-1 beta-lactamases . Escherichia coli containing TEM-1, 2, 3, 5, 7, and 9 had cefcanel MICs of greater than or equal to 16 micrograms/ml . Although cefcanel inhibited gram-positive species as well as or at lower concentrations than other cephalosporins, it lacked activity against gram-negative species that produced common plasmid beta-lactamase although it inhibited Haemophilus influenzae carrying TEM-1. Eur J Clin Microbiol Infect Dis, 1991 Aug, 10(8), 669 - 75 In vitro activity of Ro 09-1428 compared to other cephalosporins; Chin NX et al.; The in vitro activity of Ro 09-1428, a new catechol-type parenteral cephalosporin, was compared to that of ceftazidime, E-1040, cefpirome and cefepime against gram-positive and gram-negative organisms . Ro 09-1428 inhibited group A streptococci at less than or equal to 0.12 micrograms/ml, and group B, C and G streptococci and Streptococcus pneumoniae at 0.5 micrograms/ml, whereas for Staphylococcus aureus Ro 09-1428 had MICs of 8-16 micrograms/ml similar to ceftazidime and E-1040 . Against Pseudomonas aeruginosa Ro 09-1428 was the most active agent, inhibiting isolates at less than or equal to 0.12-2 micrograms/ml, and inhibited ceftazidime-resistant isolates . The majority of Escherichia coli, Klebsiella spp., Proteus mirabilis, Citrobacter diversus, Providencia, Salmonella and Shigella were inhibited by less than or equal to 0.5 micrograms/ml as with the other cephalosporins . For most Citrobacter freundii and Enterobacter cloacae Ro 09-1428 had higher MICs of 4-16 micrograms/ml; most ceftazidime-resistant isolates of these species were resistant . Anaerobes, enterococci and Listeria monocytogenes were resistant to Ro 09-1428 . Ro 09-1428 was not hydrolyzed by TEM-1, TEM-2, Staphylococcus aureus PC-1, Moraxella catarrhalis Bro-1, Enterobacter P-99, Pseudomonas aeruginosa Sabath-Abraham or Klebsiella beta-lactamases, but was hydrolyzed by TEM-3, TEM-7 and TEM-9 . Ro 09-1428 was markedly less active at an acid pH. J Infect Dis, 1991 Jul, 164(1), 195 - 8 Antibacterial activity of crotalid venoms against oral snake flora and other clinical bacteria; Talan DA et al.; Despite heavy oral and fang contamination of crotalid species with a wide variety of potentially pathogenic bacteria, crotalid envenomation is associated with a low incidence of bacterial infection . Minimal inhibitory and bactericidal concentrations of venoms from three crotalid species were determined against six aerobic and eight anaerobic reference and oral crotalid microorganisms . All anaerobic isolates were resistant to greater than 20,480 micrograms/ml, whereas variable activity (range, 5-20,480 micrograms/ml) was observed for aerobic strains . Further studies against other aerobic clinical isolates demonstrated that venom had the greatest activity (MIC, less than or equal to 80 micrograms/ml) against staphylococci, Pseudomonas aeruginosa, and Enterobacter, Citrobacter, Proteus, and Morganella species . Inhibitory activity was lost with prolonged incubation for many gram-negative species . Crotalid venoms are broadly active against aerobic gram-negative and -positive bacteria . This activity may play a role in the low incidence of infection after envenomation injuries. Jpn J Surg, 1991 Jul, 21(4), 376 - 80 The influence of clinical use of antibiotics and the sensitivity of strains isolated from postoperative infections--a comparison of nosocomial pathogens with strains isolated from the bacterial flora of patients; Takesue Y et al.; In the present study, we investigated how the recent clinical use of antibiotics have altered the antibiotic susceptibility of strains isolated from postoperative infections, especially Gram-negative rods . For Pseudomonas aeruginosa, serogroup E strains accounted for about 20 per cent of postoperative infections, but were unable to be isolated from either the feces of patients on admission or from the appendix contents of patients with appendicitis . It therefore appeared that serogroup E strains were responsible for the nosocomial infections in our department . The strains of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa serogroup E, which we assumed to be nosocomial pathogens, acquired a high level of resistance to antibiotics soon after third-generation cephems became widely used . On the other hand, the antibiotic susceptibility of Enterobacter cloacae, Citrobacter freundii, and the serogroups of Pseudomonas aeruginosa other than E, which were considered to originate from the bacterial flora of patients, did not vary throughout the several years of the study period. Mol Microbiol, 1991 Jul, 5(7), 1715 - 25 Purification and mutant analysis of Citrobacter freundii AmpR, the regulator for chromosomal AmpC beta-lactamase; Bartowsky E et al.; AmpR, the transcriptional regulator for the Citrobacter freundii ampC beta-lactamase gene, was purified . The purified AmpR had DNA-binding activity, the same molecular mass (32 kDa) on sodium dodecyl sulphate/polyacrylamide gel electrophoresis as previously described, and N-terminal sequencing of the first 15 amino acids was in agreement with that predicted from the nucleotide sequence . Two mutants were isolated that abolish DNA-binding and beta-lactamase induction and which map in the amino- and carboxyl-terminal ends of AmpR, respectively . The mutation in the amino terminus (S35F) was located in a helix-turn-helix region showing high homology to other members of the LysR regulator family . Therefore this mutation may directly abolish the contact between AmpR and its operator sequence . It is suggested that the C-terminal mutation (Y264N) affects subunit interactions in AmpR . One constitutive mutant was isolated which mapped in the centre of the ampR gene . This G102E mutant leads to constitutive beta-lactamase expression in the absence of both beta-lactam inducer and ampG, a gene essential for induction in wild-type enterobacteria . Another mutant protein, D135Y, showed wild-type properties in an ampG+ and an ampG::kan background, but could, unlike wild-type AmpR, activate the ampC gene in an ampG1 mutant background . It is thought that ampG1 is a missense mutant . These two types of ampR mutants suggest that activation of ampC transcription is dependent on the conversion of AmpR into a transcriptional activator and that this activation may normally involve interactions with AmpG. Antimicrob Agents Chemother, 1991 Jul, 35(7), 1508 - 11 In vitro comparison of GR69153, a novel catechol-substituted cephalosporin, with ceftazidime and ceftriaxone against 5,203 recent clinical isolates; Washington JA et al.; The activity of GR69153, a novel catechol-substituted cephalosporin, was compared with those of ceftazidime and ceftriaxone in a multicenter study against 5,203 fresh clinical isolates of gram-negative and gram-positive bacteria . GR69153 was generally very active at concentrations equivalent to or two- to fourfold lower than those of ceftazidime and ceftriaxone against gram-negative bacilli other than Citrobacter freundii, Enterobacter cloacae, and Xanthomonas maltophilia . Against Pseudomonas aeruginosa, MICs of GR69153 and ceftazidime for 50% of isolates tested (MIC50s) were, respectively, 1 and 2 micrograms/ml; the corresponding MIC90s were 4 and 16 micrograms/ml . Although MIC50s of GR69153 for staphylococci were two- to eightfold lower than those of ceftazidime or ceftriaxone, MIC90s against staphylococci and enterococci were greater than or equal to 16 micrograms/ml for all three compounds . Quality control MIC ranges for reference strains are proposed for the broth microdilution method on the basis of the GR69153 data derived from this multicenter study. Antimicrob Agents Chemother, 1991 Jul, 35(7), 1343 - 7 Influence of beta-lactamase inhibitors on the potency of their companion drug with organisms possessing class I enzymes; Cavalieri SJ et al.; The ability of beta-lactamase inhibitors to induce class I beta-lactamases in certain organisms in vitro suggests a potential for antagonism in vivo . Therefore, a study was designed to assess the ability of sulbactam and clavulanate to induce beta-lactamases in two strains each of Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, and Pseudomonas aeruginosa both in vitro and in vivo . Induction in vitro was observed only with S . marcescens and P . aeruginosa and generally only when inhibitor concentrations greater than 2 micrograms/ml were examined . A mouse model of lethal infection, designed to detect in vivo antagonism arising from beta-lactamase induction, was used to determine what effect sulbactam and clavulanate would have on the 50% protective doses (PD50s) of cefoperazone and ticarcillin . Antagonism (a significant increase in the PD50) was observed in only 4 of 32 tests . Three of these involved antagonism of cefoperazone by clavulanate, and one involved antagonism of cefoperazone by sulbactam . In 6 of 32 tests, enhancement of efficacy (a significant decrease in PD50) was observed . In four of these, sulbactam enhanced cefoperazone; in one, sulbactam enhanced ticarcillin; and in one, clavulanate enhanced ticarcillin . Four of the six cases of enhancement occurred when the beta-lactamase inhibitor was given at the time of challenge . None of these positive or negative in vivo effects were predicted by in vitro tests . These data suggest that beta-lactamase inhibitors can influence the in vivo potency of their companion drug in both a beneficial and detrimental fashion against organisms with class I beta-lactamases and that these effects cannot be predicted from in vitro assays. Eur J Clin Microbiol Infect Dis, 1991 Jul, 10(7), 581 - 5 In vitro activity of cefpodoxime against bacterial isolates obtained from patients with cancer; Rolston KV et al.; The in vitro activity of cefpodoxime, an oral cephalosporin ester, against 792 bacterial isolates representing 36 species was evaluated in comparison to that of ciprofloxacin and trimethoprim/sulfamethoxazole (TMP/SMX) . Cefpodoxime inhibited the majority of Streptococcus spp., Haemophilus influenzae and Proteus mirabilis at a concentration of less than or equal to 0.12 microgram/ml . It was also active against Citrobacter diversus, Escherichia coli, Klebsiella spp., Proteus vulgaris, Serratia marcescens and methicillin-susceptible Staphylococcus aureus isolates . Overall, cefpodoxime appeared to be less active than ciprofloxacin and TMP/SMX against many pathogens common in cancer patients. J Clin Microbiol, 1991 Jul, 29(7), 1480 - 5 Trabulsiella guamensis, a new genus and species of the family Enterobacteriaceae that resembles Salmonella subgroups 4 and 5; McWhorter AC et al.; In 1985 the vernacular name Enteric Group 90 was coined for a small group of strains that had been referred to our laboratory as probable strains of Salmonella but did not agglutinate in Salmonella typing antisera . By DNA-DNA hybridization (hydroxyapatite method, 32P), seven strains of Enteric Group 90 were found to be closely related (98 to 100% at 60 degrees C and 94 to 100% at 75 degrees C) to the first strain received (0370-85) . The relatedness of Enteric Group 90 to 62 strains of other species of the family Enterobacteriaceae was only 6 to 41%, with the highest values obtained with strains of Salmonella, Kluyvera, Shigella, Klebsiella, Enterobacter, and Citrobacter . We propose a new genus, Trabulsiella, with a single new species, Trabulsiella guamensis, for the highly related group of eight strains formerly known as Enteric Group 90 . The type strain is designated ATCC 49490 (CDC 0370-85) . T . guamensis strains grew well at 36 degrees C and had positive reactions in the following tests: methyl red, citrate utilization (Simmons) (38% positive at day 1, 88% positive at 2 days), H2S production, lysine decarboxylase, arginine dihydrolase (50% positive at 2 days, 100% positive at 7 days), ornithine decarboxylase, motility, growth in KCN medium, mucate fermentation, acetate utilization, nitrate reduction to nitrite, weak tyrosine hydrolysis (88% positive at 2 days, 100% positive at 7 days), and ONPG (o-nitrophenyl-beta-D-galactopyranoside) test . The strains fermented D-glucose with gas production and fermented L-arabinose, cellobiose, D-galactose, D-galacturonate, maltose, D-mannitol, D-mannose, L-rhamnose, D-sorbitol, trehalose, and D-xylose . T . guamensis strains had negative reactions in the following tests: indole production (13% positive), Voges-Proskauer, urea hydrolysis, phenylalanine deaminase, malonate utilization, lipase (corn oil), DNase, oxidase, pigment production, and acid production from adonitol, D-arabitol, dulcitol, erythritol, myo-inositol, melibiose, alpha-methyl-D-glucoside, raffinose, and sucrose . There were delayed positive reactions for gelatin liquefaction (22 degrees C), which was positive at 12 to 23 days, esculin hydrolysis (13% positive at day 1, 50% positive at 7 days), lactose fermentation (13% positive at 3 to 7 days, 100% positive at 8 to 10 days), glycerol fermentation (88% positive at 7 days), and salicin fermentation (13% positive at day 1, 88% positive at 7 days) . All strains were susceptible by the disk diffusion method to colistin, nalidixic acid, gentamicin, streptomycin, kanamycin, chloramphenicol, and trimethoprim-sulfamethoxazole, and most strains were susceptible to sulfadiazine (75% susceptible), tetracycline (88%), and carbenicillin (75%) . The strains were resistant to penicillin, cephalothin, and ampicillin . The strains were isolated from vacuum cleaner dust (five strains), soil (one strain), and human feces (two strains) . Although T . guamensis can occur in human diarrheal stools, there is no evidence that it actually causes diarrhea . Its main interest to clinical microbiologists may be its possible misidentification as a strain Salmonella. J Biochem (Tokyo), 1991 Jul, 110(1), 22 - 8 Cloning and nucleotide sequence of the gene (citA) encoding a citrate carrier from Salmonella typhimurium; Shimamoto T et al.; A cryptic citrate transport gene (citA) from Salmonella typhimurium chromosome was cloned and its nucleotide sequence was determined . The cloned plasmid conferred citrate-utilizing ability on wild-type Escherichia coli, which cannot grow on citrate as the sole source of carbon . The resultant E . coli transformant was able to transport citrate . A 1,302-base-pair open reading frame with a preceding ribosomal binding site was found in the cloned DNA fragment . The 434-amino-acid protein that could be translated from this open reading frame is highly hydrophobic (69% nonpolar amino acid residues), consistent with the fact that the transport protein is an intrinsic membrane protein . The molecular weight of this protein was calculated to be 47,188 . The gene sequence determined is highly homologous to those of Cit+ plasmid-mediated citrate transport gene, citA, from E . coli, the chromosomal citA gene from Citrobacter amalonaticus and the chromosomal cit+ gene from Klebsiella pneumoniae . The hydropathy profile of the deduced amino acid sequence suggests that this carrier has 12 hydrophobic segments, which may span the membrane lipid bilayer. J Bacteriol, 1991 Jun, 173(12), 3656 - 62 A weak adaptive response to alkylation damage in Salmonella typhimurium; Vaughan P et al.; An efficient adaptive response to alkylation damage was observed in several enterobacterial species, including Klebsiella aerogenes, Shigella sonnei, Shigella boydii, Escherichia alkalescens, Escherichia hermanii, and Escherichia fergusonii . Increased O6-methylguanine-DNA and methylphosphotriester-DNA methyltransferase activities correlated with the induction of a 39-kDa protein recognized by monoclonal antibodies raised against the Escherichia coli Ada protein . Induced methyltransferase activities were similarly observed in Aerobacter aerogenes and Citrobacter intermedius, although no antigenically cross-reacting material was present . Weak induction of a 39-kDa protein immunologically related to the E . coli Ada protein occurred in Salmonella typhimurium . This protein encoded by the cloned S . typhimurium ada gene was shown to be an active methyltransferase which repaired O6-methylguanine and methylphosphotriesters in DNA as efficiently as did the E . coli Ada protein . However, the mehtyltransferase activity of the weakly induced 39-kDa protein in S . typhimurium was not detected, apparently because it was self-methylated and thus inactivated during the adaptive N-methyl-N-nitro-N-nitrosoguanidine pretreatment . In contrast, the E . coli ada gene on a low-copy-number plasmid was efficiently induced in S . typhimurium, and high methyltransferase activities were observed . We concluded that the inefficient induction of the adaptive response in S . typhimurium results from weak transcriptional activation of its ada gene by the self-methylated protein. Antimicrob Agents Chemother, 1991 Jun, 35(6), 1235 - 8 In vitro susceptibility testing procedures for fosfomycin tromethamine; Barry AL et al.; Fosfomycin tromethamine (previously fosfomycin trometamol) is an orally administered fosfomycin which may be used for single-dose therapy of uncomplicated urinary tract infections . Fosfomycin tromethamine, norfloxacin, and trimethoprim-sulfamethoxazole inhibited greater than 90% of 352 bacterial isolates representing 25 different species; trimethoprim and nalidixic acid had narrower spectrums of activity . Strains of Escherichia, Citrobacter, Enterobacter, and Klebsiella species were much more susceptible when glucose-6-phosphate was added to the test medium, but isolates belonging to other genera were not affected. Eur J Clin Microbiol Infect Dis, 1991 Jun, 10(6), 479 - 85 Review of Citrobacter bacteremia in cancer patients over a sixteen-year period; Samonis G et al.; A review was conducted of 65 episodes of Citrobacter bacteremia in cancer patients during a 16-year period . Cases of polymicrobial bacteremia were excluded from this analysis . The infection occurred most commonly in patients with acute leukemia . Most patients acquired the infection in the hospital, and 57% had received antibiotic therapy during the preceding ten days . Fever occurred in 98% of cases and shock in 17% . Thirty-eight percent of patients had concomitant pneumonia . Patients with shock, pneumonia or hemorrhage had a substantially poorer prognosis . The response rate was 72% for patients who received appropriate antibiotics . Patients who continued to have positive blood culture results while receiving appropriate antibiotic therapy had a poor prognosis . Beta-lactam antibiotics were more effective than aminoglycosides. Acta Paediatr Scand, 1991 Jun-Jul, 80(6-7), 602 - 10 Intestinal colonization with Enterobacteriaceae in Pakistani and Swedish hospital-delivered infants; Adlerberth I et al.; Rectal cultures from Swedish and Pakistani hospital-delivered newborn infants were analysed regarding the early acquisition of enterobacteria . Swedish infants were delivered vaginally, Pakistani infants were delivered either vaginally or by caesarean section . The Swedish infants were all breast-fed, whereas breastfeeding was incomplete and often started late among the Pakistani infants . Both groups of Pakistani infants were more rapidly colonized with enterobacteria than were the Swedish infants . Cultures from Swedish infants seldom yielded more than one kind of enterobacteria; E . coli and Klebsiella were most frequently isolated . E . coli dominated in both Pakistani groups, but especially caesarean section delivered infants were in addition often colonized with Proteus, Klebsiella, Enterobacter or Citrobacter species . Breastfeeding from the first day of life reduced colonization with Klebsiella/Enterobacter/Citrobacter . The results suggest that environmental exposure, delivery mode and early feeding habits all influence the early intestinal colonization with enterobacteria. Appl Microbiol Biotechnol, 1991 Jun, 35(3), 339 - 47 DNA sequence of a Salmonella-specific DNA fragment and the use of oligonucleotide probes for Salmonella detection; Tsen HY et al.; Hybridization specificity of a 1.8-kb HindIII DNA fragment isolated from Salmonella typhimurium by a molecular cloning technique was confirmed by colony hybridization with 327 Salmonella isolates of various serotypes and 56 non-Salmonella isolates including Enterobacteriaceae closely related to Salmonella, such as Escherichia coli, Klebsiella, Citrobacter and Shigella . It was found that this 1.8-kb DNA fragment was highly specific for all the Salmonella isolates tested . The DNA sequence of this 1.8-kb fragment was then determined by the dideoxynucleotide chain termination method . According to this DNA sequence, six oligonucleotide fragments ranging from 17- to 26-mer were then chemically synthesized and tested for their hybridization specificities . Results show that three of the six oligonucleotide fragments are highly specific for all 327 Salmonella strains tested and can be used as probes for the specific detection of Salmonella in foods or other samples. Biochem J, 1991 May 1, 275 ( Pt 3), 629 - 33 Proteolytic interconversion and N-terminal sequences of the Citrobacter diversus major beta-lactamases; Franceschini N et al.; The N-terminal sequences of the two major beta-lactamases produced by Citrobacter diversus differed only by the absence of the first residue in form II and the loss of five amino acid residues at the C-terminal end . Limited proteolysis of the homogeneous form I protein yielded a variety of enzymatically active products . In the major product obtained after the action of papain, the first three N-terminal residues of form I had been cleaved, whereas at the C-terminal end the treated enzyme lacked five residues . However, this cannot explain the different behaviours of form I, form II and papain digestion product upon chromatofocusing . Form I, which was sequenced up to position 56, exhibited a very high degree of similarity with a Klebsiella oxytoca beta-lactamase . The determined sequence, which contained the active serine residue, demonstrated that the chromosome-encoded beta-lactamase of Citrobacter diversus belong to class A. Zentralbl Hyg Umweltmed, 1991 May, 191(5-6), 449 - 56 Formaldehyde-resistance in Enterobacteriaceae and Pseudomonas aeruginosa: identification of resistance genes by DNA-hybridization; Wollmann A et al.; A 4.1 . Kb large DNA fragment of a E . coli plasmid pVU 3695, on which the genes for formaldehyde-resistance are located, was used as a DNA probe to identify bacteria that carry this segment among formaldehyde-resistant bacteria . It was shown by Southern Blot-, Dot Blot-, and Colony Blot- Hybridization studies that the DNA of all formaldehyde-resistant E . coli, Serratia marcescens, Enterobacter cloacae, Citrobacter freundii and Klebsiella pneumoniae strains tested hybridize with the DNA probe from E . coli . In contrast the E . coli DNA probe does not hybridize with the DNA from formaldehyde-resistant Pseudomonas aeruginosa strains. Jpn J Antibiot, 1991 May, 44(5), 529 - 37 {Combined antibacterial activity of aztreonam and clindamycin against clinically isolated strains}; Deguchi K et al.; It has been reported in some studies that the combination of aztreonam (AZT) and clindamycin (CLDM) have high clinical effectiveness in the treatment of intractable infections . We, therefore, studied combined in vitro antibacterial activity of these 2 compounds using many freshly isolated strains . 1 . AZT and CLDM in combination had synergistic effects on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Haemophilus influenzae, which are sensitive or quasi-sensitive to CLDM, in the presence of CLDM at MIC or sub-MIC . 2 . For Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa, which are not sensitive to CLDM, the 2 drugs in combination showed synergistic effects on some species and additive or slightly additive effects on most species in the presence of CLDM at those concentrations which are usually maintained in blood . 3 . The 2 drugs showed no antagonism. J Dairy Sci, 1991 May, 74(5), 1539 - 43 N-acetyl-beta-D-glucosaminidase, etiologic agent, and duration of clinical signs for sequential episodes of chronic clinical mastitis in dairy cows; Wilson DJ et al.; This study examined effects of repeated episodes of clinical mastitis in chronically infected quarters on milk N-acetyl-beta-D-glucosaminidase activity and duration of clinical signs . Milk samples were collected at each clinical onset from 49 chronic mastitis cases on a 1700-cow Michigan dairy farm . There were 49 first episodes of clinical mastitis, 49 second episodes, and 13 episodes of third or more . Agents isolated were Staphylococcus aureus (18.4%), Staphylococcus (7.3%), no growth (20.2%), environmental pathogens (streptococci other than agalactiae, Escherichia coli, Klebsiella spp., Enterobacter spp., and Citrobacter spp.) (22.0%), other pathogens (Serratia spp., Bacillus spp., diphtheroids {Corynebacterium spp . and Actinomyces pyogenes}, Pseudomonas spp., and Nocardia spp.) (11.9%), mixed pathogens (two agents isolated) (12.8%), and contaminated samples (7.3%) . Etiologic agents, duration of clinical signs, and NAGase did not differ by episode number . The correlation between log of NAGase and log of time until clinical recovery was .34 . The relationship between NAGase and duration of clinical signs was strongest for second episodes, and weakest for third and greater episodes of chronic mastitis. Antimicrob Agents Chemother, 1991 May, 35(5), 976 - 82 Modulation of the intestinal flora of mice by parenteral treatment with broad-spectrum cephalosporins; van Ogtrop ML et al.; A study was performed to determine the effect of parenteral treatment with four broad-spectrum cephalosporins (cefoperazone, ceftriaxone, ceftazidime, and cefepime) on the number of aerobic gram-negative rods and on the outgrowth of Candida albicans and a multiresistant strain of Citrobacter freundii in the feces of mice . The estimated fractions of a parenteral dose that were excreted into the gastrointestinal tract were 0.37 for cefoperazone, 0.11 for ceftriaxone, 0.03 for ceftazidime, and 0.002 for cefepime . All four cephalosporins significantly decreased the number of aerobic gram-negative rods in the feces, and virtually all gram-negative rods were eliminated at high doses of cefoperazone, ceftazidime, and ceftriaxone . Furthermore, at high doses these three compounds led to a significant increase of the outgrowth of resistant Citrobacter freundii . The outgrowth of Candida albicans was increased at high doses of cefoperazone and ceftriaxone, whereas ceftazidime and cefepime did not have this effect . The most profound changes in the gastrointestinal ecology were observed during treatment with high doses of cefoperazone . The results suggest that the colonization resistance of the gastrointestinal tract can be substantially decreased by parenteral treatment with cefoperazone and, to a lesser extent, with ceftriaxone and ceftazidime. Infect Immun, 1991 Apr, 59(4), 1352 - 8 Pathophysiology of Citrobacter diversus neonatal meningitis: comparative studies in an infant mouse model; Soriano AL et al.; Citrobacter diversus is a cause of devastating neonatal meningitis, with illness characterized by formation of multiple brain abscesses . We developed an infant mouse intracranial inoculation model to evaluate the pathophysiology of C . diversus neonatal infections . Eighteen of 26 strains inoculated intracranially at a dose of ca . 3.3 x 10(3) CFU caused greater than 50% mortality in 2-day-old mice . No correlation was seen between the epidemiologic characteristics of a strain and its rate of mortality . When seven C . diversus isolates (four isolates from patients with meningitis, three from non-central nervous system {CNS} sites) were further evaluated, mortality was significantly correlated with bacteremia . The initial lesion in the CNS was a suppurative ventriculitis beginning 1 to 2 days postinoculation . Subsequent ventriculomegaly was associated with ventriculitis and periventricular abscessation . Brain lesions were seen with all strains, although strains of low virulence (as measured by having no bacteremia and low mortality) caused less-severe damage . An age-related susceptibility to C . diversus brain lesions was demonstrated, with 5-day-old mice showing a significant reduction in, and 8-day-old mice being apparently resistant to, infection and CNS damage . Our data indicate that C . diversus has a propensity to cause abscess formation in the neonatal mouse brain, with characteristic pathologic findings; however, the factors that determine whether a strain will cause meningitis in a human infant remain to be identified. J Chemother, 1991 Apr, 3(2), 83 - 5 Some molecular properties of Citrobacter diversus beta-lactamases; Amicosante G et al.; Citrobacter diversus ULA-27, a clinical isolate showing a broad resistance pattern towards both penicillins and cephalosporins, produces chromosome encoded beta-lactamases . However, the strain remains susceptible to some cephamycins, imipenem, ceftazidime and tetracyclines . Crude bacterial extracts analyzed by isoelectric focusing on polyacrylamide gels, revealed the presence of two main isoforms and some "satellite" bands focusing in the pH range 5.7-7.2 . The isoform showing the pIs 6.8 and 6.2 were characterized as class "A" beta-lactamases (according to Ambler's classification) based on the rate of interaction of beta-iodopenicillanate and the amino acid sequence around the active site serine . The substrate specificity of the Citrobacter diversus beta-lactamases explains the resistance phenomenon of this bacterium to penicillins and cephalosporins. Indian J Exp Biol, 1991 Apr, 29(4), 338 - 41 Antigen sharing of Salmonella typhi non-flagellar proteins with other salmonellae and some shigellae and Escherichia coli; Jesudason M et al.; Cathodal moving protein components were identified in agarose gel electrophoresis of the Veronal buffer extract of a non-motile strain of S . typhi (8393, Colindale) . Rabbit antiserum was raised against these cationic proteins; it had both agglutinating and precipitating activity . A total of 80 salmonella strains belonging to serogroups A, B, C1, C2, D, E1 and E2 including 26 S . typhi and 10 S . paratyphi A were tested against this antiserum in a slide agglutination test; all strains were agglutinated . Among 94 other bacterial strains tested, the antiserum agglutinated all 16 strains of Shigella flexneri, 2 of 5 Shigella sonnei, 5 of 34 E . coli and 1 of 8 Citrobacter species . These results show that there is antigenic sharing of the non-flagellar proteins of S . typhi with many other salmonellae as well as with some shigellae and E . coli. J Antimicrob Chemother, 1991 Apr, 27(4), 441 - 57 Concomitant dissemination of three extended-spectrum beta-lactamases among different Enterobacteriaceae isolated in a French hospital; de Champs C et al.; From January 1988 to August 1989, 267 non-repetitive strains of Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBla) derived from TEM (CTX-1/TEM-3, CAZ-6) or SHV (CAZ-5) were isolated from 219 colonized or infected patients . ESBlas were characterized by analytical isoelectric focusing . Biotypes, resistance phenotypes and plasmid patterns were determined in order to differentiate the isolates in each species . Among the 116 CTX-1-producing Enterobacteriaceae, 48 strains were differentiated: 27 from 74 Klebsiella pneumoniae isolates, seven from 22 Enterobacter aerogenes isolates, and 14 from a combined total of seven K . oxytoca, five Serratia marcescens, six Escherichia coli, 1 Enterobacter cloacae and 1 Citrobacter freundii . CAZ-5 has been isolated since January 1988 in 16 different strains among 101 K . pneumoniae isolates . CAZ-6 was first identified in K . pneumoniae (January 1988) . Among the 48 Enterobacteriaceae producing CAZ-6, 12 strains were differentiated: four from 39 E . aerogenes isolates, three from four K . pneumoniae, and five from a combined total of two S . marcescens, two E . coli and one E . cloacae . During this outbreak, CTX-1 was found to be encoded by 85 kb (Inc 7/M) or greater than or equal to 150 kb (Inc 6/C) plasmids . CAZ-6 was always encoded by an 85 kb (Inc 7/M) plasmid and CAZ-5 by a greater than 150 kb plasmid . These results show that strain epidemics and plasmid dissemination occurred mainly in K . pneumoniae and E . aerogenes for CTX-1, in E . aerogenes for CAZ-6, and in K . pneumoniae for CAZ-5 . They also suggest that the bla(tem) gene (CTX-1) has spread between different plasmids present in the same ecosystem. Rev Med Chil, 1991 Mar, 119(3), 303 - 7 {Bacteremic pneumonia caused by Citrobacter diversus: report of a case}; Zuniga J et al.; A 61 year old male with a localized gastric cancer developed a post-operative pneumonia by C . diversus which was isolated from blood and from bronchoalveolar lavage . A satisfactory response was observed after treatment with penicillin and amikacin . A brief review of the literature concerning the clinical relevance of infections by this unusual agent is offered. Eur J Biochem, 1991 Feb 26, 196(1), 197 - 201 Core region of Citrobacter O23 lipopolysaccharide . Structure elucidation by chemical methods, gas chromatography/mass spectrometry and NMR spectroscopy at 500 MHz; Katzenellenbogen E et al.; A novel enterobacterial core region in Citrobacter O23 lipopolysaccharide is described . Its structure was determined by methylation analysis/mass spectrometry, chemical degradation and one- and two-dimensional 1H-NMR spectroscopy: {formula; see text} where PPEtN stands for diphosphorylethanolamine, and dOclA for 3-deoxy-D-manno-octulosonic acid. Acta Paediatr Scand, 1991 Feb, 80(2), 205 - 12 Antibiotic susceptibility of 629 bacterial blood and CSF isolates from Swedish infants and the therapeutic implications; Tullus K et al.; Blood and CSF isolates (n = 629) from Swedish infants up to one year of age were tested in vitro against 13 antimicrobial agents in order to update the guidelines for empiric therapy of septicaemia and meningitis . Ampicillin plus gentamicin provided inadequate empiric therapy for meningitis, due to the poor CSF penetration of the aminoglycoside and the frequent occurrence of bacterial resistance to ampicillin . Ceftazidime and cefuroxime were moderately active, particularly against isolates from small infants . Cefotaxime today seemed to provide the best empiric therapy of septicaemia and meningitis in infants . Because of the occurrence of Listeria and enterococcal infections, ampicillin should initially be added and other combinations are also advisable for the occasional cases of Enterobacter, Citrobacter, Serratia, and Pseudomonas infections . For coagulase-negative staphylococci only vancomycin offered a broad activity (100% at achievable serum levels). Antimicrob Agents Chemother, 1991 Feb, 35(2), 329 - 34 In vitro activity of a catechol-substituted cephalosporin, GR69153; Wise R et al.; The in vitro activity of GR69153, a new catechol-substituted cephalosporin, was compared with those of ceftazidime, imipenem, meropenem, and ceftriaxone against 604 recent clinical isolates and other strains with known mechanisms of resistance . The MICs of GR69153 for 90% of the members of the family Enterobacteriaceae tested were less than 0.5 micrograms/ml, with the exceptions of those for Serratia spp . (4 micrograms/ml), Citrobacter spp . (2 micrograms/ml), and Enterobacter spp . (8 micrograms/ml) . Ninety percent of Pseudomonas aeruginosa isolates were susceptible to less than or equal to 1 microgram of GR69153 per ml . With the exception of methicillin-resistant strains, 90% of Staphylococcus aureus isolates were susceptible to less than or equal to 2 micrograms/ml, and GR69153 was four- to eightfold more active than ceftazidime and ceftriaxone against these strains . Isolates of Haemophilus influenzae, Branhamella catarrhalis, Neisseria spp., and Streptococcus pneumoniae (penicillin susceptible) were highly susceptible (MIC for 90% of the strains, less than or equal to 0.12 micrograms/ml) . GR69153 was stable to hydrolysis by the TEM-1 and TEM-5, SHV-1 and SHV-2, and K1 beta-lactamases, but some susceptibility to hydrolysis by the TEM-3, TEM-9, and P99 enzymes was observed . The protein-binding activity of GR69153 was 74.5 to 66.8%, depending on the concentration, and serum had little effect upon activity. Antimicrob Agents Chemother, 1991 Feb, 35(2), 259 - 66 In vitro activity and beta-lactamase stability of GR69153, a new long-acting cephalosporin; Chin NX et al.; GR69153, a new parenteral cephalosporin, inhibited 90% of Escherichia coli, Klebsiella oxytoca, Proteus mirabilis, Citrobacter diversus, shigellae, and salmonellae at less than 0.25 micrograms/ml (MIC90) . It had activity comparable to those of ceftazidime, cefpirome, cefepime, and E-1040 . Against cephalosporinase-producing Enterobacter cloacae, Citrobacter freundii, and Serratia marcescens, MICs ranged from 0.12 to greater than 32 micrograms/ml, and cefpirome and cefepime were the most active agents against these species . Pseudomonas aeruginosa was highly susceptible to GR69153, and for this organism the MIC90 was less than or equal to 2 micrograms/ml, which was similar to the E-1040 MIC90, but most Pseudomonas cepacia and Xanthomonas maltophilia isolates were resistant . GR69153 inhibited Haemophilus influenzae and Moraxella branhamella at less than or equal to 0.5 micrograms/ml . For Staphylococcus aureus GR69153 MICs were similar to those of ceftazidime and E-1040 . Enterococci and listeriae were resistant to GR69153, but Streptococcus pyogenes and Streptococcus pneumoniae were inhibited by 0.5 micrograms/ml . The activity of GR69153 was not affected by serum . GR69153 was not inactivated by the beta-lactamases of Staphylococcus aureus, TEM-1, TEM-2, SHV-1, and BRO-1, but it was hydrolyzed by TEM-3, TEM-9, and morganellae . GR69153 had overall activity comparable to those of commercially available parenteral cephalosporins or those found in clinical investigations . It is more active against bacteroides than most available aminothiazolyl parenteral cephalosporins are . GR69153 is hydrolyzed by the new plasmid beta-lactamases, and thus, its primary value may be related to its pharmacological properties. FEMS Microbiol Lett, 1991 Feb, 62(1), 7 - 10 Phosphatase production by a Citrobacter sp . growing in batch cultures retarded by anaerobic or osmotic stress, and the effect of the osmoprotectant glycine betaine; Hallett DS et al.; The effect of 500 mM NaCl on the growth, and phosphatase production of a Citrobacter sp . was investigated . Although growth was retarded, phosphatase production was enhanced by 50% . Relief from osmotic stress using the osmoprotectant glycine betaine gave normal growth, but phosphatase activity was reduced . The Citrobacter sp . ceased to grow following a shift to anaerobic conditions, but anaerobically-incubated cells continued to produce phosphatase after a transient lag. FEMS Microbiol Immunol, 1991 Feb, 3(1), 1 - 5 Saccharide-protein covalent conjugates: immunochemical characterization of Citrobacter 036 core oligosaccharide-tetanus toxoid conjugates; Lugowski C et al.; Core oligosaccharides (complete and incomplete) isolated from Citrobacter 036 lipopolysaccharide were covalently conjugated with tetanus toxoid . Serological examination of the Citrobacter 036 core oligosaccharide-tetanus toxoid conjugates showed that they are strong immunogens . The monospecific anti-conjugate sera prepared by immunization of rabbits, were used to study the antigenic relations between lipopolysaccharide core regions of 8 strains of Citrobacter . Immunoelectrophoresis, immunoblotting and quantitative microprecipitation were performed in the experiments. Zentralbl Mikrobiol, 1991, 146(2), 149 - 56 {Microbiological quality of mechanically deboned beef}; Prasovska M et al.; Microbial quality of mechanically deboned beef (MDB), which was obtained by the discontinuous hydraulic horizontal separator, type Inject-Star (firm LASKA, Austria), was analyzed for the presence of indicatory microorganisms (coliforms and enterococci), pathogenic and conditionally pathogenic microorganisms . The basic microbial parameters have been determined separately for MDB of 1st, 2nd degrees as well as for average daily samples from one collecting vessel . Apart from it, also a raw material (beef from flesh bones intended for separation) and salt MDB after 24 hrs storing in chiller before working it into meat products were examined by the same way . From our results it follows that the number of all microorganisms observed in MDB of 1st degree was lower than that of 2nd degree . During the separation process the increase of microbial parameters compared with those in initial raw material occurred by 1-2 radices and following subsequent salting and storing in chiller there was a repeated decrease by 1 radix (with exception of the number of Staphylococci remaining unchanged) . The change in the amount of microflora present was also influenced by season--in summer there was an increase by about 1 radix . From the view point of food hygiene the finding of salmonellas and the presence of large number of Staphylococci including Staphylococcus aureus on average 10(5).g-1 as well as the presence of wide extent of conditionally pathogenic microorganisms from the family of Enterobacteriaceae, especially from genera Proteus, Providencia, Morganella and Citrobacter are of great importance. Antimicrob Agents Chemother, 1991 Jan, 35(1), 14 - 9 Antibacterial activities in vitro and in vivo and pharmacokinetics of cefquinome (HR 111V), a new broad-spectrum cephalosporin; Limbert M et al.; Cefquinome is a new injectable aminothiazolyl cephalosporin derivative . It is stable against chromosomally and plasmid-encoded beta-lactamases and has a broad antibacterial spectrum . Staphylococcus aureus, streptococci, Pseudomonas aeruginosa, and members of the family Enterobacteriaceae (Escherichia coli, Salmonella spp., Klebsiella spp., Enterobacter spp., Citrobacter spp., and Serratia marcescens) are inhibited at low concentrations . Cefquinome is also active against many strains of methicillin-resistant staphylococci and enterococci . Its in vitro activity against gram-negative anaerobes is very limited . The high in vitro activity of cefquinome is reflected by its high in vivo efficacy against experimental septicemia due to different gram-positive and gram-negative bacteria . We studied the pharmacokinetic properties of cefquinome in mice, dogs, pigs, and calves . After single parenteral administrations, cefquinome displayed high peak levels, declining with half-lives of about 0.5, 0.9, 1.2, and 1.3 h, respectively . The areas under the concentration-time curve determined for dogs and mice showed linear correlations to the given doses . In dogs the urinary recovery was more than 70% within 24 h of dosing. Diagn Microbiol Infect Dis, 1991 Jan-Feb, 14(1), 79 - 83 Antimicrobial effects of the combination of ceftibuten and an orally absorbed penem SCH 29482; Chin NX et al.; Ceftibuten is a new beta-lactamase-stable 3-aminothiazolyl cephalosporin that lacks activity against staphylococci and group-B streptococci . We determined the effect of the combination of ceftibuten with SCH 29482, an orally absorbed penem . The combination of the two agents was additive for 25% or indifferent for 57% of the Gram-positive species, Haemophilus, and Moraxella tested with a mean fractional inhibitory concentration (FIC) index of 0.75 . The combination of ceftibuten and SCH 29482 was also indifferent for Bacteroides fragilis and other Bacteroides species, all of which were inhibited by less than or equal to micrograms/ml of SCH 29482 . Antagonism of the combination was found for 80% of Serratia marcescens and for 30% of Citrobacter freundii and Enterobacter cloacae . Overall, the combination of ceftibuten and SCH 29482 at concentrations that can be achieved in serum after ingestion of 400 and 50 micrograms/ml, respectively, provided antibacterial activity against most Gram-positive aerobic and anaerobic species that cause upper respiratory, intraabdominal, and urinary infections. DICP, 1991 Jan, 25(1), 27 - 9 Successful treatment of neonatal Citrobacter freundii meningitis with ceftriaxone; Rae CE et al.; Citrobacter meningitis is an uncommon enteric gram-negative infection that afflicts neonates and young children . Approximately 30 percent of children treated or untreated die from the infection . We report a case of C . freundii meningitis that was resistant to ampicillin and was successfully treated with ceftriaxone, a third-generation cephalosporin . A 13-day-old, full-term baby was admitted to the hospital with a one-day history of fever up to 38.8 degrees C . On admission the infant had a temperature of 39.2 degrees C, pulse of 140 beats/min, and a respiratory rate of 32 breaths/min . Except for a slightly bulging fontanelle, the rest of the physical examination was within normal limits . Complete blood count revealed a white blood cell (WBC) count of 12.5 x 10(9)/L, with 0.66 polymorphonuclear cells, 0.10 bands, 0.18 lymphocytes, and 0.06 monocytes . A stat lumbar puncture showed 10 WBCs per high-power field with gram-negative rods . Empiric therapy with ampicillin 225 mg q12h and gentamicin 11 mg q8h was started . Both antibiotics were discontinued after culture and sensitivity results were positive for C . freundii in the blood and spinal fluid . The patient was successfully treated with nine days of ceftriaxone 250 mg q12h. Scand J Infect Dis Suppl, 1991, 78, 7 - 16 Mechanisms of resistance to beta-lactam antibiotics; Livermore DM; The use of new beta-lactam antibiotics has led to selection of novel forms of resistance . Newer-generation cephalosporins, ureidopenicillins and monobactams, but not carbapenems (e.g . imipenem), are labile to Class I chromosomal beta-lactamases and tend to select mutants of E . cloacae and P . aeruginosa that constitutively synthesize high levels of these enzymes . Selection occurs more rarely with Serratia, Citrobacter and indole positive protease . Third-generation cephalosporins and monobactams, but not carbapenems and cephamycins, are inactivated by a range of new variants of the well-known TEM and SHV-1 plasmid-mediated beta-lactamases . These variants have arisen by spontaneous mutation and differ only marginally in amino-acid sequence from their parent enzymes . Already prevalent in France, their potential for spread is a major concern . Outer membrane impermeability is another source of resistance to beta-lactams in Gram-negative bacteria . Rare in enterobacteria, it is more important in P . aeruginosa, where broad and narrow spectrum forms can arise via mutation . The narrow spectrum form involves loss of the D2 outer membrane protein and gives resistance to carbapenems but not other beta-lactams . The broad spectrum form, of unknown mechanism, simultaneously affects many beta-lactam and unrelated (e.g . quinolone) drugs, but not imipenem . Target (penicillin-binding protein) insensitivity also can mediate resistance, most notably in MRSA . Unlike the mechanisms described above, this affects all beta-lactams, including carbapenems as well as penicillins and cephalosporins. Scand J Infect Dis Suppl, 1991, 78, 54 - 63 Clinical implications of multi-drug resistance in the intensive care unit; Snydman DR; A prospective in vitro survey of Gram-negative isolates obtained from patients hospitalized in intensive care units in 10 Boston teaching hospitals was undertaken to document current susceptibility patterns and analyze patterns of cross-resistance . One thousand and five isolates were obtained, 18% were pseudomonas, 18% Escherichia coli, 13% klebsiella, and 22% were in the enterobacter, citrobacter, serratia group . Cross-resistance among beta-lactams and beta-lactamase inhibitors was common for species with a potential to produce the type I inducible beta-lactamase (p less than 0.01) . In contrast, resistance to imipenem was not associated with cross-resistance . Ciprofloxacin and netilmicin also remained active . Clinical observations of the development of cross-resistance to the beta-lactams in enterobacter and citrobacter infections in four patients (two bacteremias and two wound infections) seen in one institution confirm these in vitro findings . Unanswered questions remain regarding the frequency of beta-lactam cross-resistance, the most likely sites of occurrence and the overall clinical significance . Clinicians should be aware of the potential selection of type-I beta-lactamase hyperproducers by the use of second or third generation cephalosporins or related beta-lactam agents. Chemotherapy, 1991, 37(3), 202 - 5 Bactericidal effect of 15-deoxyspergualin on Staphylococcus aureus; Hibasami H et al.; 15-Deoxyspergualin (DSG), an immunosuppressive agent used in organ transplantation, exerts metabolic and antiproliferative effects on methicillin- and gentamicin-resistant Staphylococcus aureus and other bacteria (e.g . Sarcina lutea, Bacillus subtilis, Shigella sonnei, Salmonella typhi and Citrobacter freundii) . DSG, at the concentration of 20 mg/l, depleted intracellular putrescine and spermidine in S . aureus to 43 and 40% of the controls, respectively . In these polyamine-depleted S . aureus cells, the synthesis of protein, DNA and RNA was decreased to 20, 85, 78% of the controls . The minimal inhibitory concentrations (MIC) of DSG for growth of S . aureus, S . lutea, B . subtilis, S . sonnei, S . typhi and C . freundii were 17, 13, 7, 15, 4, and 29 mg/l, respectively. J Hyg Epidemiol Microbiol Immunol, 1991, 35(1), 57 - 64 Bacterial isolates and drug susceptibility tests at Kaffa Regional Public Health Laboratory, south west Ethiopia; W/Tenssay Z; A two year period bacteriological data was analysed and the frequent bacterial isolates from different clinical specimens included: S . aureus, 25% E . coli, 15%; Proteus spp 14%; Citrobacter-Enterobacter group, 10% coagulase negative Staphylococcus species, 9%; and other miscellaneous bacteria each less than 9% . The majority of the bacterial isolates were resistant to commonly available antimicrobial agents like tetracycline, ampicillin, and chloramphenicol. Zhonghua Yi Xue Za Zhi (Taipei), 1991 Jan, 47(1), 39 - 44 {Pediatric bacteremia strains grow in blood culture media}; Chiang TM et al.; Bacteremia strains may influence the clinical therapy, the isolation of bacteremia strains is important for patients . In order to understand the distribution and the growth in the blood culture media of bacteremia strains, from January 1982 through December 1988 we studied the blood culture sent to us from the pediatric ward . These were three hundred and forty one bacterial strains (3.1%) isolated from patients . In the meantime we also studied the bacteremia strains growth in the blood culture media . In these positive cultures, there were 83 gram-positive, and 258 gram-negative strains . The 83 gram-positive included Staphylococcus aureus (38 strains), hemolytic streptococcus (22 strains), Enterococcus (13 strains), Streptococcus pneumoniae (8 strains) and others (2 strains) . The 258 gram-negative strains included Escherichia coli (97 strains), Salmonella spp . (43 strains), Enterobacter spp . (31 strains) . Klebsiella spp . (23 strains), Pseudomonas spp . (25 strains), Proteus spp . (17 strains), Citrobacter spp . (11 strains) and others (11 strains) . The Growth of bacteremia strains in the blood culture medium, showed that first day isolation strains were 33.7%, second day strains 24.9%, third day were 19.9%, fourth day were 13.5%, fifth day were 3.2%, sixth day were 4.1% and seventh day were 0.6% . In conclusion, the bacteremia strains showed that the gram-negative, which were 75.7%, were more prevalent than the gram-positive which were 24.3%, the isolation of the strains was more in the first to fourth day and grew by 92%, on the fifth day it grew by 3.2% and on the seventh day by only 0.6% . On the fifth day the baby had recovered and we were able to discontinue antibiotic therapy. Bull Soc Pathol Exot, 1991, 84(5 Pt 5), 627 - 34 {Virological and bacteriological study of materno-fetal infections in Brazzaville}; Yala F et al.; Serological study of serum samples taken from pregnant women and umbilical cord and bacteriological study of vaginal secretions samples and cerebrospinal fluid (CSF) showed in mothers: T . pallidum antibody (Tp ab) 9%, Rubella virus antibody (Ru ab) 85%; HBs Ag 16%, HIV antibody (HIV ab) 4% . Microbe culture showed: S . aureus 18%, Streptococcus sp . 9%, E . coli 4.9%, Klebsiella 3.6%, Citrobacter 3.6%, Candida albicans 15%; direct immunofluorescence: Chlamydia 26% . In infants: IgG umbilical cord: Tp ab 4.8%, Rub ab: 80.6%, HIV ab 4/4, Hbs Ag 11.3% Microbe culture in CSF: global frequency: 5.1%; Streptococcus sp . 31.8%, Staphylococcus 20.5%, enterobacteriaceae 27.2%, other Gram negative bacilli 20.5%. Pediatr Neurosurg, 1991-92, 17(1), 23 - 4 Neonatal meningitis and bilateral cerebellar abscesses due to Citrobacter freundii; Joaquin A et al.; We report bilateral cerebellar abscesses in a neonate with Citrobacter freundii meningitis . The mortality and morbidity of Citrobacter abscess is high . Rapidly developing drug resistance may play a role as illustrated by our case. Acta Microbiol Hung, 1991, 38(2), 147 - 54 What is the diagnostic value of beta-D-glucuronidase (BDG) activity of bacteria using Fluorocult ECD agar for their cultivation? Ralovich B, Ibrahim GA, Fabian A, Herpay M. A total of 1510 strains from 15 genera of Gram-negative and Gram-positive bacteria were studied . More than 94% of 327 Escherichia coli strains showed beta-D-glucuronidase (BDG) activity . Seventeen serotypes from 170 E . coli O serogroup representatives were negative . Relationship between the existence of BDG positive and negative E . coli strains in the same serogroup or serotype has not been observed . The rate of BDG positivity was 42% among Salmonella arizonae strains and 42.2% among Shigella strains . Only one Citrobacter strain out of the 971 strains belonging to Citrobacter, Edwardsiella, Enterobacter, Hafnia, Klebsiella, Proteus, Serratia, Yersinia, Pseudomonas, Aeromonas, Vibrio and Listeria was BDG positive . A screening method based on only BDG activity is not sufficient for the primary diagnosis of E . coli. Chemotherapy, 1991, 37(5), 310 - 7 In vitro and in vivo activity of carbamate-linked dual-action antibacterial Ro 24-4383; Beskid G et al.; Ro 24-4383 contains desacetylcefotaxime linked by a carbamate bond at the 3' position to ciprofloxacin . Ro 24-4383 was active against 99% of the 363 gram-positive and gram-negative aerobes tested in vitro, while the comparative agents cefotaxime and ciprofloxacin were active against 77 and 97%, respectively . The activities (ED50: mg/kg s.c.) of Ro 24-4383, cefotaxime and ciprofloxacin in systemic murine infections were: Escherichia coli 257, 1.4, less than 0.5, less than 0.2; Klebsiella pneumoniae A, 11, 30, 0.7; Enterobacter cloacae 5699, 3.2, 35, less than 0.2; Citrobacter freundii BS16, 3, 41, less than 0.5; Serratia marcescens SM, 35, greater than 100, 1.6; Pseudomonas aeruginosa 5712, 67, 100, 10; P . aeruginosa 8780, 33, 193, 3; Staphylococcus aureus Smith (oxacillin-susceptible), 12, 3.7, 1; S . aureus 753 (oxacillin-resistant), 28, greater than 100, 2; Streptococcus pneumoniae 6301, 10, 15, greater than 50, and S . pyogenes 4, 3.3, 1.6, 54 . Ro 24-4383, although inactive against the S.-pneumoniae-induced pneumonia following one administration of the agent, was highly active (ED50 = 1.5) when three treatments were given following infection . Ro 24-4383 was active against the K.-pneumoniae-induced pneumonia (ED50 = 37), as well as the meningitis induced by S . pneumoniae (ED50 = 158) or K . pneumoniae (ED50 = 100) . The protective effect of Ro 24-4383 was demonstrated when administered 8 h before infection with E . coli (ED50 = 37) and 4 h before infection with S . pyogenes (ED50 = 199). Drugs, 1991, 42 Suppl 3, 6 - 12 Microbiological evaluation of cefpodoxime proxetil; Wiedemann B et al.; Cefpodoxime, the active de-esterified molecule of the orally absorbable cephalosporin cefpodoxime proxetil, inhibits streptococci, Neisseria spp., and most Enterobacteriaceae, with MIC50 and/or MIC90 values of less than or equal to 2 mg/L; with regard to the latter family of bacteria, the MIC50 and/or MIC90 values of cefpodoxime are consistently greater than or equal to 4 mg/L for only Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, and Morganella morganii . The MIC50 of cedpodoxime for coagulase-negative staphylococci is greater than 2 mg/L, while the MIC for Staphylococcus aureus strains is 4 mg/L . In comparison with other orally absorbable cephalosporins, cefpodoxime is slightly less active than cefixime, cefetamet, and cefotiam against Gram-negative bacteria, but more active than cefuroxime, cefaclor, and cefalexin . Against staphylococci, the activity of cefpodoxime is comparable to that of cefotiam and cefuroxime, and superior to that of cefaclor, while cefixime and cefetamet have insufficient activity against these species . In common with other cephalosporins, cefpodoxime has no activity against enterococci . In vitro models simulating human serum cefpodoxime concentrations demonstrate that a dosage regimen of 200mg is probably sufficient to treat most infections . However, further study is needed to clarify whether infections due to bacteria such as S . aureus, with higher cefpodoxime MICs, can be treated with this dose regimen. Lab Delo, 1991, (7), 52 - 4 {The serologic diagnosis of group B salmonelloses}; Karal'nik BV et al.; Antibacterial sera activities towards Citrobacter O22 and Salmonella typhimurium were tested with O22, O1, O4, O5, O12 erythrocytic diagnostic agents . Cross activities of O22, O1, O4, O5, O12, and Hi antigens were tested with the same and Hi erythrocytic diagnostic agents in the antibody neutralization test . The findings have confirmed the identity or very close relationship between the tested O antigens . Screening for antigens of the excretions from patients with S . typhimurium and Citrobacter O22 infections has shown that indication of Hi antigen may be considered as the differentiating criterion between these infections. Lab Delo, 1991, (4), 62 - 4 {The etiologic structure of acute intestinal infections caused by opportunistic microorganisms (Irkutsk, 1984-1988)}; Kuznetsov VI et al.; The authors analyze the results of bacteriologic studies carried out in patients with intestinal infections at the laboratory of the Sanitary Epidemiologic Center of the town of Irkutsk over 1984-1988 . The records of 24,490 case histories show infections induced by opportunistic microflora in 37 percent of cases . The most frequent etiologic agents were Staphylococcus aureus and Enterobacteriaceae, genera: Proteus, Enterobacter, Citrobacter, Klebsiella, Hafnia . Analysis of the incidence of acute intestinal infections induced by opportunistic bacteria in various age groups evidence that mostly infants aged under 1 suffer from them . In older children S . aureus is no longer etiologically significant and it is replaced by Enterobacter and Klebsiella . The authors find it interesting to compare the etiological patterns of enteritis induced by opportunistic microorganisms in various regions of our country. Infection, 1991, 19 Suppl 5, S264 - 75 In vitro activity and stability against novel beta-lactamases of investigational beta-lactams (cefepime, cefpirome, flomoxef, SCE2787 and piperacillin plus tazobactam) in comparison with established compounds (cefotaxime, latamoxef and piperacillin); Bauernfeind A et al.; The therapeutic perspectives of flomoxef, SCE 2787, cefpirome, cefepime, latamoxef, cefotaxime and of piperacillin plus tazobactam were comparatively evaluated by their in vitro activity against 1119 clinical isolates of 83 bacterial species . Escherichia coli, Klebsiella spp . Enterobacter sakazakii, Proteus spp . and Shigella spp . were about equally susceptible to the cephalosporins (MIC90: 0.06 to 0.5 mg/l), while the MIC90 for piperacillin plus tazobactam was between 2 and 16 mg/l . Enterobacter cloacae, Enterobacter aerogenes and Serratia spp . were most susceptible to SCE 2787, cefpirome and cefepime (MIC90: 0.06 to 2 mg/l) followed by latamoxef, cefotaxime, flomoxef and piperacillin plus tazobactam . For Citrobacter spp., Providencia spp . and Yersinia enterocolitica MIC90 were between 0.06 and 0.5 mg/l . Flomoxef was between 2 to 4 log2 less active against these species but more active than piperacillin plus tazobactam (MIC90: 2 and 8 mg/l) . Morganella morganii and Hafnia alvei were most susceptible to cefepime, cefpirome and latamoxef (MIC90: 0.13 to 0.5 mg/l) while cefotaxime (MIC90: 8 mg/l) and piperacillin plus tazobactam (MIC90: 8 and greater than 64 mg/l) were the least active compounds . SCE 2787, cefepime and cefpirome were the most potent beta-lactams against the majority of the 13 species of non-fermentative bacilli (NFB) investigated (MIC90: 0.5 to 16 mg/l) . The oxacephems were the least active compounds against NFB . Cefepime was the most active of the compounds included against Pseudomonas aeruginosa (MIC90: 16 mg/l) . Haemophilus spp., Neisseria gonorrhoeae and Bordetella pertussis were most susceptible to cefotaxime (MIC90: 0.03 to 0.06 mg/l) . Latamoxef had the lowest activity of all compounds against gram-positive cocci . Flomoxef was the most active compound against penicillinase producing Staphylococcus aureus and about equally active as the other betalactams against methicillin susceptible staphylococci of other staphylococcal species.(ABSTRACT TRUNCATED AT 250 WORDS) J Antimicrob Chemother, 1991 Jan, 27(1), 29 - 40 In-vitro evaluation of ampicillin/brobactam and comparison with other beta-lactam antibiotics; Melchior NH et al.; The ability of brobactam to inhibit beta-lactamases and the in vitro activity of ampicillin combined with brobactam was compared with another beta-lactamase inhibitor, clavulanic acid, and other beta-lactam antibiotics . Both inhibitors showed good and similar activity against staphylococcal penicillinase and most broad-spectrum beta-lactamases found in the Enterobacteriaceae, whether plasmid or chromosomally mediated . Both inhibitors were less active against chromosomally mediated cephalosporinases in Enterobacteriaceae, but brobactam was 8-50 times more potent than clavulanic acid . The amount and type of beta-lactamase produced by a particular bacterial strain was reflected in its sensitivity to a combination of ampicillin and brobactam, and correlated well with the sensitivity of extracted beta-lactamase to inhibition by brobactam . The in-vitro activity of ampicillin/brobactam in a 3:1 ratio was compared to amoxycillin/clavulanic acid (4:1 ratio), amoxycillin, cefaclor and cefuroxime . The two inhibitor combinations were generally of similar activity, but the brobactam combination had superior activity against Proteus vulgaris, Morganella morganii, Citrobacter freundii and Yersinia enterocolitica . The cephalosporins were less effective against the Bacteroides fragilis group, Prot . vulgaris and M . morganii, but had advantages in the case of Escherichia coli, Klebsiella spp . and C . diversus . The MBC of ampicillin/brobactam was similar to the MIC . No resistant sub-populations were observed amongst the staphylococcal strains investigated . Exposure of bacteria to sub-inhibitory levels of ampicillin/brobactam did not lead generally to the development of resistance. J Antimicrob Chemother, 1990 Dec, 26 Suppl E, 7 - 12 In-vitro activity of cefpodoxime against 1834 isolates from domiciliary infections at 20 UK centres; Holt HA et al.; A total of 1834 non-copy, general practice or outpatient isolates were collected by 20 hospital laboratories within the British Isles, and identified and tested for susceptibility to nine antimicrobial agents available by oral administration at one centre . Against Enterobacteriaceae cefpodoxime was the most active beta-lactam agent tested, the MIC90s being: for Escherichia coli 1.0 mg/l, for Proteus mirabilis 1.0 mg/l, for Citrobacter spp . 2.0 mg/l, and for Enterobacter spp., Serratia spp., Morganella spp . and Klebsiella spp . 16-64 mg/l . Cefpodoxime also showed a certain amount of activity against staphylococci and high activity against streptococci, the MIC90s being for Staphylococcus aureus 2 mg/l, for coagulase negative staphylococci 8 mg/l, for Streptococcus pyogenes 0.015 mg/l, for Str . pneumoniae 0.06 mg/l and for Str . agalactiae 0.5 mg/l. Int J Food Microbiol, 1990 Dec, 11(3-4), 351 - 4 Antibiotic resistance among coliform bacteria isolated from carcasses of commercially slaughtered chickens; Turtura GC et al.; A total of 322 coliform bacteria Escherichia coli, Enterobacter spp., Citrobacter spp., Klebsiella spp . and Serratia spp., were isolated from 50 carcasses of commercially slaughtered chickens . Their resistance to ampicillin, tetracycline, gentamicin, chloramphenicol, cephalotine, cotrimoxazole, nalidixic acid and nitrofurantoin, were determined . The most commonly found resistance was to tetracycline followed by cephalotine, cotrimoxazole and nalidixic acid . A large percentage of E . coli (41%) and Klebsiella spp . (38%) showed multiple antibiotic resistance. J Bacteriol, 1990 Dec, 172(12), 7138 - 44 Genetic analysis of Escherichia coli urease genes: evidence for two distinct loci; Collins CM et al.; Studies with two uropathogenic urease-producing Escherichia coli strains, 1021 and 1440, indicated that the urease genes of each are distinct . Recombinant plasmids encoding urease activity from E . coli 1021 and 1440 differed in their restriction endonuclease cleavage sites and showed minimal DNA hybridization under stringent conditions . The polypeptides encoded by the DNA fragments containing the 1021 and 1440 urease loci differed in electrophoretic mobility under reducing conditions . Regulation of urease gene expression differed in the two ureolytic E . coli . The E . coli 1021 locus is probably chromosomally encoded and has DNA homology to Klebsiella, Citrobacter, Enterobacter, and Serratia species and to about one-half of the urease-producing E . coli tested . The E . coli 1440 locus is plasmid encoded; plasmids with DNA homology to the 1440 locus probe were found in urease-producing Salmonella spp., Providencia stuartii, and two E . coli isolates . In addition, the 1440 urease probe was homologous to Proteus mirabilis DNA. Antimicrob Agents Chemother, 1990 Dec, 34(12), 2429 - 30 Induction of the Citrobacter freundii group I beta-lactamase in Escherichia coli is not dependent on entry of beta-lactam into the cytoplasm; Everett MJ et al.; Induction of the cloned ampC Citrobacter freundii beta-lactamase in Escherichia coli by 6-aminopenicillanic acid was prevented by periplasmic TEM beta-lactamase in the same cell . In contrast, cytoplasmic TEM beta-lactamase did not prevent induction . This result implies that entry of the beta-lactam into the cytoplasm is not necessary for induction of ampC. J Antimicrob Chemother, 1990 Dec, 26(6), 749 - 62 A comparison of the mechanisms of decreased susceptibility of aztreonam-resistant and ceftazidime-resistant Enterobacteriaceae; Piddock LJ et al.; Twenty five strains of Enterobacteriaceae (five each of Enterobacter cloacae, Citrobacter freundii, Serratia marcescens, Morganella morganii and Providencia stuartii) were exposed to aztreonam and ceftazidime at 1/2 and 1 x MIC in liquid medium for 22 h, and also to 3, 5 and 10 x MIC and 16 mg/l of each agent in agar . Any putative mutant with an increase in the MIC of greater than or equal to 4 fold was examined for beta-lactamase expression and outer membrane protein profile . Mutants were selected on agar at approximately 10(7); however in liquid medium not all strains yielded mutants . Mutants lacking an outer membrane protein (OMP) with a molecular weight of 40,000 (+/- 5000) were selected with both agents, as were mutants expressing constitutive Richmond and Sykes Class 1 beta-lactamase . For the Ent . cloacae mutants increased beta-lactamase gave rise to MICs above the breakpoint of both agents, whereas with the other species ceftazidime susceptibility was more affected . Strains that were OMP- rarely had MICs above the breakpoint, unless there was also increased beta-lactamase expression, as in species such as M . morganii . Hence the major mechanism of resistance in these strains would appear to be beta-lactamase mediated rather than due to altered expression of outer membrane proteins. Diagn Microbiol Infect Dis, 1990 Nov-Dec, 13(6), 509 - 16 In vitro activity of HRE 664, a penem antibiotic; Chin XN et al.; HRE 664, a new penem antibiotic, inhibited 90% of Escherichia coli, Klebsiella, Citrobacter diversus, Proteus mirabilis, Proteus vulgaris, Salmonella, Shigella, Providencia, Aeromonas, and Morganella at less than or equal to 2 micrograms/ml but was considerably less active than cefotaxime, ceftazidime, and imipenem . It did not inhibit Pseudomonas aeruginosa (MIC greater than 128 micrograms/ml) . HRE 664 inhibited Enterobacter spp., Citrobacter freundii, and Serratia marcescens at 1-8 micrograms/ml, two- to fourfold higher MICs than imipenem . HRE 664 inhibited methicillin-susceptible Staphylococcus aureus and Staphylococcus epidermidis at less than or equal to 0.12 micrograms/ml, but methicillin-resistant S . aureus and S . epidermidis were resistant . Group A, C, and G streptococci and Streptococcus pneumoniae were inhibited by 0.06 micrograms/ml . Bacteroides and Clostridium species were inhibited by 0.25 micrograms/ml comparable to imipenem . HRE 664 was not hydrolyzed by beta-lactamases TEM-1, TEM-2, TEM-3, TEM-5, SHV-1, PSE-1, PSE-4, OXA-2, OXA-3, K-1, P99, Morganella, P . vulgaris, and S . aureus PC-1 but was hydrolyzed by the beta-lactamase of Xanthomonas maltophilia. Indian J Pediatr, 1990 Nov-Dec, 57(6), 781 - 4 Neonatal citrobacter sepsis: clinical and epidemiological aspects; Christo GG et al.; Fourteen neonates were diagnosed to have Citrobacter sepsis during 1986-89, representing 4.6% of all cases with bacteriologically proven sepsis . Most of these infants were low birth weight (mean 2046 gm, +/- 750) and preterm (mean 34.8 weeks, +/- 3.8) . Mean age at onset of sepsis was five days . In 10 cases the hematological profile was suggestive of sepsis . Infants had clinical evidence of multisystem infection; 2 with septic arthritis and 3 meningitis . The case fatality rate was 61% . Resistance to antibiotics was frequent . Citrobacter species were also cultured from other sites: umbilical stumps, eye swabs, urine, skin pustules and umbilical catheter tips . The epidemiological features and virulence of this organism call for vigilance and strict control measures. Res Microbiol, 1990 Nov-Dec, 141(9), 1103 - 16 Palindromic unit highly repetitive DNA sequences exhibit species specificity within Enterobacteriaceae; Gilson E et al.; Palindromic units (PU, or REP for repetitive extragenic palindrome) constitute a family of DNA sequences of 40 nucleotides which is highly repeated in the genome of Escherichia coli . We analysed the presence of PU sequences in 99 different bacterial genomes by cross-hybridization . When PU sequences were used as a probe, only DNA from Enterob