Rev Argent Microbiol, 1993 Jul-Sep, 25(3), 136 - 43 {Multiple resistance to heavy metals and antibiotics in bacteria isolated from the Riachuelo}; Bocca S et al.; Riachuelo is a heavy contaminated course of water, partially surrounding Buenos Aires city . The presence of bacteria resistant to antibiotics and heavy metals was studied . Among the isolated Gram positive colonies, 65, 59 and 48% were resistant to 60 micrograms/ml of Pb++, Zn++ and Cd++, respectively, and 20% grew in the presence of 50 micrograms/6ml gentamicin . Most of these microorganisms belonged to the order Actinomycetales . Accordingly, high percentages of resistance were detected (among the 11 Gram negative isolates (Enterobacteriaceae and Pseudomonaceae), although only one isolate was gentamicin resistant . Four Gram negative isolates also showed a broad spectrum of resistance to tetracycline, erythromyci, ampicillin, amikacin, chloramphenicol and gentamicin. Surgery, 1993 Jul, 114(1), 21 - 30 Risk factors for multiple organ system failure and death in critically injured patients; Tran DD et al.; BACKGROUND . This study was undertaken to evaluate the relative importance of factors related to the extent of multiple organ system failure (MOSF) and outcome in critical trauma . METHODS . We performed a retrospective case series analysis of 206 consecutive patients with trauma admitted to a surgical intensive care unit during a 5-year period . Multivariate methods were used to select independent factors related to the MOSF score and subsequent death . RESULTS . Multiple linear regression selected advancing age, prior chronic conditions, malnutrition, injury severity score (ISS), coma on admission, use of H2-receptor antagonists or antacids, number of blood transfusions, and intraabdominal infection as independent factors related to the MOSF score . Multiple logistic regression selected advancing age, chronic disease, ISS, and MOSF score as major predictors of death . CONCLUSIONS . Advancing age, prior chronic disease, malnutrition, coma on admission, and use of H2-receptor antagonists or antacids may impair host defenses of the gastrointestinal tract and predispose to invasive infection, thereby aggravating the severity of existing MOSF . These findings, together with the predominance of Enterobacteriaceae in patients with infection, suggest that bacterial translocation may be important in the late MOSF septic state . Although infection, particularly intraabdominal infection, is a major risk factor for MOSF, a nonspecific host response to critical trauma, as expressed by the ISS and transfusion requirement, and intestinal endotoxin may contribute to the development of the syndrome. Drugs, 1993 Jul, 46(1), 53 - 62 Intra-abdominal infections in children . Pathogenesis, diagnosis and management; Brook I; Intra-abdominal infections in children that follow perforation of viscus often involve the gastrointestinal aerobic and anaerobic bacterial flora . These organisms possess various virulence factors and exhibit potential synergy . The intra-abdominal infection is biphasic, with the Enterobacteriaceae as the major pathogens in the peritonitis stage, and the Bacteroides fragilis group predominating in the abscess stage . Experiments with animals and experience in patients support the need to use single or combined antimicrobial agent therapy that is effective against both Enterobacteriaceae and the B . fragilis group. Zh Mikrobiol Epidemiol Immunobiol, 1993 Jul-Aug, (4), 13 - 20 {The detection of the Shiga toxin antigen in connection with other virulence factors--the O and K antigens of enterobacteria}; Belaia IuA et al.; The results of the detection of Shiga toxin antigen in culture filtrates of 73 enterobacterial strains by the methods of countercurrent electrophoresis and coagglutination, as well as their correlation with the presence of other factors of virulence, O- and K-antigens, have been analyzed . Sharply pronounced inverse correlation between the capacity of enterobacteria to synthesize Shiga (Shiga-like) toxins and their capacity to synthesize acidic polysaccharide surface-specific K- (Vi-) antigens has been established. J Biol Chem, 1993 Jun 15, 268(17), 12321 - 4 252Cf plasma desorption mass spectrometry applied to the analysis of underivatized rough-type endotoxin preparations; Caroff M et al.; Plasma desorption mass spectrometry has recently been used with success to characterize native, underivatized Re- to Rc-type endotoxins in terms of their constituent lipopolysaccharides . The spectra give masses for the major molecular species of lipopolysaccharide present from which their probable compositions could be inferred using the overall composition determined by chemical analyses . Moreover, the relative intensities of the signals are roughly proportional to the abundance of their corresponding molecular species . Native Rc-, Rb-, and Ra-type enterobacterial endotoxins with 5-10 core sugar units have been rendered amenable to plasma-desorption mass spectrometry analysis by improvement in their solubility and the use of cellobiose as an additive . The spectra of four Salmonella and Escherichia endotoxin preparations demonstrated heterogeneity in acylation and phosphorylation . Since these sources of heterogeneity are critical for many biological activities, the spectra underline the need to define the composition of each preparation of endotoxin used in structure-function studies. Biochem J, 1993 Jun 1, 292 ( Pt 2), 537 - 43 A dramatic change in the rate-limiting step of beta-lactam hydrolysis results from the substitution of the active-site serine residue by a cysteine in the class-C beta-lactamase of Enterobacter cloacae 908R; Dubus A et al.; A cysteine residue has been substituted for the active-site serine of the class-C beta-lactamase produced by Enterobacter cloacae 908R by site-directed mutagenesis . The modified protein exhibited drastically reduced kcat./Km values on all tested substrates . However, this decrease was due to increased Km values with some substrates and to decreased kcat . values with others . These apparently contradictory results could be explained by a selective influence of the mutation on the first-order rate constant characteristic of the acylation step, a hypothesis which was confirmed by the absence of detectable acylenzyme accumulation with all the tested substrates, with the sole exception of cefoxitin. J Pediatr, 1993 Jun, 122(6), 974 - 81 Single-dose pharmacokinetics and safety of HA-1A, a human IgM anti-lipid-A monoclonal antibody, in pediatric patients with sepsis syndrome; Romano MJ et al.; The pharmacokinetics and safety of HA-1A (Nebacumab), a human IgM monoclonal antibody with specificity for the lipid A region of endotoxin, were evaluated in a multicenter trial of pediatric patients with sepsis syndrome or septic shock . Forty-two patients received a total of 44 infusions of drug, at a dose of 3 mg/kg (maximum 100 mg) . The mean age was 7 years 10 months (range, 11 months to 16 years 7 months) . The pharmacokinetic behavior of HA-1A during 36 hours was best described by a one-compartment open model . Clearance (6.1 +/- 2.0 ml/kg per hour) and apparent volume of distribution at steady state (0.11 +/- 0.03 L/kg) were larger than values reported previously in adults with sepsis syndrome . Elimination half-life (14.5 +/- 6.8 hours) and plasma concentration after infusion (30.7 +/- 14.5 mg/L) were similar to adults' values . In an additional three patients studied for 72 hours after administration, a biexponential function (i.e., two-compartment open model) best described the pharmacokinetic behavior of HA-1A: clearance (1.5 +/- 1.4 ml/hr per kilogram) and apparent volume of distribution at steady state (0.2 +/- 0.02 L/kg) were different (p < 0.002) from values observed in children's blood samples during 36 hours . Within the pediatric population, no age-related differences in pharmacokinetics could be detected . Drug disposition was unaffected by renal or hepatic dysfunction . Decreased blood pressure was the most frequently reported adverse event; 4 (9%) episodes in 44 infusions were considered possibly related to the study drug . Gram-negative bacteremia was documented in 23 (55%) of 42 patients . The overall mortality rate was 31% . Enterobacter cloacae was the most common pathogen isolated . Haemophilus influenzae type b was isolated from one child with sepsis syndrome . We conclude that infusion of HA-1A in children is associated with a low incidence of side effects . The pharmacokinetic-pharmacodynamic behavior of HA-1A in children requires further study to determine whether developmental differences exist and how these differences might affect drug administration . Efficacy remains to be studied. J Bacteriol, 1993 Jun, 175(11), 3459 - 67 The plasmid-encoded urease gene cluster of the family Enterobacteriaceae is positively regulated by UreR, a member of the AraC family of transcriptional activators; D'Orazio SE et al.; Ureolytic clinical isolates of Providencia stuartii, Salmonella spp., and some Escherichia coli strains contain large urease-encoding plasmids . Expression of urease activity from these isolates is induced at least 20-fold by urea . In order to facilitate studies on the regulatory mechanism controlling this urea-inducible expression, the plasmid-encoded urease genes were inserted into the low-copy-number vector pRK415, to form pSEF70 . Deletion mutagenesis of pSEF70 demonstrated that between 1.3 and 1.6 kb of DNA upstream of ureD (the first of seven urease genes clustered in an operon-like fashion) was required for a urease-positive phenotype . An open reading frame coding for a 34.1-kDa polypeptide was found in the DNA sequence of this upstream region . This open reading frame has been designated ureR, for urease regulator . A urea-inducible promoter region was identified upstream of ureD . Transcription from this promoter was activated only when ureR was present in trans . The predicted ureR gene product contains a helix-turn-helix motif and shows significant amino acid similarity to the AraC family of transcriptional activators . We conclude that urea-dependent expression from the plasmid-encoded urease gene cluster requires ureR and that ureR codes for a positive regulatory element controlling transcription of at least one essential urease gene, ureD. J Antimicrob Chemother, 1993 Jun, 31(6), 855 - 63 Comparison of the mechanism of action and resistance of two new fluoroquinolones, rufloxacin and MF961 with those of ofloxacin and fleroxacin in gram-negative and gram-positive bacteria; Piddock LJ et al.; For rufloxacin MF961, ofloxacin and fleroxacin the inhibition of DNA synthesis, intracellular accumulation, optimum bactericidal concentration (OBC) and killing kinetics at the OBC for Enterobacteriaceae, Pseudomonas aeruginosa and staphylococci and induction of recA in Escherichia coli were determined . All agents had good activity against all the strains and inhibited DNA synthesis by 50% at concentrations correlating with the MIC . The maximum recA inducing concentrations after 60 min exposure to the quinolones in E . coli were 0.5 mg/L of rufloxacin, MF961, ofloxacin and 0.05 mg/L of fleroxacin . Accumulation of all quinolones was rapid; however, higher concentrations of all agents were accumulated within staphylococci than in Gram-negative bacteria . Rufloxacin was accumulated to higher concentrations in all bacteria than the other three agents . Laboratory mutants with decreased susceptibility to the four drugs were selected from each strain . All agents selected mutants with decreased susceptibility to quinolones alone, with phenotypes suggesting mutations in gyrA . Multiply-resistant mutants were also selected; however, as few had decreased expression of OmpF, the mutated gene is unlikely to be an allele of marA . All mutants had MICs > or = 2 mg/L, a typical breakpoint concentration for most quinolones. Mol Cell Probes, 1993 Jun, 7(3), 171 - 8 Salmonella identification by the polymerase chain reaction; Aabo S et al.; Polymerase chain reaction (PCR) primers for genus specific detection of Salmonella have been selected from a Salmonella-specific fragment of 2.3 kilobases (kb) . Due to interserovar sequence diversity within this fragment, primer selection was based on DNA sequence alignment of sequences from 20 different Salmonella serovars . The specific PCR product of 429 base pairs (bp) was formed from 144 of 146 salmonella strains tested (116 of 118 serovars) . The two false-negative strains belonged to two different serovars of the rarely isolated subspecies IIIa (monophasic S . arizonae) . No product was produced in any of 86 non-Salmonella Enterobacteriacea strains tested, covering 41 species from 21 genera. Eur J Clin Microbiol Infect Dis, 1993 Jun, 12(6), 469 - 72 Ampicillin-sulbactam susceptibility testing criteria; Barry A et al.; In vitro studies in five different medical centers documented the susceptibility of 2,440 consecutive isolates of the Enterobacteriaceae against ampicillin-sulbactam disks of different potencies . For determination of MICs, both 2:1 or 1:1 ratios were used as long as the concentrations of sulbactam at the breakpoints remained the same, i.e . MIC < or = 16/8.0 micrograms/ml or < or = 8.0/8.0 micrograms/ml for the susceptible category . Disks containing 10 micrograms of ampicillin and 10 micrograms of sulbactam are still to be preferred with interpretive criteria of > or = 15 mm for susceptible and < or = 11 mm for resistant (MIC > or = 64/32 micrograms/ml or > or = 32/32 micrograms/ml) . The reliability of the disk test actually diminished when the amount of sulbactam in the disk was increased. Can J Microbiol, 1993 Jun, 39(6), 581 - 7 Host range and transfer efficiency of incompatibility group HI plasmids; Maher D et al.; HI plasmids are distinguished by their thermosensitive mode of conjugation (transfer efficiency is optimal at 22-30 degrees C) and their capacity to encode multiple antibiotic resistance . These traits have implicated HI plasmids as potential vectors in the dissemination of antibiotic resistance among pathogenic and indigenous bacterial species in water and soil environments . We compared the transfer efficiency of HI plasmids with that of plasmids from 13 other incompatibility groups at 37, 24, and 14 degrees C in intragenic conjugations between laboratory strains of Escherichia coli K-12 under in vitro conditions . Only the HI plasmids and a representative plasmid from incompatibility groups M, N, P alpha, T, and W were observed to be transmissible at 14 degrees C . These plasmids, along with HI plasmids and the related HII representative, were tested for their host range and transfer proficiency to Enterobacteria species and some other Gram-negative organisms of environmental significance at 24 and 14 degrees C . Notable differences in the host range of HI plasmids compared with plasmid representatives from the other enterobacterial groups were not evident at 24 degrees C . At 14 degrees C, R478 (HI2) displayed the broadest host range and transfer proficiency among the test plasmids . The ability of several plasmid groups, including HI, to transfer at 14-24 degrees C to Vibrio cholerae non 01, Salmonella typhi, and the fish pathogens Aeromonas salmonicida, Vibrio anguillarum, and Yersinia ruckeri needs to be corroborated by in situ studies. Can J Microbiol, 1993 Jun, 39(6), 555 - 61 A two-part energy burden imposed by growth of Enterobacter cloacae and Escherichia coli in sodium dodecyl sulfate; Aspedon A et al.; Enterobacter cloacae, like most enteric bacteria, can grow in the presence of 10% sodium dodecyl sulfate (SDS) . The bacteria tolerate the detergent and do not metabolize it . In a defined glucose-salts medium the growth rate remained unchanged (G = 55 min) as the detergent concentration was increased from 0 to 10% SDS . However, growth in SDS exhibited a two-part energy dependence . In part 1, the SDS-grown cells underwent rapid lysis when they ran out of energy . Cells that had entered stationary phase owing to carbon limitation lysed, while those that had entered owing to nitrogen or phosphorus limitation did not . We attribute part 1 of the energy dependence to SDS as a detergent . In part 2, the cells grown in 5 or 10% SDS exhibited longer lag periods, potassium accumulation, decreased cell yields, and higher oxygen consumption . The higher oxygen consumption occurred during both exponential phase and nitrogen-limited stationary phase . However, the decreased cell yield and higher oxygen consumption of SDS-grown cells were mimicked by cells grown in equivalent concentrations of sucrose or polyethylene glycol . We attribute part 2 of the energy dependence to SDS as a solute . Finally, with regard to the as yet unidentified bacterial osmotic stress detector, we used the micelle-forming nature of SDS to conclude that the detector was responding to turgor pressure-water activity rather than to osmolarity itself. Zentralbl Bakteriol, 1993 Jun, 278(4), 562 - 5 Fungal pathogens in etiology of septic shock in neutropenic patients with cancer (short communication); Krcmery V Jr et al.; During the 3 years from 1989 to 1991, we evaluated the etiology of septic shock cases and infection-associated mortality . A total number of 38 patients was included in the study, according to the criteria for septic shock (SS), (Intensive Care Medicine Society, 1989) . In 1989, P . aeruginosa and Enterobacteriaceae among the pathogens prevailed . In 1990 and 1991, S . aureus, enterococci and fungi were most frequent . From 8 patients with SS in 1990, the shock was due to Candida albicans in 1 and to mucoraceae in 3 patients . In 10 patients examined in 1991, 8 cases of SS were due to Candida albicans, Aspergillus niger, Fusarium solani and Acremonium strictum . The decrease of the incidence of shocks and increase of fungal etiology were found to be associated with the use of quinolones in prophylaxis and cephalosporines, aminoglycosides and vancomycine in empiric therapy in febrile neutropenic patients. J Dermatol, 1993 Jun, 20(6), 378 - 80 Necrotizing fasciitis appearing with petechiae as the first clinical sign; Kato N et al.; A 64-year-old Japanese man with necrotizing fasciitis is reported . He developed an Enterobacter agglomerans infection in his left leg without any known causative surgery or trauma, although he had acute myelocytic leukemia as a predisposing condition . Uncommonly, the first clinical sign was petechiae . Surgical debridement could not be performed because of pancytopenia due to his original disease and chemotherapy . The patient died, and an autopsy was performed . Severe intravascular coagulation was observed in the cutaneous infected tissues, while little or no disseminated intravascular coagulation was observed in the major internal organs . The local microorganism factors such as necrotoxins were suspected to cause the intravascular coagulation in the infected tissues. Cesk Epidemiol Mikrobiol Imunol, 1993 Jun, 42(2), 59 - 62 {Identification of reference strains of intestinal bacteria using the TNW, IDENTI and NIS 86 numeric identification systems}; Pacova Z et al.; A total of 176 reference strains including 63 species of Enterobacteriaceae mainly of clinical origin were tested by commercial diagnostic kits ENTEROtest 1 & 2 . The identification efficacy in both systems TNW and IDENTI was nearly in agreement 144 (81.8%), 142 (80.7%) respectively correctly identified strains . The NIS 86 system identified only 54 (30.7%) strains correctly. Ginecol Obstet Mex, 1993 Jun, 61, 163 - 7 {Clinico-microbiological profile of urinary Staphylococcus infection in gynecologico-obstetric patients}; Figueroa Damian R et al.; The Enterobacteriaceae are the major cause of urinary tract infections (UTI) . The Gram-positive Cocci also produce UTI, of these Staphylococcus saprophyticus are the most frequent reported . To know the clinical and microbiological characteristics of the UTI caused by Staphylococcus in the gyneco-obstetric patients, we made a prospective study of the case identified at the Instituto Nacional de Perinatologia during the period from January to July 1992 . There were 32 cases, 19 cystourethritis, 12 asymptomatic bacteriuria, and one pyelonephritis . Twenty nine of the Staphylococcus isolated were coagulase-negative (SCN), of them Staphylococcus epidermidis was the most regained . The 82.7% of the SCN isolated had a positive slime test . The antimicrobial susceptibility tests showed a low percent of resistance to the majority of the antimicrobial agents proved excepting penicillin and gentamicin. Clin Infect Dis, 1993 Jun, 16(6), 772 - 7 Antibiotic therapy for enterobacter meningitis: a retrospective review of 13 episodes and review of the literature; Wolff MA et al.; Enterobacter meningitis is an uncommon form of meningitis whose treatment poses a therapeutic dilemma because of the development of resistance to the third-generation cephalosporins while the patient receives therapy . In recent years, we have been using trimethoprim-sulfamethoxazole (TMP-SMZ) as treatment for this infection . In this report, we reviewed 13 episodes of enterobacter meningitis that were treated with various antibiotic regimens and 33 episodes from the literature . We found that the development of resistance to beta-lactam agents may be much higher than that seen in bacteremias (approximately 30%), that the case-fatality rate is lower among our patients than among those described previously, and that all patients who received TMP-SMZ were cured, compared with about 70% of those receiving beta-lactam agents . TMP-SMZ appears to be an acceptable alternative to the cephalosporins for the treatment of enterobacter meningitis. Can J Surg, 1993 Jun, 36(3), 245 - 50 Piperacillin versus cefazolin given perioperatively to high-risk patients who undergo open cholecystectomy: a double-blind, randomized trial; Krajden S et al.; OBJECTIVE: To study the efficacy, microbiologic features and toxicity of prophylactic cefazolin versus prophylactic piperacillin in high-risk patients who undergo open cholecystectomy . DESIGN: Double-blind randomized trial with follow-up for 6 weeks postoperatively . SETTING: An 850-bed community hospital, located in a major Canadian city . Patients admitted to hospital who satisfied published criteria for being at high-risk for infection after open cholecystectomy were entered into the protocol, and those who satisfied the criteria and provided consent were entered into the study . Eighty-one patients were randomly assigned by computer to receive either piperacillin or cefazolin as the prophylactic agent . INTERVENTIONS: Open cholecystectomy . MAIN OUTCOME: Provides detailed information on the organisms found in the biliary tree in patients with acute cholecystitis, assesses the in-vitro activity of cefazolin versus piperacillin against the isolated organisms, expecting that piperacillin would be much more active against isolated anaerobes and gram-negative bacteria . RESULTS: Bactobilia was documented in 42% of patients in the cefazolin group and 29% of patients in the piperacillin group . Piperacillin was active in vitro against 94% of all isolates versus 56% for cefazolin (p < 0.005, McNemar's test) . Adverse effects and toxicities in both the piperacillin and cefazolin group were low and were not serious . CONCLUSIONS: Both piperacillin and cefazolin are safe and effective prophylactic antimicrobials for high-risk patients who undergo open cholecystectomy . However, piperacillin had a much wider spectrum of in-vitro activity against the isolated pathogens, especially Enterococcus sp., Enterobacter cloacae and the anaerobes. Mol Gen Genet, 1993 Jun, 239(3), 435 - 40 Structure of the nifQ gene from Enterobacter agglomerans 333 and its overexpression in Escherichia coli; Siddavattam D et al.; The nifQ gene, involved in early stages of iron-molybdenum cofactor (FeMo-co) biosynthesis, was identified downstream of the nifB and nifF genes of Enterobacter agglomerans . This gene was cloned and its nucleotide sequence determined . The amino acid sequence, as deduced from the nucleotide sequence, revealed an accumulation of cysteine amino acid residues at the C-terminal end of the protein . The cysteine cluster showed the following consensus sequence Cys-X4-Cys-X2-Cys-X5-Cys, which is a typical characteristic of metal-binding proteins . Further, the nifQ gene was cloned downstream of strong transcriptional (bacteriophage lambda PLPR) and translational (atpE) signals of the expression vector pCYTEXP1 and expressed as an unfused, soluble protein in Escherichia coli . The molecular mass of 19 kDa, as deduced by SDS-PAGE, is in good agreement with the molecular mass deduced from the nucleotide sequence . The availability of high-level expression clones should facilitate purification of large quantities of the recombinant NifQ protein and elucidation of its properties. Antibiot Khimioter, 1993 Jun, 38(6), 35 - 40 {Identification and sensitivity to antimicrobial drugs of enterobacteria isolated from patients with suppurative, inflammatory diseases}; Lapteva TA et al.; The results of testing 501 specimens of pathological materials containing enterobacteria from 382 patients with various purulent inflammatory diseases treated at the Tashkent Branch of the Research Centre of Surgery in 1989-1991 were analyzed . The findings showed that Enterobacter spp., Escherichia spp . and Proteus spp . played the main role in the etiology of the surgical infections (46.9, 19.4 and 16.2 per cent respectively) . Some enterobacteria were tested for their susceptibility to antimicrobial drugs . Enterobacteria resistant to penicillins (81.8-89.9 per cent), aminoglycosides (55.4-75 per cent), tetracyclines (57.1-73.2 per cent), clindamycin (95.7 per cent), rifampicin (87.5 per cent), polymyxin (92.9 per cent) and biseptol (74.6 per cent) were especially frequent . The study showed that claforan, a 3rd generation cephalosporin, and dioxidin were the most active agents despite the species: the number of the isolates resistant to them amounted to 17.9 and 34.7 per cent respectively. Cent Afr J Med, 1993 Jun, 39(6), 110 - 2 Salmonella and shigella bacteraemia in Zimbabwe; Pithie AD et al.; In patients with HIV infection, non-typhoidal salmonellae are a recognised cause of bacteraemia . This association was initially demonstrated in the United States, but has more recently been found in Kenyan patients . This prompted us to review the cases of patients with enterobacteriaceae bacteraemia admitted to Parirenyatwa Hospital, Harare . Non-typhoidal salmonella bacteraemia as compared with typhoid fever was significantly more common in HIV infected patients than in non-HIV infected patients (p < 0.01) . It was also a cause of bacteraemia in patients with other immuno-suppressive conditions and in some patients without identifiable risk factorsPIP: The case notes of patients with blood cultures positive for enterobacteriaceae were examined retrospectively over a 6-month period in Parirenyatwa Hospital, Harare, Zimbabwe . Speciation was possible for Salmonella typhi and shigellae only . Nontyphoidal salmonellae were serotyped . Salmonella or shigella bacteremia was identified in 51 patients . There were 14 isolates of S . typhi, 32 isolates of nontyphoidal salmonellae, and 5 isolates of shigellae species . The case notes of 38 patients could be identified for review, and of these HIV serology was available for 15 seropositive and 15 seronegative patients . The male to female ratio was approximately 3:1 for both groups and the mean age was 29.7 +or- 21 . Nontyphoidal bacteremias as compared with typhoid fever were strongly associated with HIV seropositivity {p 0.01} . 3 out of 8 HIV-negative patients with nontyphoidal bacteremia had another underlying immunosuppressive disease {2 had myeloma and 1 patient had cirrhosis with complicating hepatoma} . 2 patients with nontyphoidal bacteremia whose HIV status was unknown also had another immunosuppressing disease {acute myeloid leukemia and idiopathic pancytopenia} . 13 out of 15 HIV-positive patients showed other signs of HIV infection {oral candida, herpes zoster, persistent generalized lymphadenopathy} . 3 out of 11 patients {27%} with typhoid died, while 11 out of 27 patients {40.7%} with nontyphi bacteremia died . Most strains of S . typhimurium were included in serogroup B, which accounted for 37% of nontyphoidal isolates . Earlier studies identified invasive salmonellosis in patients with other AIDS defining diseases . In Nairobi clinical features of HIV infection were found in 64% of bacteremic HIV-positive patients, but only 28% of patients fulfilled the CDC clinical case definition for AIDS . A more recent study from Nairobi demonstrated that S . typhimurium bacteremia is a common cause of intercurrent infection in HIV-positive tuberculous patients . Appl Environ Microbiol, 1993 Jun, 59(6), 1702 - 8 Use of repetitive sequences and the polymerase chain reaction technique to classify genetically related Bradyrhizobium japonicum serocluster 123 strains; Judd AK et al.; We have determined that repetitive (repetitive extragenic palindromic {REP} and enterobacterial repetitive intergenic consensus {ERIC}) sequences used in conjunction with the polymerase chain reaction technique (REP and ERIC PCR) provide an effective means of differentiating between and classifying genetically related Bradyrhizobium japonicum serocluster 123 strains . Analysis of REP and ERIC PCR-generated dendrograms indicated that this technique can effectively differentiate between closely related strains which were indistinguishable by using other classification methods . To maximize the genomic differences detected by REP and ERIC PCR fingerprint patterns, the REP and the ERIC data sets were combined for statistical analyses . REP-plus-ERIC PCR fingerprints were also found to provide a method to differentiate between highly diverse strains of Bradyrhizobium spp., but they did not provide an effective means for classifying these strains because of the relatively low number of REP and ERIC consensus sequences found in some of the bradyrhizobia . Our results also suggest that there is a relationship between nodulation phenotypes and the distribution of REP and ERIC consensus sequences within the genomes of B . japonicum serogroup 123 and 127 strains . Results obtained by restriction fragment length polymorphism hybridization analyses were correlated with the phylogenetic classification of B . japonicum serocluster 123 strains obtained by using REP and ERIC PCR. J Med Assoc Thai, 1993 Jun, 76(6), 314 - 8 Empirical antibiotic therapy in febrile neutropenic patients with single-daily dose amikacin plus ceftriaxone; Suwangool P et al.; Hematologic malignancies and cancer patients who become neutropenic as a result of disease or myelosuppressive cytotoxic therapy are at a high risk of developing life-threatening infections, and hence empirical antibiotic therapy is administered promptly . We investigated once daily regimen of amikacin, for dose-dependent bactericidal activity and post-antibiotic effects, plus ceftriaxone, with a long-half life to maximise time-dependent bactericidal activity . Microbiologically proven septicemia were 11 out of 49 febrile episodes (22.5%) and 10 (91%) of these were due to gram-negative bacilli, mostly Enterobacteriaceae . The overall success of the regimen was 63.3 per cent of patients, with no significant toxicity . In conclusion, our findings suggest that once-daily administration of amikacin plus ceftriaxone in the initial treatment of febrile episodes in neutropenic patients produces satisfactory results and more cost-effective compared with other antibiotic regimens requiring 3-4 doses a day. Drugs, 1993 Jun, 45(6), 866 - 94 Penicillins . A current review of their clinical pharmacology and therapeutic use; Nathwani D et al.; The penicillins are a large group of bicyclic ring compounds which contain a 4-membered beta-lactam ring (penams) fused to a 5-membered thiazolidine ring . Benzylpenicillin (penicillin G) was the first natural penicillin with potent activity against all Gram-positive pathogens, Gram-negative cocci and some spirochaetes and actinomycetes . For the last 50 years benzylpenicillin has been the mainstay of therapy for serious pneumococcal, streptococcal, meningococcal and gonococcal infections . However, the past decade has seen the emergence of resistance in certain parts of the world, initially among the gonococci, and more recently among the pneumococci and meningococci . Discovery of the 6-aminopenicillinamic acid nucleus has led to considerable manipulation of the basic ring structure, resulting initially in the synthesis of ampicillin, and subsequently the other aminopenicillins, analogues, esters and prodrugs . These drugs have the advantages of improved oral bioavailability and superior activity against Haemophilus influenzae, certain Gram-negative bacilli, salmonellae, enterococci and Listeria monocytogenes, making these agents popular in the treatment of upper and lower respiratory tract infections and urinary tract infections . The increasing spread of bacterial resistance, particularly among Enterobacteriaceae and H . influenzae, has curtailed the usefulness of these drugs in these clinical settings . To counteract this problem, a number of agents combining a penicillin and a beta-lactamase inhibitor (e.g . clavulanic acid, tazobactam and sulbactam) have been developed . These inhibitors have no intrinsic antibacterial activity, but combining them with a penicillin (e.g . amoxicillin/clavulanic acid) confers greater stability to beta-lactamases and hence a broader spectrum of activity . The emergence of penicillinase-producing staphylococci that rendered benzylpenicillin ineffective also stimulated the search for penicillinase-resistant penicillins--methicillin and nafcillin, followed by the acid-stable isoxazolyl penicillins . These agents are now the principle antistaphylococcal treatment . Methicillin-resistant coagulase-negative staphylococci are currently a major cause of hospital sepsis, and are resistant to these latter agents . Enteric Gram-negative bacilli have been the predominant cause of serious hospital infections during the last 30 years . Further manipulation of the penicillin structure has resulted in compounds with broader activity against Gram-negative bacilli, particularly Pseudomonas aeruginosa, while retaining activity against Gram-positive pathogens . The carboxypenicillins were the first step in this direction, but have been largely superseded by the ureidopenicillins . These agents have better activity against P . aeruginosa, and are still effective against Gram-negative and Gram-positive bacteria, including enterococci and anaerobic organisms.(ABSTRACT TRUNCATED AT 400 WORDS) Hybridoma, 1993 Jun, 12(3), 327 - 32 Surveillance of gram-negative bacteria for Pseudomonas aeruginosa lipoprotein I using a monoclonal antibody; Sciortino CV Jr; We prepared an IgG1 murine monoclonal antibody, PS2, that recognized the 8-kDa outer membrane lipoprotein I of Pseudomonas aeruginosa . The biodot-immunoblot technique was used to test 470 bacterial isolates for their reactivity with MAb PS2 . PS2 recognized 298 of 300 P . aeruginosa clinical isolates for a sensitivity of 99.3% . PS2 reacted with all Fisher-Devlin immunotype and International Antigenic Type P . aeruginosa strains . Forty-seven isolates of other Pseudomonas species were tested and only three P . cepacia reacted . PS2 did not react with 118 of 123 other gram-negative isolates, but reacted weakly with 3 of 17 Enterobacter aerogenes, 1 of 11 Eschericia coli and 1 of 2 Proteus vulgaris . The specificity of PS2 for P . aeruginosa was 95%. Pol Tyg Lek, 1993 May 17-31, 48(20-22), 448 - 51 {Urinary tract infections in the first three months following kidney transplantation}; Mroz E et al.; Eighty kidney transplants were examined . During the first three months following transplantation, urinary tract infections occurred in 68 patients (85%) . Fifty patients (74%) have had a few episodes of infections in the form of either suprainfection or recurrence whereas in the remaining patients there was only one episode of urinary infection . No difference in infection incidence was noted in both men and women . Ninety percent of urinary infections occurred within the first 4 weeks following transplantation . The most frequent cause of the urinary tract infections were gram-negative bacilli of Enterobacteriaceae family . In case of multiple infections there was a high percentage of gram-positive cocci. Gene, 1993 May 15, 127(1), 15 - 21 Versatile suicide vectors which allow direct selection for gene replacement in gram-negative bacteria; Quandt J et al.; A set of vector plasmids which greatly facilitate gene replacement and reverse genetics in many Gram-negative bacteria was constructed . These vectors are based on the P15A origin of replication (ori) and incorporate sacB from Bacillus subtilis, which is inducible by sucrose and is lethal when expressed in Gram-negative bacteria . The vectors also have a convenient antibiotic-resistance marker (gentamicin resistance) and the lacZ alpha system which allows blue/white selection of cloned fragments . Three different multiple cloning sites, allowing several distinct cloning and gene replacement strategies, are available in the 5' end of lacZ on different vectors . One of these cloning sites, which we synthesised, contains only a NotI-SmaI-NotI sequence; this allows access to most of the restriction sites within the cloned fragment for the purpose of insertion of various cassettes and interposons . The vectors carry the mob region from the broad-host-range plasmid RP4 and are thus mobilizable by conjugation into a wide range of Gram-negative bacteria; since they will not replicate in bacteria other than enterobacteria, they function as 'suicide' vectors . Variants of the vectors carrying the phage lambda cos site were also constructed . We have used these vectors to carry out gene replacement experiments in the fixN region of Rhizobium leguminosarum and have demonstrated that they are extremely useful in eliminating long and tedious screening procedures. Gene, 1993 May 15, 127(1), 111 - 5 Distribution of the Shigella sonnei insertion elements in Enterobacteriaceae; Matsutani S et al.; The distribution of IS1, IS600, IS629, IS630 and IS640, present in an Shigella sonnei strain, was examined in strains belonging to various species of enteric bacteria . Four Shigella species including Sh . sonnei contained all IS elements, several of which were in large numbers, and showed species-specific distribution patterns . The other strains contained some of the IS elements in a few copies or none at all, except for some clinical isolates in the Escherichia coli strains, which showed similar distribution patterns to those of the Shigella species, suggesting that the E . coli isolates are closely related to those in Shigella . The IS elements examined may be used to classify various bacterial strains and to identify the Shigella strains and some of the E . coli strains to be isolated from various sources. Carbohydr Res, 1993 May 7, 243(2), 273 - 91 Synthesis and NMR spectroscopic investigation of oligosaccharides containing Kdo and L-glycero-D-manno-heptopyranosyl residues; Hofinger A et al.; The disaccharides O-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->8)-sodium (allyl 3-deoxy-beta-D-manno-2-octulopyranosid)onate (8), O-L-glycero-alpha-D-manno-heptopyranosyl-(1-->7)-sodium (allyl 3-deoxy-beta-D-manno-2-octulopyranosid)onate (12), and O-alpha-D-mannopyranosyl-(1-->7)-sodium (allyl 3-deoxy-beta-D-manno-2-octulopyranosid)onate (21) and the branched trisaccharides O-L-glycero-alpha-D-manno-heptopyranosyl-(1-->7)-{O-(sodium 3-deoxy-alpha- and -beta-D-manno-2-octulopyranosylonate)-(2-->8)}-sodium (allyl 3-deoxy-beta-D-manno-2-octulopyranosid)onate (15 and 16) and O-alpha-D-mannopyranosyl-(1-->7)-{O-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->8)}-sodium (allyl 3-deoxy-beta-D-manno-2-octulopyranosid)onate (24) were prepared . Per-O-acetylated mannopyranosyl or Kdo bromide derivatives were employed for the glycosylation steps under Helferich conditions, whereas the imidate derivative 9 was used for the coupling of the L-glycero-D-manno-heptopyranosyl residues . The oligosaccharides were fully characterized by NMR spectroscopic data . Their structures correspond to an artificial linkage pattern providing a potential cross-reactive epitope for antibodies directed against the inner-core-region of enterobacterial as well as chlamydial lipopolysaccharides. Antimicrob Agents Chemother, 1993 May, 37(5), 939 - 46 Biochemical properties of a carbapenem-hydrolyzing beta-lactamase from Enterobacter cloacae and cloning of the gene into Escherichia coli; Nordmann P et al.; A clinical isolate of Enterobacter cloacae, strain NOR-1, exhibited resistance to imipenem and remained susceptible to extended-spectrum cephalosporins . Clavulanic acid partially restored the susceptibility of the strain to imipenem . Two beta-lactamases with isoelectric points (pI) of 6.9 and > 9.2 were detected in strain E . cloacae NOR-1; the higher pI corresponded to AmpC cephalosporinase . Plasmid DNA was not detected in E . cloacae NOR-1 and imipenem resistance could not be transferred into Escherichia coli JM109 . The carbapenem-hydrolyzing beta-lactamase gene was cloned into plasmid pACYC184 . One recombinant plasmid, pPTN1, harbored a 5.3-kb Sau3A fragment from E . cloacae NOR-1 expressing the carbapenem-hydrolyzing beta-lactamase . This enzyme (pI 6.9) hydrolyzed ampicillin, cephalothin, and imipenem more rapidly than it did meropenem and aztreonam, but it hydrolyzed extended-spectrum cephalosporins only weakly and did not hydrolyze cefoxitin . Hydrolytic activity was partially inhibited by clavulanic acid, sulbactam, and tazobactam, was nonsusceptible to chelating agents such as EDTA and 1,10-o-phenanthroline, and was independent of the presence of ZnCl2 . Its relative molecular mass was 30,000 Da . Induction experiments concluded that the carbapenem-hydrolyzing beta-lactamase biosynthesis was inducible by cefoxitin and imipenem . Subcloning experiments with HindIII partial digests of pPTN1 resulted in a recombinant plasmid, designated pPTN2, which contained a 1.3-kb insert from pPTN1 and which conferred resistance to beta-lactam antibiotics . Hybridization studies performed with a 1.2-kb HindIII fragment from pPtN2 failed to determine any homology with ampC of E . cloacae, with other known beta-lactamase genes commonly found in members of the family Enterobacteriaceae (bla(TEM-1)) and bla(SHV-3) derivatives), and with previously described carbapenemase genes such as those from Xanthomonas maltophilia, Bacillus cereus, Bacteroides fragilis (cfiA), and Aeromonas hydrophila (cphA) . This work describing the biochemical properties of a novel chromosome-encoded beta-lactamase from E . cloacae indicates that this enzyme differs from all the previously described carbapenemases . This is the first reported cloning of a carbapenem-hydrolyzing gene from a member of the family Enterobacteriaceae. Antimicrob Agents Chemother, 1993 May, 37(5), 1122 - 6 Activity of pirlimycin against pathogens from cows with mastitis and recommendations for disk diffusion tests; Thornsberry C et al.; Pirlimycin is an analog of clindamycin that will be recommended for therapy of bovine mastitis . It has good activity against staphylococci and streptococci, the major pathogens for bovine mastitis . Five hundred and thirty bacterial isolates recovered from cows with mastitis were studied to confirm the spectrum of activity and to develop recommendations for susceptibility testing . Pirlimycin is not active against isolates of Enterobacteriaceae, it varies in its activity against enterococci, and it is active against veterinary isolates of streptococci (MIC for 50% of strains tested, < or = 0.03 to 0.06 microgram/ml) and staphylococci (MIC for 50% of strains tested, 0.25 to 1.0 microgram/ml) . On the basis of levels of drug attained in the milk with recommended dosing schedules, we chose MIC breakpoints of < or = 2 micrograms/ml for susceptibility and > or = 4 micrograms/ml for resistance . We also recommended a disk diffusion test using a disk containing 2 micrograms/ml and breakpoints of < or = 12 mm for resistance and > or = 13 mm for susceptibility. Chemotherapy, 1993 May-Jun, 39(3), 175 - 81 Comparative antibacterial activity of the aminothiazolyl cephalosporin RU 29,246; Qadri SM et al.; A total of 1,007 clinical isolates from a tertiary care center were tested against RU 29,246, ampicillin, cephalothin, cefoxitin, ceftazidime, Augmentin, oxacillin, piperacillin, gentamicin, amikacin and vancomycin . Bacteria tested consisted of 479 strains of Enterobacteriaceae, 64 pseudomonads, 18 Xanthomonas, 42 other gram-negative bacilli, 56 enterococci and 348 isolates of staphylococci . RU 29,246 showed excellent in vitro activity inhibiting > 90% of Escherichia coli, Klebsiella pneumoniae, K . oxytoca, Enterobacter, Proteus mirabilis, Providencia, Morganella, Salmonella, Shigella, Aeromonas hydrophila, and methicillin-susceptible Staphylococcus aureus at an MIC of 0.5-1.0 mg/l . Seventy-seven percent coagulase-negative staphylococci had an MIC of 1.0-4.0 mg/l . All strains of Pseudomonas aeruginosa and X . maltophilia were resistant to RU 29,246 . Fifty-six percent of the enterococcal isolates were inhibited by 1.0-16.0 mg/l of RU 29,246. J Clin Microbiol, 1993 May, 31(5), 1179 - 84 Collaborative evaluation of the Radiometer Sensititre AP80 for identification of gram-negative bacilli; Staneck JL et al.; A multicenter trial of the Sensititre AP80 panel read on the Sensititre AutoReader (Radiometer America, Westlake, Ohio) for the automated identification of gram-negative bacilli was conducted with 1,023 clinical isolates (879 members of the family Enterobacteriaceae plus 144 nonenteric organisms) . Assignment of taxa was based on the computer-assisted interpretation of the results of a series of reactions with fluorogenic enzyme substrates after 5 h of incubation, with an incubation interval of approximately 18 h used when indicated . Accuracy was determined initially by comparison with the results obtained with the API 20E or Rapid NFT system (Analytab Products, Plainview, N.Y.) . Isolates showing discrepancies were identified by using conventional biochemical profiles . Identifications were available after 5 h of incubation for 918 isolates (90%) . Agreements with reference results for members of the family Enterobacteriaceae were 95.3 and 92.5% at the genus and species levels, respectively, and for the nonmembers of the family Enterobacteriaceae, the agreements with reference results were 95.1 and 84.7%, respectively . The Sensititre AP80 panel was found to be simple and convenient to use, allowed for the testing of three isolates per panel, required minimal supplementary testing for completion of identification, performed in a reproducible fashion, and demonstrated an accuracy of same-day identification comparable to that reported for other automated systems . The AP80 panel appears well suited for routine use in the clinical microbiology laboratory as an automated means of identifying both members of the family Enterobacteriaceae and nonenteric gram-negative bacilli. J Appl Bacteriol, 1993 May, 74(5), 595 - 602 Studies on the ecology of aquatic bacteria of the lower Niger Delta: multiple antibiotic resistance among the standard plate count organisms; Ogan MT et al.; The ecology of multiple antibiotic resistant (MAR) bacteria in the fresh-waters of the lower Niger Delta was studied in the Port Harcourt area, Rivers State . On the basis of decreasing pollution levels three zones, A, B, C, were recognized . Cell recovery by two viable count media, casein-peptone-starch (CPS) and plate count (PC) agar containing chloramphenicol, tetracycline, penicillin, streptomycin or ampicillin were compared in an initial study . Higher numbers of antibiotic resistant (AR) bacteria were recovered on CPS containing tetracycline, penicillin, streptomycin and ampicillin from the faecally-polluted New Calabar River (zone A) than on SPC agar containing similar antibiotics but the reverse was observed for forest stream (zone B) samples . Differences between the two media were also observed at individual sample sites . The proportions of strains of AR bacteria resistant to their primary isolation antibiotic varied from 55% (zone B) to 72% in the least polluted Isiokpo and Elele-Alimini streams (zone C), for ampicillin, and mostly < 50% for the other drugs in each zone . Thirty bacterial strains purified from the prevent colonial types on the count media without antibiotics included mainly species of Bacillus (12) and enterobacteria (18) . Between five and 10 strains were resistant to > or = three antibiotics; seven were resistant to all five . The antibiograms of most strains were variable and depended on the method of drug application (discs or incorporation into agar), media and temperature of incubation (25 degrees, 37 degrees or 44.5 degrees C) . Twenty-one strains were consistently resistant to ampicillin by the two methods; 10 to 19 were consistent for chloramphenicol, tetracycline and penicillin.(ABSTRACT TRUNCATED AT 250 WORDS) J Bacteriol, 1993 May, 175(9), 2727 - 33 Alpha-keto acids are novel siderophores in the genera Proteus, Providencia, and Morganella and are produced by amino acid deaminases; Drechsel H et al.; Growth promotion and iron transport studies revealed that certain alpha-keto acids generated by amino acid deaminases, by enterobacteria of the Proteus-Providencia-Morganella group (of the tribe Proteeae), show significant siderophore activity . Their iron-binding properties were confirmed by the chrome azurol S assay and UV spectra . These compounds form ligand-to-metal charge transfer bands in the range of 400 to 500 nm . Additional absorption bands of the enolized ligands at 500 to 700 nm are responsible for color formation . Siderophore activity was most pronounced with alpha-keto acids possessing an aromatic or heteroaromatic side chain, like phenylpyruvic acid and indolylpyruvic acid, resulting from deamination of phenylalanine and tryptophan, respectively . In addition, alpha-keto acids possessing longer nonpolar side chains, like alpha-ketoisocaproic acid or alpha-ketoisovaleric acid and even alpha-ketoadipic acid, also showed siderophore activity which was absent or negligible with smaller alpha-keto acids or those possessing polar functional groups, like pyruvic acid, alpha-ketobutyric acid, or alpha-ketoglutaric acid . The fact that deaminase-negative enterobacteria, like Escherichia coli and Salmonella spp., could not utilize alpha-keto acids supports the view that specific iron-carboxylate transport systems have evolved in members of the tribe Proteeae and are designed to recognize ferric complexes of both alpha-hydroxy acids and alpha-keto acids, of which the latter can easily be generated by L-amino acid deaminases in an amino acid-rich medium . Exogenous siderophores, like ferric hydroxamates (ferrichromes) and ferric polycarboxylates (rhizoferrin and citrate), were also utilized by members of the tribe Proteeae. Eur J Epidemiol, 1993 May, 9(3), 335 - 40 Urinary tract infections in the city of Florence: epidemiological considerations over a twenty-year period; Corti G et al.; Our study of significant bacteriurias indicated that the worldwide shift in the etiology of infections also holds true for the Florence area . In a twenty-year period (1970-1990), we noted a decreased frequency of Gram-negative bacilli, particularly of the family Enterobacteriaceae, and a significant increase of Gram-positive cocci in urinary patients . This finding was observed both in hospital and in community-acquired cases in the male sex and only in nosocomial bacteriurias in the female sex . There was a reduced isolation of "classic" urinary pathogens such as Proteus mirabilis: its prevalence in hospital-acquired urinary tract infection (UTI) decreased from 16% in 1970 to 5% in 1990 both in males and in females . On the other hand, we noted an increase of "difficult" microorganisms such as enterococci and methicillin-resistant staphylococci, particularly in the male sex; in 1970 enterococci were occasionally isolated in males both from hospital and from community-acquired UTIs (3% and 5%, respectively), whereas in 1990, on the contrary, they were encountered much more frequently (19% in both cases). Infection, 1993 May-Jun, 21(3), 137 - 9 Topical antimicrobial prophylaxis of nosocomial pneumonia in mechanically ventilated patients . Microbiological observations; Bonten MJ et al.; Generally, reduction of colonization and infection with potentially pathogenic microorganisms in intensive care units (ICU) is attempted by a combination of antimicrobial agents administered topically in the digestive tract and systematically . We tested the efficacy of topical antimicrobial prophylaxis of the oropharynx and stomach administered in combination with sucralfate without systemic prophylaxis in 25 mechanically ventilated ICU patients . The regimen successfully reduced colonization with potentially pathogenic microorganisms in the oropharynx and trachea without modifying the intestinal flora . However, colonization and infections with gram-positive cocci and gram-negative rods other than Enterobacteriaceae and Pseudomonadaceae and resistant to one or both the antimicrobial agents used were observed. Eur J Clin Microbiol Infect Dis, 1993 May, 12(5), 384 - 91 Antimicrobial activity of the new carbapenem biapenem compared to imipenem, meropenem and other broad-spectrum beta-lactam drugs; Sader HS et al.; The in vitro activity of biapenem was compared to that of imipenem, meropenem and other broad-spectrum beta-lactams . A total of 716 isolates from recent cases of clinical septicemia and an additional 137 stock strains possessing known beta-lactamases or other well-characterized resistance mechanisms were tested . The minimal concentrations inhibiting 90% of strains (MIC90) of Enterobacteriaceae species were for biapenem 0.03 to 1 mg/l and for imipenem 0.25 to 2 mg/l . No member of the Enterobacteriaceae was found to be resistant to biapenem . Biapenem and meropenem were the most active drugs against Pseudomonas aeruginosa, with an MIC90 of 1 mg/l . Biapenem was more active than ceftazidime against most gram-negative and gram-positive bacteria tested . Biapenem was as potent as imipenem against anaerobic bacteria (including Bacteroides fragilis), with an MIC90 of 0.25 mg/l . High MICs of biapenem were demonstrated for Xanthomonas maltophilia, oxacillin-resistant Staphylococcus spp . and Enterococcus spp . These species have demonstrated resistance to other carbapenems and to most of the newer cephalosporins . The results of this study, coupled with previously documented favorable qualities of biapenem, endorse further investigation of this broad-spectrum antibacterial agent for clinical use. Eur J Clin Microbiol Infect Dis, 1993 May, 12(5), 356 - 62 Comparison of fixed concentration and fixed ratio options for dilution susceptibility testing of gram-negative bacilli to ampicillin and ampicillin/sulbactam; Pfaller MA et al.; Ampicillin combined with sulbactam was tested at both fixed ratio (2:1 and 1:1) and fixed sulbactam concentrations (4 micrograms/ml, 8 micrograms/ml and 16 micrograms/ml) against 2440 consecutively isolated gram-negative bacilli . Sulbactam significantly enhanced the spectrum of ampicillin activity . Overall, at 8 micrograms/ml ampicillin inhibited 50% of the Enterobacteriaceae isolates, whereas 69% to 84% of the isolates were inhibited by the various sulbactam combinations . The widest spectrum of activity for ampicillin/sulbactam was achieved by testing at a fixed sulbactam concentration of 16 micrograms/ml, followed by the 1:1 ratio and the fixed 8 micrograms/ml (84%, 76% and 74% inhibited, respectively) . The amount of sulbactam at the susceptible breakpoint concentrations of ampicillin markedly affected the percentage of susceptible strains . Combinations that include 8 micrograms/ml of sulbactam are suggested for consideration. J Antimicrob Chemother, 1993 May, 31(5), 645 - 54 Identification of a novel plasmid-mediated beta-lactamase with chromosomal cephalosporinase characteristics from Klebsiella pneumoniae; Tzouvelekis LS et al.; A clinical isolate of Klebsiella pneumoniae resistant to a wide variety of beta-lactams, including third generation cephalosporins, aztreonam and cephamycins, as well as to beta-lactam/clavulanate and sulbactam combinations was examined . It was found that this resistance was transmissible to Escherichia coli recipients via a small 5.3 MDa plasmid encoding for an unusual beta-lactamase produced in relatively large quantities . The enzyme, designated LAT-1, exhibited a highly basic isoelectric point (pI = 9.4) and its hydrolytic activity resembled closely that of a class-I chromosomal cephalosporinase . In vitro, LAT-1 hydrolysed cephaloridine, cephalothin and cephalexin more rapidly than penicillins . A slow hydrolysis of cefoxitin, ceftibuten, ceftazidime and cefotaxime was also observed . The enzyme was inhibited by low concentrations of aztreonam and cloxacillin but it was virtually unaffected by clavulanate . Under stringent conditions, the LAT-1 encoding plasmid did not hybridize with probes specific for TEM-1 and Enterobacter cloacae AmpC beta-lactamase genes . The plasmid was not self-transferable but was readily mobilized by a conjugative R-plasmid harboured by the same K . pneumoniae strain. Genetika, 1993 May, 29(5), 768 - 76 {Characterization of enterobacteria producing the broad-spectrum antibiotics microcins}; Khmel' IA et al.; As a result of screening among 11956 enterobacteria strains isolated from feces of normal children, grown-ups and lambs, seven active microcin-producing strains were obtained . The microcins were shown to be peptides or their derivatives with a low molecular weight (less than 10,000) and a broad spectrum of activity, mainly against gram-negative bacteria . According to cross immunity criteria the microcins studied belonged to two different types . Those of type I could be further classified into two subtypes on the account of difference in the spectrum of antibacterial activity . In 5 cases out of 7 the microcin-producing ability and immunity to microcins have been attributed to plasmids that the strains harboured . The effect of microcins on sensitive cells depended on ompR and ompF gene products. Neurol Clin, 1993 May, 11(2), 419 - 40 Neurologic complications of infective endocarditis; Tunkel AR et al.; The average overall incidence of neurologic complications in patients with infective endocarditis is 30%, with the vast majority of these complications in patients with left-sided valvular disease . The incidence of central nervous system manifestations, particularly of embolic events, tends to be higher in cases of endocarditis caused by more virulent organisms, such as S . aureus and the Enterobacteriaceae . The clinical presentation is dependent on the area of the central nervous system involved . CT and MRI scanning are useful radiologic imaging techniques for the diagnosis of central nervous system complications in patients with infective endocarditis; cerebral angiography should be used in patients with suspected intracranial mycotic aneurysm . The cornerstone of management is appropriate antimicrobial therapy . Neurosurgical intervention may be required for certain patients with intracranial mycotic aneurysms that do not disappear after antimicrobial therapy or for aneurysms that enlarge or bleed . Anticoagulants should be continued in patients with prosthetic valve endocarditis who do not have evidence of intracranial hemorrhage . Anticoagulants should be avoided (unless thromboembolic events are from a site other than the vegetation) in patients with native valve endocarditis owing to the risk of hemorrhagic central nervous system complications . Case fatality rates tend to be higher in patients with neurologic complications of infective endocarditis . Earlier diagnostic and therapeutic interventions for patients with central nervous system complications of infective endocarditis will, it is hoped, improve the outcome in patients with this disorder. Support Care Cancer, 1993 May, 1(3), 124 - 9 Bacterial resistance: new threats, new challenges; Pechere JC; Bacterial resistance remains a major concern . Recently, genetic transfers from saprophytic, non-pathogenic, species to pathogenic S . pneumoniae and N . meningitidis have introduced multiple changes in the penicillin target molecules, leading to rapidly growing penicillin resistance . In enterobacteriaceae, a succession of minute mutations has generated new beta-lactamases with increasingly expanded spectrum, now covering practically all available beta-lactam antibiotics . Resistance emerges in the hospital environment but also, and increasingly, in the community bacteria . Widespread resistance is probably associated with antibiotic use, abuse and misuse but direct causality links are difficult to establish . In some countries as in some hospitals, unusual resistance profiles seem to correspond to unusual antibiotic practices . For meeting the resistance challenge, no simple solutions are available, but combined efforts may help . For improving the situation, the following methods can be proposed . At the world level, a better definition of appropriate antibiotic policies should be sought, together with strong education programmes on the use of antibiotics and the control of cross-infections, plus controls on the strategies used by pharmaceutical companies for promoting antibiotics . At various local levels, accurate guidelines should be adapted to each institution and there should be regularly updated formularies using scientific, and not only economic, criteria; molecular technologies for detecting subtle epidemic variations and emergence of new genes should be developed and regular information on the resistance profiles should be available to all physicians involved in the prevention and therapy of infections. J Bacteriol, 1993 May, 175(9), 2770 - 8 Rapid, synchronous, and stable induction of type 1 piliation in Escherichia coli by using a chromosomal lacUV5 promoter; Woodall LD et al.; Type 1 pili are filamentous proteinaceous appendages produced by certain members of the family Enterobacteriaceae . In Escherichia coli, the adhesive properties of these pili are due to the binding of at least one minor pilus component to mannose, a sugar common to cell surface molecules of many eukaryotic cells . The study of pilus assembly may be benefited by a rapid way of inducing pilus synthesis de novo . We describe herein the construction and characterization of a strain in which piliation can be rapidly induced by the addition of lactose or its analog isopropyl-beta-D-thiogalactopyranoside . This was accomplished by placing the chromosomal fimA gene (encoding the major structural subunit of pili) under lacUV5 promoter control . Further experiments suggested that transcription of genes downstream of fimA, whose products are required for normal pilus assembly and function, may also be controlled by the lacUV5 promoter . The construction described herein may have a variety of applications apart from aiding the study of pilus assembly since its adhesive properties can be rapidly and easily turned on and off. Infect Immun, 1993 May, 61(5), 1667 - 73 Enhanced virulence of Escherichia coli bearing a site-targeted mutation in the major structural subunit of type 1 fimbriae; May AK et al.; Type 1 fimbriae promote enterobacterial adherence to a variety of mammalian cells and are thought to play an important role in the establishment of various extraintestinal infections . Whether or not this adhesin has a role in the pathogenesis of peritoneal Escherichia coli infections, such as those initiated by bowel leakage during intraabdominal surgery, is unclear . By using two genetically engineered E . coli strains, each bearing an antibiotic resistance element inserted at a different site within the type 1 fimbria operon, we examined the role of type 1 fimbriation in intraperitoneal infection in rats . A permanently nonfimbriated insertion mutant was compared with an analogously constructed normally fimbriated one . After intraperitoneal inoculation of adult rats, the permanently nonfimbriated mutant produced mortality more rapidly and resulted in a greater number of culturable organisms from both the peritoneum and the blood . Moreover, the differences between these two insertion mutants were dramatically enhanced by preinoculation growth conditions favoring fimbrial expression . After growth under these conditions, 10(3) CFU of the fimbriation-proficient strain inoculated intraperitoneally caused no mortality; in sharp contrast, the permanently nonfimbriated insertion mutant resulted in death in 60% of the animals inoculated . Notwithstanding evidence that type 1 fimbriae mediate enterobacterial adherence to mammalian oropharyngeal and bladder mucosae, the results presented here demonstrate that type 1 fimbrial expression can lead to diminution of the number of E . coli organisms within the peritoneum. New Horiz, 1993 May, 1(2), 162 - 71 Nosocomial infections in intensive care units: an overview of their epidemiology, outcome, and prevention; Martin MA; Among all hospitalized patients, ICU patients are at greatest risk for both endemic and epidemic nosocomial infections . The highest infection rates are seen in surgical, burn, trauma, and neonatal ICUs . Acquisition of infection is a major determinant of mortality in ICUs, and prolongs the length of ICU stay . Predominant pathogens include Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus aureus, enterococci, and Candida spp . They are more likely to be resistant to antimicrobial agents than are isolates from elsewhere in the hospital . Exposure to invasive medical devices is the predominant risk factor for infection, and strategies to prevent infection are aimed at reducing microbial colonization on and around devices . Improvements in technology, such as coating devices with antimicrobial agents, have been shown to be efficacious in preventing infection . Handwashing, particularly with antiseptic soaps, remains the cornerstone of infection control in the ICU. J Am Vet Med Assoc, 1993 Apr 15, 202(8), 1230 - 6 Costs of clinical mastitis and mastitis prevention in dairy herds; Miller GY et al.; A stratified random sample of 50 Ohio dairy herds, monitored for 1 year between March 1988 and May 1989, was used to estimate the component costs of clinical mastitis per cow-year overall and by organism, the component costs of an episode of clinical mastitis overall and by organism, and the incidence of clinical mastitis by organism . Each herd was visited monthly by a veterinarian who conducted on-farm interviews and completed standardized data-collection forms designed to elicit economic information about the on-farm costs of clinical mastitis and mastitis prevention . Producers collected milk samples prior to treatment of clinical mastitis cases . Culturing methods allowed identification of 18 specific mastitis pathogen classifications . Annual costs estimated were on a per cow-year and clinical episode basis . The monthly mean population of cows monitored was 4,068 . Mastitis prevention cost $14.50/cow-year, whereas the cost incurred by producers because of clinical cases of mastitis was $37.91 . Organisms prevalent in the cows' environment caused the most costly types of mastitis . Disregarding contaminated samples and episodes for which no milk samples were taken, mastitis for which 2 organisms were isolated accounted for 35.5% of costs of clinical mastitis, followed by cases for which Escherichia coli (21.3%) was isolated, cases for which culturing yielded no growth (8.6%), and cases for which esculin-positive Streptococcus spp (6.4%), Klebsiella spp (5.7%), esculin-negative CAMP-negative Streptococcus spp (5.1%), Enterobacter spp (4.8%), coagulase-negative Staphylococcus spp (4.1%), coagulase-positive Staphylococcus spp (3.0%), S agalactiae (2.5%), and Bacillus spp (1.2%) were isolated.(ABSTRACT TRUNCATED AT 250 WORDS) Gene, 1993 Apr 15, 126(1), 135 - 9 The pab gene of Streptomyces griseus, encoding p-aminobenzoic acid synthase, is located between genes possibly involved in candicidin biosynthesis; Criado LM et al.; The nucleotide (nt) sequence of the gene (pab) encoding p-aminobenzoic acid (PABA) synthase, a key enzyme in the biosynthesis of candicidin by Streptomyces griseus IMRU3570, was determined and an open reading frame (ORF) of 2171 nt was found . The predicted amino acid sequence demonstrated extensive sequence identity with PABA synthases (Pab) from Gram-negative Enterobacteria . The protein encoded by ORF pab shows a clear relationship at the N terminus with PabA and at the C terminus with PabB from Escherichia coli, Serratia and Klebsiella . We also determined the extent of a spontaneous deletion that removed the ORF located upstream from pab near the 5' end of the cloned fragment . The deletion occurred when the gene was cloned in the BamHI site of pBR322 and allowed pab expression in E . coli. J Chemother, 1993 Apr, 5(2), 94 - 102 In-vitro activity of ciprofloxacin and sixteen other antimicrobial agents against blood culture isolates; Eltahawy AT; The in-vitro antibacterial activities of seventeen antimicrobial agents including ampicillin, amikacin, Augmentin, aztreonam, cefazolin, cefuroxime, cefotaxime, ceftizoxime, ceftriaxone, ciprofloxacin, cloxacillin, erythromycin, gentamicin, penicillin G, piperacillin and vancomycin were compared against 100 Gram-negative and Gram-positive strains isolated from blood culture specimens received at the King Abdulaziz University Hospital (KAUH), in Jeddah, Saudi Arabia . The antibacterial susceptibility was determined by the minimal inhibitory concentration (MIC), using an agar dilution method . Ciprofloxacin exhibited the greatest activity, inhibiting 90% of the tested strains (MIC90) at a concentration ranging from < 0.015-0.5 mg/L . Against cloxacillin resistant or susceptible strains of Staphylococcus aureus and coagulase-negative staphylococci, ciprofloxacin had similar activity with MIC90 of 0.2 mg/L . Salmonella typhi and salmonella species which were resistant to ampicillin and augmentin remained sensitive to ciprofloxacin (MIC90 < 0.015-0.125) mg/L.) . Against gentamicin sensitive and resistant Pseudomonas aeruginosa and Pseudomonas species, ciprofloxacin MIC90 was 0.5 and 1 mg/L respectively . Aminoglycosides, third generation cephalosporins, aztreonam and antipseudomonal penicillins, on the other hand, showed high MIC90 well above the obtainable serum concentrations against Enterobacteriaceae and Pseudomonas species. J Antimicrob Chemother, 1993 Apr, 31(4), 473 - 80 Activity of the beta-lactamase inhibitor BRL 42715 against cephalosporinases produced by Enterobacteriaceae; Zhou XY et al.; BRL 42715, a novel beta-lactamase inhibitor, was evaluated for its capacity to inhibit cephalosporinases . BRL 42715 was effective in potentiating the activity of antibiotics against clinical isolates of Enterobacteriaceae that produced high levels of cephalosporinases . This correlated well with the very low 50% inhibition values (< 0.004 mg/L) of BRL 42715 for cephalosporinases extracted from different species . When compared in vitro to clavulanic acid, sulbactam, and tazobactam, BRL 42715 was the most efficient inhibitor of cephalosporinase. Eur J Clin Microbiol Infect Dis, 1993 Apr, 12(4), 293 - 7 Comparative pharmacokinetics of ciprofloxacin, ofloxacin and pefloxacin in human aqueous humour; Giamarellou H et al.; Eighty-five patients undergoing cataract surgery were given for prophylaxis of intraocular infection two intravenous doses each of 200 mg, 300 mg or 400 mg ciprofloxacin (35 patients), 400 mg or 800 mg pefloxacin (30 patients), or 400 mg ofloxacin (20 patients) . Ciprofloxacin levels in aqueous humour ranged from 0.02 to 0.50 microgram/ml, pefloxacin levels from 1.04 to 7.80 micrograms/ml, and ofloxacin levels from 0.44 to 2.27 micrograms/ml with ratios of aqueous humour to serum levels ranging from 3.8% to 25%, 21% to 48.1% and 44% to 88.4%, respectively . It is concluded that the quinolones studied might be suitable for surgical prophylaxis or treatment of anterior chamber infections due to Enterobacteriaceae, while ciprofloxacin at high doses is preferable for Pseudomonas aeruginosa infections. Ann Plast Surg, 1993 Apr, 30(4), 289 - 95 Infection of mammary prostheses: a survey and the question of prevention; Brand KG; Seventy-three plastic surgeons reported 60 early and late mammary implant infections among 54,661 implantations . Smooth, textured, and polyurethane-coated implants had similar infections rates (respectively, 0.06%, 0.16%, and 0.12% for augmentations and 0.6%, 0.4%, and 0.3% for reconstructions including revisions and expansions) . Insertion routes and implant placements had no influence on infection rates . Causative bacteria included Staphylococcus aureus and S . epidermidis, Streptococci A and B, enterobacteria, Klebsiella, Pseudomonas, and mycobacteria . Most surgeons followed a regimen of topical and/or systemic prophylaxis . Some (approximately 20%) used the Dolsky insertion sleeve . Whereas smoking, obesity, and diabetes did not significantly predispose to infection, the following did: skin atrophy and scarring, corticosteroids in subglandular augmentation, additional simultaneous surgery, pregnancy, preceding lactation, and vigorous exercising, massage, and trauma postsurgically . Few late implant infections were recorded resulting from bacterial milk duct invasion or hematogenously from antecedent infection foci . The need for and the possibilities of preventive measures are critically discussed. Antimicrob Agents Chemother, 1993 Apr, 37(4), 893 - 5 Antimicrobial activity and disk diffusion susceptibility testing of Ro 40-6890, the active metabolite of the new cephalosporin ester, Ro 41-3399; Pfaller MA et al.; Ro 40-6890, the active metabolite of Ro 41-3399, was tested against 391 gram-negative and gram-positive clinical isolates . Ro 40-6890 was active against members of the family Enterobacteriaceae, Moraxella catarrhalis, pneumococci, other Streptococcus spp., and methicillin-susceptible staphylococci . Preliminary disk diffusion interpretive zone criteria were calculated for 5-, 10-, and 30-micrograms Ro 40-6890 disks and several possible MIC susceptibility breakpoints . We recommend the use of the 5-micrograms disk and suggest that the following zone diameters be used as breakpoints in clinical trials: susceptible, > or = 21 mm (MIC, < or = 1 microgram/ml); intermediate, 18 to 20 mm (MIC, 2 micrograms/ml); and resistant, < or = 17 mm (MIC, > or = 4 micrograms/ml). Antimicrob Agents Chemother, 1993 Apr, 37(4), 667 - 74 The Pseudomonas cepacia 249 chromosomal penicillinase is a member of the AmpC family of chromosomal beta-lactamases; Proenca R et al.; Pseudomonas cepacia 249 produces an inducible beta-lactamase with penicillinase activity . The nucleotide sequence of the penA gene, which encodes this beta-lactamase, was determined and found to include regions with a significant homology to the ampC-encoded beta-lactamases of members of the family Enterobacteriaceae and Pseudomonas aeruginosa . The predicted amino acid sequence of the PenA beta-lactamase contained 17 amino acids immediately preceding the putative active-site serine which were highly conserved among the enzymes of the AmpC family . Although the penA-coding sequence had a total GC content of 60%, the predicted codon usage was more characteristic of Escherichia coli ampC-encoded beta-lactamase, with 53% of the codons having G or C in the third position, in contrast to the values for the P . aeruginosa ampC (88.5%) or Pseudomonas cepacia (88 to 92%) metabolic genes . The inducible expression of penA can be regulated by the E . coli gene product AmpD . A putative P . cepacia AmpR homolog was associated with the positive regulation of both Enterobacter cloacae ampC and P . cepacia penA expression, as confirmed by gel retardation studies . The E . cloacae AmpR did not regulate penA expression . Thus, by homology studies, codon usage, and genetic analysis, the P . cepacia penA beta-lactamase appears to have been acquired from members of the family Enterobacteriaceae and belongs to the class C group of beta-lactamases. Epidemiol Infect, 1993 Apr, 110(2), 317 - 25 Bacterial load of cockroaches in relation to urban environment; Rivault C et al.; Sanitation is an important problem in relation to the control of pests in urban environments . This investigation analysed the potential risk related to the presence of cockroaches and their capacity for disseminating bacteria in six different types of buildings: hospital nursing area and out-patient area, swimming-pool pool-side and toilet area, low-income flats and food-handling places . Fifty-six species of bacteria were identified from 157 samples, 14 of these have previously been reported as potentially pathogenic for man and vertebrates . Similarities were found between samples collected in (a) the hospital out-patient area and food-handling establishments and (b) the hospital nursing area and flats . Pool-sides possessed a poorer bacterial flora . There was a greater bacterial specific diversity in food-handling establishments, flats and swimming-bath toilet area . Enterobacter cloacae . Klebsiella pneumoniae and Klebsiella oxytoca were dominant species in flats and the hospital nursing area . Therefore, cockroaches can play a role in disseminating bacteria, which they can carry passively on their cuticle. Carcinogenesis, 1993 Apr, 14(4), 743 - 7 Mutagenicity of the bile of dogs with an experimental model of an anomalous arrangement of the pancreaticobiliary duct; Qian D et al.; To learn the reasons for the high incidence of biliary carcinoma in patients with anomalous arrangement of the pancreaticobiliary duct (APBD) mutagenicity of the bile of APBD-modeled dogs that had received a dorsal pancreatico-cholecystostomy was assayed by the Ames Salmonella mutation test . The bile from two out of 18 APBD dogs was mutagenic for Salmonella typhimurium strain TA98 under the condition of metabolic activation by rat liver S9 fraction, while the bile from 17 normal dogs was not mutagenic . Furthermore, the bile from five APBD dogs i.p . administered 1-nitropyrene (1-NP), which is a typical environmental mutagen, was more mutagenic for strain TA98 than that from 1-NP-treated normal dogs . The bile from the APBD dogs had very high amylase activity, indicating that the bile contained pancreatic juice as a result of the pancreatico-cholecystostomy . When pancreatic juice from a normal dog was added to the bile from 1-NP-treated normal dogs, mutagenicity of the bile increased 1.6- to 2.0-fold . Furthermore, sulfatase increased the mutagenic activity of the bile in the presence of the pancreatic juice . HPLC revealed that the bile from a 1-NP-treated APBD dog contained mutagenic 1-nitro-6/8-hydroxypyrene and 1-nitro-3-hydroxypyrene, while bile from a 1-NP-treated normal dog did not contain these deconjugated products . The pancreatic juice from a normal dog had very high gamma-glutamyltransferase (GGT) and aminopeptidase activities and low sulfatase activity, but it had no beta-glucuronidase activity . In addition, the bacteria that easily infect the biliary duct of APBD dogs, Escherichia coli, Klebsiella, Enterobacter and Proteus, had high beta-glucuronidase activity . In particular, Klebsiella showed a very high sulfatase activity . These results suggest that pancreatic juice enzymes and bacteria infecting the biliary duct deconjugate the detoxified mutagens in the bile and induce mutagenicity of the bile from APBD dogs or APBD patients. J Clin Microbiol, 1993 Apr, 31(4), 798 - 803 Comparison of phage typing and DNA fingerprinting by polymerase chain reaction for discrimination of methicillin-resistant Staphylococcus aureus strains; van Belkum A et al.; A typing procedure for methicillin-resistant Staphylococcus aureus (MRSA) based on the polymerase chain reaction (PCR) amplification of both mecA sequences and variable DNA sequences as present in the prokaryotic genome has been developed . Two primers based on the sequences of DNA repeats as discovered in gram-negative members of the family Enterobacteriaceae allow detection of variable regions in the genome of a gram-positive bacterium such as S . aureus, as does a newly described arbitrary primer . This procedure, enabling the detection of 23 different genotypes in a collection of 48 MRSA isolates, was validated by comparisons with phage typing studies . It appeared that within the same group of isolates only 13 different phagovars could be identified . Combination of the results from both phage typing and genotyping allowed the discrimination of 34 of 48 isolates . However, depending on the primer-variable complexity of the PCR fingerprints, which could also be modulated by combination of PCR primers, clear homologies between the groups defined by either phage typing or fingerprinting were observed . An analysis of an MRSA outbreak in a geriatric institution showed a collection of genetically homogeneous isolates . In agreement with phage typing, PCR fingerprinting revealed the identical natures of the MRSA strains isolated from all patients. J Clin Microbiol, 1993 Apr, 31(4), 793 - 7 Comparison of the BacT/Alert pediatric blood culture system, Pedi-BacT, with conventional culture using the 20-milliliter Becton-Dickinson supplemented peptone broth tube; Krisher KK et al.; The performance of the Pedi-BacT system, the BacT/Alert (Organon Teknika Corp., Durham, N.C.) pediatric blood culture bottle, was compared with that of a conventional 20-ml supplemented peptone broth tube (Becton-Dickinson Corp., Cockeysville, Md.) (BD system) in matched aerobic cultures . The tubes of the BD system were visually examined daily for 7 days and were subcultured during the first 24 h of incubation . Pedi-BacT cultures were mechanically agitated and continuously monitored for growth by the instrument . Of the 6,628 compliant pairs, 331 (5.0%) were positive in both systems, 220 (3.3%) were positive in the Pedi-BacT system only, and 170 (2.6%) were positive in the BD system only . One (0.02%) false-negative culture and 15 (0.2%) false-positive cultures occurred with the Pedi-BacT system while 20 (0.3%) false-negative cultures and 35 (0.5%) false-positive cultures occurred with the BD system . Of 288 clinically significant organisms detected in matched pairs from which a single isolate was recovered, 176 (61%) were recovered from both systems, 83 (29%) were recovered from the Pedi-BacT system only (P < 0.0001), and 29 (10%) were recovered from the BD system only . Members of the family Enterobacteriaceae (P < 0.01), miscellaneous nonfermenters (P < 0.05), and Candida spp . (P < 0.01) were isolated more frequently in the Pedi-BacT system than in the BD system . No significant difference in recovery of other organisms was found between the systems . The average time to detection for the Pedi-BacT system ranged from 11.5 h for streptococci to 29.7 h for enterococci, while that for the BD system ranged from 20.3 h for streptococci to 66.4 h for some nonfermenters . The BacT/Alert system is a reliable, labor-saving alternative to conventional blood culture methods. Infect Immun, 1993 Apr, 61(4), 1346 - 51 The major outer membrane protein of Haemophilus ducreyi is a member of the OmpA family of proteins; Spinola SM et al.; Haemophilus ducreyi contains a major outer membrane protein (MOMP) whose apparent molecular weight is 39,000 to 42,000 for all strains tested . Two monoclonal antibodies (MAbs), designated 9D12 and 2C7, bound to the MOMP for all strains of H . ducreyi tested . As reported previously, MAb 9D12 was H . ducreyi specific (E . J . Hansen and T . A . Loftus, Infect . Immun . 44:196-198, 1984) . MAb 2C7 bound to all members of the family Pasteurellaceae tested, suggesting that the MAbs bound to distinct epitopes on the MOMP . The MOMP was purified by extraction of whole cells with Zwittergent and ion-exchange chromatography . A peak eluted from a cation-exchange column contained three bands . All three species bound both MAbs, and the fraction yielded a single N-terminal amino acid sequence, suggesting that the bands represented different conformations of the MOMP . The MOMP was heat modifiable, contained two cysteine residues, and was cationic at pH 8.0, features not usually associated with classical porin proteins . The N-terminal amino acid sequence and total amino acid content of the MOMP were homologous to the OmpA proteins of members of the family Enterobacteriaceae and the OmpA-like protein of Actinobacillus actinomycetemcomitans . An OmpA-specific polyclonal serum bound to the MOMP, and MAb 2C7 bound to Haemophilus influenzae protein 5, an OmpA-like protein, indicating that the MOMP was antigenically related to OmpA . These data indicated that the most abundant protein in the outer membrane of H . ducreyi was not a classical porin and belonged to the OmpA family of proteins. Mol Cell Probes, 1993 Apr, 7(2), 139 - 44 A survey of clinical isolates of Enterobacteriaceae using a series of DNA probes for aminoglycoside resistance genes; Flamm RK et al.; DNA probes specific for the aminoglycoside adenylyltransferase ANT(2"), the aminoglycoside phosphotransferases APH(3')-I and APH(3')-II, and the aminoglycoside acetyltransferases AAC(3)-I, AAC(3)-V and AAC(6')-I were used to screen 151 clinical isolates for the presence of these resistance determinants . The two most common resistance genes in the study isolates were those encoding ANT(2") and APH(3')-I . The phenotypic pattern of aminoglycoside resistance, as determined by a modified disk diffusion test correlated well with the genotypes of the organisms as established using DNA probes, although strains carrying the ANT(2") gene could express one of several phenotypes. J Antimicrob Chemother, 1993 Apr, 31(4), 497 - 504 The in-vitro activity of OPC-17116, a new 5-methyl substituted quinolone; Wise R et al.; The in-vitro activity of the new 5-methylated fluoroquinolone OPC-17116 was compared with that of other fluoroquinolines and beta-lactams against a total of 690 bacterial strains . With the exception of Klebsiella and Serratia spp., 90% of the Enterobacteriaceae were inhibited by 0.25 mg/L . OPC-17116 inhibited 90% of Serratia spp . at 8 mg/L and Klebsiella spp . at 4 mg/L . Moraxella catarrhalis and Haemophilus influenzae were highly susceptible (MIC90 < or = 0.03 mg/L) . Pseudomonas aeruginosa were more susceptible to ciprofloxacin (MIC90 0.25 mg/L) than OPC-17116 (MIC90 1 mg/L) . Generally, OPC-17116 was more active than ciprofloxacin against Gram-positive cocci, 90% of Staphylococcus spp . being inhibited by < or = 0.25 mg/L . OPC-17116 displayed greater activity than ciprofloxacin against Chlamydia spp . (MICs < or = 0.12 and < or = 2 mg/L, respectively). Can J Microbiol, 1993 Apr, 39(4), 442 - 7 Comparative analyses of Serratia spp . outer membrane porin proteins; Hutsul J et al.; Eight Serratia strains and several members of the Enterobacteriaceae family were used in immunoblot and Southern DNA hybridization experiments and probed with antibody and DNA probes specific for the 41-kDa Serratia marcescens porin, to determine the extent of homology between Gram-negative porins . Immunoblot analyses performed using porin-specific rabbit sera and cell envelope preparations from these strains revealed that all strains produced at least one cross-reactive protein in the 41-kDa molecular weight range . Chromosomal DNA from each of the same strains was used in Southern analyses, probed with a 20-base-length oligonucleotide probe deduced from the N-terminal amino acid sequence of the 41-kDa Serratia marcescens porin . The probe hybridized to DNA from all of the Serratia species and six of the nine other enteric bacteria . Putative porin proteins from all the Serratia species were subjected to N-terminal amino acid sequencing and porin functional analysis using the black lipid bilayer method . All amino acid sequences were identical, with one exception in which an asparagine was substituted for an aspartic acid in Serratia rubidaea . All porins had very similar porin function (single channel conductance ranging between 1.72 and 2.00 nS) . The results from this study revealed that a strong conservation exists among the Serratia porins and those produced by other enteric bacteria. Acta Paediatr, 1993 Apr, 82(4), 355 - 9 Fever and neutropenia: bacterial etiology revealed by serological methods; Riikonen P et al.; In a prospective study, 91 episodes of fever in neutropenic children with cancer were evaluated . Fifteen episodes were septicemias, verified by a positive blood culture, 62 were fevers of unknown origin, 6 were focal infections and 8 were of other etiologies (i.e . drug fevers and viral infections) . Serum antibody responses to bacteria were measured in paired sera by an enzyme immunoassay method . Bacterial infection was demonstrated serologically in 20% of documented septicemias, in 35% of fevers of unknown origin and occasionally in the other groups . Tests were available and found positive in the fever of unknown origin group for Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and enterobacteria . Some had multiple etiology . In conclusion, bacterial serology is a promising method of identifying bacterial etiology in fever of otherwise unknown origin in neutropenic children with cancer. Mol Microbiol, 1993 Apr, 8(2), 343 - 55 Conservation and evolution of the rpsU-dnaG-rpoD macromolecular synthesis operon in bacteria; Versalovic J et al.; The macromolecular synthesis (MMS) operon contains three essential genes (rpsU, dnaG, rpoD) whose products (S21, primase, sigma-70) are necessary for the initiation of protein, DNA, and RNA synthesis respectively . PCR amplifications with primers complementary to conserved regions within these three genes, and subsequent DNA sequencing of rpsU-dnaG PCR products, demonstrate that the three genes appear to be contiguous in 11 different Gram-negative species . Within the Gram-negative enteric bacterial lineage, the S21 amino acid sequence is absolutely conserved in 10 species examined . The putative nuteq antiterminator sequence in rpsU consists of two motifs, boxA and boxB, conserved in primary sequence and secondary structure . The terminator sequence, T1, located between rpsU and dnaG is conserved at 31 positions in nine enterobacterial species, suggesting the importance of primary sequence in addition to secondary structure for transcription termination . The intergenic region between rpsU and dnaG varies in size owing to the presence or absence of the Enterobacterial Repetitive Intergenic Consensus (ERIC) DNA element . The rpoD gene contains rearrangements involving a divergent sequence, although two carboxy-terminal regions which encode functional domains are conserved in primary sequence and spacing . Our data suggest that primary sequence divergence and DNA rearrangements in both coding and non-coding sequences account for the interspecies variation in operon structure . However, MMS operon gene organization and cis-acting regulatory sequences appear to be conserved in diverse bacteria. Pathol Biol (Paris), 1993 Apr, 41(4), 329 - 36 {Detection of the phenotypes of resistance of enterobacteriaceae to aminoglycosides with ATB Plus Expert System}; Peyret M et al.; ATB Plus Expert (Biomerieux SA) is an expert system which has been developed to perform an interpretative reading of ATB susceptibility tests . The system was tested on the results obtained for 217 strains of enterobacteriaceae . These strains were selected in order to cover a maximum of bacterial species and resistance mechanisms . The isolates were tested on rapid ATB E, rapid ATB G-, rapid ATB Ur, ATB G- and ATB Ur strips . In parallel, a disc diffusion susceptibility test was performed with 5 discs of aminoglycosides (kanamycin, gentamicin, tobramycin, netilmicin, amikacin) and the interpretation was carried out according to the criteria usually followed . Of the 217 strains tested, 122 showed a resistance phenotype . Only the rapid ATB E strips included kanamycin and allowed the detection of APH(3') phenotypes . Amikacin was not included in the ATB Ur strip, consequently it was impossible to discriminate AAC(3)-II and AAC(6') + AAC(3)-I phenotypes . 12 strains did not grow within 5 hours using the rapid ATB methodology . Not taking into account the problems previously encountered, different phenotypes between the 6 susceptibility tests were found for 16 strains . In 5 cases the expert system detected an anomaly instead of the correct phenotype, and in 3 cases of unknown phenotypes, the answers were variable . In the other cases, the main difficulty was the detection of the isolated resistance to gentamicin (AAC(3)-I phenotype) . The expert system automatically corrects the susceptibility test result according to the phenotype observed. Int J Gynaecol Obstet, 1993 Apr, 41(1), 43 - 52 A randomized trial of penicillin and streptomycin in the prevention of post-partum infection in Uganda; Kampikaho A et al.; We report findings of a randomized trial of penicillin and streptomycin to prevent post-partum infection conducted on 737 women who delivered consecutively at Kawempe Maternity Centre (KMC) in Kampala from 1st October, 1989 to 31st May, 1990 . The objectives were: (i) to identify clinical post-partum infection using at least two of its symptoms and signs (fever, lower abdominal pain, lower abdominal tenderness, vaginal discharge); (ii) to identify the causes of post-partum infection using laboratory methods; and (iii) evaluate the effectiveness of prophylactic fortified procaine penicillin (PPF) and streptomycin on post-partum infection . Clinical infection occurred in 36.4% of the group not given antibiotics, 23.3% in the PPF group and 20.3% in the streptomycin group . Laboratory-confirmed infection occurred in 15.5% of the group not given antibiotics, 9.2% in the PPF group and 8.4% in the streptomycin group . However, severe laboratory-confirmed infection (severe clinical infection plus positive laboratory findings) occurred in 4.9% of the group not given antibiotics, 6.1% in the PPF group and 6.6% in the streptomycin group . In general, the organisms isolated included enterobacteria (35.9%), yeast and protozoa (31.6%), staphylococci (23.9%), streptococci (69%) and Neisseria (1.7%) . The advantage of PPF and streptomycin was evident in most subgroups defined by clinical characteristics or laboratory findings . In view of the findings in this study, we believe that prophylactic antibiotics given in labor may have a role to play at reducing the incidence of post-partum infection . However, as the cost of antibiotics in developing countries is significant, the development of resistant organisms due to indiscriminate antibiotic use is also a concern and health resources are best used when targeted at specific populations, we feel that antibiotic prophylaxis should not be used routinely and that a more realistic view can be obtained by studying high-risk groups of women with more severe infection. Zentralbl Bakteriol, 1993 Apr, 278(2-3), 396 - 406 Use of the enterobacterial outer membrane protein PhoE in the development of new vaccines and DNA probes; Tommassen J et al.; PhoE protein is a major outer membrane protein of Escherichia coli . The polypeptide spans the membrane 16 times, thereby exposing 8 regions at the cell surface . Insertions in these regions did not affect the biogenesis of the protein . Therefore, we considered the possibility of using PhoE as a vector for the exposure of foreign antigenic determinants at the cell surface, with the ultimate goal of constructing new (live oral) vaccines . Via recombinant DNA techniques, B-cell epitopes of VP1 protein of foot-and-mouth-disease virus were inserted in the exposed regions of PhoE . The inserted epitopes were antigenic and immunogenic in the PhoE-associated conformation . Guinea pigs, immunized with such a hybrid protein were protected against viral challenge . Similarly, a T-cell epitope of the 65 kDa heat-shock protein of Mycobacterium tuberculosis remained antigenic and immunogenic in the PhoE-associated conformation, although recognition by the cells of the immune system was dependent on the amino acids, flanking the epitope . When the amino acid sequences of the PhoE proteins of different members of the family of Enterobacteriaceae are compared, the cell surface-exposed regions are hypervariable . Therefore, we considered the possibility that the DNA segments encoding these regions are species-specific . By using synthetic oligonucleotides corresponding to such DNA segments, primer couples for the specific detection and identification of different enterobacterial species, including Salmonella, by polymerase chain reactions have been developed. Drugs, 1993 Apr, 45(4), 589 - 621 Cefetamet pivoxil . A review of its antibacterial activity, pharmacokinetic properties and therapeutic use; Bryson HM et al.; Cefetamet pivoxil is an oral third-generation cephalosporin which is hydrolysed to form the active agent, cefetamet . Cefetamet has excellent in vitro activity against the major respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and group A beta-haemolytic streptococci; it is active against beta-lactamase-producing strains of H . influenzae and M . catarrhalis, but has poor activity against penicillin-resistant S . pneumoniae . Cefetamet has marked activity against Neisseria gonorrhoeae and possesses a broad spectrum of activity against Enterobacteriaceae . Both staphylococci and Pseudomonas spp . are resistant to cefetamet . Cefetamet pivoxil has been investigated in the treatment of both upper and lower community-acquired respiratory tract infections and has demonstrated equivalent efficacy to a number of more established agents, namely cefaclor, amoxicillin and cefixime . In patients with group A beta-haemolytic streptococcal pharyngotonsillitis, a 7-day course of cefetamet pivoxil was as effective as a 10-day course of the standard agent, phenoxymethylpenicillin, in this indication . In complicated urinary tract infections, cefetamet pivoxil showed similar efficacy to cefadroxil, cefaclor and cefuroxime axetil . Cefetamet pivoxil was effective in the treatment of otitis media, pneumonia, pharyngotonsillitis and urinary tract infections in children . Preliminary data indicate that single dose cefetamet pivoxil can effectively eradicate N . gonorrhoeae from both men and women . Cefetamet pivoxil has a tolerability profile similar to that of other oral cephalosporins, with gastrointestinal effects being the most commonly reported adverse events . To date, no symptoms of carnitine deficiency have been reported with cefetamet pivoxil . Cefetamet pivoxil offers effective alternative oral therapy for outpatient treatment of community-acquired respiratory tract infections, with the advantage of improved activity against H . influenzae and increased beta-lactamase stability . However, its use in areas with a high incidence of penicillin-resistant S . pneumoniae is likely to be limited . Cefetamet pivoxil is also effective in the treatment of urinary tract infections, although further trials are required to define any comparative advantages over other oral agents. J Clin Pathol, 1993 Apr, 46(4), 374 - 5 Latex agglutination test for identification of Pseudomonas pseudomallei; Smith MD et al.; A latex agglutination test was developed and evaluated for the rapid presumptive identification of Pseudomonas pseudomallei, the causative organism of melioidosis . The test was 100% sensitive for 52 isolates of Ps pseudomallei and 100% specific when tested with other medically important Pseudomonas species and Enterobacteriaceae . A subsequent field trial, with clinical specimens from patients with suspected melioidosis, confirmed the sensitivity and specificity of the test. Am J Med, 1993 Mar 22, 94(3A), 9S - 16S In vitro activity of fleroxacin in combination with other antimicrobial agents; Neu HC et al.; The trifluoroquinolone fleroxacin inhibits the majority of Enterobacteriaceae at concentrations < or = 1 micrograms/mL and most Pseudomonas aeruginosa and staphylococci at < or = 2 micrograms/mL . The purpose of this study was to determine the effect of the combination of fleroxacin with other antimicrobial agents . Previous studies that used checkerboard assay, fixed concentrations, and killing curves were reviewed, and these methods were used to evaluate the combination of fleroxacin and agents that had not been previously studied . The combination of fleroxacin with such aminoglycosides as gentamicin, amikacin, and tobramycin is indifferent against most Enterobacteriaceae, as is the combination of fleroxacin with penicillins, cephalosporins, rifampin, clindamycin, and metronidazole . Combinations of fleroxacin with penicillins, cephalosporins, imipenem, aminoglycosides, clindamycin, metronidazole, and rifampin are indifferent against P . aeruginosa . Fosfomycin and fleroxacin acted synergistically against P . aeruginosa . Against staphylococci, combinations of fleroxacin with oxacillin, rifampin, or fosfomycin had synergistic or additive effects, whereas combinations of fleroxacin with vancomycin, gentamicin, or metronidazole have shown indifference . No synergy or antagonism has been found for combinations of fleroxacin with penicillin, vancomycin, erythromycin, clindamycin, or rifampin against streptococci or enterococci . The combination of fleroxacin and metronidazole has proved synergistic against various Bacteroides species . In general, combinations of fleroxacin with other antimicrobial agents display indifference and rarely synergy . Thus, fleroxacin can be combined with other antibiotics to enlarge the spectrum of activity. Am J Med, 1993 Mar 22, 94(3A), 105S - 107S Fleroxacin versus norfloxacin for oral treatment of serious urinary tract infections; Childs SJ; Fleroxacin, 400 mg once daily, and norfloxacin, 400 mg twice daily, both administered orally, were compared for the treatment of serious urinary tract infections (UTIs) . In total, 301 patients from multiple centers who had serious UTIs were randomized to receive fleroxacin or norfloxacin in a double-blind study . The demographic parameters of the two groups were similar . A total of 190 patients were evaluable for efficacy, 94 in the fleroxacin group and 96 in the norfloxacin group . The reasons for exclusion from the efficacy analysis were not significantly different in the two groups, but more patients receiving fleroxacin were prematurely withdrawn from the study . The majority (134) of the diagnoses were complicated UTI, and the pathogens were primarily Enterobacteriaceae . The clinical responses were cure or improvement in 98% of the fleroxacin group and 92% of the norfloxacin group and failure in 2% of the fleroxacin group and 7% of the norfloxacin group . The bacteriologic results by infection were cure in 98% of the fleroxacin group and 89% of the norfloxacin group (including cure with superinfection in 4% of the fleroxacin group and 5% of the norfloxacin group) and failure in 2% of the fleroxacin group and 11% of the norfloxacin group . Adverse events were more common in the fleroxacin group and were mostly nausea, insomnia, and headache . Fleroxacin, 400 mg once daily, was as effective as norfloxacin, 400 mg twice daily, in eradicating UTIs but was associated with more adverse events. Am J Med, 1993 Mar 22, 94(3A), 2S - 8S A multicenter study on the comparative in vitro activity of fleroxacin and three other quinolones: an interim report from 27 centers; Beskid G et al.; A multicenter study was designed to compare the in vitro activity of fleroxacin to that of three other oral quinolones (ciprofloxacin, ofloxacin, and lomefloxacin) against fresh clinical bacterial isolates in hospital or medical center laboratories throughout the United States . Each of the 50 centers was asked to test 500 gram-negative and gram-positive strains using the MicroScan (Baxter) microtiter system . This report includes the results of the study, begun in October 1990, on 12,013 isolates tested in 27 centers . Susceptibility was based on minimum inhibitory concentration (MIC) interpretive criteria from the National Committee for Clinical Laboratory Standards guidelines or published literature . Fleroxacin and the three other quinolones were all active against Enterobacteriaceae, with 95-97% of the strains susceptible . Against other aerobic gram-negative bacilli, 79-83% of the strains were susceptible to fleroxacin, ciprofloxacin, and ofloxacin, and 75% were susceptible to lomefloxacin . With regard to the gram-positive isolates, 79% were susceptible to ofloxacin, 74% to ciprofloxacin, and 52% to fleroxacin and lomefloxacin . The susceptibility data were further delineated for the various species in each of the three major bacterial groups . All four quinolones were highly active against Enterobacteriaceae and were moderate to excellent in activity against other aerobic gram-negative organisms . Activity against oxacillin-susceptible staphylococci was also excellent; however, all four agents were generally much less active against oxacillin-resistant strains . Ofloxacin and ciprofloxacin were clearly superior to fleroxacin and lomefloxacin against streptococci and enterococci. Am J Med, 1993 Mar 22, 94(3A), 17S - 22S Selection of a fluoroquinolone-class disk for susceptibility tests; Barry AL et al.; A study was conducted to select a fluoroquinolone disk that could be used to represent other members of the fluoroquinolone class of drugs for routine susceptibility testing in the laboratory . Eight different fluoroquinolone agents were tested by disk diffusion and broth microdilution methods using 185 bacterial isolates, including 60 Enterobacteriaceae, 50 Pseudomonas species, 45 other gram-negative bacilli, and 30 Staphylococcus aureus . False-susceptible and false-resistant test results occurred at rates of 0-10% when disks containing different agents were tested against this unusually resistant collection of isolates . Much lower error rates would be expected with the type of microorganisms routinely encountered in clinical laboratories . Pefloxacin, enoxacin, or ciprofloxacin disks were not useful as class representatives . However, amifloxacin, lomefloxacin, ofloxacin, temafloxacin, or fleroxacin disks could be used to represent the other fluoroquinolones for routine susceptibility testing with a minimal chance of incurring serious errors. Eur J Biochem, 1993 Mar 15, 212(3), 791 - 9 The sum of the control coefficients of all enzymes on the flux through a group-transfer pathway can be as high as two; van Dam K et al.; In simple metabolic pathways the control exerted by enzyme concentrations on the pathway flux adds up to one when the control is quantified in terms of control coefficients . In this paper we demonstrate that this classical summation theorem has to be modified in pathways where the enzymes participate by transferring a group between each other . We derive the corresponding new control theorem and show how it is consistent with standard metabolic control analysis . In group-transfer pathways lacking enzyme complexes, the sum of the flux control by enzyme concentrations and by the donor and acceptor couples of the pathway, equals two . In group-transfer pathways with enzyme-enzyme interactions the flux control by the dissociation rate constants of the enzyme-enzyme complexes must be added to obtain this sum of two . In all cases, the sum of the controls by all reaction activities remains one . Both by using the new theorem and by numerical simulations, we then demonstrate that, in group-transfer pathways with or without enzyme interactions, the sum of the control of enzymes on the pathway flux is higher than one and can reach a value of two . The total control of all enzymes on the concentration of any intermediate either with or without the transferred group can be equal to one, rather than to the zero found in the classical case . Examples of group-transfer pathways are the bacterial phosphoenolpyruvate:sugar phosphotransferase system, the main pathway for uptake of sugars in Enterobacteriaceae, and the electron-transfer chain in free-energy transducing membranes. Biochem J, 1993 Mar 15, 290 ( Pt 3), 833 - 42 Proton-linked L-rhamnose transport, and its comparison with L-fucose transport in Enterobacteriaceae; Muiry JA et al.; 1 . An alkaline pH change occurred when L-rhamnose, L-mannose or L-lyxose was added to L-rhamnose-grown energy-depleted suspensions of strains of Escherichia coli . This is diagnostic of sugar-H+ symport activity . 2 . L-Rhamnose, L-mannose and L-lyxose were inducers of the sugar-H+ symport and of L-{14C}rhamnose transport activity . L-Rhamnose also induced the biochemically and genetically distinct L-fucose-H+ symport activity in strains competent for L-rhamnose metabolism . 3 . Steady-state kinetic measurements showed that L-mannose and L-lyxose were competitive inhibitors (alternative substrates) for the L-rhamnose transport system, and that L-galactose and D-arabinose were competitive inhibitors (alternative substrates) for the L-fucose transport system . Additional measurements with other sugars of related structure defined the different substrate specificities of the two transport systems . 4 . The relative rates of H+ symport and of sugar metabolism, and the relative values of their kinetic parameters, suggested that the physiological role of the transport activity was primarily for utilization of L-rhamnose, not for L-mannose or L-lyxose . 5 . L-Rhamnose transport into subcellular vesicles of E . coli was dependent on respiration, was optimal at pH 7, and was inhibited by protonophores and ionophores . It was insensitive to N-ethylmaleimide or cytochalasin B . 6 . L-Rhamnose, L-mannose and L-lyxose each elicited an alkaline pH change when added to energy-depleted suspensions of L-rhamnose-grown Salmonella typhimurium LT2, Klebsiella pneumoniae, Klebsiella aerogenes, Erwinia carotovora carotovora and Erwinia carotovora atroseptica . The relative rates of subsequent acidification varied, depending on both the organism and the sugar . L-Fucose promoted an alkaline pH change in all the L-rhamnose-induced organisms except the Erwinia species . No L-rhamnose-H+ symport occurred in any organism grown on L-fucose . 7 . All these results showed that L-rhamnose transport into the micro-organisms occurred by a system different from that for L-fucose transport . Both systems are energized by the trans-membrane electrochemical gradient of protons . 8 . Neither steady-state kinetic measurements nor binding-protein assays revealed the existence of a second L-rhamnose transport system in E . coli. Ital J Biochem, 1993 Mar-Apr, 42(2), 79 - 89 Kinetics of alpha-dicarbonyls reduction by L-glycol dehydrogenase (NAD+) from Enterobacter aerogenes; Carballo J et al.; L-glycol dehydrogenase from Enterobacter aerogenes shows a high affinity by NADH (Ks = 2-4 microM; Km = 4.3-9.7 microM), which indicates that it must operate in vivo saturated with this coenzyme . Michaelis and dissociation constants for the reduction of the carbonyl substrates assayed (diacetyl, 2,3-pentanedione, methylglyoxal and ethyl pyruvate) are similar to those reported for other diacetyl reducing enzymes . The kinetic mechanism followed by these reactions has also been studied . Our results prove that the reduction of diacetyl and ethyl pyruvate takes place via an Ordered Bi-Bi system with the coenzyme as the leading substrate . Methylglyoxal and 2,3-pentanedione are reduced by the same mechanism or by a Theorell-Chance one. Appl Environ Microbiol, 1993 Mar, 59(3), 942 - 4 Comparison of chemical assay, bioassay, enzyme-linked immunosorbent assay, and dot blot hybridization for detection of aerobactin in members of the family Enterobacteriaceae; Le Roy D et al.; In order to determine the best strategy for detection of aerobactin in members of the family Enterobacteriaceae, we compared the results of three phenotypic assays, including a chemical assay, a cross-feeding bioassay, and an enzyme-linked immunosorbent assay (ELISA), with the results of a dot blot hybridization assay using a specific probe for the aerobactin genes . The sensitivity and specificity of the ELISA were better than those of the chemical and cross-feeding assays, but the results of dot blot hybridization were the most reproducible . However, none of the Serratia and Enterobacter cloacae strains which produced aerobactin hybridized with the probe . We concluded that the best strategy for aerobactin detection is a two-step procedure that combines screening by dot blot hybridization with an ELISA for negative strains. Diagn Microbiol Infect Dis, 1993 Mar-Apr, 16(3), 185 - 9 Effect of antibiotics on endotoxin release from gram-negative bacteria; Eng RH et al.; Antibiotics may inhibit bacterial growth or may kill bacteria by inhibiting cell wall synthesis or protein synthesis . The amount of endotoxin released during antibiotic action has been found to be clinically important . Nine antibiotics, representing seven classes, were studied for the amounts of endotoxin released during their action on susceptible strains of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomonas aeruginosa . Staphylococcus aureus, which produces no endotoxin, was used as a control organism . Aztreonam induced the highest release of endotoxin, whereas other antibiotics such as imipenem and the quinolones induced the lowest release of endotoxin . Although the quantities of endotoxin released are not easily explained from the established mechanisms of antibiotic action, our findings may have implications for therapy of the acutely ill, septic patient in whom release of large quantities of endotoxin may be catastrophic. Int J Food Microbiol, 1993 Mar, 18(1), 1 - 14 Microbial ecology of fresh pork stored under modified atmosphere at -1, 4.4 and 10 degrees C; McMullen LM et al.; The prevalent bacteria on fresh pork packaged in modified atmosphere with elevated CO2 were determined by selection of representative colonies from the greatest dilution of meat samples . The pork samples were stored in two packaging films of different oxygen permeability at three storage temp