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| Am J Infect Control, 1997 Dec, 25(6), 458 - 62 Nosocomial infections in an oncology intensive care unit; Velasco E et al.; INTRODUCTION: Treatment of cancer has contributed to a growing number of immunocompromised patients with life-threatening nosocomial infections (NI) . High mortality with considerable cost is observed when they are admitted to the intensive care unit (ICU) . Few studies on infection control and surveillance have been undertaken in this population group . METHODS: All patients treated at a six-bed medical-surgical oncology ICU for > 48 hours were prospectively observed for the development of an NI and the influence of device utilization on infection rates . The analysis used the standard definitions of the National Nosocomial Infection Surveillance System Intensive Care Unit surveillance component . RESULTS: From September 1993 through November 1995, 370 infections occurred in 623 patients during 4034 patient-days, for an overall rate of 50.0 per 100 patients or 91.7 per 1000 patient-days . Pneumonia (28.9%), urinary tract infections (25.6%), and bloodstream infections (24.1%) were the main types of infection . The most common microorganisms isolated were Enterobacteriaceae (29.7%), fungi (22.2%), and Pseudomonas aeruginosa (13.2%) . The median device utilization ratios were 0.63, 0.83, and 0.86 for ventilator, indwelling urinary catheter, and central venous catheter, respectively . The highest median device-specific associated infection rate was 41.7 for ventilator . The median for the average length of stay was 8.8 days, and the average severity of illness score was 4.0 . There was a strong positive correlation between the overall NI patient rate and device utilization (r = 0.56, p < 0.01), average severity of illness score (r = 0.54, p < 0.01), and average length of stay (r = 0.67, p < 0.01) . No correlations were statistically significant when patient-days were used in the denominator . Among the devices only the number of central venous catheter days was significantly correlated with infections (r = 0.51, p = 0.01) . The NI patient-day rates were progressively higher the longer the patients stayed in the ICU . CONCLUSIONS: The high rates reported in this study may reflect a combination of several factors related to the underlying illness, neutrophil count, and exposure to invasive procedures . The adjusted infection rates described here provide specific surveillance data for further interhospital comparisons and also to assess the influence of invasive medical interventions, allowing the implementation of preventable measures to control infections. Semin Respir Infect, 1997 Dec, 12(4), 294 - 9 Nonantibiotic measures in the prevention of ventilator-associated pneumonia; Stoutenbeek CP et al.; Aspiration of oropharyngeal and/or gastrointestinal (GI) contents is the main cause of ventilator-associated pneumonia . A number of nonantibiotic measures have been proposed to prevent aspiration eg, drainage of subglottic secretions or the semirecumbent position or to prevent gastric microbial overgrowth by stress-ulcer prophylaxis with sucralfate or early enteral feeding . Critical review of the studies shows that subglottic drainage does not prevent colonization or infection of the respiratory tract with intensive care unit-acquired Enterobacteriaceae or Pseudomonas aeruginosa . The effect of subglottic drainage on primary endogenous infections caused by Staphalococcus aureus and Streptococcus spp in patients not receiving antibiotics is only found in a post-hoc subgroup analysis and might reflect differences in carriage of community-acquired potentially pathogenic microorganisms (PPM) caused by previous antibiotic treatment, rather than a true treatment effect . The semirecumbent position may reduce the incidence of aspiration, particularly in patients without a nasogastric tube, but the aspiration rate remains high even in the short observation periods of the studies . There is no evidence that it reduces the ventilator-associated pneumonia rate . Sucralfate may reduce the increased pneumonia rate caused by H2-antagonists and/or antacids, but it remains to be proven whether it is superior to placebo . Sucralfate has no effect on the oropulmonary route of infection and has therefore no effect on early-onset (primary endogenous) pneumonia, which is characteristically caused by PPM carried in the oropharynx . Early enteral feeding is preferable to total parenteral feeding . However, there is limited evidence that it prevents ventilator-associated pneumonia . The studies showing a benefit of early enteral feeding were relatively small studies, partly in nonventilated patients, and used poorly defined criteria for pneumonia . The oropulmonary route is the most important route in the pathogenesis of pneumonia . Preventive strategies (both antibiotic and nonantibiotic strategies) have to block both the oropulmonary route and the gastropulmonary route to be fully effective . Because microaspiration cannot be fully prevented in critically ill patients, preventive strategies should attempt to eliminate PPM from the oropharynx and GI-tract. Scand J Infect Dis Suppl, 1997, 105, 13 - 23 Antimicrobial susceptibility testing in Sweden . III . Methodology for susceptibility testing; Olsson-Liljequist B et al.; A subcommittee of the Swedish Reference Group for Antibiotics, SRGA-M, has worked with standardization of methodology for susceptibility testing . In vitro data obtained with the disk diffusion procedure were collected from 5 clinical laboratories, compiled and presented as histograms of inhibition zones, and compared with data {minimum inhibitory concentrations (MICs) and inhibition zones} obtained from the reference laboratory at the Swedish Institute for Infectious Disease Control on a collection of clinically relevant bacterial species . Results from the reference collection of strains were presented as MIC histograms, and their corresponding inhibition zones were inserted in the compiled zone histograms as identifiable bars . These distributions formed the basis for decisions of breakpoints . Special tests were recommended for the detection of certain resistance mechanisms . A beta-lactamase test should be used for Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae and enterococci . Screening for beta-lactam resistance caused by altered penicillin binding proteins should be done by using oxacillin 1 microgram for Streptococcus pneumoniae and Staphylococcus aureus (MRSA), and by phenoxymethylpenicillin 10 micrograms for H, influenzae . The standardized disk diffusion procedure was helpful in detecting enterobacteria carrying beta-lactamases with extended spectra . Registration of inhibition zones will provide a powerful tool for the epidemiological surveillance of antibiotic resistance. Plasmid, 1997, 38(3), 210 - 9 Isolation and characterization of a ColE1-like plasmid from Enterobacter agglomerans with a novel variant of rom gene; Mikiewicz D et al.; Complete nucleotide sequence of a plasmid isolated from Enterobacter agglomerans has been determined . The plasmid, called pPIGDM1, consists of 2495 base pairs . The analysis of its nucleotide sequence suggested that pPIGDM1 may be a ColE1-like replicon . We confirmed this hypothesis by constructing a pPIGDM1-derived plasmid harboring the cat gene (pBW4), which could be introduced into Escherichia coli cells, and demonstrating that pBW4 cannot replicate in the absence of the polA function and that its copy number is significantly decreased in the pcnB mutant . Like some other ColE1-type replicons (e.g., pBR322), pPIGDM1-derived plasmids can be amplified both by chloramphenicol method and in isoleucine-starved relA mutants but not in relA+ bacteria . Inactivation of the putative rom gene by insertion of an amplicillin-resistance gene resulted in significant increase in pPIGDM1-derived plasmid copy number in E . coli-despite the fact that amino acid sequence of the putative RNA 1 modulator (Rom) protein is only 55.7% identical to the ColE1 analog . The pPIGDM1-derived rom-like coding sequence is also homologous to the rom-like gene present in the Proteus vulgaris plasmid pPvul . We suggest to group all these gene products into a new family called ROMS (RNA one modulators) . Since a pPIGDM1-derived plasmid is compatible with other ColE1-like replicons (pMB1-, p15A, RSF1030-, and CloDF13-derived) in E . coli, one may consider pPIGDM1 as a progenitor of new cloning vehicles compatible with most (if not all) of currently used plasmid vectors . Moreover, this plasmid may serve as a source of the new rom-like gene coding for a protein useful in investigation of RNA-protein interactions . A role for the pPIGDM1 plasmid in the host strain is not known. Crit Care Med, 1998 Jan, 26(1), 31 - 9 Aerosolized antibiotics in mechanically ventilated patients: delivery and response; Palmer LB et al.; OBJECTIVES: To determine whether aerosolized antibiotics can be delivered efficiently to the lower respiratory tract in mechanically ventilated patients and to define possible clinical responses to these agents . DESIGN: Prospective serial study with cases as their own control . SETTING: A 10-bed respiratory care unit for patients with chronic respiratory failure in a tertiary university hospital . PATIENTS: Ventilator dependent patients who are otherwise medically stable . All subjects had a tracheostomy in place, were colonized with gram-negative organisms, and produced purulent secretions which could be sampled daily . INTERVENTIONS: Six patients received nine courses of nebulized therapy, which consisted of treatments every 8 hrs of gentamicin (80 mg) or amikacin (400 mg) for 14 to 21 days . MEASUREMENTS AND MAIN RESULTS: Doses to the lung were measured using radiolabeled aerosols and antibiotic concentrations in sputum . The response was assessed by a) changes in the volume of respiratory secretions; b) effect on bacterial cultures; and c) changes in the inflammatory cells and mediators of inflammation of the respiratory secretions (interleukin-1beta {IL-1beta}, tumor necrosis factor-alpha {TNF-alpha}, soluble intercellular adhesion molecule-1 {sICAM-1}, and human leukocyte elastase) . On average, patients inhaled 35.4 +/- 5.08% (SD) of the initial drug placed in the nebulizer (neb-charge) . Of this neb-charge, 9.50 +/- 2.78% was found on the respirator tubing and tracheostomy tube and 21.9 +/- 7.15% was actually deposited in the lungs . The remainder of the neb-charge was sequestered in the nebulizer or exhaled . Trough sputum concentrations averaged 4.3 +/- 3.2 microg/mL/mg neb-charge (range 234 to 520 microg/mL) and increased to 16.6 +/- 8.1 microg/mL/mg neb-charge (range 1005 to 5839 microg/mL) immediately after therapy (p = .011) . Serum concentrations were undetectable in most determinations except for a single patient who was in renal failure (8.7 microg/mL amikacin) . Treatment caused a significant reduction in the volume of secretions (p = .002) . Weekly cultures revealed eradication of Pseudomonas species, Serratia marcescens, and Enterobacter aerogenes in most of the trials . Before antibiotic treatment, concentrations of IL-1beta were higher than those reported in acute respiratory distress syndrome . Throughout the duration of the study, IL-1beta correlated significantly with the absolute number of macrophages, neutrophils, and lymphocytes, respectively (r2 = .55, p = .002; r2 = .50, p < .0004, r2 = .36, p = .005) . TNF-alpha concentrations correlated with lymphocytes and neutrophils, respectively (r2 =.27, p = .013, r2 = .21, p = .033) . sICAM-1 concentrations increased two-fold (p < .001) during treatment and then returned to baseline . The volume of secretions was related to neutrophil and IL-1beta concentrations, respectively (r2 = .25, p = .008, r2= .35, p = .006) . CONCLUSIONS: Nebulizer delivery of aerosolized aminoglycosides is efficient and predictable . In our clinical model, aerosolized antibiotics can make a significant impact on respiratory secretions . Their efficacy in treatment of critically ill patients remains to be determined. Mol Microbiol, 1997 Dec, 26(5), 1005 - 11 rpoB sequence analysis as a novel basis for bacterial identification; Mollet C et al.; Comparison of the sequences of conserved genes, most commonly those encoding 16S rRNA, is used for bacterial genotypic identification . Among some taxa, such as the Enterobacteriaceae, variation within this gene does not allow confident species identification . We investigated the usefulness of RNA polymerase beta-subunit encoding gene (rpoB) sequences as an alternative tool for universal bacterial genotypic identification . We generated a database of partial rpoB for 14 Enterobacteriaceae species and then assessed the intra- and interspecies divergence between the rpoB and the 16S rRNA genes by pairwise comparisons . We found that levels of divergence between the rpoB sequences of different strains were markedly higher than those between their 16S rRNA genes . This higher discriminatory power was further confirmed by assigning 20 blindly selected clinical isolates to the correct enteric species on the basis of rpoB sequence comparison . Comparison of rpoB sequences from Enterobacteriaceae was also used as the basis for their phylogenetic analysis and demonstrated the genus Klebsiella to be polyphyletic . The trees obtained with rpoB were more compatible with the currently accepted classification of Enterobacteriaceae than those obtained with 16S rRNA . These data indicate that rpoB is a powerful identification tool, which may be useful for universal bacterial identification. Optom Vis Sci, 1997 Dec, 74(12), 1030 - 8 Potential sources of bacteria that are isolated from contact lenses during wear; Willcox MD et al.; PURPOSE . The aim of this paper was to determine the possible contamination sources of contact lenses during wear . METHODS . Potential sources of the microbiota that colonized hydrogel contact lenses during wear were examined . The microorganisms that colonize contact lenses were grown, identified, and compared to those microorganisms that colonized the lower lid margins, upper bulbar conjunctiva, hands, and contact lens cases of contact lens wearers . In addition, the incidence of contamination of the domestic water supply in the Sydney area was obtained, and this was compared to the incidence of colonization of contact lenses by microorganisms in general and gram-negative bacteria in particular . RESULTS . There was a wide diversity of bacteria that were isolated from each site sampled . Coagulase-negative staphylococci and Propionibacterium spp . were the most common isolates from all ocular sites examined, and constituted the normal ocular microbiota . Other bacteria, including members of the families Enterobacteriaceae and Pseudomonadaceae, were isolated infrequently from all sites, but most frequently from contact lens cases . Statistical analysis revealed that there was a correlation between the isolation of bacteria from the contact lens and the lower lid margin (p < 0.001) . Analysis of this correlation revealed that this was true for the normal microbiota . A correlation was also noted between the colonization of contact lenses by gram-negative bacteria and contamination of the domestic water supply . DISCUSSION . This study has demonstrated that the likely route for the normal ocular microbiota colonizing contact lenses is via the lid margins, whereas colonization by gram-negative bacteria, including potential agents of microbial keratitis, is likely to be from the domestic water supply. Antimicrob Agents Chemother, 1997 Dec, 41(12), 2773 - 5 Canadian Multicenter Susceptibility Study, with a focus on cephalosporins, from 15 Canadian medical centers . The Canadian Multicenter Study Group; Blondeau JM et al.; We have previously reported on the in vitro susceptibilities of 4,482 microorganisms to 10 antimicrobial agents tested as part of a Canadian multicenter study . We now report on the remaining 10 agents tested in that study . Of the cephalosporins reported here, ceftriaxone had the greatest activity (82 to 100% susceptible isolates) against Enterobacteriaceae, compared to ceftizoxime (78 to 100%) and cefoperazone (78 to 100%) . Cefoperazone activity against Pseudomonas aeruginosa was 87%, compared to 92% for ticarcillin-clavulanate . All agents had 97% or greater activity against Staphylococcus aureus. Antimicrob Agents Chemother, 1997 Dec, 41(12), 2742 - 8 In vitro and in vivo antibacterial activities of GV129606, a new broad-spectrum trinem; Di Modugno E et al.; GV129606 is a new parenteral trinem antibiotic belonging to the beta-lactam class . It combines broad-spectrum activity (against gram-negative and -positive bacteria, aerobes and anaerobes), with high potency and resistance to beta-lactamases . Comparative in vitro and in vivo antibacterial activities were determined for GV129606 against more than 400 recent clinical isolates (aerobes, including beta-lactamase producers, and anaerobes), using representative antibacterial agents (meropenem, piperacillin, ceftazidime, cefpirome, ciprofloxacin, and gentamicin for aerobes and metronidazole, cefoxitin, piperacillin, and clindamycin for anaerobes) . Against methicillin-susceptible staphylococci and streptococci, GV129606 and meropenem were the most active of the drugs tested . GV129606 showed an MIC for 90% of strains tested (MIC90) ranging from < or =0.015 to 0.06 microg/ml against methicillin-susceptible staphylococci and Streptococcus sanguis, Streptococcus pyogenes, and Streptococcus agalactiae . Against penicillin-susceptible and -resistant Streptococcus pneumoniae isolates, GV129606, meropenem, and cefpirome showed MIC90s of < or =0.015 and 1 microg/ml, respectively . Meropenem was the most active compound against members of the family Enterobacteriaceae with MIC90s of < or =0.5 microg/ml . Against these species, GV129606 possessed activity superior to those of piperacillin, ceftazidime, cefpirome, and gentamicin, with MIC90s of < or =8 microg/ml, but its activity was two- to sixfold less than that of ciprofloxacin (with the exception of Proteus rettgeri and Providencia stuartii) . Haemophilus spp., Moraxella catarrhalis, Neisseria gonorrhoeae, and Pseudomonas aeruginosa were also included in the spectrum of GV129606 . GV129606 showed good antianaerobe activity, similar to metronidazole . It was stable against all clinically relevant beta-lactamases (similar to meropenem) . The in vitro activity was confirmed in vivo against septicemia infections induced in mice by selected gram-positive and -negative bacteria with 50% effective doses (ED50s) of < or =0.05 and < or =0.5 mg/kg of body weight/dose, respectively . GV129606 was as effective as meropenem against septicemia in mice caused by ceftazidime-resistant Pseudomonas aeruginosa, exhibiting an ED50 of 0.33 mg/kg/dose. Harefuah, 1997 Oct 2, 133(7-8), 275 - 81, 335 {Gram-negative enteric bacteremia in children in the Negev (1989-1994)}; Maimon-Greenwald M et al.; During 1989-1994, there were 322 episodes of Gram-negative enteric bacteremia in 308 children . The incidence increased from 31/100,000 in children younger than 15 years of age during 1989-1991, to 50/100,000 during 1992-1994 . The most common pathogens were Klebsiella, E . Coli, Salmonella and Enterobacter . 39% of episodes were nosocomial and a significant increase was recorded for each species during the last 3 years of the study . Klebsiella represented the most common pathogen causing nosocomial bacteremia, while E . coli and Salmonella were the main pathogens causing community-acquired bacteremia . In this study in southern Israel, the incidence of Gram-negative enteric bacteremia was significantly higher in Bedouin children, with the exception of bacteremia due to Salmonella, which occurred mainly in Jewish children. Lett Appl Microbiol, 1997 Nov, 25(5), 309 - 12 Evaluation of three decarboxylating agar media to detect histamine and tyramine-producing bacteria in ripened sausages; Roig-Sagues AX et al.; Histidine- and tyrosine-decarboxylase activity of 175 strains of bacteria isolated from eight retail samples of Spanish ripened sausages was tested in three decarboxylating agars (Niven medium, Joosten and Northolt medium and modified decarboxylating agar of Maijala) and confirmed by an enzymic method (histamine) and thin-layer chromatography (tyramine) . Enterobacteria and pseudomonads showed the highest percentage of positive responses to histamine and tyramine in the three decarboxylating agars, but only enterobacteria were subsequently confirmed as histamine-producing . Confirmed tyramine-producing strains were all identified as enterococci or lactic acid bacteria . The medium described by Joosten and Northolt was more sensitive and faster at detecting tyramine-producing microorganisms . However, all three media failed to detect one histamine-positive strain of lactic acid bacteria used as a control. J Appl Microbiol, 1997 Nov, 83(5), 613 - 8 Spoilage microflora in fresh chicken breast stored at 4 degrees C: influence of packaging methods; Jimenez SM et al.; Chicken breasts with skin were packaged either in air, under vacuum or in modified atmospheres of (i) 30% CO2/70% N2 and (ii) 70% CO2/30% N2 . After 3, 7, 14 and 21 days of storage at 4 degrees C, the samples were evaluated for spoilage microbial growth, odour and overall aspect . As expected, pseudomonads grew well in air or under vacuum, but growth was suppressed in both types of modified atmosphere packaging (MAP) . However, growth of lactobacilli, Enterobacteriaceae and Brochothrix thermosphacta was not inhibited in MAPs . Modified atmosphere packaging (ii) extended shelf-life up to 21 days compared to 5 days for air-packed samples. Acta Oncol, 1997, 36(6), 643 - 9 Resistance pattern of 2816 isolates isolated from 17631 blood cultures and etiology of bacteremia and fungemia in a single cancer institution; Trupl J et al.; The resistance pattern of 2816 isolates from 17631 blood cultures and the etiology of isolates causing bacteremia and fungemia among 14591 admissions were investigated in an 80-bed single cancer institute during seven years (1990-1996) under the same empiric therapeutic antibiotic policy but with different prophylactic strategies . No change was found in the proportion of Gram-positive versus Gram-negative bacteria isolated from bacteremias (70% vs . 30%) during the past seven years . Furthermore, the proportion of coagulase-negative staphylococci and enterococci was about the same before and after the introduction of ofloxacin in prophylaxis . However, the proportion of Pseudomonas aeruginosa and Stenotrophomonas maltophilia causing bacteremia increased . There was no increase in Candida krusei and Candida glabrata after the introduction of fluconazole into our prophylactic regimen in 1992 . Penicillin-resistance in viridans streptococci increased after penicillin was introduced into prophylaxis in acute leukemia in 1993 . Until 1995 no quinolone-resistant Enterobacteriaceae were observed . Susceptibility to quinolones did not significantly change within the past seven years in Enterobacteriaceae after their introduction to prophylaxis in 1991, but Pseudomonas aeruginosa decreased from 90 to 58.2% . Glycopeptide resistance in enterococci and staphylococci was minimal in the observed period (0.9-4.3%). J Dent Res, 1997 Nov, 76(11), 1770 - 5 Isolation of Enterobacteriaceae from the mouth and potential association with malodor; Goldberg S et al.; Bad breath is a common phenomenon, usually the result of bacterial metabolism in the oral cavity . It is generally accepted that Gram-negative bacteria are responsible for this problem, largely through degradation of proteinaceous substances . In initial experiments, screening of malodorous isolates following outgrowth of samples obtained from saliva, periodontal pockets, and the tongue dorsum yielded enterobacterial isolates . Clinical studies were conducted to examine the prevalence of such bacteria in four different populations: orthodontic patients, malodor clinic patients, complete-denture wearers, and a healthy young population . The prevalence of Enterobacteriaceae in the oral cavities of the denture-wearing population was very high (48.0%) as compared with the other groups: 27.1% in the malodor clinic patients, 16.4% in the normal population, and 13% among orthodontic patients . Isolates of Klebsiella and Enterobacter emitted foul odors in vitro which resembled bad breath, with concomitant production of volatile sulfides and cadaverine, both compounds related to bad breath . When incubated on a sterile denture, enterobacterial isolates produced typical denture foul odor . Isolates exhibited cell-surface hydrophobic properties when tested for adhesion to acryl and aggregation with ammonium sulphate . The results, taken together, suggest that Klebsiella and related Enterobacteriaceae may play a role in denture malodor. FEBS Lett, 1997 Nov 24, 418(1-2), 27 - 9 Ribosomal efficiency and growth rates of freshly isolated Escherichia coli strains originating from the gastrointestinal tract; Rang CU et al.; It has been previously reported that for natural Escherichia coli isolates from the ECOR collection, there were differences in the ribosomal efficiencies and there was a direct correlation between growth rate and the ribosome efficiency (R-factor) . The aim of this study was to determine whether strains freshly isolated (i.e . subcultured < 5 times) from the gastrointestinal tract ecosystem also exhibited this correlation . Eleven E . coli and two Enterobacter spp . isolates from either humans, pigs, rats or a mammoth were investigated . Considerable variability in the R-factor was noted using an in vitro translation assay, however no consistent correlation between the R-factor and growth rate was noted. Antibiot Khimioter, 1997, 42(9), 27 - 32 {Analysis of the etiologic structure of urinary tract infection and antibiotic-resistance of its pathogens}; Derevianko II et al.; The main pathogens of inflammatory diseases of the kidneys and upper urinary tracts in inpatients of an urological unit were gramnegative organisms of the family Enterobacteriaceae while the pathogens of the infection of the lower urinary tracts (nonspecific urethritis) and male genitalia were grampositive cocci . Pseudomonas aeruginosa, Enterobacter agglomerans and Proteus spp . (indole positive) were the chief causative agents of the hospital infections . The analysis of the materials revealed a tendency towards an increase in the microflora resistance to the most widely used antibiotics: aminoglycosides, cephalosporins and fluoroquinolones . This especially applied to the "problem" pathogen P.aeruginosa . Thus, in 1987 the portion of the P.aeruginosa gentamicin susceptible strains amounted to 52 per cent whereas in 1996 it was 13 per cent . The strains susceptible to ofloxacin equaled 79 per cent in 1988 and 44 per cent in 1995 . At present the drugs of choice in the treatment of urinary tract infections due to P.aeruginosa are ceftazidime, cefpirome and amikacin (65, 64 and 62 per cent of the susceptible strains respectively) . The importance of permanent microbiological monitoring and the respective correction of the therapy are indicated. Antibiot Khimioter, 1997, 42(8), 26 - 30 {Antimicrobial effects of medicines which are not antibiotics}; Shenderov BA; The data on antimicrobial activity of 69 different drugs not belonging to the class of typical antibiotics were examined . It was shown that many of them had antimicrobial activity against enterobacteria susceptible and resistant to antibiotics . Some of such drugs were able to eliminate the property of resistance to antibiotics and in particular that to chloramphenicol and tetracyclines . The data are indicative of the fact that many of the so called nonantibiotics have the capacity of active interference with the human microbial ecology. Med Dosw Mikrobiol, 1997, 49(1-2), 89 - 94 {Aerobic and anaerobic bacterial flora in chronic sinusitis in adults}; Radosz-Komoniewska H et al.; The aim of the study was to analyse microbiologically samples obtained from 30 patients aged from 21 to 73 years treated for chronic sinusitis . Aerobic bacteria only were isolated in 16 patients (53%), and anaerobic organisms only in 5 patients (17%) . Mixed aerobic and anaerobic isolates were recovered from 9 patients (30%) . The isolated aerobic bacteria were as follows: streptococci from the species Streptococcus salivarius, Streptococcus anginosus, Streptococcus group C, Streptococcus sanguis, Staphylococcus aureus, Gram-negative rods from the genus Haemophilus and rods from the Enterobacteriaceae family, and strains of Moraxella catarrhalis . The isolated anaerobic microorganisms Gram-negative rods from the genus Prevotella, Bacteroides, Fusobacterium, Gram-positive cocci from the genus Peptostreptococcus . Other organisms from the genus Vailonella, Eubacterium and Actinomyces were isolated less frequently . In 15 patients only one isolate was recovered, in 15 patients isolated bacteria were mixed with other microorganisms. Med Dosw Mikrobiol, 1997, 49(1-2), 75 - 81 {Analysis of aerobic and anaerobic bacterial flora colonizing drains after surgical abdominal incisions}; Michalska W et al.; Aerobic and anaerobic bacterial flora of post-operative incisions with drainage were examined . From each of 28 patients three specimens were taken; during operation (smear from peritoneal cavity), liquid from drain (taken at 3-th day after operation) and smear from drain taken at the end of drainage . Enterococci, Enterobacteriaceae spp . and anaerobes, especially Bacteroides spp . were most often isolated from specimens taken during operation . Enterococci and coagulase negative Staphylococci-often resistant to methicillin, were most often isolated from specimens taken at the end of drainage. Klin Lab Diagn, 1997 Mar, (3), 18 - 21 {Biovars and antibiotic resistance of enterobacter cloacae strains isolated from colonized newborns}; Morozova OT et al.; A total of 120 strains of E . cloacae were isolated from colonized newborns in a maternity hospital (96 strains) and from inpatients of other hospitals (23 strains) . Biovars of these strains and of 1 reference strain were determined by two methods of biochemical typing and their sensitivity to 14 antibiotics assessed . The overwhelming majority of isolates from newborns were referred to type 2 according to typing after Old (original) or to biovar 62 if typed using the modification of this method . The phenotypical profile of determinants of resistance to 10 antibacterial drugs were the same, including those to aminoglycosides (except amikacin) and third-generation cephalosporins . The strains isolated from non-obstetrical inpatients belonged to biovars with phenotypical profiles of resistance to only 3 antibiotics and sensitive to aminoglycosides and third-generation cephalosporins. Contracept Fertil Sex, 1997 Jul-Aug, 25(7-8), 572 - 5 {Acute salpingitis: current antibiotic protocols}; Judlin PG et al.; Nowadays, most patients with uncomplicated acute salpingitis undergo ambulatory treatment . The choice of medications must take features of PID into account: they are mult-microbial infections and a prolonged follow-up is necessary in order to decrease the risk of sequellae . To fulfil these goals, combination of antibiotics are prescribed that are active against C . trachomatis, enterobacteria and anaerobes. Enferm Infecc Microbiol Clin, 1997 Sep, 15 Suppl 1, 69 - 72 {Monotherapy with meropenem in febrile granulocytopenic patients}; Sanz MA et al.; Infection remains the major cause of morbidity and mortality for cancer patients who become granulocytopenic . Combinations of beta-lactams plus aminoglycosides have been the standard empiric therapy for febrile granulocytopenic patients, especially those with profound long-lasting granulocytopenia . The advent of new broad-spectrum cephalosporins and carbapenems has favoured the possibility of empiric monotherapy . Meropenem is a parenteral carbapenem antibiotic stable to renal dehydropeptidase-I which has excellent bactericidal activity against almost all clinically significant aerobic and anaerobic organisms . Meropenem hasta an antibacterial spectrum similar to that of imipenem but it is more active against Pseudomonas aeruginosa, all Enterobacteriaceae, Haemophilus influenzae, Proteus spp, Morganella spp and Providencia spp . Recently, the efficacy, safety, and tolerance of meropenem monotherapy for the empirical treatment of fever in granulocytopenic cancer patients have been compared in two large prospective randomized multicenter trials . The Meropenem Study Group compared monotherapy with meropenem versus ceftazidime and the EORTC conducted a comparative study of meropenem monotherapy versus the combination of ceftazidime plus amikacin . In both groups, success rates were similar by type of infection and infection-related mortality was low . Related adverse events were also similar in both groups . These studies confirm that monotherapy with meropenem is as effective as ceftazidime-containing regimens for the empiric treatment of fever in granulocytopenic patients. Enferm Infecc Microbiol Clin, 1997 Sep, 15 Suppl 1, 20 - 6 {in vitro activity of carbapenems against Enterobacteriaceae and Pseudomonas aeruginosa hyperproducers of group 1 chromosomal beta-lactamases}; Martinez-Beltran J et al.; Resistance to imipenem and meropenem, reported sporadically in Enterobacteriaceae and more frequently in Pseudomonas aeruginosa, can be caused, among other mechanisms, by the combination of changes in permeability and hyperproduction of inducible chromosomal beta-lactamases . In this study, the in vitro activity of imipenem and meropenem was analysed by the agar dilution method against cefotaxime, ceftazidime, and aztreonam resistant clinical strains of Enterobacteriaceae (n = 202) and P . aeruginosa (n = 90) . This phenotype is consistent with the hyperproduction of group 1 chromosomal beta-lactamases and was previously determined in stably derepressed mutants in the same species, obtained from strains with inducible beta-lactamase expression by selection with cefotaxime and ceftazidime . Likewise, the activity of imipenem and meropenem against the same number of clinical isolates susceptible to cefotaxime, ceftazidime, and aztreonam was evaluated . In general, imipenem and meropenem showed an excellent activity, which was intrinsically greater for meropenem against Enterobacteriaceae and P . aeruginosa organisms . Nevertheless, imipenem and meropenem activity was slightly affected on cefotaxime, ceftazidime, and aztreonam resistant isolates of E . cloacae (MIC90, 1 and 0.2 microgram/ml, respectively), E . aerogenes (1 and 0.2 microgram/ml), C . freundii (1 and 0.1 microgram/ml), M . morganii (1 and 0.5 microgram/ml), and S . marcescens (4 and 0.5 micrograms/ml) . On the other hand, the activity of imipenem and meropenem against ceftazidime and aztreonam resistant isolates of P . aeruginosa was more significantly affected, with MIC90 values of 64 and 16 micrograms/ml, respectively. Enferm Infecc Microbiol Clin, 1997 Sep, 15 Suppl 1, 14 - 9 {Penetration of meropenem in gram-negative bacilli . Differences in activity with imipenem}; Garcia de Lomas J et al.; The outer membrane of gramnegative bacteria cell-wall contain channels formed by proteins known as porins, which facilitate the penetration of molecules into the cell . Imipenem and meropenem possess an important intrinsic activity against most gramnegative bacteria due to their high affinity for the penicillin-binding proteins PBP-2 and/or PBP-3 . Meropenem is slightly more active against certain species of Enterobacteriaceae, Pseudomonas aeruginosa and nonfermenters bacilli . In this sense the differences in the activity between the two carbapenems may be attributable to differences in their affinity for PBPs, differences in their resistance to beta-lactamases hydrolysis, or to the differences in the capacity to employ certain porin channels . OprF is the main porin channel involved in the beta-lactam penetration of bacteria, though OprC and OprD2 may also contribute to the penetration of carbapenems into P . aeruginosa . However, evidences suggest that although impenem requires the presence of OprD2, meropenem may use other pathways for penetration . In Escherichia coli both carbapenems use ompF and ompC, and no specific porin channels have been detected . Only in the case of Enterobacter cloacae may exceptions exists among Enterobacteriaceae. Biochim Biophys Acta, 1997 Oct 9, 1354(1), 7 - 12 Sequence of a melibiose transporter gene of Enterobacter cloacae; Okazaki N et al.; We cloned a fragment of the chromosomal DNA of Enterobacter cloacae, which enabled a melibiose-negative Escherichia coli mutant lacking melB to grow on melibiose as the sole source of carbon . Transformed cells harboring the hybrid plasmid carrying the cloned DNA showed melibiose transport activity . The nucleotide sequence of the DNA region was determined . One complete open reading frame (ORF) and a part of another ORF were found in the region, and the amino acid sequences were deduced . The complete ORF was found to encode a melibiose transporter which consisted of 425 amino acid residues . Hydropathy analysis revealed that there are about 12 hydrophobic domains in this transporter . The incomplete ORF which exists in the upstream region of the transporter gene seemed to encode an alpha-galactosidase. Br J Rheumatol, 1997 Oct, 36(10), 1051 - 3 IgM, IgG and IgA class enterobacterial antibodies in serum and synovial fluid in patients with ankylosing spondylitis and rheumatoid arthritis; Maki-Ikola O et al.; IgM, IgG and IgA class antibodies against three Klebsiella pneumoniae capsular types, Escherichia coli and Proteus mirabilis, as well as total immunoglobulin concentrations, were measured by enzyme immunoassay and radial immunodiffusion technique, respectively, in paired serum and synovial fluid samples from eight patients with ankylosing spondylitis and 10 with rheumatoid arthritis . No clear evidence for intra-articular antibody production against any of the studied microbes was found. J Antimicrob Chemother, 1997 Oct, 40(4), 543 - 9 Detection of mutations in the gyrA and parC genes in quinolone-resistant clinical isolates of Enterobacter cloacae; Deguchi T et al.; We have determined partial sequences of the gyrA and parC genes of Enterobacter cloacae type strain including the regions analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene . The deduced 65- and 49-amino acid sequences of the determined regions of the E . cloacae gyrA and parC genes were identical to the corresponding regions of the E . coli GyrA and ParC proteins, respectively . We examined 40 clinical strains of E . cloacae isolated from patients with urinary tract infection for susceptibilities to nalidixic acid and ciprofloxacin . Based on the nalidixic acid and ciprofloxacin MICs, these isolates were divided into 19 quinolone-susceptible strains (MICs of nalidixic acid, 3.13-25 mg/L; MICs of ciprofloxacin, < or = 0.025 mg/L) and 21 quinolone-resistant strains (MICs of nalidixic acid, 400 to > 800 mg/L; MICs of ciprofloxacin, 0.39-100 mg/L) . We analysed five quinolone-susceptible and 21 quinolone-resistant strains for alterations in GyrA and ParC . The five quinolone-susceptible strains had amino acid sequences in GyrA and ParC identical to those of type strain . Of the 21 quinolone-resistant isolates, three (MICs of nalidixic acid, 400 to > 800 mg/L; MICs of ciprofloxacin, 0.39-3.13 mg/L) had a single amino acid change at the position equivalent to Ser-83 in the E . coli GyrA protein and no alterations in ParC; one (MIC of nalidixic acid, > 800 mg/L; MIC of ciprofloxacin, 3.13 mg/L) had a single amino acid change at Ser-83 in GyrA and a single amino acid change at the position equivalent to Glu-84 in the E . coli ParC protein; two (MIC of nalidixic acid, > 800 mg/L; MIC of ciprofloxacin, 25 mg/L) had double amino acid changes at Ser-83 and Asp-87 in GyrA and no alterations in ParC; and 15 (MICs of nalidixic acid, > 800 mg/L; MICs of ciprofloxacin, 25-100 mg/L) had double amino acid changes at Ser-83 and Asp-87 in GyrA and a single amino acid change at Ser-80 or Glu-84 in ParC . This study suggests, that in clinical isolates of E . cloacae, DNA gyrase is a primary target of quinolones, that only a single amino acid change at Ser-83 in GyrA is sufficient to generate high-level resistance to nalidixic acid and to decrease susceptibility to ciprofloxacin, and that the accumulation of amino acid changes in GyrA and the simultaneous presence of the ParC alterations play a central role in developing high-level resistance to ciprofloxacin. J Antimicrob Chemother, 1997 Oct, 40(4), 533 - 41 Bases of variation in resistance to beta-lactams in Klebsiella oxytoca isolates hyperproducing K1 beta-lactamase; Gheorghiu R et al.; Nineteen isolates of Klebsiella oxytoca were examined, representing 18 distinct strains . All were from a 1994 survey of resistance amongst klebsiellae in intensive care units in Europe, and all had reduced susceptibility, or were resistant, to cefuroxime, ceftriaxone and aztreonam, suggesting hyperproduction of the chromosomal K1 beta-lactamase . We sought to confirm this mechanism and to identify why the levels of resistance varied between isolates . Possible reasons for variation were differences in the quantity or subtype of the K1 enzyme or differences in this enzyme's interplay with permeability . Spectrophotometric assays showed that all 19 isolates had K1-like beta-lactamases and that these were present at > or = 15-fold higher levels than in beta-lactam-sensitive K . oxytoca isolates . Fourteen of the 19 isolates had the OXY-2 form of K1 enzyme, while the remaining five had the OXY-1 form, as determined by isoelectric focusing and PCR amplification . Most isolates with the OXY-2 enzyme were more resistant than those with the OXY-1 subtype, but this difference partly reflected enzyme quantity rather than subtype . More generally, and irrespective of enzyme subtype, levels of resistance were broadly related to beta-lactamase specific activity, and the degree of hyperproduction was a major determinant of the level of resistance . Nevertheless, other factors had a role too: several isolates had reduced susceptibility or were resistant to cefoxitin, which is not a substrate for K1 enzyme, and examination of outer membrane protein profiles revealed considerable strain-to-strain diversity in the molecular weight range typical of the major enterobacterial porins (40-48 kDa). Res Microbiol, 1997 Jan, 148(1), 87 - 93 Electrochemical measurement of trace concentrations of biological hydrogen produced by Enterobacteriaceae; Podesta JJ et al.; Accurate measurements of the hydrogen gas produced by Escherichia coli and Hafnia alvei pure cultures during glucose metabolism were performed under different growth conditions: stagnant, with magnetic stirring or with vibrational shaking . These measurements were carried out using an electrochemical hydrogen sensor based on a platinum-coated solid polymer electrolyte membrane (Pt-SPE) . The results obtained were dependent on the hydrodynamic conditions of the growth, with greater hydrogen production being associated with the stagnant conditions . These measurements will eventually enable us to elucidate whether the pathway used for glucose metabolism is either strictly or mainly anaerobic and to modify experimental conditions so as to influence the reaction. Mol Microbiol, 1997 Nov, 26(3), 531 - 44 The rap and hor proteins of Erwinia, Serratia and Yersinia: a novel subgroup in a growing superfamily of proteins regulating diverse physiological processes in bacterial pathogens; Thomson NR et al.; The enteric bacterium Serratia marcescens is an opportunistic human pathogen . The strain ATCC39006 makes the red pigment, prodigiosin (Pig), and the beta-lactam antibiotic carbapenem (Car) . Mutants were isolated that were concomitantly defective for Pig and Car production . These mutants were found to have a mutation in the rap gene (Regulation of Antibiotic and Pigment) . Sequence analysis of the rap gene revealed a predicted protein product showing strong homology to SlyA, originally thought to be a haemolytic virulence determinant in Salmonella typhimurium . Homologues of rap were detected in several bacterial genera, including Salmonella, Yersinia, Enterobacter, and species of the plant pathogen, Erwinia . The Erwinia hoeEr (homologue of rap) and the Yersinia horYe genes were also found to be very similar to rap and slyA . Marker exchange mutagenesis of horEr revealed that it encoded a regulatory protein controlling the production of antibiotic and exoenzyme virulence determinants in the phytopathogen, Erwinia carotovora subspecies carotovora . We have shown that these new homologues of SlyA form a highly conserved subgroup of a growing superfamily of bacterial regulatory proteins controlling diverse physiological processes in human, animal and plant pathogens. Diagn Microbiol Infect Dis, 1997 Nov, 29(3), 173 - 86 Comparative in vitro assessment of sparfloxacin activity and spectrum using results from over 14,000 pathogens isolated at 190 medical centers in the USA . SPAR Study Group; Ballow CH et al.; Sparfloxacin, a new orally administered fluoroquinolone, was tested against 14,182 clinical strains isolated (generally blood stream and respiratory tract cultures) at nearly 200 hospitals in the United States (USA) and Canada . Sparfloxacin activity was compared with 13 other compounds by Etest (AB BIODISK, Solna, Sweden), broth microdilution, or a standardized disk diffusion method . Using the Food and Drug Administration/product package insert MIC breakpoint for sparfloxacin susceptibility (< or = 0.5 microgram/ml), 94% of Streptococcus pneumoniae (2666 isolates) and 89% of the other streptococci (554 isolates) were susceptible . However, at < or = 1 microgram/ml (the breakpoint for all nonstreptococcal species) sparfloxacin susceptibility rates increased to 100% and 98%, respectively, for the two groups of streptococci . Only 50% and 65% of pneumococci were susceptible to ciprofloxacin (MIC90, 3 micrograms/ml) and penicillin (MIC90, 1.5 micrograms/ml), respectively . Although there were significant differences between regions in the USA in the frequency of penicillin-resistant pneumococcal strains, results indicate that the overall sparfloxacin MIC90 was uniformly at 0.5 microgram/ml . Nearly all (> or = 99%) Haemophilus species and Moraxella catarrhalis, including those harboring beta-lactamases, were susceptible to sparfloxacin, ciprofloxacin, and amoxicillin/clavulanic acid . Only cefprozil and macrolides demonstrated lower potency and spectrum against these two species . Sparfloxacin was active against oxacillin-susceptible Staphylococcus aureus (96 to 97%), Klebsiella spp . (95%), and other tested enteric bacilli (93%) . Comparison between broth microdilution MIC and disk diffusion interpretive results for M . catarrhalis, Staphylococcus aureus, and the Enterobacteriaceae showed an absolute intermethod categorical agreement of > 95% using current sparfloxacin breakpoints, in contrast to those of cefpodoxime for S . aureus where a conspicuous discord (98% versus 59%) between methods was discovered . These results demonstrate that sparfloxacin possesses sufficient in vitro activity and spectrum versus pathogens that cause respiratory tract infections (indications), especially strains resistant to other drug classes such as the earlier fluoroquinolones, oral cephalosporins, macrolides, and amoxicillin/clavulanic acid . The sparfloxacin susceptibility breakpoint for streptococci may require modification (< or = 1 microgram/ml) based on the MIC population analysis presented here . A modal MIC (0.38 to 0.5 microgram/ml) was observed at the current breakpoint . Regardless, sparfloxacin inhibited 89% (nonpneumococcal Streptococcus spp.) to 100% (Haemophilus spp., M . catarrhalis) of the isolates tested with a median activity of 97% against indicated species. Infect Control Hosp Epidemiol, 1997 Nov, 18(11), 769 - 71 Ribotyping and random amplification of polymorphic DNA for nosocomial Enterobacter cloacae isolates in a pediatric intensive-care unit; Hou ST et al.; Between 1987 and 1989, two sequential outbreaks of nosocomial infection caused by Enterobacter cloacae occur-red in the pediatric intensive-care unit of a tertiary-care teaching hospital . Seventeen strains retrieved from the outbreaks and two control strains identified in other wards were typed by ribotyping and random amplification of polymorphic DNA (RAPD) . The results indicated that the genomic pattern of strains identified between the first and second outbreaks was different . We conclude that both ribotyping and RAPD are highly discriminatory and reproducible methods for typing E cloacae . RAPD seems to be more efficacious and cost-effective. Chemotherapy, 1997 Nov-Dec, 43(6), 393 - 3 In vitro activity of biapenem against recent gram-negative and gram-positive clinical isolates; Bonfiglio G et al.; The in vitro activity of biapenem, a new carbapenem, against 535 clinical recent isolates was compared with those of other antibiotics . Biapenem showed broad-spectrum activity against gram-negative and gram-positive clinical isolates . The new carbapenem was more active than imipenem against members of the family Enterobacteriaceae with MIC90S ranging from 0.12 to 2 mg/l and from 0.25 to 4 mg/l, respectively . Moreover it was 2-fold more active than imipenem against Pseudomonas aeruginosa (MIC90, 8 and 16 mg/l, respectively) . Taken together, these results indicate that biapenem shares the favorable in vitro activity properties of imipenem and merits further study in the treatment of infections caused by a wide range of pathogens. Kansenshogaku Zasshi, 1997 Oct, 71(10), 1017 - 24 {Trend of bacterial meningitis in children over a 14 year period (1981 through 1994) in Japan--an analysis based on studies in 27 institutions}; Kobayashi Y et al.; We observed 266 children with purulent meningitis in 27 institutions in Japan during the 14 years from 1981 on dividing these years into 3 periods, 1981-1985, 1986-1990 and 1991-1994, and studied the trend of causative organisms identified in 254 among the 266 patients . Their ages were less than 3 months after birth in 50 children and 3 months or older in 216: there were 141 boys and 125 girls . The causative organisms were H . influenzae in 134 patients and S . pneumoniae in 50, most of them being aged 3 months or older . Next to the above bacteria ranked S . agalactiae in 29 and E . coli in 12, many of the patients were aged less than 3 months . Staphylococcus spp . was found in 7 patients and about 70% of them were aged 3 months or older . L . monocytogenes was found in 4 patients and N . meningitidis in 3 and they were aged 3 months or older in both patient groups . S . pyogenes, Enterococcus spp., Peptostreptococcus spp., P . Mirabilis and Enterobacter spp . were detected each in 1 patient . The causative organism was unknown in 21 patients and there was no double infection . H . influenzae were detected in 18 patients in 1981-1985 period (36.7%), in 56 in 1986-1990 (54.9%) and in 60 in 1991-1994 (63.8%) showing an increasing tendency, but S . pneumoniae exhibited neither an increasing nor decreasing tendency . There was a decreasing tendency with S . agalactiae and E . coli, but the details were not clear because there were few patients aged less than 3 months . Although the period of coexistence of 4 main bacterial species was not made clear in this study . Listeria is considered to develop mainly in the early childhood, and we believe that the conventional way of using a cephem preparation and ampicillin combined for patients under 6 years need not be altered . However, panipenem (phonetic) is likely to be effective for insensible S . pneumoniae for the time being. J Bacteriol, 1997 Nov, 179(22), 7063 - 71 Temperature-dependent regulation of the ribosomal small-subunit protein S21 in the cyanobacterium Anabaena variabilis M3; Sato N et al.; The rpsU gene, which encodes the ribosomal small-subunit protein S21 in Anabaena, is not a part of the macromolecular-synthesis operon as in most enterobacteria but rather is located downstream of the rbpA1 gene, which encodes an RNA-binding protein . Two types of transcripts were detected for this gene cluster . The level of the major rbpA1-rpsU transcript was about 10 times higher at 22 degrees C than at 38 degrees C, whereas the minor monocistronic rpsU transcript was more abundant at the higher temperature . The level of the S21 protein in relation to total protein was three times lower at 38 degrees C than at 22 degrees C . Analysis of isolated ribosomes indicated that S21 was present at an equimolar ratio with regard to other ribosomal proteins at 22 degrees C but that its level decreased with temperature . Conversely, the relative abundance of S5 increased with temperature . A decrease in the level of S21 at high temperature was also found in Synechocystis, in which rpsU is located downstream of the rrn operon . These results suggest that S21 is involved in the adaptation to changes in temperature in cyanobacteria. Antimicrob Agents Chemother, 1997 Nov, 41(11), 2544 - 6 Improved antimicrobial activity of DU-6859a, a new fluoroquinolone, against quinolone-resistant Klebsiella pneumoniae and Enterobacter cloacae isolates with alterations in GyrA and ParC proteins; Deguchi T et al.; MICs of DU-6859a, a novel fluoroquinolone, for 18 Klebsiella pneumoniae isolates and 21 Enterobacter cloacae isolates with altered GyrA or altered GyrA and ParC ranged from < or =0.025 to 6.25 microg/ml and from 0.1 to 3.13 microg/ml, respectively . Based on the MICs at which 90% of the isolates were inhibited for these strains of K . pneumoniae and E . cloacae, DU-6859a exhibited 16- to 256-fold-greater activity than currently available fluoroquinolones. J Med Microbiol, 1997 Nov, 46(11), 941 - 8 Comparison of Vibrio cholerae O1 isolates by polymerase chain reaction fingerprinting and ribotyping; Shangkuan YH et al.; The rRNA gene restriction patterns and the polymerase chain reaction (PCR) fingerprinting types of 53 Vibrio cholerae O1 isolates were studied . Five and eight patterns were observed from 27 toxigenic and 26 non-toxigenic O1 isolates after BglI cleavage . PCR fingerprinting with three primer sets aimed at enterobacterial repetitive intergenic consensus (ERIC) sequences, ERIC-related sequences in V . cholerae, another kind of repeated sequences in V . cholerae (VCR) and arbitrary sequences divided the same strains into seven and 10 PCR types, respectively . Eight ribotypes had unique PCR patterns . PCR fingerprinting identified more than one pattern among isolates within each of the remaining ribotypes . However, ribotyping was able to differentiate the same PCR types in one case . A single ribotype and a single PCR pattern were found in toxigenic O1 strains isolated in Taiwan from imported food and imported cases of cholera between 1993 and 1995 . Typing of V . cholerae O1 by PCR fingerprinting correlated well with ribotyping, but was more discriminating . PCR assay provides a rapid and simple means of typing these strains for epidemiological studies. J Med Microbiol, 1997 Nov, 46(11), 903 - 12 Serratia marcescens; Hejazi A et al.; Over the last 30 years, Serratia marcescens has become an important cause of nosocomial infection . There have been many reports concerning the identification, antibiotic susceptibility, pathogenicity, epidemiological investigations and typing of this organism . Accurate identification is important in defining outbreaks . The API 20E system has been used widely, but is not individually satisfactory . The growth of S . marcescens in the environment has been investigated in relation to water, disinfectants and plastics such as blood bags . Certain extracellular products are unique to S . marcescens . Pigment (prodigiosin) biosynthesis by S . marcescens has been investigated fully since the emergence of the organism as a cause of infection . Many other aspects of the pathogenicity and virulence of S . marcescens have been studied, including adherence and hydrophobicity, lipopolysaccharide (LPS) and extracellular products . Two modes of adhesion to host epithelial surfaces have been suggested . These are mannose-resistant (MR) pili and mannose-sensitive (MS) pili . LPS, which is responsible for the biological activity of endotoxin, has been investigated fully and 24 somatic antigens have been described . The production of different enzymes by S . marcescens as virulence factors has also been reported, including chitinase, lipase, chloroperoxidase and an extracellular protein, HasA . Antibiotics used to treat serratia infection include beta-lactam agents, aminoglycosides and fluoroquinolones and a variety of different resistance mechanisms have been demonstrated . Typing methods used to study the epidemiology of S . marcescens include biotyping, bacteriocin typing, phage typing, plasmid analysis, polymerase chain reaction amplification of enterobacterial repetitive intergenic consensus sequences (ERIC-PCR) and ribotyping . Serological typing has also been used and this method seems to be a suitable first-line typing method for S . marcescens, although some strains remain untypable . RAPD-PCR has also been applied to a small number of isolates and seems to be a promising method, especially for rapid monitoring of an outbreak and tracing the source of initial infection. J Immunol, 1997 Nov 15, 159(10), 4868 - 78 Bacterial lipoprotein and lipopolysaccharide act synergistically to induce lethal shock and proinflammatory cytokine production; Zhang H et al.; Septic shock is a major cause of death in the world . Although much is known about the role of LPS in septic shock, little is known about the role of other bacterial components . Lipoprotein (LP) is a major component of bacteria in the family Enterobacteriaceae . LP purified from Escherichia coli was shown to induce TNF-alpha and IL-6 production in peritoneal exudate macrophages obtained from LPS-responsive (C3H/HeOuJ) and LPS-nonresponsive (C3H/HeJ) mice . LP and LPS acted synergistically to induce cytokine production not only in C3H/HeOuJ macrophages but also in C3H/HeJ macrophages . These results suggest that LPS can induce cellular signaling in C3H/HeJ macrophages, and that LPS and LP activate macrophages via different receptors and/or signaling pathways . The role LP plays in septic shock was investigated using the mouse D-galactosamine model . LP induced lethal shock and in vivo production of TNF-alpha and IL-6 in both LPS-responsive and LPS-nonresponsive mice . LPS failed to induce lethal shock or in vivo cytokine production in C3H/HeJ mice . However, LP and LPS acted synergistically in inducing lethal shock and in vivo cytokine production in both LPS-responsive and LPS-nonresponsive mice . Finally, a heat-killed preparation of an E . coli mutant strain that lacked LP was shown to be less efficient than heat-killed wild-type E . coli at inducing lethal shock in C3H/HeJ mice . Collectively, these results suggest that LP and LPS induce cytokine production via different mechanisms and that LP plays an important role in septic shock induced by bacteria in the family Enterobacteriaceae. Mol Microbiol, 1997 Sep, 25(5), 831 - 8 Control of virulence gene expression by plant calcium in the phytopathogen Erwinia carotovora; Flego D et al.; Plant calcium can modulate a particular plant-pathogen interaction and have a decisive role in disease development . Enhanced resistance to the phytopathogenic enterobacterium Erwinia carotovora, the causal agent of bacterial soft rot disease, is observed in high-calcium plants . One of the main virulence determinants of E . carotovora, the PehA endopolygalacturonase, is specifically required in the early stages of the infection . Production of PehA was found to be dependent on the calcium concentration in the bacterial environment . An increase in extracellular calcium to mM concentrations repressed pehA gene expression without reducing or even enhancing expression of other extracellular enzyme-encoding genes of this pathogen . An increase in plant calcium levels could be correlated to enhanced resistance to E . carotovora infection and to an inhibition of in planta production of PehA . Ectopic expression of pehA from a calcium-insensitive promoter allowed E . carotovora to overcome this calcium-induced resistance . The results imply that plant calcium can constitute an important signal molecule in plant-pathogen interaction, which acts by modulating the expression of virulence genes of the pathogen. Appl Environ Microbiol, 1997 Nov, 63(11), 4331 - 9 Identification of N2-fixing plant- and fungus-associated Azoarcus species by PCR-based genomic fingerprints; Hurek T et al.; Most species of the diazotrophic Proteobacteria Azoarcus spp . occur in association with grass roots, while A . tolulyticus and A . evansii are soil bacteria not associated with a plant host . To facilitate species identification and strain comparison, we developed a protocol for PCR-generated genomic fingerprints, using an automated sequencer for fragment analysis . Commonly used primers targeted to REP (repetitive extragenic palindromic) and ERIC (enterobacterial repetitive intergenic consensus) sequence elements failed to amplify fragments from the two species tested . In contrast, the BOX-PCR assay (targeted to repetitive intergenic sequence elements of Streptococcus) yielded species-specific genomic fingerprints with some strain-specific differences . PCR profiles of an additional PCR assay using primers targeted to tRNA genes (tDNA-PCR, for tRNA(IIe)) were more discriminative, allowing differentiation at species-specific (for two species) or infraspecies-specific level . Our protocol of several consecutive PCR assays consisted of 16S ribosomal DNA (rDNA)-targeted, genus-specific PCR followed by BOX- and tDNA-PCR; it enabled us to assign new diazotrophic isolates originating from fungal resting stages (sclerotia) to known species of Azoarcus . The assignment was confirmed by phylogenetic analysis of 16S rDNA sequences . Additionally, the phylogenetic distances and the lack of monophyly suggested emendment of the genus Azoarcus: the unnamed species Azoarcus groups C and D and a new group (E) of Azoarcus, which was detected in association with fungi, are likely to have the taxonomic rank of three different genera . According to its small subunit rRNA, the sclerotium-forming basidiomycete was related to the Ustilagomycetes, facultatively biotrophic parasites of plants . Since they occurred in a field which was under cultivation with rice and wheat, these fungi might serve as a niche for survival for Azoarcus in the soil and as a source for reinfection of plants. J Infect Dis, 1997 Nov, 176(5), 1260 - 8 Antiserum against Escherichia coli J5 contains antibodies reactive with outer membrane proteins of heterologous gram-negative bacteria; Hellman J et al.; The binding of IgG in antiserum to Escherichia coli J5 to the surface of Enterobacteriaceae and to cell wall fragments released from serum-exposed bacteria was studied in a search for potentially protective epitopes other than lipopolysaccharide (LPS) . IgG titers to multiple heterologous gram-negative smooth bacteria increased following incubation of the bacteria in serum and decreased following absorption with serum-exposed heterologous bacteria . IgG eluted from absorbing bacteria bound to at least three conserved bacterial outer membrane proteins (OMPs), but not LPS, as assessed by immunoblotting . The same OMPs were present in LPS-containing macromolecular cell wall fragments released by incubation of heterologous gram-negative bacteria in human serum . Part of the protection offered by J5 antiserum could be from binding of IgG to conserved OMPs at the bacterial surface or to OMPs in cell-wall fragments released from dying bacteria. Avian Dis, 1997 Jul-Sep, 41(3), 548 - 58 Inhibition of Salmonella typhimurium attachment to chicken cecal mucus by intestinal isolates of Enterobacteriaceae and lactobacilli; Craven SE et al.; The ability of selected strains of Enterobacteriaceae or lactobacilli isolated from the intestines of adult chickens to inhibit in vitro attachment of Salmonella typhimurium 3333/O to cecal mucus in the presence or absence of D-mannose was determined . Attachment in the absence of mannose was reduced by prior exposure of mucus to cultures of two isolates of Enterobacteriaceae, an Escherichia coli and a Hafnia alvei strain, but not to a third isolate, an Enterobacter agglomerans strain . Attachment of S . typhimurium was not inhibited when mannose was present in the blocking or attachment step . Formation of fimbriae by the two inhibitory Enterobacteriaceae strains and the S . typhimurium strain, as indicated by titers of mannose-sensitive hemagglutination of guinea pig erythrocytes was optimal in Z biphasic medium (consisting of tryptone, yeast extract, dextrose, and NaCl) incubated anaerobically at 42 C . Fimbriae of each of three strains prepared from these cultures also inhibited attachment . These are characteristics consistent with attachment and inhibition of attachment mediated by a mannose-sensitive adhesin associated with type 1 fimbriae on bacterial cells of Enterobacteriaceae strains . Attachment in the presence of mannose was significantly reduced by prior exposure of mucus to cultures of a Lactobacillus salivarius strain and a Lactobacillus delbrueckii delbrueckii strain but not to a strain of Lactobacillus for which the species had not been determined . Washed cells or spent culture supernatant fluid from brain-heart infusion broth, Z broth, or Z biphasic cultures of the inhibitory strains of lactobacilli incubated at 37 or 42 C inhibited this form of attachment . Of 27 intestinal isolates of Enterobacteriaceae and 21 of lactobacilli, the lactobacilli strains were generally more hydrophobic than the Enterobacteriaceae as determined by adherence to hexadecane . The lactobacilli isolates did not agglutinate guinea pig erythrocytes . The data suggest more than one mechanism for mediating attachment of inhibitory bacterial strains and for subsequent attachment of S . typhimurium. J Biochem (Tokyo), 1997 Jun, 121(6), 1129 - 33 Chemical structure of lipid A from Helicobacter pylori strain 206-1 lipopolysaccharide; Suda Y et al.; The chemical structure of a novel lipid A, which was obtained as a major component from lipopolysaccharide of Helicobacter pylori strain 206-1, was determined to be a glucosamine beta(1-6) disaccharide 1-(2-aminoethyl)phosphate acylated by (R)-3-hydroxyoctadecanoic acid and (R)-3-(octadecanoyloxy)octadecanoic acid at the 2- and 2'-position, respectively . The absence of a phosphoryl group at the 4'-position and fatty acyl groups at the 3- and 3'-position, and the stoichiometric presence of 2-aminoethyl phosphate at the 1-position are unique features, distinguishing it from the lipid A of enterobacteria. Microbiologia, 1997 Sep, 13(3), 321 - 30 Purification of OmpU from Vibrio cholerae classical strain 569B: evidence for the formation of large cation-selective ion-permeable channels by OmpU; Benz R et al.; The outer membrane of the classical Vibrio cholerae strain 569B was isolated by sucrose density centrifugation . The simple treatment of the isolated outer membrane or the cell envelopes with different detergents allowed the purification of two outer membrane proteins, the 38 kDa OmpU and the 25 kDa OmpV . Furthermore, a 35 kDa outer membrane protein (probably the 35 kDa OmpA-like protein) was purified by two-fold treatment of the cell envelope with 2% SDS solution . A subsequent wash of the SDS-pellet with 2% Genapol buffer yielded in the 38 kDa OmpU protein, which formed SDS-resistant oligomers (66 kDa) . The Genapol pellet contained OmpV . Reconstitution experiments with lipid bilayer membranes demonstrated that OmpU was a channel-forming component, whereas OmpV had a small channel-forming ability if any . The OmpU channels appeared to be large and water-filled and had a single-channel conductance of about 2 nS in 1 M KCl for the monomer in a trimer, which means that they have a larger cross-section than enterobacterial porins . The channels showed rapid switching between open and closed configuration . They were slightly cation-selective, which suggests that they contain an excess of negatively charged amino groups. EMBO J, 1997 Nov 3, 16(21), 6394 - 406 The chaperone-assisted membrane release and folding pathway is sensed by two signal transduction systems; Jones CH et al.; The assembly of interactive protein subunits into extracellular structures, such as pilus fibers in the Enterobacteriaceae, is dependent on the activity of PapD-like periplasmic chaperones . The ability of PapD to undergo a beta zippering interaction with the hydrophobic C-terminus of pilus subunits facilitates their folding and release from the cytoplasmic membrane into the periplasm . In the absence of the chaperone, subunits remained tethered to the membrane and were driven off-pathway via non-productive interactions . These off-pathway reactions were detrimental to cell growth; wild-type growth was restored by co-expression of PapD . Subunit misfolding in the absence of PapD was sensed by two parallel pathways: the Cpx two-component signaling system and the sigma E modulatory pathway. J Appl Microbiol, 1997 Oct, 83(4), 456 - 63 A selective medium for the rapid detection by an impedance technique of Pseudomonas spp . associated with poultry meat; Salvat G et al.; A new medium for detecting and enumerating Pseudomonas spp . associated with poultry meat spoilage by a rapid impedance technique was developed, after testing potential growth promoters for eight Pseudomonas strains and inhibitors against eight competing strains (Enterobacteriaceae) able to grow on the medium of Mead and Adams (1977) . Four basal media (brain heart infusion, brucella broth, Shaedler broth and Whitley impedance broth (WIB)) and a synthetic medium were evaluated . Whitley impedance broth was the best basal medium for detecting variations in impedance in relation to Pseudomonas growth . The efficiency of WIB was improved by adding compounds which enhanced the growth of Pseudomonas on the synthetic medium . Among the incubation temperatures tested, 22 degrees C proved to be the best compromise between growth of Pseudomonas associated with poultry meat spoilage and inhibition of competitors . Among the 15 inhibitory substances evaluated against Pseudomonas competitors, five were chosen for inclusion in the final medium: metronidazole, carbenicilline, cetrimide, cycloheximide and diamide (MCCCD medium) . Preliminary results obtained from experiments with beef and pork meat showed that this medium could also be used without diamide and at an incubation temperature of 25 degrees C . The impedance technique using MCCCD medium was then compared with an official method which uses the medium of Mead and Adams (1977) on 106 samples of poultry neck skin . The linear regression coefficient between the two techniques was approximately r = 0.85 . Impedance was able to detect 10(3) Pseudomonas g-1 within less than 19 h making it a promising technique for predicting poultry meat spoilage. J Appl Microbiol, 1997 Sep, 83(3), 367 - 74 Growth of enterobacteria on fructo-oligosaccharides; Hartemink R et al.; Fructo-oligosaccharides (FOS) can be fermented by most species of enterobacteria present in the human intestine . Fermentation was confirmed by increased growth rates, low final pH and degradation patterns using high performance anion exchange chromatography (HPAEC) . Growth rates were increased when FOS was added to the growth medium . Growth rates on all substrates differed widely between strains within the same species . HPAEC analysis showed that each strain degraded the oligosaccharides differently, but a preference for the smaller oligosaccharides was observed . No differences were observed between the two commercial preparations, the inulo-oligosaccharides and neosugars . Fermentation was rapid as could be determined by acidification tests using cell suspensions . It can be concluded that enterobacteria may play a role in overall fermentation of FOS in the colon and, in addition, due to competitive exclusion, may prevent survival of ingested pathogenic enterobacteria. Trends Microbiol, 1997 Oct, 5(10), 389 - 94 Origins of the mobile gene cassettes found in integrons; Recchia GD et al.; Many of the acquired antibiotic resistance genes found in enterobacteria and pseudomonads are part of small mobile elements known as gene cassettes, and other genes are also likely to be found in cassettes . The origins of the genes and the recombination sites that make up cassettes are not known, but recent analyses of available data suggest that cassettes may be ancient structures, and some hypotheses for how they are formed can now be examined. J Clin Microbiol, 1997 Nov, 35(11), 2773 - 7 Evaluation of BBL CHROMagar orientation medium for detection and presumptive identification of urinary tract pathogens; Hengstler KA et al.; The microbiological performance of BBL CHROMagar Orientation medium and CPS ID2 agar was compared to that of Columbia agar with 5% sheep blood and MacConkey agar without crystal violet for the enumeration and presumptive identification of bacteria responsible for urinary tract infections . Of a total of 658 clinical urine specimens, 118 specimens yielded no growth, 402 specimens yielded growth with cell counts of > or = 10(5) CFU/ml, and 138 specimens yielded growth with cell counts of < 10(5) CFU/ml . Of the specimens with cell counts of > or = 10(5) CFU/ml, 163 were pure cultures and 239 were mixed cultures . A total of 266 Escherichia coli organisms were isolated on both chromogenic media, 260 were isolated on blood agar, and 248 were isolated on MacConkey agar . One strain (0.4%) failed to develop the expected pink color on CHROMagar Orientation medium, and 23 strains (8.7%) failed to develop the expected pink color on CPS ID2 agar . Enterococci (CHROMagar Orientation medium, n = 266; CPS ID2 agar, n = 265) produced small blue-green colonies on both chromogenic media . Fifty of the mixed cultures contained enterococci that were detected only on the chromogenic media . The Klebsiella-Enterobacter-Serratia (KES) and the Proteus-Morganella-Providencia (PMP) groups could be identified on both chromogenic media . Of 66 isolates of the KES group, 63 grew with the expected color on CHROMagar Orientation medium and 58 of 64 isolates grew with the expected color on CPS ID2 agar . Other microorganisms required further identification . The use of chromogenic medium formulations offers a time-saving method for the reliable detection, enumeration, and presumptive identification of urinary tract pathogens . One of the greatest advantages of these media is the easy recognition of mixed cultures. Ann Biol Clin (Paris), 1997 Sep-Oct, 55(5), 465 - 9 {Molecular typing by pulsed field gel electrophoresis of Enterobacter cloacae strains isolated from osteoarticular infections at the Nancy University Hospital 1990-1994}; Simeon D et al.; Enterobacteriaceae represent more than 11% of bacteria involved in osteoarticular infections in adult and, among them, Enterobacter cloacae is found in 12% of the cases . The increased evolution of the antibiotic resistance rate of this species is worrying . However, all isolates responsible for this type of infection at the University Hospital of Nancy from 1990 to 1994 (24 strains isolated from 22 patients presented an identical antibiotype with especially a natural resistance phenotype to beta-lactam antibiotics except one cephalosporinase-over-producing strain . The DNA of these strains was studied by pulse-field gel electrophoresis after digestion by the restriction enzyme XbuI . The great genomic diversity obtained showed that the stability of the antibiotic susceptibility during the period studied was not due to the existence of unique clone but to that of multiple clones . The analysis of the restriction profiles has permitted to achieve a better differenciation of the strains than biotyping and antibiotyping, which confirms the high discrimination power of this genotypic method. Biochem Biophys Res Commun, 1997 Oct 9, 239(1), 240 - 6 Synthetic genes specifying periodic polymers modelled on the repetitive domain of wheat gliadins: conception and expression; Elmorjani K et al.; In order to optimise new polypeptide based biomaterials, we developed a procedure for producing homoblock polypeptides using recombinant DNA technology . Synthetic genes encoding periodic polypeptides modelled on the consensus sequence of wheat gliadins (a family of wheat storage proteins) were devised to be expressed in Escherichia coli . The construction strategy followed allows the construction of three genes encoding 8, 16, and 32 copies of the PQQPY module . The optimal expression conditions in the enterobacteria were established and a convenient purification procedure was shown to be useful in recovery of sizable amounts of strictly periodic polypeptides . The identities of the synthesized polypeptides were assessed using positive cross reactions to antibodies raised against a synthetic decapeptide (PQQPYPQQPA) and amino acid composition was determined as well. J Am Vet Med Assoc, 1997 Oct 15, 211(8), 1029 - 35 Number of viable bacteria and presumptive antibiotic residues in milk fed to calves on commercial dairies; Selim SA et al.; OBJECTIVE: To assess the number of bacteria and presumptive antibiotic residues in milk fed to calves and to identify those bacteria and the antibiotic susceptibility of selected bacterial strains . DESIGN: Cross-sectional prospective study . SAMPLE POPULATION: 189 samples obtained from 12 local dairies . PROCEDURE: Samples of waste milk and milk-based fluids (eg, milk replacer, colostrum, bulk-tank milk) were obtained . Cumulative number of viable bacteria was determined . Bacteria were cultured aerobically, and antibiotic susceptibility testing of selected strains was performed . Presumptive antibiotic residues were detected by use of test kits . RESULTS: Geometric mean of the cumulative number of bacteria for waste milk samples was significantly higher than for other types of milk or milk-based products . Streptococcus sp (84/165 samples) and Enterobacteriaceae (83/165 samples) were the predominant bacteria identified, followed by Staphylococcus sp (68/165 samples) . Escherichia coli was the gram-negative species most commonly isolated (52/165 samples; 32%); however, none were strain O157 . Salmonella sp or Mycoplasma sp were not isolated . Of 189 samples, 119 (63%) were positive when tested for beta-lactams or tetracycline by use of 2 commercially available assays . In vitro, some bacteria were resistant to commonly used antibiotics . CLINICAL IMPLICATIONS: Waste milk that has not been effectively treated (eg, pasteurization) to reduce microbial load prior to use as calf feed should be used with caution, because it may contain a high number of bacteria that may be pathogenic to cattle and human beings . Antibiotic residues that would constitute violative amounts and existence of multiple antibiotic resistant bacterial strains are concerns in calf health management and dairy food safety. Zh Mikrobiol Epidemiol Immunobiol, 1997 Jul-Aug, (4), 89 - 92 {The effect of therapeutic mud on the viability and persistence properties of bacteria}; Abdrakhmanov AR et al.; The influence of therapeutic salt mud on the viability and some biological properties of bacteria, responsible for their survival in the macroorganisms, was shown . Therapeutic mud had low bactericidal properties, and enterobacteria were, on the whole, even less sensitive to these properties than staphylococci . Therapeutic mud inhibited the capacity of bacteria for inactivating complement, lysozyme and the bactericidal component of the preparation of interferon and also reduced the hydrophobic properties of bacterial cells . At the same time Escherichia were found to be more susceptible to the modifying action of the mud than staphylococci . The greatest effect on the hydrophobic properties and anticomplement activity of bacteria was observed after their incubation in mud solution. J Bacteriol, 1997 Oct, 179(19), 6192 - 5 Isolation and characterization of Enterobacter cloacae mutants which are defective in chemotaxis toward inorganic phosphate; Kusaka K et al.; Enterobacter cloacae IFO3320 is attracted to Pi when cells are starved for Pi . Two Tn1737KH-induced mutants, which were constitutive for alkaline phosphatase, failed to exhibit Pi taxis even under conditions of Pi limitation . Both of the mutant strains exhibited normal chemotactic responses to peptone, suggesting that they are specifically defective in Pi taxis . Cloning and sequence analysis showed that the TN1737KH insertions were located in either the pstA or pstB genes which encode the channel-forming proteins of the Pi-specific transport (Pst) system in E . cloacae . These results suggest that the E . cloacae Pst system is required for Pi chemoreception. J Antimicrob Chemother, 1997 Sep, 40(3), 393 - 9 Plasmid-encoded fosfomycin resistance in bacteria isolated from the urinary tract in a multicentre survey; Arca P et al.; Sixty out of 219 fosfomycin-resistant bacteria selected from more than 7400 urinary pathogens in an epidemiological multicentre survey performed in Italy were screened for plasmid genes fosA and fosB conferring fosfomycin resistance . Only five strains, three enterobacteria and two staphylococci, carried plasmids harbouring, respectively, fosA and fosB genes . Fosfomycin resistance in the other isolates was caused by an alteration of the chromosomally encoded GlpT transport system . One strain, Morganella morganii 279, incorporated alpha-glycerolphosphate and its mechanism of fosfomycin resistance needs to be further investigated . Our study showed that PCR amplification is the most accurate, simple and rapid method for epidemiological studies of plasmid-encoded fosfomycin resistance, and that fosfomycin resistance conferred by plasmid genes (both fosA and fosB) accounts for only a low percentage of the fosfomycin-resistant strains. Nature, 1997 Oct 9, 389(6651), 636 - 9 Survival of FimH-expressing enterobacteria in macrophages relies on glycolipid traffic; Baorto DM et al.; Strains of Escherichia coli persist within the human gut as normal commensals, but are frequent pathogens and can cause recurrent infection . Here we show that, in contrast to E . coli subjected to opsonic interactions stimulated by the host's immune response, E . coli that bind to the macrophage surface exclusively through the bacterial lectin FimH can survive inside the cell following phagocytosis . This viability is largely due to the attenuation of intracellular free-radical release and of phagosome acidification during FimH-mediated internalization, both of which are triggered by antibody-mediated internalization . This different processing of non-opsonized bacteria is supported by morphological evidence of tight-fitting phagosomes compared with looser, antibody-mediated phagosomes . We propose that non-opsonized FimH-expressing E . coli co-opt internalization of lipid-rich microdomains following binding to the FimH receptor, the glycosylphosphatidylinositol-linked protein CD48, because (1) the sterol-binding agents filipin, nystatin and methyl beta-cyclodextrin specifically block FimH-mediated internalization; (2) CD48 and the protein caveolin both accumulate on macrophage membranes surrounding bacteria; and (3) antibodies against CD48 inhibit FimH-mediated internalization . Our findings bring the traditionally extracellular E . coli into the realm of opportunistic intracellular parasitism and suggest how opportunistic infections with FimH-expressing enterobacteria could occur in a setting deprived of opsonizing antibodies. Electrophoresis, 1997 Aug, 18(9), 1512 - 8 Amplification of anonymous DNA fragments using pairs of long primers generates reproducible DNA fingerprints that are sensitive to genetic variation; Gillings M et al.; The reproducibility and potential applications of anonymous amplification protocols can be improved by using pairs of primers, each of 18 to 24 bases, to replace the single 8 to 10 base primers normally used in randomly amplified polymorphic DNA (RAPD) or DNA amplification fingerprinting (DAF) methods . Amplification using large primer pairs (LP-RAPD) generates 5 to 30 bands that can be resolved on standard agarose gels . Complex fingerprints can be readily generated from viruses, bacteria, fungi, plants, invertebrates and vertebrates . We also present evidence that a number of polymerase chain reaction (PCR) methods, including those based on the use of enterobacterial repetitive intergenic consensus (ERIC-PCR) or microsatellite primed (MP-PCR) sequence, may in essence operate by the same mechanism as LP-RAPD . Using standard LP-RAPD protocols, reproducible fingerprints can be generated from a single specimen using different thermocyclers, regardless of the mechanism used for thermocycling (air-cooled, Peltier effect, or robotic arm) . LP-RAPD is sensitive to intraspecific and interspecific genetic variation, demonstrated here by analysis of mites and apple cultivars . Approximately 50% of LP-RAPD products are expected to have different primers at either end . Polymorphic bands with this arrangement can be recovered from the gel and directly sequenced using the LP-RAPD primers themselves . The efficiency of sequencing is improved by the length of the LP-RAPD primers . This method has the potential to allow the production of allele-specific species markers in less than two days. Int J Syst Bacteriol, 1997 Oct, 47(4), 1253 - 4 Phylogenetic relationships of Salmonella typhi and Salmonella typhimurium based on 16S rRNA sequence analysis; Chang HR et al.; The 16S rRNA gene sequences of Salmonella typhi and Salmonella typhimurium were amplified by PCR, cloned, and sequenced . These sequences were analyzed by comparison with reference organisms from the family Enterobacteriaceae . Both S . typhi and S . typhimurium belong to the gamma subdivision of the class Proteobacteria. Rev Assoc Med Bras, 1997 Apr-Jun, 43(2), 137 - 44 {Evaluation of in vitro activity of new fluoroquinolones, cephalosporins and carbapenems against 569 gram-negative bacteria}; Gales AC et al.; OBJECTIVE: Evaluation of the in vitro activity of new fluoroquinolones, cephalosporins and carbapenems against gram-negative bacteria . MATERIAL AND METHOD: A total of 569 clinical isolates were obtained from inpatients at Sao Paulo Hospital--UNIFESP/EPM in June and July of 1992 . The species distribution was as follows: Enterobacter sp . (62), Escherichia coli (308), Klebsiella pneumoniae (27), Klebsiella sp . (9), Proteus mirabilis (23), Pseudomonas aeruginosa (88), Pseudomonas sp . (4), Serratia sp . (30) and other gram-negatives (7) . Susceptibility tests were performed by broth microdilution . The antimicrobials agents tested were: ciprofloxacin, ofloxacin, levofloxacin, grepafloxacin, DU 6859-alpha, ceftazidime, cefepime, FK 037, imipenem, meropenem and biapenem . RESULTS: DU 6859-alpha showed the highest anti-microbial activity among the fluoroquinolones . It was two- to four-fold more active than ciprofloxacin against some species . The potency and antimicrobial spectrum were similar between the fourth-generation cephalosporins against Enterobacteriaceae, except for Enterobacter sp . strains which were more susceptible to cefepime than they were to cefetazidime or FK 037 . When testing Pseudomonas aeruginosa, ceftazidime was slightly more active than the other cephalosporins . Against Enterobacteriaceae and Pseudomonas aeruginosa strains, meropenem was more active than imipenem or biapenem . In addition, the percentage of strains, susceptible to meropenem was higher than the percentage susceptible to the other cerbapenems against these species . CONCLUSION: The new antimicrobial agents demonstrated in vitro activity higher than that of agents commercially available . However, more studies are necessary to further evaluate the in vivo activity and the clinical benefit of these compounds. Antimicrob Agents Chemother, 1997 Oct, 41(10), 2312 - 6 Comparative in vitro activities of trovafloxacin (CP-99,219) against 221 aerobic and 217 anaerobic bacteria isolated from patients with intra-abdominal infections; Citron DM et al.; Four hundred thirty-eight bacteria cultured from specimens of patients with serious intra-abdominal infections were tested by agar dilution against trovafloxacin and other quinolones and antimicrobial agents . Trovafloxacin inhibited 435 strains (99.3%) at < or =2 microg/ml . All the quinolones had similar activities against Enterobacteriaceae and Pseudomonas sp., but trovafloxacin showed superior activities against streptococci, enterococci, and anaerobic organisms . Because of its excellent in vitro activities against diverse bacteria, trovafloxacin has potential use as a single agent for polymicrobial infections. Antimicrob Agents Chemother, 1997 Oct, 41(10), 2113 - 20 The signal molecule for beta-lactamase induction in Enterobacter cloacae is the anhydromuramyl-pentapeptide; Dietz H et al.; Beta-lactamase induction in Enterobacter cloacae, which is linked to peptidoglycan recycling, was investigated by high-performance liquid chromatographic analysis of cell wall fragments in genetically defined cells of Escherichia coli . After treatment of cells with beta-lactams, we detected an increase in a D-tripeptide (disaccharide-tripeptide, N-acetylglucosaminyl-1,6-anhydro-N-acetylmuramyl-L-alanyl-D-glutamyl-mes o-diaminopimelic acid), aD-tetrapeptide (disaccharide-tetrapeptide, N-acetylglucosaminyl-1,6-anhydro-N-acetylmuramyl-L-alanyl-D-glutamyl-mes o-diaminopimelic acid-D-alanine), and aD-pentapeptide (disaccharide-pentapeptide, N-acetylglucosaminyl-1,6-anhydro-N-acetylmuramyl-L-alanyl-D-glutamyl-mes o-diaminopimelic acid-D-alanyl-D-alanine)levels in the periplasms of bacterial cells . Furthermore, only the accumulation of aD-pentapeptide correlates with the beta-lactamase-inducing capacity of the beta-lactam antibiotic . The transmembrane protein AmpG transports all three aD-peptides into the cytoplasm, where they are degraded into the corresponding monosaccharide peptides . In the absence of AmpD the constitutive overproduction of beta-lactamase is accompanied by an accumulation of aM-tripeptide (monosaccharide-tripeptide, anhydro-N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid) and aM-pentapeptide (L1,6-anhydro-N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanyl-D-alanine), but not aM-tetrapeptide (anhydro-N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine), in the cytoplasm . Only the amount of aM-pentapeptide is increased upon treatment with imipenem . These findings indicate that aD-pentapeptide is the main periplasmic muropeptide, which is converted into the cytoplasmic signal molecule for beta-lactamase induction, the aM-pentapeptide. Eur J Cardiothorac Surg, 1997 Sep, 12(3), 443 - 9 Mediastinitis after aorto-coronary bypass surgery; Antunes PE et al.; OBJECTIVES: To identify risk factors in 60 cases of mediastinitis amongst 2512 patients (2.3%) subjected to isolated coronary bypass surgery from March 1988 through December 1995, treated by a closed irrigation/drainage system . PATIENTS AND METHODS: The mean age of the 60 patients was 56.9 +/- 6.8 years (45-81 years) and 55 (91.6%) were male . Early mediastinal reexploration was performed in all cases immediately after the diagnosis of mediastinitis, with debridement of necrosed tissues, followed by implantation of a closed-circuit irrigation system of the mediastinum constituted by irrigation catheter and drain, closure of the sternum and skin, and specific systemic antibiotic therapy . The mean interval between the original surgery and reexploration was 9.4 days (range 6-14 days) . No patient required more extensive procedures, namely omental or muscular flaps . Twenty potential risk factors in patients with mediastinitis, including diabetes mellitus, obesity, coexistence of peripheral vascular disease, decreased LV function, use of inotropes, mediastinal blood drainage and utilization of double IMA, were compared with the group without mediastinitis . RESULTS: Mean cardiopulmonary bypass time was 74.1 +/- 8.1 min, anesthetic time 3.5 +/- 0.8 h and postoperative mechanical ventilation 18 +/- 3 h . A total of 23 patients (38.3%) received one IMA and 35 (58.3%) two IMAs . In the postoperative period, 7 of the 60 patients (11.6%) had required inotropes because of low output . Mediastinal blood loss was 1112cc +/- 452cc and 9 patients (15%) were transfused . Cultures were positive in 40 cases (66.6%) and the most frequent infecting agent was the Staph . epidermidis in 25 cases (62.5%), followed by Candida albicans and Enterobacter and Serratia species (7.5% each); 1 patient (1.7%) died and 9 (15%) had renal failure . The irrigation/drainage was maintained for a mean of 9.1 days (5-83 days) . Patients with mediastinitis had a significantly higher prevalence of diabetes (41.6% vs . 18.8%; P < 0.01), obesity (48.3% vs . 15.2%; P < 0.001), peripheral vascular disease (11.6% vs . 4.0%; P < 0.05), but a lower incidence of poor LV function (18.3% vs . 32.7%; P < 0.05) . A double IMA was used more frequently in patients who had mediastinitis (58.3% vs . 23.5%; P < 0.001) CONCLUSIONS: Diabetes mellitus, obesity, co-existence of peripheral vascular disease and use of double IMA are risk factors for mediastinitis after coronary artery surgery . The efficacy of the closed method of treatment with a mediastinal irrigation/drainage system was increased with early diagnosis and reintervention. Clin Infect Dis, 1997 Aug, 25(2), 318 - 20 Incidence and epidemiology of nosocomial infections in patients infected with human immunodeficiency virus; Frank U et al.; In a prospective study, we investigated the incidence, characteristics, and risk factors of nosocomial infections (NIs) in patients with human immunodeficiency virus disease . There was a total of 528 admissions of 405 eligible patients; 46 NIs (8.7% per discharge) were identified in 39 patients . The proportional frequencies of NIs were as follows: 16 skin and/or soft-tissue infections (including localized catheter-associated infections), 3.0%; 14 respiratory tract infections, 2.7%; 11 bloodstream infections, 2.1%; and 5 urinary tract infections, 0.9% . The most common etiologic agents were Staphylococcus aureus (27.6%), Pseudomonas aeruginosa (13.8%), and Enterobacter cloacae (13.8%) . The duration of hospitalization was not significantly prolonged by NI in the cohort. Am J Med Sci, 1997 Oct, 314(4), 245 - 9 Urinary tract infection: an overview; Barnett BJ et al.; Urinary tract infection (UTI) remains very common . As many as 50% of women report having had at least one UTI in their lifetimes . Urinary tract infection is the most common cause of infection in nursing home residents and the most common source of bacteremia in the elderly population . Urinary tract infection occurs in patients with structurally or functionally abnormal urinary tracts (complicated UTI) and in patients with anatomically normal urinary tracts (uncomplicated UTI) . Escherichia coli (E coli) is the most common cause of uncomplicated UTI, whereas antibiotic-resistant Enterobacteriaceae, enterococci, and Candida species often are the causes of complicated UTI . In this article we review current concepts of the epidemiology, microbiology, pathophysiology, clinical manifestations, diagnosis, and treatment of urinary tract infection. Harefuah, 1997 Jul, 133(1-2), 1 - 2, 80 {Bacterial culture of chip tissue of enucleated prostates}; Ben-Zion IZ et al.; To assess the prevalence of infection and colonization of the prostate by bacteria, chip tissue samples from 166 patients undergoing retropubic prostatectomy were submitted for bacterial tissue culture . In 28 patients with an indwelling catheter before surgery, E . coli, Klebsiella, Pseudomonas and Enterobacter were the commonest species encountered, the first the most common . In only 7 patients (20%) who didn't have an indwelling catheter before operation was the culture positive . We confirmed that the longer the time the catheter was indwelling before surgery, the greater the likelihood of positive cultures . However, postoperative outcome and morbidity were not related to culture results . We conclude that even though it is worth trying to sterilize the urine and prostate before prostatectomy, the effect on the postoperative outcome is minimal when proper antimicrobial therapy is given perioperatively. Acta Microbiol Immunol Hung, 1997, 44(2), 165 - 71 In vitro antimicrobial properties of azidothymidine (AZT); Monno R et al.; In addition to the activity against a number of retroviruses, azidothymidine (AZT) has antibacterial activity against many bacteria . The effect of AZT on 224 bacterial species, including 25 strains of Salmonella spp . isolated from HIV-positive patients, was tested . AZT had no activity against all the strains of tested Gram-positive bacteria and Pseudomonas species (MIC > 128 micrograms/ml), whereas a different activity against Enterobacteriaceae (MIC range, 128 to 0.06 micrograms/ml) was found . In particular 76% of Salmonella spp . isolated from HIV-positive patients showed MICs > 1 microgram/ml, whereas similar MICs value were found in 50% of the Salmonella strains isolated from HIV-negative subjects . In addition, strains of Salmonella isolated from stools were more resistant to AZT when compared to strains isolated from blood even if this difference was not statistically significant . No correlation was found between length of therapy and Salmonella resistance to AZT in HIV-positive patients and a low incidence of Salmonella relapses in subjects treated with AZT was observed . The possibility that AZT may have an ancillary benefit in controlling some bacterial infections in AIDS patients is discussed. FEMS Immunol Med Microbiol, 1997 Sep, 19(1), 33 - 45 Tracking of clinical and environmental Vibrio cholerae O1 strains by combined analysis of the presence of toxin cassette, plasmid content and ERIC PCR; Colombo MM et al.; Clinical and environmental Vibrio cholerae O1 strains associated with the cholera epidemic in the Luanda province of Angola from 1991 to 1994 were tracked by toxin distribution, plasmid content and chromosomal polymorphism of the enterobacterial repetitive intergenic consensus (ERIC) sequences by PCR fingerprinting . To follow the distribution of ace, zot and ctxA toxin genes, 6 specific PCR tests were applied to 100 Vibrio strains, after preliminary hybridization experiments . Clinical isolates of Vibrio cholerae O1 were characterized by high stability of the toxigenic cassette and the presence of a large conjugative multi-resistant plasmid of incompatibility class C . Such characteristics were present in all isolates during the four years of the epidemic . Environmental strains, isolated from the river supplying water to the Luanda population showed three different genetic profiles: the presence of both cassette and plasmid, the presence of cassette only or absence of both . To assess the clonal relationship between the clinical isolates and the three groups of environmental strains, the strains were analyzed by PCR ERIC polymorphism . This analysis, supported by the toxin and plasmid content, suggested the stability of the epidemic strain in clinical cases during the epidemic and led to the finding that there was a strict genetic relationship of the epidemic strain with the environmental ones as characterized by the presence of the toxin cassette . The role of the water supply from Bengo River as a reservoir of the Vibrio epidemic strain is discussed. J Hosp Infect, 1997 Sep, 37(1), 25 - 37 Role of quantitative cultures and microscopic examinations of endotracheal aspirates in the diagnosis of pulmonary infections in ventilated patients; Albert S et al.; Endotracheal aspirates (EA) from 20 intubated patients in a surgical intensive care unit (mean ventilation time/patient = 16.5 days) were investigated serially by performing quantitative cultures using growth of 10(5) cfu/mL as a cut-off point . Microscopic examinations were made using Giemsa's stain for polymorphonuclear neutrophils (PMN) . The spectrum of pathogens encountered was determined and compared with clinical data to distinguish colonization from infection of the lower respiratory tract . Out of 301 EA cultures, 156 (51.8%) were positive and 145 (48.2%) were below the cut-off point . Counts of PMN were significantly higher in samples which gave positive cultures . Seventy-five different bacterial strains were isolated (64% were Gram-negative bacilli) . Seventeen patients (85%) were colonized with Gram-negative bacteria . Nine patients (45%) developed nosocomial pneumonia (NP), five (25%) had no signs of pneumonia, and six (30%) had an uncertain status . Main causative agents for NP were Pseudomonas aeruginosa, Enterobacteriaceae and Staphylococcus aureus . Quantitative EA cultures had a sensitivity of 81.5%, a specificity of 64.8%, a positive predictive value of 55% and a negative predictive value of 87% . Our results suggest that EA quantitative cultures (cut-off value 10(5) cfu/mL), species identification and microscopic examination of EA may help to differentiate tracheobronchial colonization and infection, especially when bronchoscopic techniques are not available. Infect Immun, 1997 Oct, 65(10), 4199 - 206 Specificity of the high-mannose recognition site between Enterobacter cloacae pili adhesin and HT-29 cell membranes; Pan YT et al.; Enterobacter cloacae has been implicated as one of the causative agents in neonatal infection and causes a septicemia thought to be initiated via the gastrointestinal tract . The adhesion of radiolabeled E . cloacae to HT-29 cells was concentration and temperature dependent and was effectively blocked by unlabeled bacteria or by millimolar concentrations of alpha-mannosides and micromolar concentrations of high-mannose oligosaccharides . A variety of well-characterized mannose oligosaccharides were tested as inhibitors of adhesion . The best inhibitor was the Man9(GlcNAc)2-tyrosinamide, which was considerably better than other tyrosinamide-linked oligosaccharides such as Man7(GlcNAc)2, Man6(GlcNAc)2 or Man5(GlcNAc)2 . Further evidence that the bacteria preferred Man9(GlcNAc)2 structures was obtained by growing HT-29 cells in the presence of glycoprotein processing inhibitors that block mannosidase I and increase the amount of protein-bound Man9(GlcNAc)2 at the cell surface . Such cells bound 1.5- to 2-fold more bacteria than did control cells . The adhesin involved in binding to high-mannose structures was purified from isolated pili . On sodium dodecyl sulfate-gels, a 35-kDa protein was identified by its specific binding to a mannose-containing biotinylated albumin . The amino acid sequences of several peptides from the 35-kDa subunit showed over 85% identity to FimH, the mannose-specific adhesin of Salmonella typhimurium . Pili were labeled with 125I and examined for the ability to bind to HT-29 cells . Binding showed saturation kinetics and was inhibited by the addition of Man9(GlcNAc)2-tyrosinamide but not by oligosaccharides with fewer mannose residues . Polyclonal antibody against this 35-kDa protein also effectively blocked adhesion of pili or E . cloacae, but no effect was observed with nonspecific antibody . These studies demonstrate that the 35-kDa pilus subunit is a lectin whose specificity is directed toward Man, (GlcNAc)2 oligosaccharides. J Clin Microbiol, 1997 Oct, 35(10), 2642 - 8 Evaluation of a fluorescence-labelled oligonucleotide probe targeting 23S rRNA for in situ detection of Salmonella serovars in paraffin-embedded tissue sections and their rapid identification in bacterial smears; Nordentoft S et al.; A method for the detection of Salmonella based on fluorescence in situ hybridization (FISH) has been developed and applied for the direct detection of Salmonella in pure cultures and in formalin-fixed, paraffin-embedded tissue sections . On the basis of the 23S rRNA gene sequences representing all of the S . enterica subspecies and S . bongori, an 18-mer oligonucleotide probe was selected . The specificity of the probe was tested by in situ hybridization to bacterial cell smears of pure cultures . Forty-nine of 55 tested Salmonella serovars belonging to subspecies I, II, IIIb, IV, and VI hybridized with the probe . The probe did not hybridize to serovars from subspecies IIIa (S . arizonae) or to S . bongori . No cross-reaction to 64 other strains of the family Enterobacteriaceae or 18 other bacterial strains outside this family was observed . The probe was tested with sections of formalin-fixed, paraffin-embedded tissue from experimentally infected mice or from animals with a history of clinical salmonellosis . In these tissue sections the probe hybridized specifically to Salmonella serovars, allowing for the detection of single bacterial cells . The development of a fluorescence-labelled specific oligonucleotide probe makes the FISH technique a promising tool for the rapid identification of S . enterica in bacterial smears, as well as for the detection of S . enterica in histological tissue sections. Chemosphere, 1997 Oct, 35(7), 1487 - 95 Volatile metabolites from some gram-negative bacteria; Scholler C et al.; A survey of volatile organic compounds (VOCs) excreted from various Gram-negative bacteria (Pseudomonas spp., Serratia spp . and Enterobacter spp.) was carried out . Compounds were identified by gas chromatography-mass spectrometry . VOCs identified included dimethyl disulphide, dimethyl trisulphide and isoprene. FEMS Microbiol Lett, 1997 Sep 15, 154(2), 245 - 50 Induction of gram-negative bacterial growth by neurochemical containing banana (Musa x paradisiaca) extracts; Lyte M; Bananas contain large quantities of neurochemicals . Extracts from the peel and pulp of bananas in increasing stages of ripening were prepared and evaluated for their ability to modulate the growth of non-pathogenic and pathogenic bacteria . Extracts from the peel, and to a much lesser degree the pulp, increased the growth of Gram-negative bacterial strains Escherichia coli O157:H7, Shigella flexneri, Enterobacter cloacae and Salmonella typhimurium, as well as two non-pathogenic E . coli strains, in direct relation to the content of norepinephrine and dopamine, but not serotonin . The growth of Gram-positive bacteria was not altered by any of the extracts . Supplementation of vehicle and pulp cultures with norepinephrine or dopamine yielded growth equivalent to peel cultures . Total organic analysis of extracts further demonstrated that the differential effects of peel and pulp on bacterial growth was not nutritionally based, but due to norepinephrine and dopamine . These results suggest that neurochemicals contained within foodstuffs may influence the growth of pathogenic and indigenous bacteria through direct neurochemical-bacterial interactions. Int J Food Microbiol, 1997 Jul 22, 37(2-3), 225 - 9 Effect of nitrate and nitrite curing salts on microbial changes and sensory quality of rapid ripened sausages; Sanz Y et al.; The effect of the use of either nitrite or nitrate curing salts on microbial changes and sensory quality in rapid ripened sausages inoculated with a mixed starter culture (Lactobacillus sake and Staphylococcus carnosus) was investigated . Lactic acid bacteria and Micrococcaceae were not greatly affected by the added curing salt . Conversely, the inhibition exerted by nitrite on the undesirable flora (Enterobacteriaceae and psychrotrophs) was evident from the early stages of the processing keeping highly significant differences (P < 0.01) with respect to nitrate made sausages till the end of the ripening stage . The use of nitrite in sausage processing was found to reduce hygienic risks. Behring Inst Mitt, 1997 Feb, (98), 103 - 13 The Escherichia coli hemolysin secretion apparatus--a versatile antigen delivery system in attenuated Salmonella; Gentschev I et al.; The E . coli hemolysin (HlyA) secretion apparatus represents a type I secretion system that is fully functional in Salmonella . The system which consists of the two specific membrane proteins HlyB and HlyD and the outer membrane protein TolC, recognizes on HlyA a C-terminally located signal sequence of about 60 amino acids . Fusion proteins to which this signal sequence is covalently linked at the C-terminus are also recognized by this secretion apparatus . The efficiency of secretion is dependent on the rate of folding of the reporter protein . Secretion-competent regions of a given reporter protein that is not secretable as entire protein can be screened by a recently constructed transposon TnhlyAs which allows the insertion of the secretion signal into any region of the reporter protein . The genetic information for antigens of any source ranging in size between 10 and 1000 amino acids can be easily inserted into a recently constructed secretion vector which will allow the secretion of the fused antigen(s) in attenuated Salmonella typhimurium strains and in other attenuated Enterobacteriaceae . By manipulation of the Hly secretion system the antigen can be either completely secreted into the environment, fixed on the outer membrane or arrested in the cytoplasm of the used carrier strain . By the use of appropriate attenuated Salmonella strains the antigen is delivered in isolated compartments or to the cytosolic compartment . The extracellular delivery of such antigens is also possible with the help of appropriate carrier strains . The immunological consequences of the different display of the processed antigen will be discussed in the paper by Hess et al in this volume . With a similar antigen delivery system the easy identification and molecular characterization of unknown antigens recognized by the immune system in an infection is also feasible. Can J Microbiol, 1997 Aug, 43(8), 770 - 3 Nematophin, a novel antimicrobial substance produced by Xenorhabdus nematophilus (Enterobactereaceae); Li J et al.; A new antibiotic, nematophin, was isolated from strain BC1 of Xenorhabdus nematophilus and detected in all strains of X . nematophilus studied . Its structure is fully established as 3-indoleethyl (3'-methyl-2'-oxo)pentanamide by extensive spectroscopic study . The production of nematophin is affected by the strain type and culture conditions . The compound shows strong in vitro bioactivity against a series of fungal and bacterial species. Can J Microbiol, 1997 Aug, 43(8), 729 - 33 Purification and characterization of a cytotoxin from Enterobacter cloacae; Barnes AI et al.; Leukotoxic activity was assayed in clinical isolates of Enterobacter cloacae . Two strains were selected out of 38 by their greater hemolytic activity in blood agar plates . Leukotoxin was purified by salt precipitation, dialysis, chromatography by gel filtration, and high pressure liquid chromatography (HPLC) . Human leukocytes, when incubated with purified E . cloacae toxin, showed high percentages of death and lysis, with time and dose dependence . The chromatographic profile of gel filtration presented three protein peaks and toxic activity was detected in the second peak . After HPLC, leukotoxin coeluted with the hemolytic activity and both activities were detected only after 2-mercaptoethanol treatment . Coomassie-stained sodium dodecyl sulfate--polyacrylamide gels showed a single band . This band was estimated to represent a protein of 13300 Da on the basis of both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography. Nephrologie, 1997, 18(3), 95 - 101 {Pefloxacin as a first-line treatment for nephrotic syndrome in minimal glomerular lesions in the adult . Multicenter study of 32 patients}; Pruna A et al.; Minimal change nephrotic syndrome (MCNS) is the most frequent single cause of nephrotic syndrome occurring both in adults and children . Although it appears to be a self-limiting disorder (10% spontaneous remissions within the fortnight following the initial flare), MCNS displays a high rate of complications during the nephrotic period (10 to 15% cases) and prompts one to treat patients as early as possible . Corticosteroids are currently used as first-line treatment . A 16 weeks full-dose steroid course (1 mg/kg/day) usually induces remission in 75% MCNS in adults . Nevertheless, duration of treatment (9 months) and occurrence of relapses despite a slowly tapering dosage schedule, expose patients to steroids side-effects . Immunosuppressive drugs are recommended in case of steroid resistance and their side-effects are not harmless . Therefore, an alternative to steroids or immunosuppressives would lend a serious helping hand in MCNS management . The present work is dealing with pefloxacin efficacy in 40% MCNS in adults . Thirty-two MCNS adult patients were treated in a national multicenter study . A short-duration pefloxacin course (4 to 6 weeks) allowed partial or complete remission in 13 out of 32 cases . Thus far, this effect was undescribed for this class of drugs . Pefloxacin belongs to antibacterial agents of the fluoroquinolone family and is active against Gram negative Enterobacteria species . Fluoroquinolones also act on eukaryotic cells as lymphocytes and chondrocytes and alter IL2, gamma IFN and integrin expression . Although their precise mode of action is unknown in this kind of immunological disorder, fluoroquinolones might represent an alternative to steroids in some adult form of MCNS . However, predictive criteria for sensitivity to fluoroquinolones are currently not available and further controlled studies would be helpful using fluoroquinolones as first-line treatment in all the MCNS. Res Microbiol, 1996 Nov-Dec, 147(9), 733 - 7 Biochemical identification of a lipoprotein with maltose-binding activity in the thermoacidophilic Gram-positive bacterium Alicyclobacillus acidocaldarius; Herrmann A et al.; Growth of the thermoacidophilic Gram-positive bacterium Alicyclobacillus acidocaldarius strain ATCC 27009 on maltose resulted in the increased production of a protein with apparent molecular mass of 40 kDa . By metabolic labelling with 14C-palmitic acid, the 40-kDa protein was identified as a lipoprotein . The protein exhibited maltose-binding activity at pH 3.5, as demonstrated by chromatography on cross-linked amylose . Partial amino acid sequence analysis revealed that the 40-kDa protein corresponds to the product of an open reading frame downstream from the amylase gene (amy) that displays similarity to enterobacterial maltose-binding proteins. Pathol Biol (Paris), 1997 May, 45(5), 425 - 9 {Study of in vitro activity of 3 cephalosporins and their combination with 2 beta-lactamase inhibitors against 4 enterobacteria strains producing extended spectrum beta-lactamase}; Cattoen C et al.; The in vitro antibacterial activity of cefotaxime, cefepime and cefpirome was evaluated alone and in association with two beta-lactamase inhibitors: clavulanic acid and sulbactam against 65 extended broad spectrum beta-lactamase producing enterobacteriaceae strains {Klebsiella pneumoniae (35), Proteus mirabilis (9), Escherichia coli (11), Enterobacter aerogenes (10)} . The lowest MICs were observed for cefepime and cefpirome used alone . In association with inhibitors cefotaxime was less effective against E . aerogenes . Most isolates of K . pneumoniae, P . mirabilis, E . coli were susceptible to all the different tested associations. Pathol Biol (Paris), 1997 May, 45(5), 404 - 8 {Emergence of Enterobacter aerogenes strains producing derepressed cephalosporinase at CHU in Limoges: molecular epidemiology by the RAPD technique}; Ploy MC et al.; From the beginning of the year 1996, an increase of multiresistant Enterobacter aerogenes isolates was observed . These strains overproduced their chromosomally cephalosporinase . From February to September 1996, we studied the genotypic diversity of multiresistant E . aerogenes isolates . Fifty-seven strains were analysed with the RAPD technique . These strains were isolated from 38 patients in 25 different units . These isolates were collected from urines (37), respiratory tracts (14) and wounds (6) . We have observed two distinct profiles . The predominant profile (A) was recovered from 55 strains (36 patients) and the second profile (B) from 2 strains (2 patients) . The clonal relatedness of strains isolated (profile A) showed an epidemic spread in our hospital . The RAPD technique is easy to perform and gives results in less than 48 h with a good discriminatory power. Pathol Biol (Paris), 1997 May, 45(5), 389 - 93 {Evaluation of a new and rapid antibiotic sensitivity method testing for Enterobacteriaceae responsible for urinary infections}; Laudat P et al.; URIFAST Es et Es Plus (International Microbio, Signes, France) are rapid antimicrobial susceptibility testing method in broth medium without using an automatic reader . A screening assay (URIFAST Quatro 1C ou URIFAST Twin 1C) is performed with a 4 or 9 antimicrobial agents with a concentration c' below the low critical concentration (c) defined by the Comite de l'Antibiogramme de la Societe Francaise de Microbiologie (CA-SFM) . When a bacterial strain is presumed resistant, an antimicrobial susceptibility test with the two critical concentrations (CA-SFM) can be performed with 5 or 10 antimicrobial agents antibiotiques (URIFAST Twin ABG ou URIFAST ABG) . 140 strains of Enterobacteriaceae from urinary tract infections; E . coli (n = 94), P . mirabilis (n = 13), K . pneumoniae (n = 4), K . oxytoca (n = 6), C . diversus (n = 3), P . vulgaris (n = 1), M . morganii (n = 3), C . freundii (n = 4), E . aerogenes (n = 2), E . cloacae (n = 5) and S . marcescens (n = 5); were isolated with CPS ID2 (bioMerieux, Marcy l'Etoile, France) . URIFAST results were compared to Rapid ATB Ur et ATB Ur results obtained after reading with ATB expression (bioMerieux) . For each discrepancy, the minimal inhibitory concentration (MIC) by agar dilution was used as the reference method . Agreement obtained were 98.57% with Quatro 1C, 98.40% with Twin 1C, 98.14% with Twin ABG and 98.39% with ABG . 94% of beta-lactams susceptible Enterobacteriaceae were detected by the screening tray with the antimicrobial agent concentration c' . URIFAST Es et Es Plus are standardized and easy-to-use methods . Because of their good performances, the URIFAST methods can be used to test antimicrobial susceptibility for Enterobacteriaceae from urinary tract infections. Pathol Biol (Paris), 1997 May, 45(5), 383 - 8 {Statistical study of the SIRSCAN computerised camera}; Acar J et al.; The antibiograms of 1162 bacterial strains, including references, have been performed within four centres . They have been read manually and by the SIRSCAN camera, which yields to 30936 couples of diameters values . A non-concordance, at a 3 mm level, was observed fot 11.14% of the diameters . The mean of difference is 0.82 mm and the standard deviation 3.34 mm . Round Petri dishes gave results less reliable than those obtained with square dishes . A deviation in function of the centres is obtained for wild-strains as for the references . For the whole population a S/R discordance (sensible/resistant confusion) is obtained for 1.76% of the diameters . This value drops to 0.93% for enterobacteriaceae, P . aeruginosa and S . aureus (968 strains). Pathol Biol (Paris), 1997 Apr, 45(4), 331 - 5 {Bactericidal activity determination of Biseptine, combination of chlorhexidine, benzalkonium chloride and benzylic alcohol, on 124 hospital bacterial strains}; Reverdy ME et al.; Biseptine is an antiseptic composed of chlorhexidine digluconate (CHX), benzalkonium chloride (BC) and benzylic alcohol . Minimal Bactericidal Concentrations (MBCs) of Biseptine were determined on 124 clinical strains: 76 Enterobacteriaceae, 16 other Gram negative bacilli, (Pseudomonas spp, Aeromonas spp, Haemophilus spp) and 32 Gram positive bacteria (Staphylococcus spp, Streptococcus spp, Listeria spp, Bacillus cereus), using microdilution method, in comparison with Hibitane Champ . Modal MBC of Biseptine was 25 mg/l of CHX/2.5 mg/l BC (1/100 dilution) . Proteus (MBC: 133 mg/l CHX/ 13 mg/l CB) and B . cepacia (MBC: 100 mg/l CHX/ 10 mg/l CB) were the most resistant strains, as expected with cationic antiseptics . 4/5 Bacillus cereus, strains were weakly susceptible to Biseptine and Hibitane Champ . In Biseptine, the association of CHX and CB showed a synergic activity, MBCs are usually 2 fold lower that Hibitane Champ MBCs. J Bacteriol, 1997 Sep, 179(18), 5783 - 8 Identification of a new porin, RafY, encoded by raffinose plasmid pRSD2 of Escherichia coli; Ulmke C et al.; The conjugative plasmid pRSD2 carries a raf operon that encodes a peripheral raffinose metabolic pathway in enterobacteria . In addition to the previously known raf genes, we identified another gene, rafY, which in Escherichia coli codes for an outer membrane protein (molecular mass, 53 kDa) similar in function to the known glycoporins LamB (maltoporin) and ScrY (sucrose porin) . Sequence comparisons with LamB and ScrY revealed no significant similarities; however, both lamB and scrY mutants are functionally complemented by RafY . Expressed from the tac promoter, RafY significantly increases the uptake rates for maltose, sucrose, and raffinose at low substrate concentrations; in particular it shifts the apparent K(m) for raffinose transport from 2 mM to 130 microM . Moreover, RafY permits diffusion of the tetrasaccharide stachyose and of maltodextrins up to maltoheptaose through the outer membrane of E . coli . A comparison of all three glycoporins in regard to their substrate selectivity revealed that both ScrY and RafY have a broad substrate range which includes alpha-galactosides while LamB seems to be restricted to malto-oligosaccharides . It supports growth only on maltodextrins but not, like the others, on raffinose and stachyose. J Ethnopharmacol, 1997 Aug, 57(3), 177 - 81 The antimicrobial activity of 3,5,7-trihydroxyflavone isolated from the shoots of Helichrysum aureonitens; Afolayan AJ et al.; Extracts from Helichrysum aureonitens are used topically by the indigenous people of South Africa against infections . The antimicrobial activity-guided fractionation by bioautography of the acetone extract from the aerial parts of H . aureonitens led to the isolation of 3,5,7-trihydroxyflavone (galangin) . Evaluation of the antibacterial activity of the compound against ten randomly selected bacteria indicated significant activity against all the Gram-positive bacteria tested with the minimum inhibitory concentration (MIC) ranging from 0.1 to 0.5 mg/ml . The compound was not active on Gram-negative bacteria except for Enterobacter cloacae which was significantly inhibited at an MIC of 0.1 mg/ml . Galangin indicated considerable activity against the fungi tested with the exception of Cladosporium herbarum . Penicillium digitatum and P . italicum appeared to be particularly susceptible at a concentration of 0.01 mg/ml. Proc Natl Acad Sci U S A, 1997 Sep 2, 94(18), 9763 - 7 Molecular keys to speciation: DNA polymorphism and the control of genetic exchange in enterobacteria; Vulic M et al.; Speciation involves the establishment of genetic barriers between closely related organisms . The extent of genetic recombination is a key determinant and a measure of genetic isolation . The results reported here reveal that genetic barriers can be established, eliminated, or modified by manipulating two systems which control genetic recombination, SOS and mismatch repair . The extent of genetic isolation between enterobacteria is a simple mathematical function of DNA sequence divergence . The function does not depend on hybrid DNA stability, but rather on the number of blocks of sequences identical in the two mating partners and sufficiently large to allow the initiation of recombination . Further, there is no obvious discontinuity in the function that could be used to define a level of divergence for distinguishing species. J Bacteriol, 1997 Sep, 179(17), 5288 - 91 A homoserine lactone autoinducer regulates virulence of an insect-pathogenic bacterium, Xenorhabdus nematophilus (Enterobacteriaceae); Dunphy G et al.; N-beta-Hydroxybutanoyl homoserine lactone (HBHL), the autoinducer of the luminescent system of Vibrio harveyi, has been identified as the first small compound to restore virulence to avirulent mutants of Xenorhabdus nematophilus . HBHL stimulated the level of lipase activity excreted by avirulent X . nematophilus and lowered the phenoloxidase activity in the hemolymph of insects infected with X . nematophilus, parameters that are both associated with insect pathogenesis . Moreover, mortality of the insects infected with avirulent X . nematophilus was restored upon injection with HBHL . Chloroform extraction of medium conditioned with wild-type but not avirulent X . nematophilus led to the isolation of a compound with the same chromatographic mobility as HBHL as well as the ability to stimulate the luminescence of a dim autoinducer-dependent mutant of V . harveyi . Transfer of the V . harveyi lux operon into avirulent and wild-type X . nematophilus generated dim and bright luminescent strains, respectively, which responded to HBHL and an agonist and antagonist in a manner analogous to their effects on the luminescence of dim autoinducer-deficient and bright wild-type strains of V . harveyi, indicating that similar HBHL-dependent regulatory systems exist in these two bacterial species. J Clin Microbiol, 1997 Sep, 35(9), 2410 - 2 Use of the isolator 1.5 microbial tube for culture of synovial fluid from patients with septic arthritis; Yagupsky P et al.; Synovial fluid specimens obtained from patients with arthritis were plated onto solid media (conventional cultures) or inoculated into an Isolator 1.5 microbial tube (Isolator cultures), and the yield and time to detection of organisms were compared . Overall, 144 specimens obtained from 137 patients were processed, and 31 (21.5%) cultures obtained from 29 patients were positive by at least one method . Staphylococcus aureus was isolated from 12 patients, Streptococcus pneumoniae and Kingella kingae were isolated from 4 patients each, group G streptococci were isolated from 3 patients, Staphylococcus epidermidis and members of the family Enterobacteriaceae were isolated from 2 patients each, and Streptococcus mitis and Peptostreptococcus prevotii were isolated from 1 patient each . Overall, the causative organism was detected in 31 of 31 (100.0%) Isolator cultures and 24 of 31 (77.4%) conventional cultures (P < 0.02) . Twenty-nine of 31 (93.5%) positive Isolator cultures and 20 of 24 (83.3%) conventional cultures were positive by the second day of incubation . Among the 24 cultures positive by both methods, higher numbers of CFU per milliliter were detected with the Isolator system in 13 cultures and with conventional cultures in 2 cultures (P < 0.002) . Inoculation of synovial fluid into an Isolator 1.5 microbial tube improves the recovery of organisms causing septic arthritis. Biochemistry, 1997 Aug 19, 36(33), 10301 - 10 Mechanisms of action of the bactericidal/permeability-increasing protein BPI on endotoxin and phospholipid monolayers and aggregates; Wiese A et al.; We have investigated the mechanisms of interaction of the recombinant N-terminal portion of bactericidal/permeability-increasing protein, rBPI21, with lipopolysaccharide (LPS) isolated from enterobacterial deep rough mutant strains . Experimentally, the ability of rBPI21 to form monolayers at the air/water interface and its action on lipid monolayers were analyzed . We have further studied the interaction of rBPI21 with aggregates from phospholipids and Re mutant LPS by infrared and resonance energy transfer spectroscopy and laser Doppler velocimetry . From monolayer experiments, the molecular area of a single rBPI21 molecule was estimated to be about 12 nm2 . At lateral pressures of </=25 mN/m, rBPI21 incorporated into monolayers from negatively charged LPS and phosphatidylglycerol (PG) but not into those from neutral phosphatidylcholine . rBPI21 incorporated not only into monolayers but also into liposomes made from or containing negatively charged phospholipids, reducing the absolute value of the zeta-potential of LPS and PG aggregates . Furthermore, due to intercalation, rBPI21 caused the rigidification of the acyl chains of lipids in the gel as well as in the fluid phase and significantly immobilized their phosphate groups . High concentrations of Mg2+ ions were found to have a protective effect against the action of rBPI21 . On the basis of these results, the biophysical characteristics of rBPI21 are discussed and a model is proposed as to how the rBPI21-induced influence on lipid monolayers and bilayers could explain rBPI21-mediated effects on the bacterial membrane. J Med Chem, 1997 Aug 15, 40(17), 2788 - 92 Immunologically specific activation of a cephalosporin derivative of mitomycin C by monoclonal antibody beta-lactamase conjugates; Vrudhula VM et al.; The syntheses of two cephalosporin derivatives 2 and 3 of mitomycin C (1) containing 7-phenylacetamido and 7-delta-carboxybutanamido side chains, respectively, are described . These compounds were prepared for evaluation as cephalosporin prodrugs capable of being activated by mAb-beta-lactamase conjugates . In vitro cytotoxicity assays performed on H2987 lung adenocarcinoma and clone 62 melanoma cell lines indicated that compound 2 was comparable in cytotoxicity to the parent drug . In an effort to improve upon the cytotoxic differential of 2, an alternative prodrug 3 containing a polar carboxyl group in the side chain of the cephalosporin moiety was prepared . Compound 3 consistently behaved as a prodrug and was approximately 40- and 10-fold less toxic than 1 toward H2987 and clone 62, respectively . Determination of kinetic constants for hydrolysis by beta-lactamase from Enterobacter cloacae P99 indicated kcat values of 476 +/- 170 and 248 +/- 15.1 s-1 for 2 and 3, respectively . The kcat/Km ratios for 2 and 3 were found to be approximately 9.7 and 2.1 microM/s, respectively . Comparison of these kcat/Km values with those obtained for similar cephalosporin derivatives of other antitumor agents demonstrated that compounds with delta-carboxybutanamido side chains generally have slightly diminished efficiency of enzymatic hydrolysis compared to the corresponding 7-phenylacetamido analog . It was also demonstrated that the less toxic prodrug 3 was activated in an immunologically specific manner by L6-F(ab')-beta-lactamase and 96.5-F(ab')-beta-lactamase conjugates, selective for H2987 and clone 62 cells, respectively. J Appl Microbiol, 1997 Aug, 83(2), 259 - 65 The use of bacteriophage-based systems for the separation and concentration of Salmonella; Bennett AR et al.; Techniques for the separation/concentration of micro-organisms from background food matrices can be applied to increase the speed of analysis and ease of isolation and detection of target micro-organisms . One recent example of such a technique is the immunomagnetic separation (IMS) procedure that has been used for the separation of specific micro-organisms from foods . This paper describes the use of a novel biosorbent consisting of a Salmonella-specific bacteriophage (phage) immobilized to a solid phase that was used for the separation and concentration of Salmonella from food materials . This work has shown that a Salmonella-specific phage-based biosorbent could remove Salmonella from culture fluid and separate Salmonella from suspensions of other Enterobacteriaceae . The ease of production of phage, high affinity of phage-cell interaction and the ability of phage to infect host cells in heterogeneous environments indicates the potential of such a biosorbent as the basis for a reliable separation system in food microbiological analysis. Pediatr Infect Dis J, 1997 Aug, 16(8), 768 - 73 A prospective study of neonatal sepsis and meningitis in southern Israel; Greenberg D et al.; OBJECTIVE: To study the epidemiology of neonatal sepsis and meningitis in the Negev area of southern Israel . DESIGN: A prospective 8-year study conducted at the neonatal intensive care unit and pediatric wards of the Soroka University Medical Center . RESULTS: Two hundred twenty-nine cases of hospital and community-acquired neonatal sepsis occurred during the study period . Thirty-two patients (14%) were meningitis . During this period 70,709 births (59% Jews and 41% Bedouins) were recorded; thus the rates of neonatal sepsis and meningitis were 3.2 and 0.5/1000 live births, respectively . One hundred seventeen (4/1000 live births) cases were recorded in Bedouins and 112 (2.6/1000 live births) in Jewish neonates (P < 0.001) . Twenty-six percent of all sepsis cases occurred within < 24 h from birth, 25% from Days 2 to 7 of life and 49% between Days 8 and 28 . A total of 251 organisms that were considered true pathogens were isolated . Fifty-seven of all isolates were Gram-negative organisms (mainly Klebsiella pneumoniae (20%) and Escherichia coli (16%)) . Gram-positive organisms were isolated in 41% of cases . Although E . coli was the most frequently recovered Gram-negative pathogen in community-acquired late onset sepsis, Klebsiella and Enterobacter spp . represented the most commonly isolated Gram-negative organisms in nosocomial late onset sepsis . All Staphylococcus aureus isolates recovered in late onset sepsis were nosocomial . The incidence of Streptococcus agalactiae was 3 times higher in early onset sepsis than in late onset sepsis . All cases of Streptococcus pneumoniae sepsis occurred in Bedouins . CONCLUSIONS: Neonatal sepsis and meningitis rates in southern Israel are similar to those reported in Western Europe and the United States . The incidence of neonatal sepsis is significantly higher for Bedouins than for Jewish neonates . The distribution of the main pathogens is different in southern Israel and although Gram-negative enteric organisms are predominant, S . agalactiae plays a relatively minor role in the etiology of sepsis during the first month of life . In southern Israel the etiology of community-acquired late onset sepsis is different from that of nosocomial late onset sepsis. Chest, 1997 Aug, 112(2), 406 - 15 Sequential therapy with cefuroxime followed by cefuroxime axetil in community-acquired pneumonia; Van den Brande P et al.; STUDY OBJECTIVES: To compare the efficacy of two sequential therapy regimens of IV cefuroxime followed by oral cefuroxime axetil for the treatment of community-acquired pneumonia (CAP) . DESIGN: Prospective, multicenter, randomized, open-label, parallel-group study . SETTING: Sixty-six centers in 11 countries (Belgium, Canada, Czech Republic, Germany, Hungary, Ireland, Israel, Poland, Portugal, South Africa, and the United Kingdom) . PATIENTS: Six hundred thirty-six adults with CAP requiring hospitalization and initial IV antibiotic treatment . INTERVENTIONS: Cefuroxime, 1.5 g IV tid or bid for 48 to 72 h followed by oral cefuroxime axetil, 500 mg bid for 7 days . MEASUREMENTS AND RESULTS: For clinically evaluable patients, the clinical response rates were equivalent for cefuroxime tid and bid groups posttreatment (cure/improvement, 79% and 84%, respectively) and at follow-up (maintained cure, 87% and 82%, respectively) . All signs and symptoms of pneumonia showed improvement at the time of switch from IV to oral therapy . A total of 111 pathogens were isolated, the most common being Streptococcus pneumoniae (23%), Haemophilus influenzae (18%), and Enterobacteriaceae (15%) . Bacteriologic clearance was obtained posttreatment in 47 of 49 and 36 of 42 of bacteriologically evaluable patients in the cefuroxime tid and bid groups, respectively . Both regimens were well tolerated with a low incidence of drug-related adverse events, the most common being GI . CONCLUSIONS: Twice daily IV cefuroxime followed by oral cefuroxime axetil is a simple and effective sequential therapy regimen for the treatment of CAP . It offers potential cost savings and can replace the current tid regimen in this indication. Biotechnol Appl Biochem, 1997 Aug, 26 ( Pt 1), 51 - 61 Enhancement of cyclodextrin production through use of debranching enzymes; Rendleman JA Jr; In the presence of a complexant and a debranching enzyme capable of cleaving alpha-(1-->6) linkages in alpha-D-glucans, Bacillus mascerans cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19) converted starch, maltodextrin and glycogen into cyclodextrin (CD) in yields higher than those obtainable in the absence of debranching enzyme . The extent of yield enhancement by pullulanase (EC 3.2.1.41; from Enterobacter aerogenes) was dependent upon temperature, type of substrate (including source of starch) and kind of complexant . Highest yields with pullulanase were attained generally by use of low temperature (15-25 degrees C) and starches of low amylose content . At 25 degrees C and pH 7, with cyclodecanone as complexant, 91-93% yields of beta-CD were obtainable from amylopectin, waxy-maize starch, and tapioca starch . With decan-I-ol as complexant, amylopectin was converted at 15 degrees C into alpha-CD in 84% yield . With cyclotridecanone as complexant, amylopectin was converted at 40 degrees C into gamma-CD in 72% yield . The debranching enzyme isoamylase (EC 3.2.1.68; from Pseudomonas amyloderamosa) was also employed successfully to achieve high beta-CD yields . A 90% yield of beta-CD from amylopectin was obtained by applying isoamylase, CGTase and cyclodecanone at pH 6 and 25 degrees C. Antimicrob Agents Chemother, 1997 Aug, 41(8), 1818 - 24 In vitro activity of Bay 12-8039, a new 8-methoxyquinolone; Fass RJ; MICs of Bay 12-8039 and comparative antimicrobials were determined for 820 recent clinical isolates . Ciprofloxacin was approximately 2-fold more active than Bay 12-8039 and ofloxacin against Enterobacteriaceae and approximately 8-fold more active against Pseudomonas aeruginosa . Bay 12-8039 was approximately 2- to 16-fold more active than ciproiloxacin and ofloxacin against nonfermenters (except P . aeruginosa), staphylococci, streptococci, enterococci, and anaerobes . As determined by regression analysis, there was a high degree of correlation among quinolone MICs. J Clin Microbiol, 1997 Aug, 35(8), 2115 - 9 Multicenter laboratory evaluation of the bioMérieux Vitek antimicrobial susceptibility testing system with 11 antimicrobial agents versus members of the family Enterobacteriaceae and Pseudomonas aeruginosa; Doern GV et al.; A four-center study in which a total of 1,082 recent clinical isolates of members of the family Enterobacteriaceae and Pseudomonas aeruginosa were examined versus 11 antimicrobial agents with the bioMerieux Vitek susceptibility test system (Hazelwood, Mo.) and the GNS-F6 card was conducted . In addition, a challenge set consisting of the same 200 organisms was examined in each of the four participating laboratories . Results obtained with the Vitek system were compared to MICs determined by a standardized broth microdilution method . For purposes of comparison, susceptibility categories (susceptible, intermediate, or resistant) were assigned on the basis of the results of both methods . The result of the broth microdilution test was considered definitive . The total category error rate with the Vitek system and the recent clinical isolates (11,902 organism-antimicrobial comparisons) was 4.5%, i.e., 1.7% very major errors, 0.9% major errors, and 1.9% minor errors . The total category error rate calculated from tests performed with the challenge set (i.e., 8,800 organism-antimicrobial comparisons) was 5.9%, i.e., 2.2% very major errors, 1.1% major errors, and 2.6% minor errors . Very major error rates higher than the totals were noted with Enterobacter cloacae versus ampicillin-sulbactam, aztreonam, ticarcillin, and ticarcillin-clavulanate and with P . aeruginosa versus mezlocillin, ticarcillin, and ticarcillin-clavulanate . Major error rates higher than the averages were observed with Proteus mirabilis versus imipenem and with Klebsiella pneumoniae versus ofloxacin . Excellent overall interlaboratory reproducibility was observed with the Vitek system . The importance of inoculum size as a primary determinant in the accuracy of susceptibility test results with the Vitek system was clearly demonstrated in this study . Specifically, when an inoculum density fourfold higher than that recommended by the manufacturer was used, high rates of false resistance results were obtained with cell wall-active antimicrobial agents versus both the Enterobacteriaceae and P . aeruginosa. J Clin Microbiol, 1997 Aug, 35(8), 2061 - 7 Detection and clinical significance of extended-spectrum beta-lactamases in a tertiary-care medical center; Emery CL et al.; The prevalence of extended-spectrum beta-lactamase (ESBL)-mediated resistance remains unknown for most hospitals, and national guidelines for testing and reporting ESBL-mediated resistance have not yet been developed . We undertook a study to determine the prevalence of ESBLs and the clinical need for testing in our tertiary-care medical center . Members of the family Enterobacteriaceae isolated over a 6-month period for which ceftazidime or ceftriaxone MICs were greater than 1 microg/ml were tested for production of ESBLs by the double-disk synergy method . Approximately 1.5% of isolates of the family Enterobacteriaceae (50 of 3,273), which were isolated from 1.2% of patients (23 of 1,844), were found to express ESBLs . ESBL-producing strains included eight different species and were isolated from patients located throughout the hospital, including outpatient clinics . By using the interpretive guidelines of the National Committee for Clinical Laboratory Standards, 26 to 39% of the isolates would have been reported to be susceptible to ceftazidime, depending upon the routine susceptibility method used . However, tests with cefpodoxime found all of the ESBL-producing strains to be resistant or intermediate . Nine patients infected with ESBL-producing isolates were treated with therapy which included an expanded-spectrum cephalosporin . Seven were cured . The deaths of the other two patients were not attributed to bacterial resistance missed by routine susceptibility testing . These observations suggest that in our tertiary-care medical center, it may not be clinically necessary or cost-effective at this time to institute additional testing on a routine basis to detect ESBL production in all clinical isolates of the family Enterobacteriaceae. J Perinatol, 1997 Jul-Aug, 17(4), 305 - 8 Urinary tract infection in premature infants: the role of imaging studies and prophylactic therapy; Eliakim A et al.; BACKGROUND: The prevalence of urinary tract infection (UTI) in premature infants ranges from 4% to 25% . It is surprising, however, that scant information exists regarding management of UTI in premature infants, particularly the need for radiologic evaluation of the urinary tract and the use of preventive antibiotic therapy after the first episode of UTI occurs . The aim of this study was to answer these questions . PATIENTS AND METHODS: Twenty-seven (8%) premature infants (< 1750 gm birth weight) born during the period from 1990 through 1993 had UTI . Eleven of them were of extreme low birth weight (ELBW) (birth weight < 1000 gm) . Ultrasound examination of the urinary tract was performed in all premature infants 7 days after a diagnosis of UTI was made and was repeated 1 month later, if disease was detected . Voiding cystography was performed in 21 premature infants (8 with ELBW) 6 to 8 weeks after a diagnosis of UTI was made . RESULTS: The mean birth weight of premature infants with UTI was 1112 +/- 294 gm . The prevalence of UTI was significantly higher (p < 0.01) in infants with ELBW (13%) compared with that in premature infants with birth weight >1000 gm (6%) . The male/female ratio in all premature infants was 2.9:1 and was significantly higher in infants with ELBW (10:1; p < 0.01) . Organisms involved were Klebsiella (59%), Candida albicans (15%), Escherichia coli (15%), and Enterobacter (11%) . Only premature infants with ELBW had Candida UTI . Five premature infants (four with ELBW) had mild transient hydronephronis, and one had persistent hydronephrosis and hydroureter . Voiding cystography showed that three premature infants had vesicoureteral reflux and that one had a bladder diverticulum . All premature infants with pathologic voiding cystography had birth weight >1000 gm and had normal ultrasound examination . CONCLUSIONS: Premature infants with birth weight 1000 to 1750 gm should be given preventive antibiotic therapy at least until imaging evaluation (ultrasonography and voiding cystography) is complete . Premature infants with ELBW are more susceptible to fungal infection and do not seem to have underlying urinary tract abnormalities . Prophylactic therapy and voiding cystography may be unwarranted in this population subset. J Infect, 1997 Jul, 35(1), 17 - 23 Analysis of 5 years of bacteraemias: importance of stratification of microbial susceptibilities by source of patients; Yinnon AM et al.; Many factors need to be considered when selecting empiric antimicrobial treatment for infections; foremost are the principal pathogens causing the diagnosed infection and their antimicrobial susceptibility patterns . These susceptibilities are location specific . This study analyses blood cultures of a 5-year period (1990-94) at a 550 bed community hospital and stratifies antimicrobial susceptibilities by source of patients . Data included: date of culture, patient location, number of positive bottles with the same organism over a period of 2 weeks and results of susceptibility testing . Positive cultures from patients in the Emergency Department were deemed to reflect community-acquired strains: positive cultures from patients in the Intensive Care Unit were considered nosocomial organisms . During the study period 52055 blood cultures were drawn; 5652 (11%) from 2742 patients grew at least one organism, excluding skin contaminants . Organisms cultured most frequently were: Enterobacteriaceae: 1162 patients (42%); Staphylococcus aureus: 442 (16%); Enterococcus; 429 (16%); and Pseudomonas: 196 (7%) . Antimicrobial susceptibility percentages of Enterobacteriaceae from Emergency Room patients (n = 370) were significantly greater to all tested antimicrobials than from ICC patients (n = 161) (P < 0.001) . Overall, 143 isolates of S . aureus from 442 patients (32%) were methicillin resistant (MR); stratification by department revealed a range of 20/142 (14%) MR in community acquired strains to 49/67 (73%) from ICU patients (P < 0.001) . Detailed tables with antimicrobial susceptibilities according to strains, and stratified by source of patients are presented . When selecting empiric antimicrobial therapy for patients with bacterial infections, it is crucially important to physicians to have access to antimicrobial susceptibility percentages, stratified by source of patients. APMIS, 1997 Jul, 105(7), 566 - 70 Microbiology of semen specimens from males attending a fertility clinic; Kjaergaard N et al.; The relationship between semen quality, pyospermia and bacteriology was studied in 201 semen specimens from male patients attending a fertility clinic . Semen quality parameters were within normal limits in 115 (57%) patients, slightly reduced in 60 (30%), and 26 (13%) had findings indicating reduced fertility . Twelve patients (6%) had pyospermia . In 182 patients, 552 microorganisms were detected, including Enterobacteriaceae (2.8%), Gardnerella vaginalis (9.6%), Chlamydia trachomatis (1.6%), Mycoplasma genitalium (0.9%), and Ureaplasma urealyticum (11.8%) . Semen quality was neither related to occurrence of microorganisms nor pyospermia . However, pyospermia was associated with simultaneous growth of Gardnerella vaginalis and Ureaplasma urealyticum . The exact nature of this association could not be ascertained, in as far as the males were not questioned about urethritis symptoms. Hepatogastroenterology, 1997 Jul-Aug, 44(16), 927 - 36 Peritonitis: pathophysiology and local defense mechanisms; Heemken R et al.; The peritoneal cavity can be divided in the supracolic infracolic and paracolic spaces, the lesser sack and the pelvis . The peritoneum is a semipermeable membrane which allows a flux of solutes into and from the peritoneal cavity . In addition, particles can be absorbed through the stomata of the diaphragmatic peritoneum . Secondary peritonitis is always a polymicrobial infection . The flora consists of aerobic enterobacteriaeceae and anaerobs mainly B . fragilis . These two groups of bacteria act synergistically . Besides unspecific defence mechanisms, i.e . the direct absorption of bacteria and the entrapment of bacteria in fibrin, the immunological defence mechanisms of the peritoneal cavity are triggered by endotoxin contained in the cell wall of the invading bacteria leading to the production of cytokines by macrophages, activation of complement and as a result the migration of granulocytes from the intervascular space into the peritoneal cavity. Bioconjug Chem, 1997 Jul-Aug, 8(4), 510 - 9 Construction, expression, and activities of L49-sFv-beta-lactamase, a single-chain antibody fusion protein for anticancer prodrug activation; Siemers NO et al.; The L49 (IgG1) monoclonal antibody binds to p97 (melanotransferrin), a tumor-selective antigen that is expressed on human melanomas and carcinomas . A recombinant fusion protein, L49-sFv-bL, that contains the antibody binding regions of L49 fused to the Enterobacter cloacae r2-1 beta-lactamase (bL) was constructed, expressed, and purified to homogeneity in an Escherichia coli soluble expression system . The variable regions of L49 were cloned by reverse transcription-polymerase chain reaction from L49 hybridoma mRNA using signal sequence and constant region primers . Construction of the gene encoding L49-sFv-bL was accomplished by hybridization insertion of VH, VL, and sFv linker sequences onto a pET phagemid template containing the bL gene fused to the pelB leader sequence . Optimal soluble expression of L49-sFv-bL in E . coli was found to take place at 23 degrees C with 50 microM isopropyl beta-D-thiogalactopyranoside induction and the use of the nonionic detergent Nonidet P-40 for isolation from the bacteria . Construction and expression of a soluble form of the p97 antigen in Chinese hamster ovary cells allowed affinity-based methods for analysis and purification of the fusion protein . Surface plasmon resonance, fluorescent activated cell sorting, and Michaelis-Menten kinetic analyses showed that L49-sFv-bL retained the antigen binding capability of monovalent L49 as well as the enzymatic activity of bL . In vitro experiments demonstrated that L49-sFv-bL bound to 3677 melanoma cells expressing the p97 antigen and effected the activation of 7-(4-carboxybutanamido)cephalosporin mustard (CCM), a cephalosporin nitrogen mustard prodrug . On the basis of these results, L49-sFv-bL was injected into nude mice with subcutaneous 3677 tumors, and localization was determined by measuring bL activity . Tumor to blood conjugate ratios of 13 and 150 were obtained 4 and 48 h post conjugate administration, respectively, and the tumor to liver, spleen, and kidney ratios were even higher . A chemically produced L49-Fab'-bL conjugate yielded a much lower tumor to blood ratio (5.6 at 72 h post administration) than L49-sFv-bL . Therapy experiments established that well-tolerated doses of L49-sFv-bL/CCM combinations resulted in cures of 3677 tumors in nude mice . The favorable pharmacokinetic properties of L49-sFv-bL allowed prodrug treatment to be initiated 12 h after the conjugate was administered . Thus, L49-sFv-bL appears to have promising characteristics for site-selective anticancer prodrug activation. Eur J Biochem, 1997 Jul 1, 247(1), 402 - 10 Structural studies on the short-chain lipopolysaccharide of Vibrio cholerae O139 Bengal; Knirel YA et al.; A Vibrio cholerae O139 strain, MO10-T4, lacking capsular polysaccharide, produces a short-chain lipopolysaccharide (LPS), similar to enterobacterial SR strains . It was studied by acidic and alkaline degradation, dephosphorylation, sugar and methylation analysis, high-performance anion-exchange chromatography, one- and two-dimensional 1H-, 13C-, and 31P-NMR spectroscopy, and electrospray ionization mass spectrometry . The following structure was proposed for the core region of the LPS: {structure: see text} where PEtn stands for 2-aminoethyl phosphate, Fru for fructose, Hep for L-glycero-D-manno-heptose, and Kdo for 3-deoxy-D-manno-octulosonic acid; unless otherwise stated, the monosaccharide residues are D and present in the pyranose form . An O-acetyl group is present on a secondary position, tentatively O4 of the alpha-linked glucosyl group . Some LPS species contain an additional putative fructose residue whose location remains unknown . An O139-negative mutant strain, Bengal-2R, derived from V . cholerae O139, has also been investigated and shown to produce an O-antigen-lacking LPS similar to those from enterobacterial R strains, some of the LPS species containing the same core region as the strain MO10-T4 LPS and the other lacking the lateral heptose residue . The carbohydrate backbone core structure is the same for the V . cholerae O139 and V . cholerae O1 LPS, thus confirming the close relation between these bacteria; however, the 2-aminoethyl phosphate, the O-acetyl group, and the second fructose residue have not been reported for the O1 LPS . In the V . cholerae O139 strain MO10-T4 LPS, a short O-side chain is attached at position 3 of the 7-substituted heptose residue and has the same structure as one repeating unit of the V . cholerae O139 capsular polysaccharide . Some details of the structure proposed are at variance with those recently published for another V . cholerae O139 strain {Cox, A . D., Brisson, J.-R., Varma, V . & Perry, M . B . (1996) Carbohydr . Res . 290, 43-58; Cox, A . D . & Perry, M . B . (1996) Carbohydr . Res . 290, 59-65.} Lett Appl Microbiol, 1997 Jul, 25(1), 17 - 21 Repetitive element PCR fingerprinting (rep-PCR) using enterobacterial repetitive intergenic consensus (ERIC) primers is not necessarily directed at ERIC elements; Gillings M et al.; We examined the use of enterobacterial repetitive intergenic consensus (ERIC) sequences in PCR on the DNAs of various bacteria, bacteriophage, invertebrates, fungi, plants and vertebrates and have shown that complex ERIC-PCR patterns can be readily produced from all of these target organisms . A range of annealing temperatures was tested, from 52 degrees C (the commonly used annealing temperature) to 66 degrees C (the approximate Tm of ERIC primers) . At the higher temperatures, most bands failed to amplify, the exception being a subset of bands from enterobacterial targets . It was concluded that ERIC-PCR does not necessarily direct amplification from genuine ERIC sequences. J Pediatr Surg, 1997 Jul, 32(7), 1014 - 6 The protective role of gastric acidity in neonatal bacterial translocation; Dinsmore JE et al.; The acid environment of the stomach serves as an important defense against intestinal colonization by potentially pathogenic bacteria . The purpose of this study was to examine the effect of increased gastric pH on bacterial translocation in a neonatal rabbit model . Fifty-nine rabbit pups were delivered by cesarean section and randomly divided into normal acid (NA) and reduced acid (RA) groups . All were gavage fed and challenged with Enterobacter cloacae, 1 x 10(6) CFU/mL . The RA group received ranitidine, 20 mg/kg/d with all feeds . Gastric pH was measured by pH probe before and 4 hours after bacterial challenge . Mesenteric lymph node (MLN), spleen, liver, midjejunum, and cecum were harvested for culture at 72 hours . Gastric pH in the RA group was significantly increased before and 4 hours after the bacterial challenge . The incidence of bacterial translocation to the MLN, spleen, and liver was significantly higher in the RA group . Log cecal and jejunal colony counts were significantly increased in the RA animals . The authors conclude that the gastric acidity is protective against intestinal colonization and translocation of potentially pathogenic bacteria in this neonatal rabbit model. Microbiology, 1997 Jul, 143 ( Pt 7), 2423 - 32 Anaerobic pathways of glycerol dissimilation by Enterobacter agglomerans CNCM 1210: limitations and regulations; Barbirato F et al.; Continuous cultures of Enterobacter agglomerans CNCM 1210 were performed under regulated pH conditions (pH 7.0) with glycerol or glucose (20 g l-1) as carbon source . Cultures grown on glucose produced mainly acetate, ethanol and formate . In contrast, 1,3-propanediol (PPD) was the main product with glycerol . The carbon flow distribution at branching metabolic points was investigated . Higher PPD yields with increased dilution rate were correlated with an important increase in the relative ratio of glycerol dehydratase to glycerol dehydrogenase . Determination of intracellular triose-phosphate and fructose 1,6-biphosphate concentrations demonstrated that glyceraldehyde-3-phosphate dehydrogenase is the limiting step in glycerol dissimilation . At the pyruvate branching point, pyruvate dehydrogenase (PDH) activity was systematically detected . The pyruvate flow shifted to PDH is suspected to represent up to 22% of the acetyl-CoA formed . In addition, this enzyme pattern combined with the enhanced in vivo lactate dehydrogenase activity at high growth rates, was correlated with a decrease in the pyruvate formate-lyase activity . A regulation of this latter enzyme by the accumulation of triose-phosphate is suspected. Intern Med, 1997 Jul, 36(7), 479 - 83 Effectiveness of aldose reductase inhibitors for diabetic gastroenteropathy with constipation; Nakamura T et al.; We present a diabetic patient with long-standing constipation complicated by paralytic ileus and septic shock . She successfully recovered from a critical condition, and her diabetes was well controlled . However, the constipation did not improve even after the administration of conventional medications . Epalrestat, an aldose reductase inhibitor (ARI), improved her bowel motility and autonomic cardiovascular dysfunction, as evident from her heart rate and blood pressure response . Gastroenteropathy is a major diabetic complication which may cause disturbed bowel motility leading to serious enterobacterial infections, thus, its amelioration is important . ARI may be beneficial in the treatment of diabetic gastroenteropathy refractory to conventional therapies. Acad Emerg Med, 1997 Jul, 4(7), 711 - 4 Morganella morganii: a newly reported, rare cause of neonatal sepsis; Salen PN et al.; This case report reviews the clinical course of an 11-day-old boy who developed late-onset neonatal sepsis secondary to a rare neonatal pathogen, Morganella morganii . This gram-negative enteric bacterium, within the Enterobacteriaceae family, has most commonly been a nosocomial pathogen in debilitated, postsurgical patients . Like many other Enterobacteriaceae, M . morganii has an inducible beta-lactamase and is resistant to multiple antibiotics . When caring for neonates with culture-proven M . morganii sepsis, the authors recommend administering both a third-generation cephalosporin and an aminoglycoside to ensure that both antibiotics are bactericidal and to reduce the induction of resistance. Drugs, 1997 Jul, 54(1), 117 - 40 Cefpirome . A review of its antibacterial activity, pharmacokinetic properties and clinical efficacy in the treatment of severe nosocomial infections and febrile neutropenia; Wiseman LR et al.; Cefpirome is an injectable extended-spectrum or 'fourth generation' cephalosporin . Its antibacterial activity encompasses many of the pathogens involved in hospital-acquired infections such as Enterobacteriaceae, methicillin-susceptible Staphylococcus aureus, coagulase-negative staphylococci and viridans group streptococci . Cefpirome also has in vitro activity against Streptococcus pneumoniae regardless of penicillin susceptibility . It is stable against most plasmid- and chromosome-mediated beta-lactamases, with the exception of the extended-spectrum plasmid-mediated SHV enzymes . Intravenous cefpirome 2g twice daily has shown clinical efficacy comparable to that of ceftazidime 2g 3 times daily in the treatment of hospitalised patients with moderate to severe infections . Clinical response and bacteriological eradication rates were similar in patients with severe pneumonia or septicaemia treated with either cefpirome or ceftazidime . Cefpirome appeared more effective than ceftazidime in the eradication of bacteria in patients with febrile neutropenia in 1 study; however, clinical response rates were similar in the 2 treatment groups . The tolerability of cefpirome appears similar to that of ceftazidime and other third generation cephalosporins, diarrhoea being the most frequently observed event . Thus, cefpirome is likely to be a valuable extended-spectrum agent for the treatment of severe infections . Cefpirome offers improved coverage against some Gram-positive pathogens and Enterobacteriaceae producing class I beta-lactamases compared with the third generation cephalosporins, although this has yet to be demonstrated in clinical trials. Chemotherapy, 1997 Jul-Aug, 43(4), 245 - 53 In vitro time-kill curves of cefepime and cefpirome combined with amikacin, gentamicin or ciprofloxacin against Klebsiella pneumoniae producing extended-spectrum beta-lactamase; Elkhaili H et al.; Extended-spectrum beta-lactamases (ESBLs) are found in numerous Enterobacteriaceae, mainly in Klebsiella pneumoniae . We investigated the pharmacodynamics of two new extended-spectrum cephalosporins, cefepime and cefpirome, alone and combined with either amikacin or gentamicin or ciprofloxacin by means of time-kill curves against ESBL-producing, aminoglycoside-resistant K . pneumoniae . When used alone, cefepime (8 and 16 mg/l) resulted in a 2 and 3 log decrease at 6 h, respectively, but at 24 h regrowth occurred . The combination of cefepime (8 mg/l) with amikacin (4 mg/l) resulted in a 4 log decrease at 6 h, but there were no surviving bacteria at 6 h when combined with amikacin (8 mg/l) . The combination of cefepime (16 mg/l) with gentamicin (4 mg/l) resulted in a 4 log decrease in 24 h . The antimicrobial combination of cefepime (32 mg/l) with ciprofloxacin (2 mg/l) resulted in a 4 log decrease in 24 h . Cefpirome (8 mg/l) induced a 2 log decrease at 4 h; 32 mg/l cefpirome resulted in a 3 log decrease followed by regrowth at 24 h . The regrowth observed in the late phase with cefpirome alone disappeared when combined with aminoglycoside . When cefpirome (32 mg/l) was used in combination with ciprofloxacin (1 mg/l), it resulted in a 4 log decrease in 24 h. J Bacteriol, 1997 Jul, 179(13), 4443 - 5 A melibiose transporter and an operon containing its gene in Enterobacter cloacae; Okazaki N et al.; We detected inducible melibiose transport activity in cells of Enterobacter cloacae IID977 . H+, but not Na+, was found to be the coupling cation for this transporter . We cloned and sequenced the gene encoding the melibiose transporter . A homology search of a protein sequence database revealed that this melibiose transporter has high sequence similarity with the lactose transporter (LacY) and the raffinose transporter (RafB) and has some similarity with the melibiose transporter (MelB) of Escherichia coli. J Bacteriol, 1997 Jul, 179(13), 4438 - 42 Conservation of the Escherichia coli dnaX programmed ribosomal frameshift signal in Salmonella typhimurium; Blinkova A et al.; Escherichia coli DNA polymerase III subunits tau and gamma are produced from one gene, dnaX, by a programmed ribosomal frameshift which generates the C terminal of gamma within the tau reading frame . To help evaluate the role of the dispensable gamma, the distribution of tau and gamma homologs in several other species and the sequence of the Salmonella typhimurium dnaX were determined . All four enterobacteria tested produce tau and gamma homologs . S . typhimurium dnaX is 83% identical to E . coli dnaX, but all four components of the frameshift signal are 100% conserved. J Bacteriol, 1997 Jul, 179(13), 4143 - 57 Aspartate transcarbamylase from the deep-sea hyperthermophilic archaeon Pyrococcus abyssi: genetic organization, structure, and expression in Escherichia coli; Purcarea C et al.; The genes coding for aspartate transcarbamylase (ATCase) in the deep-sea hyperthermophilic archaeon Pyrococcus abyssi were cloned by complementation of a pyrB Escherichia coli mutant . The sequence revealed the existence of a pyrBI operon, coding for a catalytic chain and a regulatory chain, as in Enterobacteriaceae . Comparison of primary sequences of the polypeptides encoded by the pyrB and pyrI genes with those of homologous eubacterial and eukaryotic chains showed a high degree of conservation of the residues which in E . coli ATCase are involved in catalysis and allosteric regulation . The regulatory chain shows more-extensive divergence with respect to that of E . coli and other Enterobacteriaceae than the catalytic chain . Several substitutions suggest the existence in P . abyssi ATCase of additional hydrophobic interactions and ionic bonds which are probably involved in protein stabilization at high temperatures . The catalytic chain presents a secondary structure similar to that of the E . coli enzyme . Modeling of the tridimensional structure of this chain provides a folding close to that of the E . coli protein in spite of several significant differences . Conservation of numerous pairs of residues involved in the interfaces between different chains or subunits in E . coli ATCase suggests that the P . abyssi enzyme has a quaternary structure similar to that of the E . coli enzyme . P . abyssi ATCase expressed in transgenic E . coli cells exhibited reduced cooperativity for aspartate binding and sensitivity to allosteric effectors, as well as a decreased thermostability and barostability, suggesting that in P . abyssi cells this enzyme is further stabilized through its association with other cellular components. Arch Med Res, 1997 Summer, 28(2), 285 - 7 beta-Lactamase bioassay: a simplified method to determine extended-spectrum beta-lactamases (ESBL) in enterobacteria; Silva-Sanchez J et al.; With the simultaneous use of an isoelectric focusing gel (IEF) and a nitrocefin/cefotaxime bioassay, it is possible to identify the Extended-Spectrum beta-lactamases (ESBL) with precision . A mixture of soft agar and susceptible bacterial cells are layered over the gel following overnight incubation and areas of cell growth are detected where the antibiotic has been hydrolyzed by specific enzymes . This innovative method improves sensitivity and specificity for the identification of ESBLs in those enterobacteria strains producing more than one beta-lactamase and are resistant to third generation cephalosporines. Aust Vet J, 1997 Jun, 75(6), 433 - 8 Effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function; Raidal SL et al.; OBJECTIVE: To evaluate the effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function in horses and to compare results from transported horses with those obtained in earlier experiments from horses confined with heads elevated . DESIGN: A prospective study . PROCEDURE: Six horses were transported by road for 12 h . Clinical and haematological examination, transtracheal aspiration and cell function studies were conducted before and after transportation . Results obtained after transportation were compared to pre-transportation values . RESULTS: After transportation, peripheral blood leucocyte and neutrophil numbers were increased and rectal temperatures were evaluated . Transtracheal aspirates showed an accumulation of purulent respiratory tract secretions with increased numbers of bacteria, particularly beta-haemolytic Streptococcus spp and members of the Pasteurellaceae family . Three horses also had increased numbers of bacteria from the Enterobacteriaceae family relative to corresponding samples from earlier studies . Phagocytosis by peripheral blood neutrophils was significantly reduced, while the oxidative burst activity of peripheral blood leucocytes was either unchanged or enhanced . CLINICAL IMPLICATIONS: Bacterial contamination of the lower respiratory tract occurs as a routine consequence of transportation of horses and is likely to be an important determinant in the development of transport-associated respiratory disease . Inflammatory airway secretions and increased numbers of bacteria were rapidly cleared, without clinical evidence of significant pulmonary disease and without additional treatment, in normal horses that were allowed to lower their heads after transportation . Peripheral blood neutrophilia and a reduction in neutrophil phagocytic function were evident for at least 36 h after transportation, suggesting that horses may require a number of days to recover from the stress of transportation . As the potential role of bacteria from the Enterobacteriaceae family in the development of transport-associated respiratory disease has not been elucidated, horses which develop clinical disease following transportation should undergo thorough bacteriological investigation to ensure appropriate treatment. Diagn Microbiol Infect Dis, 1997 Jun, 28(2), 101 - 4 Accuracy of the Vitek system for antimicrobial susceptibility testing Enterobacteriaceae bloodstream infection isolates: use of "direct" inoculation from Bactec 9240 blood culture bottles; Putnam LR et al.; A recent investigation indicates that rapid antimicrobial susceptibility tests (AST) can affect patient therapy leading to reductions in health-care costs for some patient populations . However, there is little information relative to the often performed direct inoculation of positive blood culture bottles into rapid AST systems . AST results of direct inoculated Vitek (bioMerieux Vitek, Hazelwood, MO, USA) GNS cards were compared to those inoculated per package insert recommendations and a reference broth microdilution test using 50 consecutive Enterobacteriaceae bloodstream infection isolates . Escherichia coli (44% of isolates), Klebsiella ssp . (30%), and six other members of this family were tested against 15 antimicrobial agents . The direct inoculation method produced only two false-susceptible (0.3%), seven false-resistant (0.9%; six different drugs), and 48 minor errors (6.4%) . The GNS cards inoculated in the usual, recommended manner had no very major error, and 7.5% combined major and minor errors . If the results of the urinary infection-specific drugs (nitrofurantoin, trimethoprim/sulfamethoxazole; not appropriate for bacteremia therapy) and ampicillin/sulbactam were deleted, both Vitek inoculation methods yielded results well within acceptable limits (< or = 4.5% overall error) . These results indicate that the direct inoculation method of Vitek GNS cards from Enterobacteriaceae bloodstream infections (detected by Bactec 9240, Becton-Dickinson, Cockeysville, MD, USA) performed as well as the NCCLS broth microdilution test . Thus, a procedural modification of this type could further accelerate rapid access to accurate AST data. Diagn Microbiol Infect Dis, 1997 Jun, 28(2), 87 - 92 Evaluation of the in vitro activity of cefepime compared to other broad-spectrum cephalosporins against clinical isolates from eighteen Brazilian hospitals by using the Etest; Sader HS et al.; The in vitro activity of cefepime was compared to that of ceftazidime, ceftriaxone, and cefotaxime in a multicenter study involving 10 clinical microbiology laboratories and clinical isolates from 18 Brazilian hospitals from 7 cities (4 states) . A total of 982 isolates consecutively collected between December 1995 and March 1996 were susceptibility tested by using Etest and following the NCCLS procedures for agar diffusion tests . The cefepime spectrum was broader than that of the other broad-spectrum cephalosporins against both Gram-negative rods and Gram-positive cocci . Cefepime was particularly more active against Enterobacter sp . (MIC90, 2 micrograms/ml), Serratia sp . (MIC90, 2 micrograms/ml) and oxacillin-susceptible Staphylococcus aureus (MIC90, 3 micrograms/ml) . Against Pseudomonas aeruginosa, cefepime (MIC90, 16 micrograms/ml) was slightly more active than ceftazidime (MIC90, 32 micrograms/ml) and 8- to 16-fold more active than ceftriaxone of cefotaxime (MIC90, > 256 micrograms/ml) . Our results show that nosocomial bacteria, especially Gram-negative rods, have a high rate of cephalosporin resistance in Brazil . However, part of these resistant bacteria remains susceptible to cefepime . The Etest was shown to be an excellent method for multicenter studies of the in vitro evaluation of new antimicrobial agents. J Hosp Infect, 1997 Jun, 36(2), 95 - 103 Serratia marcescens infections in neonatal departments: description of an outbreak and review of the literature; van Ogtrop ML et al.; An outbreak of colonization and infection with Serratia marcescens occurred in a neonatal intensive care unit (NICU) . S . marcescens was isolated from five preterm infants (gestational age 25-30 weeks) . Two infants developed septicaemia, which were both fatal, and one infant (the presumed index case) had conjunctivitis due to S . marcescens . Two infants were colonized without clinical signs of infection . All infants were treated with antibiotic regimens including ciprofloxacin and gentamicin . The DNA fingerprints of isolates were determined by enterobacterial repetitive intergenic consensus primers by the polymerase chain reaction . This showed that a single strain had spread in the NICU . An extensive investigation pointed to an infant born from a mother with an intra-uterine infection after prolonged rupture of foetal membranes as a presumed source of the outbreak . A reservoir, other than the infected or colonized infants and their immediate vicinity, was not found, with the sole exception of the waste jar of a Na+/ K(+)-analysis apparatus . Containment of the outbreak was achieved by closure of the NICU for new admissions, strict hygienic measures and cohort nursing of the infected and colonized infants . It was considered especially important to handle the infants with gloves, since frequent hand carriage of staff with S . marcescens was found when gloves were not used. J Chemother, 1997 Jun, 9(3), 232 - 7 Bacteremia in cancer patients with solid tumors undergoing chemotherapy versus surgery: risk factors, etiology and outcome in 276 patients; Krcmery V Jr et al.; Etiology, risk factors, outcome and complications of bacteremia in 276 patients with solid tumors were analyzed . A group of 78 patients with solid tumors and surgical therapy only was compared with 172 patients with solid tumors who were treated with chemotherapy only . The most frequently observed risk factors of bacteremia in patients after surgery was urinary catheter insertion, wound as source of bacteremia, age > 60, staphylococci, enterococci and Enterobacteriaceae as etiologic agents . In comparison, viridans streptococci and Pseudomonas aeruginosa as etiologic agents as well as vascular catheters were significantly more frequently found in those treated with chemotherapy only . Patients with bacteremia after surgery only had a lower incidence of septic shock (6.4 vs . 16.9%, P < 0.03) and also lower mortality (5.6 vs . 14.9%, P < 0.04) attributable to shock than patients being treated for solid tumors with chemotherapy only. Clin Infect Dis, 1997 Jun, 24(6), 1243 - 4 An outbreak of Enterobacter hormaechei infection and colonization in an intensive care nursery; Wenger PN et al.; Enterobacter hormaechei was first identified as a unique species in 1989 . Between 29 November 1992 and 17 March 1993, an outbreak of E . hormaechei occurred among premature infants in the intensive care nursery (ICN) at The Hospital of the University of Pennsylvania . The 10 infants whose cultures were positive for E . hormaechei (six were infected and four were colonized) had a lower median estimated gestational age and birth weight than did other ICN infants; other risk factors for infection or colonization with E . hormaechei were not identified . Cultures from three isolettes and a doorknob in the ICN were positive for E . hormaechei . Pulsed-field gel electrophoresis of isolates from six patients and two isolettes were identical . Observations of health care workers revealed breaks in infection control techniques that may have allowed transmission of this organism . We found that E . hormaechei is a nosocomial pathogen that can infect vulnerable hospitalized patients and that can be transmitted from patient to patient when infection control techniques are inadequate. J Infect Dis, 1997 Jun, 175(6), 1404 - 12 Contrasting effects of lipopolysaccharides (endotoxins) from oral black-pigmented bacteria and Enterobacteriaceae on platelets, a major source of serotonin, and on histamine-forming enzyme in mice; Endo Y et al.; By measurement of serotonin levels, the translocation of platelets to various tissues was examined following intravenous injection of a lipopolysaccharide (LPS) into C3H/HeN mice . There was a rapid platelet accumulation (within 5 min and particularly in the lung), followed by a slower accumulation in the liver, which reached its plateau 3-5 h later . The severity of the anaphylactoid shock corresponded well with the magnitude of the rapid response . LPSs from the oral black-pigmented bacteria, Porphyromonas gingivalis and Prevotella intermedia, were much more potent in inducing the rapid platelet response than were those from the Enterobacteriaceae Escherichia coli and Salmonella typhimurium . However, LPSs from these Enterobacteriaceae were significantly more potent than those from black-pigmented bacteria in inducing the slow platelet response . There was also a contrast between their abilities to induce histidine decarboxylase, which forms histamine from histidine: LPSs from the Enterobacteriaceae were much more potent than those from black-pigmented bacteria. J Bacteriol, 1997 Jun, 179(11), 3756 - 60 Structural characterization of the lipids A of three Bordetella bronchiseptica strains: variability of fatty acid substitution; Zarrouk H et al.; The structures of lipids A isolated from the lipopolysaccharides (LPSs; endotoxins) of three different pathogenic Bordetella bronchiseptica strains were investigated by chemical composition and methylation analysis, gas chromatography-mass spectrometry, nuclear magnetic resonance, and plasma desorption mass spectrometry (PDMS) . The analyses revealed that the LPSs contain the classical lipid A bisphosphorylated beta-(1-->6)-linked D-glucosamine disaccharide with hydroxytetradecanoic acid in amide linkages . Their structures differ from that of the lipid A of Bordetella pertussis endotoxin by the replacement of hydroxydecanoic acid on the C-3 position with hydroxydodecanoic acid or dodecanoic acid and the presence of variable amounts of hexadecanoic acid . The dodecanoic acid is the first nonhydroxylated fatty acid to be found directly linked to a lipid A glucosamine . The lipids A were heterogeneous and composed of one to three major and several minor molecular species . The fatty acids in ester linkage were localized by PDMS of chemically modified lipids A . B . pertussis lipids A are usually hypoacylated with respect to those of enterobacterial lipids A . However, one of the three B . bronchiseptica strains had a major hexaacylated molecular species . C-4 and C-6' hydroxyl groups of the backbone disaccharide were unsubstituted, the latter being the proposed attachment site of the polysaccharide . The structural variability seen in these three lipids A was unusual for a single species and may have consequences for the pathogenicity of this Bordetella species. J Bacteriol, 1997 Jun, 179(11), 3443 - 50 Topology of the outer membrane phospholipase A of Salmonella typhimurium; Merck KB et al.; The outer membrane phospholipase A (OMPLA) of Enterobacteriaceae has been proposed to span the membrane 14 times as antiparallel amphipathic beta-strands, thereby exposing seven loops to the cell surface . We have employed the epitope insertion method to probe the topology of OMPLA of Salmonella typhimurium . First, missense mutations were introduced at various positions in the pldA gene, encoding OMPLA, to create unique BamHI sites . These BamHI sites were subsequently used to insert linkers, encoding a 16-amino-acid B-cell epitope . Proper assembly of all mutant proteins was revealed by their heat modifiability in sodium dodecyl sulfate-polyacrylamide gel electrophoresis . The accessibility of the inserted epitopes was assessed . Immunofluorescence analysis of intact cells with antibodies against the inserted epitope showed that three of seven predicted loops are indeed cell surface exposed . Trypsin accessibility experiments verified the cell surface exposure of two additional loops and provided support for the proposed periplasmic localization of three predicted turns . For two other predicted exposed loops, the results were not conclusive . These results support to a large extent the proposed topology model of OMPLA . Furthermore, the observation that the substitutions Glu66Pro and Glu247Gly virtually abolished enzymatic activity indicates that these residues might play a major role in catalysis. J Immunol Methods, 1997 May 26, 204(2), 169 - 74 A monoclonal antibody reacts with maltose-binding protein of Escherichia coli and related enteric bacteria; Hsu SC et al.; Maltose-binding protein (MBP) encoded by malE is essential for the energy-dependent translocation of maltose through the cytoplasmic membrane of bacteria . Its property of specific binding to maltose has been used in constructing fusion proteins for easy affinity purification . A monoclonal antibody named MAb SC1D7 was produced against Escherichia coli MBP . This MAb also bound to MBP-containing recombinant proteins in both Western blotting and immunoprecipitation analysis . As a result, this MAb can be a useful probe for tracing MBP-fusion proteins in various applications . Furthermore, intrinsic MBPs from E . coli, Shigella dysenteriae, Salmonella typhimurium, Enterobacter cloacae, and Klebsiella pneumoniae were also detected by this MAb . No reaction was observed with the total proteins from Serratia marcescens, Aeromonas hydrophila and Plesiomonas shigelloides . These observations suggest that the MAb SC1D7-defined epitope is conserved among some enteric bacteria, but not the others . The results strengthen the phylogenetic positions of these closely related bacteria previously placed by other means. N Z Med J, 1997 May 23, 110(1044), 187 - 9 Susceptibility patterns of bacterial isolates from intensive care and haematology/oncology patients in New Zealand; Morris AJ et al.; AIMS: To determine the current susceptibility pattern of bacterial isolates from intensive care and haematology/oncology patients in New Zealand . METHOD: Over a 6 month period 417 consecutive clinically relevant bacterial isolates from intensive care and haematology/oncology patients from seven New Zealand hospitals had their susceptibility to multiple antimicrobial agents determined by the agar plate dilution method . Methicillin resistant staphylococci were not included . RESULTS: Of the 417 isolates, 224 (54%) were gram negative and 193 were gram positive . Predominant species/groups were: Escherichia coli 63 (15%), Enterobacter spp 26 (6%), other Enterobacteriacae 41 (10%), Pseudomonas aeruginosa 42 (10%), Staphylococcus aureus 111 (27%), coagulase negative staphylococci 30 (7%), Streptococcus spp 31 (7%), and Enterococcus spp 19 (5%) . Isolate sources were: respiratory tract, 170 (41%); cutaneous sites, 81 (19%); blood, 64 (15%); and urine 63 (15%) . Resistance was uncommon amongst staphylococci, streptococci, enterococci, and H influenzae . No vancomycin resistant or beta-lactamase-positive enterococci were encountered . For different groups of enteric gram negative bacilli: amoxycillin and amoxycillin-clavulanic acid resistance was common, 46-93% and 24-85% respectively; cefpirome was the most active cephalosporin; aminoglycoside resistance was uncommon; and no isolate possessed extended spectrum beta-lactamase . For P aeruginosa: most isolates were susceptible to cefpirome and ceftazidime, and aminoglycoside resistance was uncommon . CONCLUSION: Gram positive bacteria make up a higher proportion of isolates than in a similar European study . At present New Zealand does not have widespread resistance amongst common isolates . Several agents currently available in New Zealand provide adequate cover for commonly encountered pathogens . The choice of which agent to choose therefore rests more with their purchase and administration costs, as well as safety and efficacy data than simply susceptibility data alone. Biochim Biophys Acta, 1997 May 22, 1326(1), 83 - 91 Characteristics of the melibiose transporter and its primary structure in Enterobacter aerogenes; Okazaki N et al.; Cells of Enterobacter aerogenes can grow on melibiose as a sole source of carbon . This suggests the presence of melibiose operon in this organism . We found that E . aerogenes cells possess both alpha-galactosidase activity and melibiose transport activity, which were induced by melibiose . Neither Na+ nor Li+ stimulated the melibiose transport . However, transport of methyl-beta-thiogalactoside (TMG) was stimulated by Li+ but not by Na+ . These findings suggest that the major coupling cation for the melibiose transporter in E . aerogenes is H+ . In fact, we observed H+ entry into cells caused by an influx of melibiose and some of its analogs . We cloned the melB gene which encodes the melibiose transporter, and sequenced it . Deduced amino acid sequence of the transporter revealed that the melibiose transporter consists of 471 amino acid residues and the molecular weight was calculated to be 52214 Da . The sequence showed high homology with the sequences of the melibiose transporters of Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae . Higher homology was found with the melibiose transporter of K . pneumoniae than with that of E . coli and S . typhimurium. Int J Food Microbiol, 1997 May 20, 36(2-3), 231 - 4 Influence of aging treatment on the bacterial quality of South African springbok (Antidorcas marsupialis marsupialis) wholesale cuts; Buys EM et al.; The left sides of 20 springbok carcasses were aged with the skin on (treatment 1), while the right sides were aged without the skin (treatment 2) . Another 20 carcasses were skinned, halved and cut into wholesale cuts . The loin and leg cuts from the right sides were deboned before vacuum packaging (treatment 3), while the loin and leg cuts from the left sides were vacuum packed with the bone in (treatment 4) . All the carcass sides (36 h post mortem) and vacuum packed cuts (36 h post mortem) were aged for either 2, 5, 12 and 19 days respectively (ca . 0 degrees C) . The examined groups of bacteria indicate that, for an ageing period of 12 days or less, vacuum packaging does not have an advantage over the hung in air method . However, when considering an extended ageing period ( > 12 days) vacuum packaging ensures that spoilage bacteria are inhibited and that the Enterobacteriaceae group of bacteria do not increase (ca . 0 degrees C), while the results clearly show that this is not the case with the hung in air ageing treatments (1 and 2). Int J Food Microbiol, 1997 May 20, 36(2-3), 199 - 206 Identification and quantification of risk factors regarding Salmonella spp . on pork carcasses; Berends BR et al.; The main elements of a descriptive epidemiological model for Salmonella spp . in Dutch pig slaughterlines, and the subsequent quantification of risk factors regarding the contamination of carcasses, are described . There is a strong correlation between the number of live animals that carry Salmonella spp . in their faeces and the number of contaminated carcasses at the end of the slaughterline . Live animals that carry Salmonella spp . are 3-4 times more likely to end up as a positive carcass than Salmonella-free animals . Currently, about 70% of all carcass contamination results from the animals themselves being carriers, and 30% because other animals were carriers (i.e . cross contamination) . Furthermore, it is estimated that in general between 5-30% of the carcasses produced may contain Salmonella spp . With respect to carcass contamination with Enterobacteriaceae and Salmonella spp., inadequately cleaned polishing machines (odds ratio, OR, 6) and 'inapt procedures during evisceration' (OR 11), i.e . faulty evisceration and hygiene practices, are the most important risk factors . An estimated 5-15% of all carcass contamination with Salmonella spp . occurs during polishing after singeing . The remainder is the result of current evisceration practices (55-90%) and, to a lesser extent, further processing (5-35%), i.e dressing, splitting and meat inspection . Less likely Salmonella spp . already present on the skin of the live animals survive scalding and singeing . However, because pigs are the only important source for the Salmonella contamination of the line and the carcasses produced, it can also be concluded that if Salmonella-free pigs were produced, consumers could be provided with virtually Salmonella-free pork . As long as Salmonella-positive animals enter abattoirs, there will always be transmission of Salmonella spp . to consumers, even if the process is carried out according to stringent codes of good manufacturing practices (GMP) . EU regulations should, therefore, allow for the decontamination of caracasses with a safe substance, e.g . lactic acid, on the condition that the slaughterhouse strictly adhers to GMP principles. Ugeskr Laeger, 1997 May 19, 159(21), 3167 - 71 {Experience with daily single dose administration of gentamicin}; Christensen SB et al.; The purpose of the study was to evaluate the effect and side-effects of once daily (OD) administration of gentamicin . The study was a retrospective analysis of patients treated with gentamicin OD for at least two days for proven or suspected infection . Of the 101 patients included, 60 were female, and the median age was 64 years (range: 20-90 years) . Median duration of treatment was six days (2-63 days) . All patients received combination therapy with two (36 patients), three (64 patients) or four (one patient) antibiotics, apart from gentamicin usually ampicillin, cefuroxime and/or metronidazole . Gentamicin doses were usually 240 mg on a fixed basis, but reduced in patients with pre-treatment impairment of serum-creatinine . Bacteriological cultures were taken in 90% of the patients, of which 59% were positive, most often with Enterobacteriaceae (57%) or other Gram-negative rods (11%) . Effect of antibiotic treatment was seen in 82% of the patients . Nephrotoxicity defined as a 44 umol/l increase in serum-creatinine during treatment was found in five patients (5%) . Ototoxicity, i.e . clinical signs of tinnitus, dizziness and/or impaired hearing, was reported in two patients . In conclusion, gentamicin OD with 240 mg is easy to administer, appears to be sufficient with regard to effect and has a low frequency of side-effects. Orv Hetil, 1997 May 4, 138(18), 1113 - 7 {Risk factors of infected pancreatic necrosis, its microbiology and antibiotic treatment}; Pulay I et al.; Acute pancreatitis is associated with greater and smaller necrosis in 20% of the cases . The lethality rate of sterile and infected necrosis is 10 and 15-40%, respectively . The results of a retrospective and a prospective study in acute pancreatitis have been analyzed in this study . Twenty patients suffering from infected necrosis due to acute necrotising pancreatitis were selected into the retrospective study . They were divided into two groups: Group 1 (N = 10) survivors, Group 2 (N = 10) those who died . The fate of patients was determined by their age, the severity of pancreatitis, and the effectiveness of the operation . In a prospective study 63 patients were operated due to benign pancreatic disease with fluid collection . Microbiological samples were taken during surgery in every case . It could be stated that the Enterobacteriaceae spp . play the principal role in the infection, and the anaerobic bacteria occur sporadically . The omission of bacteriological sample taking during surgery frustrates the targeted antibiotic treatment . The blood culturing may have useful contribution . The targeted antibiotic therapy based on relevant microbiological sample taking is substantial complementary of the surgical intervention in the treatment of the inflammatory pancreatic diseases. Tierarztl Prax, 1997 May, 25(3), 200 - 6 {Contribution to the treatment of acute bovine mastitis with cefquinome}; Shpigel NY et al.; Cefquinome is the first 4th generation cephalosporin antibiotic developed for use in veterinary medicine . A European multicentre study established a high in vitro activity for this modern antimicrobial drug against a wide spectrum of bovine pathogens . Gram-positive and gram-negative mastitis agents were inactivated even at very low active ingredient concentrations, including Enterobacteriaceae which are often resistant to other drugs . The results of clinical trials using experimental E . coli mastitis as an example demonstrate the efficacy of cefquinome in vivo . Parenteral administration at a dose rate of 1 mg/kg body weight when compared with conventional therapy using a control drug with equally good in vitro activity, produced significantly better therapeutic results. Epidemiol Mikrobiol Imunol, 1997 May, 46(2), 73 - 80 {beta-Lactam antibiotics--mechanisms of action and resistance in Enterobacteriaceae}; Lausova A et al.; Beta-lactams are considered to be very important drugs used in the therapy of many serious bacterial infections . In the last few years, the number of isolated clinical strains from the Enterobacteriaceae family, mainly Enterobacter and Klebsiella spp . resistant to 3rd generation cephalosporins, rapidly increased . Resistance can be located on chromosomes or be determined by plasmids and transposons . The production of beta-lactamases is the most frequent manifestation of beta-lactam resistance . Spread of such resistance, especially plasmid-encoded, is believed to be a serious risk factor . Therefore the study of the resistance mechanism is Gram-negative bacilli to beta-lactams not only indicates the present situation, but also trends in future medical therapy. Burns, 1997 May, 23(3), 225 - 7 The use of aztreonam as an alternate therapy for multi-resistant Pseudomonas aeruginosa; Walton MA et al.; The emergence of multi-resistant Gram-negative bacteria has created a most alarming clinical situation . The armamentarium of antibiotics used against this group of organisms is rapidly being depleted . Our routine therapeutic approach to control and prevent these Gram-negative bacteria from gaining a foothold was the empirical use of an aminoglycoside combined with piperacillin . However, aminoglycoside resistance is now routine rather than unusual . We evaluated the role of the monobactam aztreonam in burn wound infections and compared it to the aminoglycosides amikacin and gentamicin as well as piperacillin for the Enterobacteriacae and Pseudomonas aeruginosa . A total of 1274 Gram-negative isolates including P . aeruginosa were evaluated for susceptibility to the above-mentioned antibiotics from January 1995 to August 1995 (Table I) . Among the Enterobacteriacae, aztreonam was more effective than amikacin and piperacillin (58.4 per cent vs . 45.8 per cent, respectively) . However, it still fluctuated among the Enterobacteriacae as did the aminoglycosides . One major significant finding was that while susceptibility to aztreonam was variable for the Enterobacteriacae, P . aeruginosa remained 90 per cent susceptible to aztreonam and 90 per cent susceptible to piperacillin, whereas it was 79 per cent resistant to the aminoglycosides . Consequently, when choosing an antimicrobial in a suspected P . aeruginosa burn wound infection, aztreonam and piperacillin should be considered as the first line of defense. Diagn Microbiol Infect Dis, 1997 May, 28(1), 35 - 40 Critical evaluation of the Vitek GNS F6 card results compared to standardized, reference susceptibility test methods; Jones RN et al.; A large number of Enterobacteriaceae (291 unselected and 30 clinical challenge isolates) were used to evaluate the accuracy of the Vitek GNS-F6 susceptibility testing card for 10 antimicrobial agents (ampicillin, ampicillin/sulbactam, aztreonam, ciprofloxacin, imipenem, mezlocillin, ofloxacin, piperacillin, ticarcillin, and ticarcillin/clavulanate) . Results were compared to reference broth microdilution and disk diffusion methods . Highest interpretive error on initial processing were observed with ticarcillin/clavulanate (very major false-susceptible error, 3.4%), imipenem (major false-resistant error, 1.9%), and ampicillin/sulbactam (minor error, 15.9%) . Repeat testing resolved many very major errors (21 of 41 results), and the overall accuracy rate was improved from 92.1 to 93.4% . Analysis of all minor interpretive errors demonstrated that the trend for Vitek was to report slightly lower MICs (6 of 10 drugs; 97 of 159 results) in comparison to the reference test results . If a heavy inoculum was used in the Vitek cards, false resistance was observed more frequently with aztreonam and penicillins . These data demonstrate that susceptibility testing accuracy with Vitek GNS-F6 card based on categorical agreement varies from 83.2% (ampicillin/sulbactam) to 99.4% (ciprofloxacin) when testing enteric bacilli . Some antimicrobial agents (beta-lactamase inhibitor/penicillin combinations, antipseudomonal penicillins) may require slight modification of interpretive software . Finally, the overall accuracy of the Vitek System was greater than 91% for 9 of 10 drugs tested with a very low, acceptable rate of false-susceptible error (0.8%). Diagn Microbiol Infect Dis, 1997 May, 28(1), 5 - 18 Microbiologic and pharmacodynamic principals applied to the antimicrobial susceptibility testing of ampicillin/sulbactam: analysis of the correlations between in vitro test results and clinical response; Jones RN et al.; The correlation between various ampicillin/sulbactam in vitro antimicrobial susceptibility test results and the clinical outcome of patients treated with this agent have been examined . A survey of over 29,000 clinical isolates of the family Enterobacteriaceae found that the proportion of susceptible pathogens as assessed by current susceptibility testing interpretive guidelines (NCCLS) for disk diffusion and dilution (MIC) assays was significantly less than the proportion of patients cured or clinically improved in ampicillin/sulbactam clinical trials . Also, the results of two NCCLS methods differ greatly in the perceived percentages of susceptible strains (63.9% versus 72.2%; unacceptable variation) . Furthermore, the current interpretive criteria resulted in high false-susceptible (4.2%) and total (19.7%) error rates . When proposed interpretive guidelines were applied, approximately 73 to 87% of the Enterobacteriaceae strains were observed to be susceptible, the variation between methods was minimized, and the error rates were reduced . A retrospective analysis of data from clinical trials with ampicillin/sulbactam indicated that the proportion of patients who were cured or clinically improved and bacterially eradicated was not appreciably different in patients having baseline Enterobacteriaceae pathogens with MICs of 16 or 32 micrograms/ml (ampicillin MIC component) as compared to those with pathogens having MICs of < or = 8 micrograms/ml . Studies in animals, in vitro models, and pharmacokinetic considerations indicate that a change in the MIC breakpoint for ampicillin/sulbactam should be considered . The proposed interpretive guideline revisions for ampicillin/sulbactam susceptibility testing of the Enterobacteriaceae were 1) use current diagnostic reagents with criteria of < or = 16/8 micrograms/ml (> or = 14 mm) as susceptible and > or = 64/32 micrograms/ml (< or = 10 mm) as resistant; e.g., 75.9 to 76.0% spectrum and 1.3% false-susceptible error; 2) use alternative diagnostic reagents (1:1 ratio MIC; 20/20 micrograms disks) with criteria of < or = 8/8 micrograms/ml (> or = 18 mm) as susceptible and > or = 32/32 micrograms/ml (< or = 14 mm) as resistant; e.g., 73.3 to 76.9% spectrum and 1.8% false-susceptible error; or 3) use alternative diagnostic reagents with criteria of < or = 16/16 micrograms/ml (> or = 14 mm) as susceptible and > or = 64/64 micrograms/ml (< or = 10 mm) as resistant; e.g., 84.7 to 86.9% spectrum and 1.3% false-susceptible error . Data from a comprehensive in vitro survey of clinical isolates, retrospective analyses of clinical trials, and studies of animal models support the modification of contemporary interpretive guidelines for ampicillin/sulbactam antimicrobial susceptibility tests . The best short-term criteria would apply current in vitro diagnostic reagents and a modified susceptible breakpoint (< or = 16/8 micrograms/ml as susceptible; option 1 above) until new diagnostic reagents can be qualified by means of studies needed for quality assurance of standardized methods (NCCLS M23-A and FDA procedures) . These changes would provide a better in vitro prediction of ampicillin/sulbactam efficacy in clinical practice. Gan To Kagaku Ryoho, 1997 May, 24 Suppl 1, 253 - 6 New strategy of bio-chemoprevention on recurrence of superficial bladder cancer based on a hypothesis of the mechanism of recurrence; Akaza H; There are theoretical limits to the efficacy of intravesical chemotherapy for prevention of tumor recurrence after transurethral resection of a superficial bladder cancer . Our multi-institutional studies revealed that the direct efficacy of BCG, intravesical instillation for treatment of an existing tumor is very promising . This efficacy persisted over a long period of time, and the subsequent recurrence rate was markedly reduced . Bladder cancer, sometimes earlier known as an occupational disease, might be related to unknown chemical carcinogens . Since enterobacterias are thought to produce carcinogens and mutagens, including nitroso-compounds in the intestinal tract, BLP (lactobacillus casei preparation), treatment may suppress the production of such compounds by altering the intestinal flora . Preclinical studies have demonstrated that BLP suppresses the development of bladder cancer induced by N-butyl-N-(4-hydroxy-butly)-nitrosamine in mice and rats . A double-blind clinical trial recently revealed that BLP was effective for preventing the recurrence of superficial bladder cancer . Bropirimine, a interferon inducer, is now an internationally developing agent for superficial bladder cancer, which is discussed on the basis of Japanese phase II trial data. Recenti Prog Med, 1997 May, 88(5), 237 - 41 Role of lipopolysaccharide and related cytokines in Helicobacter pylori infection; Pece S et al.; Helicobacter pylori is a gram-negative bacterium which accounts for the development of chronic gastritis and peptic ulcer in man . In this review, emphasis has been laid on the role of lipopolysaccharide (LPS) of the H . pylori cellular wall in the pathogenesis of gastroduodenal disease . H . pylori LPS exhibits a reduced endotoxic potency in terms of pyrogenicity, lethality, toxicity, mitogenicity, cytokine (CK) release and chromogenic limulus amebocyte lysate assay . This low biological activity of the LPS could be ascribed to the underacylation and underphosphorylation pattern of the lipid A backbone . However, also LPS core structures seem to contribute to the biological activity of the molecule . Despite this low immunological potential, an array of proinflammatory CKs are produced both in vitro and in vivo following stimulation of mucosal cells with H . pylori organisms . It is likely that LPS plays a major role in triggering interleukin (IL)-8, IL-1 and tumor necrosis factor-alpha production from both epithelial cells and macrophages . Finally, the lower immune response elicited by H . pylori LPS in comparison with other enterobacterial LPS may represent an escape mechanism from the host immunosurveillance exerted by this bacterium, thus allowing its survival and persistence in the gastric niche. Mol Microbiol, 1997 May, 24(4), 857 - 67 Catabolite repression by glucose 6-phosphate, gluconate and lactose in Escherichia coli; Hogema BM et al.; While catabolite repression by glucose has been studied extensively and is understood in large detail in Enterobacteriaceae, catabolite repression by carbohydrates that are not transported by the phosphotransferase system (PTS) has always remained an enigma . Examples of non-PTS carbohydrates that cause catabolite repression in Escherichia coli are gluconate, lactose and glucose 6-phosphate . In this article it is shown that enzyme IIA(Glc) of the PTS is not involved in catabolite repression by these carbon sources . Carbon sources that caused strong catabolite repression of beta-galactosidase lowered the concentration of both cAMP and the cAMP receptor protein (CRP) . A strong correlation was found between the amounts of cAMP and CRP and the strength of the repression . The levels of cAMP and CRP were modulated in various ways . Neither overproduction of CRP nor an increased cAMP concentration could completely relieve the repression by glucose 6-phosphate, lactose and gluconate . Simultaneously increasing the cAMP and the CRP levels was lethal for the cells . In a mutant expressing a constant amount of cAMP-independent CRP* protein, catabolite repression was absent . The same was found in a mutant in which lac transcription is independent of cAMP/CRP . These results, combined with the fact that both the cAMP and the CRP levels are lowered by glucose 6-phosphate, lactose and gluconate, lead to the conclusion that the decreased cAMP and CRP levels are the cause of catabolite repression by these non-PTS carbon sources. Mol Microbiol, 1997 May, 24(4), 815 - 23 Characterization of BpH3, an H-NS-like protein in Bordetella pertussis; Goyard S et al.; This study describes the characterization of BpH3, a Bordetella pertussis DNA-binding protein . Sequence analysis reveals significant homology with the H-NS sequence of Escherichia coli and Haemophilus influenzae, particularly in the C-terminal part of the proteins . Our results provide evidence that H-NS and BpH3 display functional homology . First, expression of BpH3 in an hns mutant results in restoration of motility, an H-NS-dependent phenotype . This effect is dependent on the level of BpH3 expression and results from transcriptional activation of the flagellar master operon . Second, the high level of beta-glucosidase associated with hns mutations is reversed to the low wild-type level in the presence of BpH3 . Third, BpH3 is able, like H-NS, to preferentially bind in vitro to curved DNA fragments, such as flhDC and bla promoter regions . Our results are the first demonstration that proteins homologous to H-NS exist in bacteria phylogenetically distant from H . influenzae and enterobacteria. Histopathology, 1997 May, 30(5), 472 - 7 Histopathology and microbiology of isolated rectal bleeding in neonates: the so-called 'ecchymotic colitis'; Canioni D et al.; Rectal bleeding in neonates is an alarming event which suggests a possible necrotizing enterocolitis (NEC) but is usually the only symptom of an unexplained colitis characterized endoscopically by ecchymotic mucosal lesions, the so-called 'ecchymotic colitis' (EC) . We studied histologically and bacteriologically 18 infants (mean age: 18 days) presenting with rectal bleeding by systematic rectosigmoidoscopy and intestinal biopsies . The 18 infants were hospitalized . Prematurity was found in seven cases and an underlying condition in 14 cases (respiratory distress: six cases; infection: six cases; surgery: two cases) . Histology showed a mild to moderate inflammation (10/12) of the mucosa with a prevalence of polymorphonuclear cells (8/10), frequent focal haemorrhages (11/12) and foci of pneumatosis (4/12) . Numerous bacteria were seen in the mucus layer focally forming large clusters . Cultures of intestinal biopsies yielded exclusively Enterobacteriaceae species: Escherichia coli (seven cases), Klebsiella spp . (seven cases), and Enterobacter cloacae (three cases); four cases were sterile . Our study demonstrates that neonatal bleeding is associated with endoscopic and histological 'ecchymotic colitis' lesions and with a peculiar microbial flora of EBC strains . EC and necrotizing enterocolitis share similar features raising the question of the link between the two syndromes. J Appl Microbiol, 1997 May, 82(5), 597 - 609 Isolation and characterization of coliforms from glacial ice and water in Canada's High Arctic; Dancer SJ et al.; Ellesmere Island is the northern most member of the Canadian Arctic Archipelago with over one-third of the land mass covered by ice . A joint services expedition to the island's Blue Mountains offered a unique opportunity for microbiological studies of resident bacteria in an environment uninhabited by man . Over 100 samples of water and ice were collected from stream, lake and glacier and the filtrate cultured under canvas . Bacterial growth was harvested onto swabs for transport back to the UK and 50 coliforms chosen at random for identification and antibiotic susceptibility testing . Most of the glacial strains were capsulated, pigmented and some over 2000 years old . Genera such as Serratia, Enterobacter, Klebsiella and Yersinia were found; speciation was inconclusive and some organisms remain unidentified . Ampicillin resistance was evident in 80% of water isolates as opposed to 30% of the glacial organisms, but the isolates were generally exquisitely susceptible to antibiotics . The facility for ampicillin resistance did not appear to be transferable . Plasmid DNA was found in 33% of the glacial organisms and over 50% of the water isolates . Similar profiles were identified within and apparently between species and required plasmid restriction analysis to help establish identity . Plasmid-free Serratia spp . were subjected to genomic fingerprinting . Indistinguishable patterns were found within sets of isolates both widely spaced by distance and collection date and it was postulated that coliforms able to survive an Arctic environment had spread extensively throughout the expedition area . In conclusion, this study contributes towards knowledge of naturally occurring antibiotic resistance, confirms the presence of plasmids and genotypic data provided evidence that potentially ancient organisms from glaciers can be cultured from water samples significantly distant. Nippon Rinsho, 1997 May, 55(5), 1272 - 80 {Development of beta-lactamase inhibitors}; Hyodo A et al.; The proportion of beta-lactamase producing bacteria in each species of clinical isolates is high (over 90%) in these years . According to the survey of bacterial resistance in 1995, higher proportion of resistant bacterial species against ampicillin, piperacillin (PIPC), cefazolin, cefotiam was observed . To overcome the bacterial resistance against these beta-lactam antibiotics, we have made a development of beta-lactamase inhibitor and its combination antibiotic . New beta-lactamase inhibitor, tazobactam (TAZ) showed strong inhibitory activity against various kinds of beta-lactamases including cephalosporinases . The combination antibiotic, TAZ/PIPC(TAZ combined with PIPC by 1 to 4) showed stronger antibacterial activity than PIPC against beta-lactamase producing stains . And also the activity of TAZ/PIPC was superior to PIPC in the mixed bacterial infection model in mouse . The in vitro and in vivo frequency of emergence of resistant bacteria from Enterobacteriacae treated with TAZ/PIPC was lower than that of PIPC or ceftazidime (CAZ) . By these data, combined antibiotics with beta-lactamase inhibitor was effective to resolve the problems of bacterial resistances caused by beta-lactamases. J Bacteriol, 1997 May, 179(10), 3371 - 3 The Bacillus subtilis ureABC operon; Cruz-Ramos H et al.; The Bacillus subtilis ureABC operon encodes homologs of the three subunits of urease enzymes of the family Enterobacteriaceae . Disruption of ureC prevented utilization of urea as a nitrogen source and resulted in a partial growth defect in minimal medium containing limiting amounts of arginine or allantoin as the sole nitrogen source. Antimicrob Agents Chemother, 1997 May, 41(5), 943 - 9 Survey and molecular genetics of SHV beta-lactamases in Enterobacteriaceae in Switzerland: two novel enzymes, SHV-11 and SHV-12; Nuesch-Inderbinen MT et al.; Sixty isolates of Enterobacteriaceae resistant to beta-lactam antibiotics were collected over a period of 2 years in Switzerland and screened by hybridization for the carriage of SHV genes . Thirty-four positive strains were found, and their SHV genes were amplified and sequenced . SHV extended-spectrum beta-lactamases (ESBLs) were found: 13 strains contained SHV-2a, 12 harbored SHV-2, and SHV-5 was found twice . Four strains were shown to contain SHV-1 . In addition, we report two new SHV variants, termed SHV-11 (non-ESBL) and SHV-12 (ESBL) . In spite of the carriage of SHV ESBLs, many strains showed only low resistance to one or more third-generation cephalosporins . In addition, 26 did not transfer the blaSHV gene in mating experiments. Clin Diagn Lab Immunol, 1997 May, 4(3), 264 - 9 Vibriocidal antibody responses in North American volunteers exposed to wild-type or vaccine Vibrio cholerae O139: specificity and relevance to immunity; Losonsky GA et al.; The emergence of a new agent of cholera, Vibrio cholerae O139, has prompted a reevaluation of the vibriocidal antibody assay . This assay, primarily directed to lipopolysaccharide, is an important correlate of O1 immunity . V . cholerae O139 strains are encapsulated, rendering them relatively resistant to killing by serum . Recent reports suggest that there is strain-to-strain variability in the sensitivity of the vibriocidal assay to fully encapsulated O139 strains . We have assessed a modified vibriocidal assay for fully encapsulated O139 strain AI-1837 and its unencapsulated mutant 2L in sera from 53 volunteers given wild-type AI-1837 or its attenuated derivative CVD 112 and from 48 controls challenged with V . cholerae O1 or strains of the family Enterobacteriaceae . Vibriocidal responses to the AI-1837 and 2L strains were seen in 67 and 89% of volunteers, respectively, following a single exposure to the wild-type strain . However, >50% of all controls had low-level vibriocidal responses to both strains . These nonspecific responses were transient and of the immunoglobulin G isotype . No binding activity against purified O139 lipopolysaccharide (LPS) by immunoblotting was seen in control sera . In contrast, vibriocidal assay and strain 2L LPS responses by immunoblotting were detectable in 91% of tested volunteers following a single exposure to O139 . The presence of vibriocidal antibody to AI-1837 or 2L was not associated with protection in rechallenge studies with O139 strain AI-1837 . The vibriocidal assay with unencapsulated strain 2L may be used to detect exposure to O139 strain AI-1837 in controlled research trials . However, its lack of specificity does not make it useful for determining exposure to V . cholerae O139 in the field. Drugs, 1997 May, 53(5), 817 - 24; discussion 825-7 Grepafloxacin; Wagstaff AJ et al.; Grepafloxacin (OPC-17116) is a new once-daily fluoroquinolone antimicrobial agent which appears to have high tissue penetration and the wide spectrum of antimicrobial activity typical of this class of agents, but with improved activity against Gram-positive organisms, notably Streptococcus pneumoniae . The in vitro activity of grepafloxacin was similar to or slightly lower than that of ciprofloxacin against Enterobacteriaceae but better than that of ciprofloxacin against most Gram-positive organisms . In particular, grepafloxacin showed good activity against pathogens implicated in community-acquired pneumonia, with 4-fold higher potency than ciprofloxacin against S . pneumoniae, including penicillin-resistant strains . In animal studies, grepafloxacin did not induce convulsions when administered at high doses in conjunction with nonsteroidal anti-inflammatory agents . Grepafloxacin has a weak propensity for causing phototoxicity, similar to that of ciprofloxacin . In comparative clinical trials, grepafloxacin demonstrated similar efficacy to amoxicillin in community-acquired pneumonia, ofloxacin in pneumonia and chronic respiratory tract infection, and cefixime in uncomplicated gonococcal urethritis and gonococcal cervicitis . Grepafloxacin has also shown clinical efficacy in preliminary studies in patients with chlamydial endocervical infection or bacillary dysentery. J Infect Dis, 1997 May, 175(5), 1121 - 7 Enterobacteria-infected T cells as antigen-presenting cells for cytotoxic CD8 T cells: a contribution to the self-limitation of cellular immune reactions in reactive arthritis? Ackermann B, Staege MS, Reske-Kunz AB, Dienes HP, Meyer zum Buschenfelde KH, Marker-Hermann E. In enterobacteria-induced reactive arthritis (ReA), different T cell subsets play a role in the induction and maintenance of the synovitic process . Synovial fluid-derived alphabeta CD4, alphabeta CD8, and gammadelta T lymphocyte clones (TLC) that recognize Yersinia or Salmonella antigens on professional antigen-presenting cells (APC) have been characterized, and T cells themselves can function as nonprofessional APC . T cells were infected with the facultatively intracellular, arthritogenic enterobacterium Yersinia enterocolitica O:3 . A CD8 TLC isolated from a patient with Yersinia-induced ReA recognized and efficiently lysed autologous and allogeneic Yersinia-infected T cells . Infected cytotoxic T lymphocytes (CTL) had a reduced lytic capacity against syngeneic and allogeneic infected target cells, suggesting that the infection of CTL by bacteria may represent a mechanism of immune escape . In ReA, antigen presentation by T cells may modify the antibacterial immune response and may also contribute to network control mechanisms of T cell-mediated cytotoxicity. Nucleic Acids Res, 1997 May 1, 25(9), 1830 - 5 Primer design for a prokaryotic differential display RT-PCR; Fislage R et al.; We have developed a primer set for a prokaryotic differential display of mRNA in the Enterobacteriaceae group . Each combination of ten 10mer and ten 11mer primers generates up to 85 bands from total Escherichia coli RNA, thus covering expressed sequences of a complete bacterial genome . Due to the lack of polyadenylation in prokaryotic RNA the type T11VN anchored oligonucleotides for the reverse transcriptase reaction had to be replaced with respect to the original method described by Liang and Pardee { Science , 257, 967-971 (1992)} . Therefore, the sequences of both the 10mer and the new 11mer oligonucleotides were determined by a statistical evaluation of species-specific coding regions extracted from the EMBL database . The 11mer primers used for reverse transcription were selected for localization in the 3'-region of the bacterial RNA . The 10mer primers preferentially bind to the 5'-end of the RNA . None of the primers show homology to rRNA or other abundant small RNA species . Randomly sampled cDNA bands were checked for their bacterial origin either by re-amplification, cloning and sequencing or by re-amplification and direct sequencing with 10mer and 11mer primers after asymmetric PCR. Insect Mol Biol, 1997 May, 6(2), 183 - 90 Phylogeny and potential transmission routes of midgut-associated endosymbionts of tsetse (Diptera:Glossinidae); Aksoy S et al.; Many tsetse species (Diptera: Glossinidae) harbour two morphologically different intracellular endosymbiotic microorganisms associated with gut tissue: primary (P) and secondary (S) endosymbionts . The P-endosymbionts of tsetse (Wigglesworthia glossinidia) are sequestered in specialized epithelial cells, bacteriocytes, which form a structure (bacteriome) in the anterior portion of the gut . Phylogenetic characterization of P-endsymbionts from the three subgenera of genus Glossina has shown that these organisms constitute a distinct lineage within the gamma-subdivision of Proteobacteria and have evolved concordantly with their insect host species, suggesting an evolutionarily ancient association for this symbiosis . The S-endosymbiont is a smaller (1-2 micron) gram-negative rod and is harboured in midgut epithelial cells . Its phylogenetic characterization from Glossina morsitans morsitans had shown that it is a member of the family Enterobacteriaceae within the gamma-3 subdivision of the Proteobacteria, closely related to enteric bacteria . Some tsetse species harbour a third bacterium in their reproductive tissue, which was shown phylogenetically to belong to to the Wolbachia pipientis assemblage of microorganisms . Here, we show that S-endosymbionts from five tsetse species, representing all three subgenera, form a cluster of closely related microorganisms, based on their almost identical 16S rRNA gene sequences . The high similarity provides strong evidence of recent independent acquisition of S-endosymbionts by individual tsetse species, unlike Wigglesworthia which displays concordant evolution with host insect species . A PCR-based assay and restriction fragment length polymorphism (RFLP) analysis was developed to localize the S-endosymbionts and Wigglesworthia in ovary, egg, milk-gland and spermatheca tissues in order to investigate the potential routes for the vertical transmission of these symbionts to the intrauterine larvae . Only S-endosymbionts were found to infect milk gland tissue, suggesting that milk gland secretions represent a route of transmission for these symbionts into the developing larva . The ovary tissue was found to harbour only Wolbachia, confirming its transovarial transmission, whereas the mode of transmission of Wigglesworthia remains unknown. Int J Food Microbiol, 1997 Apr 29, 36(1), 61 - 7 Microbial quality of lamb carcasses during processing and the acridine orange direct count technique (a modified DEFT) for rapid enumeration of total viable counts; Sierra ML et al.; This study was designed to set up a hazard analysis and critical control points (HACCP) system for sheep slaughtering operations at four different plants in Ireland and to determine the differences between plants in terms of microbial contamination . A single carcass area, the abdomen, was examined by swabbing and a microbiological profile was determined at different stages along the slaughter line . The level of contamination was assessed from the total bacteria counts, Enterobacteriaceae and Listeria spp . For the total counts, a modified direct epifluorescent filter technique (acridine orange direct count technique (AODC)) was developed and tested . No significant differences were found among plants in the levels of bacterial contamination . This was observed for all groups of organisms . The rapid direct technique (AODC) was found to be very successful . A correlation coefficient of 0.87 was obtained for this method and the standard plate count . Each test could be carried out in about 10-15 min and could be used to predict the standard plate count. Int J Food Microbiol, 1997 Apr 15, 35(3), 287 - 92 Minimum growth temperatures of Hafnia alvei and other Enterobacteriaceae isolated from refrigerated meat determined with a temperature gradient incubator; Ridell J et al.; Minimum growth temperatures of Hafnia alvei (n = 156) and other Enterobacteriaceae isolates (n = 162) from refrigerated meat samples (n = 88) and control strains of H . alvei (n = 81) from clinical and environmental samples were determined with a plate-type continuous temperature gradient incubator on nutrient agar . The dominant species, Hafnia alvei and Serratia liquefaciens had mean minimum growth temperatures of 2.6 (range, 0.2-3.7 degrees C) and 1.7 (range, 0.2-2.6 degrees C), respectively . Values for other species included: Enterobacter agglomerans, 1.3 (0.7-1.7 degrees C); Escherichia coli, 8.7 (8.4-8.9); Escherichia vulneris, 1.6 (0.8-2.6 degrees C); and Serratia fonticola, 2.0 (1.1-3.0 degrees C) . The H . alvei reference strains did not differ markedly from the meat isolates, with the exception of the diarrhoeagenic eae A positive strains (10.6, 10.2-11.5 degrees C) . The representatives of H . alvei hybridization groups (HG) 1 and 2 did not differ in their minimum growth temperatures . The observed heterogeneity of the minimum growth temperatures of many Enterobacteriaceae species may be explained by limitations of the systems used for identification of enterobacteria, inadequacy of the Enterobacteriaceae taxonomy or true growth temperature heterogeneity within the various species. Tierarztl Prax, 1997 Apr, 25(2), 108 - 15 {Federal investigations on the distribution and in vitro resistance of udder pathogenic bacteria in the milk of cows with subclinical mastitis}; Sobiraj A et al.; 1644 quarter milk samples of 948 dairy cows with subclinical mastitis, collected from 63 veterinary practices all over Germany origined by 262 livestocks with problems in udder health were examined semiquantitatively by "Aulendorfer Mastitistest" for cell count and additionally bacteriologically . Potentially udder pathogenic bacteria were tested for in vitro-sensitivity to penicillin G, ampicillin, oxacillin, cefacetril, tylosin, neomycin, gentamicin, polymyxin B and enrofloxacin . 24.5% of all tested milk samples were bacteriologically negative . In 35.3% of the bacteriological positive milk samples Staphylococcus (S) aureus was detected . Enterococci, Streptococcus (Sc.) uberis, Sc . dysgalactiae and Sc . agalactiae were found in 8.9%, 8.2%, 8.1% and 4.9% of all positive milk samples, respectively . G-streptococci were found only occasionally . Apathogenic bacteria like coagulase-negative staphylococci, micrococci, aerobic bacilli and coryneforms were detected in 45.0% of all positive milk samples . Enterobacteriaceae (E . coli, klebsiella spp., proteus spp . and other coliforms) were isolated in 3.3% of all cases and should be considered as insignificant for the subclinical mastitis of dairy cows in Germany . Against S . aureus cefacetril and oxacillin were mostly effective in vitro, whereas penicillin G was ineffective because 40% of these bacteria are penicillinase-positive . Streptococci and enterococci were mostly sensitive to cefacetril, oxacillin, penicillin G and ampicillin . Concerning the distribution of bacteria regional differences were recognized . Regional differences concerning in vitro-sensitivity were negligible . The results are discussed. Kansenshogaku Zasshi, 1997 Apr, 71(4), 318 - 22 {Study of septicemia due to Enterobacter cloacae in a neonatal intensive care unit}; Sakata H et al.; A study was made of Enterobacter cloacae septicemia in 15 newborns in the neonatal intensive care unit (NICU) of the Asahikawa Kosei Hospital from April, 1979 to March, 1996 . Their gestational age was 29.7 +/- 4.5 (mean +/- SD) weeks and their birth weight was 1,270 +/- 562 g . The age at the onset of septicemia was 10.3 +/- 7.2 days . Four infants died and the mortality was 26.7% . These infants died within 72 hours after onset of septicemia . Thrombocytopenia (< 50,000/microliter) in the patients who died was significantly more than in the patients who improved (p < 0.05) . Antibiotic susceptibilities were determined by the Kirby-Bauer method . Three E . cloacae strains isolated in 1982 were sensitive to ampicillin (ABPC) and cefotaxime (CTX), 4 strains between 1983 and 1984 were resistant to ABPC and were sensitive to CTX, 5 strains between 1985 and 1992 were resistant to ABPC and CTX, and 3 strains between 1993 and 1995 were resistant to ABPC and were sensitive to CTX . These results suggested that the emergence of resistant E . cloacae was related to the use of corresponding antibiotics . Our observations showed that E . cloacae was one of the potential pathogens seen in nosocomial infections which is becoming progressively common in newborns and routine bacteriological surveillance is very important in the NICU. J Clin Microbiol, 1997 Apr, 35(4), 915 - 22 Comparison of axenic and monoxenic media for isolation of Acanthamoeba; Penland RL et al.; Acanthamoeba is a genus of ubiquitous, free-living amebae that can be difficult to isolate by standard microbiologic techniques . We retrospectively reviewed the laboratory records of patients with ocular acanthamoebic infection for the period from January 1973 to June 1996 and found that Acanthamoeba isolates were recovered from 73, 71, and 70% of clinical specimens inoculated onto buffered charcoal-yeast extract agar (BCYE), nonnutrient agar with live or dead Escherichia coli, and tryptic soy agar (TSA) with horse or sheep blood, respectively . We then prospectively compared the recovery of a corneal isolate of Acanthamoeba on commercial media from Remel and BBL (TSA with 5% sheep blood, TSA with 5% horse blood, TSA with 5% rabbit blood, V agar, chocolate agar, BCYE, and selective BCYE with polymyxin B, anisomycin, and vancomycin) and on axenic and monoxenic media prepared with live or dead bacteria (Enterobacter aerogenes, E . coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, and Stenotrophomonas maltophilia) . Good recovery of trophozoites was obtained on BCYE, TSA with rabbit blood, TSA with horse blood, and Remel TSA with sheep blood . BBL TSA with horse blood or rabbit blood provided good recovery of cysts . All species of live or dead bacteria yielded good recovery of trophozoites; however, only nonnutrient agar with live P . aeruginosa, live E . aerogenes, or live S . maltophilia gave good recovery of cysts . TSA with either rabbit blood or horse blood, BCYE, and nonnutrient agar prepared with live P . aeruginosa, E . aerogenes, or S . maltophilia offer optimal recovery of Acanthamoeba. J Clin Microbiol, 1997 Apr, 35(4), 1008 - 10 A nosocomial outbreak due to Enterobacter cloacae strains with the E . hormaechei genotype in patients treated with fluoroquinolones; Davin-Regli A et al.; During a 7-month period, we isolated 21 highly fluoroquinolone-resistant Enterobacter cloaecae strains in units from two hospitals in Marseille, France . Random amplification of polymorphic DNA showed clonal identity between isolates which, furthermore, presented the Enterobacter hormaechei genotype on DNA-DNA hybridization . The emergence of this clone was observed only in patients treated with fluoroquinolones. Mol Microbiol, 1997 Apr, 24(1), 7 - 17 H-NS: a modulator of environmentally regulated gene expression; Atlung T et al.; H-NS is a small chromatin-associated protein found in enterobacteria . H-NS has affinity for all types of nucleic acids but binds preferentially to intrinsically curved DNA . The major role of H-NS is to modulate the expression of a large number of genes, mostly by negatively affecting transcription . Many of the H-NS-modulated genes are regulated by environmental signals, and expression of most of these genes is positively regulated by specific transcription factors . Therefore one of the purposes of H-NS could be to repress expression of some genes under conditions characteristic of a non-intestinal environment, but allow expression of specific genes in response to certain stimuli in the intestinal environment . The hns gene is autoregulated . In vivo the H-NS to DNA ratio is fairly constant except during cold shock, when it increases three- to fourfold . In this review we propose that only the preferential binding to intrinsically curved DNA plays a role under normal growth conditions, and we discuss the different mechanisms by which H-NS might affect gene expression and how H-NS could be involved in the response to different stress situations . Finally, we summarize the evolutionary and functional relationship between H-NS and the homologous StpA. J Appl Microbiol, 1997 Apr, 82(4), 532 - 6 Note: cyclohexenoesculetin-beta-D-glucoside: a new substrate for the detection of bacterial beta-D-glucosidase; James AL et al.; A new substrate for the detection of bacterial beta-D-glucosidase was evaluated as an alternative to aesculin . This substrate, 3,4-cyclohexenoesculetin-7-beta-D-glucoside, was compared with aesculin for the detection of beta-D-glucosidase in 150 enterococci, 40 streptococci, 12 Listeria sp . and 250 strains of Enterobacteriaceae . In the Gram-positive strains tested, aesculin hydrolysis correlated with hydrolysis of 3,4-cyclohexenoesculetin-7-beta-D-glucoside . In the Gram-negative strains the new substrate was hydrolysed by all aesculin-positive strains and also by four strains (10%) of Escherichia coli which gave a negative aesculin reaction . 3,4-Cyclohexenoesculetin-7-beta-D-glucoside was shown to be a reliable alternative to aesculin and was shown to have significant advantages over aesculin when incorporated into solid media . This was due to the non-diffusible end product produced by hydrolysis of 3,4-cyclohexenoesculetin-7-beta-D-glucoside in the presence of iron. J Wildl Dis, 1997 Apr, 33(2), 328 - 31 Aerobic bacterial flora of addled raptor eggs in Saskatchewan; Houston CS et al.; In south-central Saskatchewan, Canada, in 1986, 1987 and 1989, the aerobic bacterial flora was evaluated from 75 unhatched raptor eggs of three species: 42 of the Swainson's hawk (Buteo Swainsoni), 21 of the ferruginous hawk (Buteo regalis), and 12 of the great horned owl (Bubo virginianus) . In addled Swainson's hawk eggs, the most common bacterial genera were Enterobacter (18 eggs), Escherichia (12), and Streptococcus (10) . Seven great horned owl eggs and six ferruginous hawk eggs also contained Escherichia coli . Salmonella spp . were not isolated . These bacteria were interpreted as secondary contaminants and not the primary cause of reproductive failure. Clin Microbiol Rev, 1997 Apr, 10(2), 220 - 41 Enterobacter spp.: pathogens poised to flourish at the turn of the century; Sanders WE Jr et al.; Knowledge of the genus Enterobacter and its role in human disease has expanded exponentially in recent years . The incidence of infection in the hospital and the community has increased . New clinical syndromes have been recognized . Enterobacter spp . have also been implicated as causes of other syndromes that traditionally have been associated almost exclusively with more easily treatable pathogens, such as group A streptococci and staphylococci . Rapid emergence of multiple-drug resistance has been documented in individual patients during therapy and in populations and environments with strong selective pressure from antimicrobial agents, especially the cephalosporins . Therapeutic options for patients infected with multiply resistant strains have become severely limited . Carbapenems or, alternatively, fluoroquinolones are the most predictively active options, although resistance to both classes has been observed on rare occasions . Enterobacter spp . appear well adapted for survival and even proliferation as the turn of the century approaches. Int J Syst Bacteriol, 1997 Apr, 47(2), 402 - 7 Phylogenetic evidence for the taxonomic heterogeneity of Photorhabdus luminescens; Szallas E et al.; The sequences of the 16S rRNA gene of 40 strains of bacterial symbionts isolated from the nematodes Heterorhabditis spp . and seven bacterial symbionts of the nematodes Steinernema spp . which were isolated from different geographical areas, as well as the type strain of Xenorhabdus japonicus, were determined and compared to each other and to the sequences of several reference strains of members of the Enterobacteriaceae . The data confirmed the separate status of the two genera of symbionts of entomopathogenic rhabditid nematodes . The symbionts of Heterorhabditis spp . clustered with the type strain of Photorhabdus luminescens, while the symbionts of Steinernema spp . grouped with Xenorhabdus species . X . japonicus clustered with the other Xenorhabdus species . Phylogenetic analysis of 15 almost complete 16S ribosomal DNA (rDNA) sequences of the Heterorhabditis symbionts indicated that there were several subclusters . The properties correlated with these subclusters are not yet apparent, although there may be some geographical and ecological correlations . For example, among the nematode-symbiotic bacteria, the members of subclusters I and III are from southeastern and midwestern North America, respectively, while the members of subclusters II and IV are primarily from Europe and Australia, respectively . The nonsymbiotic strains of P . luminescens form a highly homologous subcluster by themselves . The results of DNA-DNA hybridization studies performed with a few selected strains of five of the 16S rDNA subclusters support the existence of several genospecies within P . luminescens. J Bacteriol, 1997 Apr, 179(8), 2740 - 7 Novel Vibrio cholerae O139 genes involved in lipopolysaccharide biosynthesis; Stroeher UH et al.; The sequence of part of the rfb region of Vibrio cholerae serogroup O139 and the physical map of a 35-kb region of the O139 chromosome have been determined . The O139 rfb region presented contains a number of open reading frames which show similarities to other rfb and capsular biosynthesis genes found in members of the Enterobacteriaceae family and in V . cholerae O1 . The cloned and sequenced region can complement the defects in O139 antigen biosynthesis in transposon insertions within the O139 rfb cluster . Linkage is demonstrated among IS1358 of V . cholerae O139, the rfb region, and the recently reported otnA and otnB genes (E . M . Bik, A . E . Bunschoten, R . D . Gouw, and F . R . Mooi, EMBO J . 14:209-216, 1995) . In addition, the whole of this region has been linked to the rfaD gene . Furthermore, determination of the sequence flanking IS1358 has revealed homology to other rfb-like genes . The exact site of insertion with respect to rfaD is defined for the novel DNAs of both the Bengal and the Argentinian O139 isolates. J Bacteriol, 1997 Apr, 179(7), 2097 - 102 CTnscr94, a conjugative transposon found in enterobacteria; Hochhut B et al.; Conjugational transposons are important for horizontal gene transfer in gram-positive and gram-negative bacteria, but have not been reported yet for enteric bacteria . Salmonella senftenberg 5494-57 has previously been shown to transfer by conjugation genes for a sucrose fermentation pathway which were located on a DNA element called scr-94 . We report here that the corresponding scr genes for a phosphoenolpyruvate-dependent sucrose:phosphotransferase system and a sucrose metabolic pathway are located on a large (ca . 100 kb) conjugative transposon renamed CTnscr94 . The self-transmissible element integrates at two specific attachment sites in a RecA-independent way into the chromosome of Escherichia coli K-12 strains . One site was identified within pheV, the structural gene for a tRNA(Phe) . Sequencing of both ends of CTnscr94 revealed the presence of the 3' part of pheV on one end such that after integration of the element, a complete pheV gene is retained . CTnscr94 represents, to our knowledge, the first conjugational transposon found in enteric bacteria. Arch Microbiol, 1997 Mar 7, 167(2/3), 78 - 88 Anaerobic citrate metabolism and its regulation in enterobacteria Bott M. Several species of enterobacteria are able to utilize citrate as carbon and energy source . Under oxic conditions in the presence of a functional tricarboxylic acid cycle, growth on this compound solely depends on an appropriate transport system . During anaerobiosis, when 2-oxoglutarate dehydrogenase is repressed, some species such as Klebsiella pneumoniae and Salmonella typhimurium, but not Escherichia coli, are capable of growth on citrate by a Na+-dependent pathway forming acetate, formate, and CO2 as products . During the last decade, several novel features associated with this type of fermentation have been discovered in K . pneumoniae . The biotin protein oxaloacetate decarboxylase, one of the key enzymes of the pathway besides citrate lyase, is a Na+ pump . Recently it has been shown that the proton required for the decarboxylation of carboxybiotin is taken up from the side to which Na+ ions are pumped, and a membrane-embedded aspartate residue that is probably involved both in Na+ and in H+ transport was identified . The Na+ gradient established by oxaloacetate decarboxylase drives citrate uptake via CitS, a homodimeric carrier protein with a simultaneous-type reaction mechanism, and NADH formation by reversed electron transfer involving formate dehydrogenase, quinone, and a Na+-dependent NADH:quinone oxidoreductase . All enzymes specifically required for citrate fermentation are induced under anoxic conditions in the presence of citrate and Na+ ions . The corresponding genes form a cluster on the chromosome and are organized as two divergently transcribed operons . Their co-ordinate expression is dependent on a two-component system consisting of the sensor kinase CitA and the response regulator CitB . The citAB genes are part of the cluster and are positively autoregulated . In addition to CitA/CitB, the cAMP receptor protein (Crp) is involved in the regulation of the citrate fermentation enzymes, subjecting them to catabolite repression. Curr Opin Pulm Med, 1997 Mar, 3(2), 159 - 69 Antimicrobial resistance: implications for managing respiratory failure; Chenoweth C et al.; The prevalence of antibiotic resistance in respiratory pathogens is increasing rapidly . In the community, resistance to beta-lactam antibiotics has escalated dramatically among Moraxella catarrhalis, Haemophilus influenzae, and Streptococcus pneumoniae . Resistance to penicillin among S . pneumoniae has developed at an alarming rate over the past two decades . Recent studies in the United States have cited rates of penicillin resistance as high as 23.6%, with 9.5% exhibiting high-level resistance . Many of these strains are resistant to multiple antibiotics . Antimicrobial resistance in hospital-acquired pathogens is a problem, which in large part reflects patterns of antibiotic use . Antimicrobial resistance may arise via multiple mechanisms . Pseudomonas aeruginosa and other gram-negative bacilli have become increasingly resistant to beta-lactam antibiotics, including imipenem . Extended-spectrum beta-lactamases are seen with increasing frequency in Enterobacteriaceae, primarily Klebsiella spp . Fluoroquinolone resistance has increased in P . aeruginosa and Staphylococcus aureus and has now been identified in Escherichia coli isolated from hematology wards . Excessive use of antibiotics may promote the emergence and spread of resistant microorganisms . Rigorous infection control measures and modification of antibiotic use patterns may limit or reduce the prevalence of resistant organisms. East Afr Med J, 1997 Mar, 74(3), 162 - 5 Susceptibility pattern of uropathogenic gram negative bacilli to antimicrobial chemotherapeutic agents in a National Hospital in Dar es Salaam; Urassa WK et al.; In a period of two months, 232 consecutive urinary tract pathogens were isolated from hospitalised and non-hospitalised patients . Among the isolates, 200 (86.2%) were gram negative bacilli, including E . coli 109 (54.5%), Klebsiella species, 44 (22.5%), Enterobacter species 19 (9.5%), Proteus species 18 (9%), Morganella morganii 9 (4.5%) and Salmonella typhimurium, one (0.5%) . Antimicrobial susceptibility testing to amoxycillin/clavulanic acid, nitrofurantoin, gentamicin and cefuroxime was performed using Stoke's method . Among the 109 E . coli isolates, 107 (98.2%), 104 (94.5%), 105(95.5% and 107 (98.2%) were sensitive to amoxycillin/clavulanic acid, cefuroxime, nitrofurantoin and gentamicin, respectively . Of the 44 Klebsiella isolates, 42 (95.5%), 41 (95.5%), 40 (90.9%) and 34 (77.3%) were sensitive to amoxycillin/clavulanic acid, cefuroxime, nitrofurantoin and gentamicin, respectively . There was no significant difference when the suceptibility patterns of isolates from hospitalised patients were compared to those from outpatients . Although the susceptibility pattern of urinary tract pathogens to the commonly used antimicrobial agents in the hospital is still favourable, there is a need to establish strategies to prevent emergence of resistant bacterial strains. Ann Biol Clin (Paris), 1997 Mar-Apr, 55(2), 129 - 37 {Role of hygiene and bacteriological laboratories in the management of an epidemic of Enterobacter aerogenes multiresistant to antibiotics}; Meunier O et al.; We describe a multiresistant Enterobacter aerogenes outbreak in an intensive care-unit . An epidemiology study based on phenotypic characters (species diagnosis and antibiotype) was completed by a genotypic study (pulsed field electrophoresis) to confirm bacterial clonality . The hygiene laboratory proposed numerous preventive measures to limit bacterial dispersion . We describe the role of bacteriologists, hygienists and medical staff to stop the bacterial dispersion. Glycobiology, 1997 Mar, 7(2), 315 - 22 Polyisoprenyl phosphate specificity of UDP-GlcNAc:undecaprenyl phosphate N-acetylglucosaminyl 1-P transferase from E.coli; Rush JS et al.; N-Acetyl-D-glucosaminylpyrophosphorylundecaprenol (GlcNAc-P-P-Und), an intermediate in the biosynthesis of the enterobacterial common antigen in E.coli and some O-antigen chains in gram-negative bacteria, is formed by the transfer of GlcNAc 1-P from UDP-GlcNAc to Und-P, analogous to the reaction forming GlcNAc-P-P-dolichol (GlcNAc-P-P-Dol) in mammalian cells . Since the microsomal enzyme from animal cells exhibits a strong preference for Dol-P, which contains a saturated alpha-isoprene unit, the polyisoprenyl phosphate specificity of the homologous bacterial enzyme was characterized . The enzyme remained bound to the membrane fraction when spheroplasts, formed by lysozyme-EDTA treatment, were lysed in hypotonic buffer . GlcNAc-P-P-Und synthase (GPT) activity was elevated in a strain of E.coli bearing the rfe gene, which encodes GPT on a multicopy plasmid, and virtually absent from rfe null mutants . GPT actively utilized fully unsaturated polyprenyl phosphate (Poly-P) substrates with maximal activity seen with (C55) Und-P, but was unable to utilize (C55)Dol-P . This substrate specificity contrasts with the microsomal GPT from pig brain, which actively utilized (C55)Dol-P, but not Und-P, as substrate . GPT activity bound to particulate fractions from three strains of bacilli also exhibited a strict preference for fully unsaturated Poly-P substrates . Unexpectedly, E.coli GPT activity cofractionated with the cytosolic marker enzyme, beta-galactosidase, and not the membrane-bound enzyme, D-lactate dehydrogenase, in cells disrupted in a French pressure cell . The properties and polyisoprenyl phosphate specificity of the soluble form of GPT were identical to the activity associated with the membrane preparations obtained from spheroplasts . The evolutionary and functional significance of the use of polyisoprenyl glycosyl carrier lipids with saturated alpha-isoprene units in eukaryotes remains uncertain. Kaohsiung J Med Sci, 1997 Mar, 13(3), 155 - 61 Treatment of PermCath-related sepsis in uremic patients; Chang JM et al.; Patients who use PermCath as the vascular access for long-term hemodialysis are occasionally confronted with catheter-related infections . Recently, we have treated 17 patients suffering from PermCath-related sepsis . The clinical presenting features were leukocytosis in 14/17, high fever and shaking chill during dialysis in 12/17, and signs of exit site infection in 3/17 . No shock was found . All patients received clinical evaluation to exclude infection sources other than from blood and inside the catheter, such as pulmonary, genitourinary, hepatobiliary and cutaneous systems . Blood drawn from both PermCath and peripheral vein was sent for bacterial culture . Bacterial culture of the blood samples from PermCath revealed Staphylococcus sp . in 7/17, Pseudomonas sp . in 5/17, Enterobacter sp . in 4/17, Streptococcus sp . in 1/17 . Fourteen blood samples from peripheral vein showed positive culture results identical to those from PermCath, but negative study were noted in three other patients . The patients were divided into two treatment groups: Group I: systemic antibiotics without PermCath removal in 7, Group II: "locked-in" retention in addition to systemic anti-biotics in 10 . Antibiotics were empirically chosen according to bacteriological studies . In the "locked-in" retention treatment, antibiotics were retained into both the inflow and outflow PermCath lumens in the exact volume of each lumen for 24 hours . The antibiotics solutions were replaced on a daily basis . The same antibiotics were also given intravenously . Duration of treatment depended on clinical progression and follow-up blood culture results and ranged between 13 and 24 days . The schedule of dialysis was not changed through the period of PermCath-related sepsis . The sepsis was cured in all group II cases but not in 2 of group I and resulted in mortality in these 2 patients . The PermCaths were preserved in 5/7 in group I with two mortality cases and all except one preserved in group II patients without mortality . We suggested that "locked-in" retention in addition to systemic antibiotics is the treatment of choice for the patients with PermCath-related sepsis . This method also preserves the functional integrity of PermCath, which is the lifeline vascular access of the patients with exhausted native vessels. J Antimicrob Chemother, 1997 Mar, 39(3), 363 - 9 Cefepime and amikacin synergy against a cefotaxime-susceptible strain of Enterobacter cloacae in vitro and in vivo; Mimoz O et al.; We developed an experimental model of pneumonia to evaluate the efficacy of new antibiotic regimens against Enterobacter cloacae . Rats were infected by administering 8.5 log10 cfu E . cloacae intratracheally, and therapy was initiated 24 h later . At that time, animals' lungs showed bilateral pneumonia containing more than 7 log10 cfu/g of tissue . Because rats eliminate amikacin and cefepime much more rapidly than humans, renal impairment was induced in all animals to simulate the pharmacokinetic parameters in humans . Using this model, we compared the bactericidal activities of cefepime and amikacin alone or in combination against the same cefotaxime-susceptible E . cloacae strain . The MICs of cefepime and amikacin for this strain were 0.5 and 2 mg/L, respectively . In-vitro killing studies showed that antibiotic combinations were synergic only at intermediate concentrations . At peak concentrations, the combination was only as effective as amikacin alone . At trough concentrations, a non-significant trend towards the superiority of the combination over cefepime alone was found . In-vivo studies showed that each antibiotic alone failed to decrease bacterial counts in the lungs except at 6 h, whereas the combination of both antibiotics induced a significant decrease in the lung bacterial count 6, 12 and 24 h after the onset of therapy when compared with tissue bacterial numbers in untreated animals or animals treated with either antibiotic alone . In-vivo synergy between cefepime and amikacin was observed at the three time points studied . No resistant clones emerged during treatment with any of the antibiotic regimens studied. Pediatr Infect Dis J, 1997 Mar, 16(3 Suppl), S49 - 55 Comparative susceptibility of clinical isolates producing extended spectrum beta-lactamases to ceftibuten: effect of large inocula; Medeiros AA et al.; BACKGROUND: Infections caused by Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs) are a growing clinical problem . However, there is wide variation in the level of resistance to third generation beta-lactams conferred by these enzymes . METHODS: We studied 33 Klebsiella pneumoniae and 4 Escherichia coli isolates producing ESBLs obtained from outbreaks in 14 different hospitals and a nursing home in the United States . Microdilution testing with standard (10(4-5) colony-forming units/ml) and large (10(6-7) colony-forming units/ml) inocula, was used to compare the minimum inhibitory concentrations (MICs) of ceftibuten, a novel oral oxyimino beta-lactam, with those of other third generation beta-lactams (cefotaxime, ceftazidime, aztreonam, cefixime, cefpodoxime and cefoxitin) . RESULTS: Twenty-seven of the clinical isolates had well-characterized ESBLs of 10 different types, 7 of which produced TEM-1; 1 isolate also produced LXA-1 . Two strains produced more than 1 ESBL . The remaining 10 strains produced 8 as yet uncharacterized types of ESBL . With large inocula 73% tested susceptible to ceftibuten, whereas 8 to 22% tested susceptible to the other third generation beta-lactam antibiotics . Ceftibuten MICs increased with higher inocula when tested against strains producing SHV-4 or SHV-5 and, to a lesser extent, strains producing multiple beta-lactamases . Only cefoxitin showed a smaller inoculum effect . CONCLUSION: Ceftibuten merits clinical evaluation in infections caused by bacteria that produce ESBLs. J Urol, 1997 Mar, 157(3), 935 - 9 Post-intercourse versus daily ciprofloxacin prophylaxis for recurrent urinary tract infections in premenopausal women; Melekos MD et al.; PURPOSE: We evaluated and compared the efficacy of post-intercourse and daily oral ciprofloxacin prophylaxis against recurrent lower urinary tract infections in 135 sexually active premenopausal women . MATERIALS AND METHODS: Post-intercourse (group 1, 70 patients) and daily (group 2, 65 patients) prophylactic regimens of 125 mg . ciprofloxacin were started following a curative, conventional treatment of the initial acute urinary tract infection . Prophylaxis was maintained for 12 months and during this period patients were followed clinically and bacteriologically with urine and introital samples . Patients were subsequently followed for an additional year after the end of preventive treatment . RESULTS: While 3.67 urinary tract infections per patient in group 1 and 3.74 in group 2 occurred during an identical mean time of 12.2 months before start of the corresponding prophylactic regimen, only 0.043 infection per patient in group 1 and 0.031 in group 2 developed during prophylaxis (p < 0.0001) . Before prophylaxis 86% of the vaginal vestibule cultures yielded gram-negative Enterobacteriaceae, equally distributed between both treatment arms, compared to 5.6% and 2.5% during postcoital and daily prophylaxis, respectively . The overall improvement in the incidence of the urinary infections per patient and the rate of introital colonization with enteric gram-negative bacteria was maintained after the end of prophylaxis, with a mean incidence of infections of 0.44 per patient (occurring in 34% of the total patient population), while 36% of all women had abnormal introital colonization . CONCLUSIONS: Long-term post-intercourse prophylaxis with ciprofloxacin proved to be equally effective as daily prophylaxis, and the major advantage of the former therapy was use of only a third of the amount of drug consumed in daily prophylaxis. Antimicrob Agents Chemother, 1997 Mar, 41(3), 563 - 9 Imipenem resistance in Klebsiella pneumoniae is associated with the combination of ACT-1, a plasmid-mediated AmpC beta-lactamase, and the foss of an outer membrane protein; Bradford PA et al.; Six Escherichia coli and 12 Klebsiella pneumoniae isolates from a single hospital expressed a common beta-lactamase with a pI of approximately 9.0 and were resistant to cefoxitin and cefotetan (MIC ranges, 64 to > 128 and 16 to > 128 micrograms/ml, respectively) . Seventeen of the 18 strains produced multiple beta-lactamases . Most significantly, three K . pneumoniae strains were also resistant to imipenem (MICs, 8 to 32 micrograms/ml) . Spectrophotometric beta-lactamase assays with purified enzyme indicated hydrolysis of cephamycins, in addition to cephaloridine and benzylpenicillin . The 4ene encoding the pI 9.0 beta-lactamase (designated ACT-1 for AmpC type) was cloned and sequenced, which revealed an ampC-type beta-lactamase gene that originated from Enterobacter cloacae and that had 86% sequence homology to the P99 beta-lactamase and 94% homology to the partial sequence of MIR-1 . Southern blotting revealed that the gene encoding ACT-1 was on a large plasmid in some of the K . pneumoniae strains as well as on the chromosomes of all of the strains, suggesting that the gene is located on an easily mobilized element . Outer membrane protein profiles of the K . pneumoniae strains revealed that the three imipenem-resistant strains were lacking a major outer membrane protein of approximately 42 kDa which was present in the imipenem-susceptible strains . ACT-1 is the first plasmid-mediated AmpC-type beta-lactamase derived from Enterobacter which has been completely sequenced . This work demonstrates that in addition to resistance to cephamycins, imipenem resistance can occur in K . pneumoniae when a high level of the ACT-1 beta-lactamase is produced in combination with the loss of a major outer membrane protein. Appl Environ Microbiol, 1997 Mar, 63(3), 834 - 9 Molecular cloning, structural analysis, and expression in Escherichia coli of a chitinase gene from Enterobacter agglomerans; Chernin LS et al.; The gene chiA, which codes for endochitinase, was cloned from a soilborne Enterobacter agglomerans . Its complete sequence was determined, and the deduced amino acid sequence of the enzyme designated Chia_Entag yielded an open reading frame coding for 562 amino acids of a 61-kDa precursor protein with a putative leader peptide at its N terminus . The nucleotide and polypeptide sequences of Chia_Entag showed 86.8 and 87.7% identity with the corresponding gene and enzyme, Chia_Serma, of Serratia marcescens, respectively . Homology modeling of Chia_Entag's three-dimensional structure demonstrated that most amino acid substitutions are at solvent-accessible sites . Escherichia coli JM109 carrying the E . agglomerans chiA gene produced and secreted Chia_Entag . The antifungal activity of the secreted endochitinase was demonstrated in vitro by inhibition of Fusarium oxysporum spore germination . The transformed strain inhibited Rhizoctonia solani growth on plates and the root rot disease caused by this fungus in cotton seedlings under greenhouse conditions. Am J Clin Pathol, 1997 Mar, 107(3), 359 - 61 Enterobacter cancerogenus ("Enterobacter taylorae") infections associated with severe trauma or crush injuries; Abbott SL et al.; Five cases of Enterobacter cancerogenus infections (wound, n = 4; bacteremia, n = 1) in adults are described . All infections seemed to be community acquired and occurred after precipitating events such as multiple trauma to the head or severe crush injuries . All five strains of E cancerogenus were recovered in pure culture, and three of these were isolated on multiple occasions . The results indicate that E cancerogenus can cause wound infections and septicemia in persons environmentally exposed to these organisms during traumatic events. Hepatology, 1997 Mar, 25(3), 642 - 7 Effect of Lactobacillus supplementation with and without arginine on liver damage and bacterial translocation in an acute liver injury model in the rat; Adawi D et al.; In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut . This may explain some of the infectious complications seen in these conditions . To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure . Sprague-Dawley rats were used and five different Lactobacillus strains (Lb . reuteri R2LC, Lb . rhamnosus DSM 6594 (= strain 271), Lb . plantarum DSM 9843 (= strain 299v), Lb . fermentum 8704:3 (= strain 245), and Lb . reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine . Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after 24 and 48 hours . Bacterial translocation was evaluated by bacterial culture from portal and arterial blood, mesenteric lymph nodes, and liver tissue . Liver enzymes and bilirubin were evaluated in the serum . The bacterial load in the cecum and colon was determined and the liver histopathological changes were studied . There was no mortality at any time . The liver enzymes and bilirubin decreased in some of the groups supplemented with lactobacilli with and without arginine compared with the ALI control group . The incidence of bacterial translocation and the number of the translocated bacteria decreased significantly in some of the supplemented groups . Lb . plantarum + arginine administration significantly reduced the level of the released liver enzymes, hepatocellular necrosis and inflammatory cell infiltration, bacterial translocation, and the number of Enterobacteriaceae in the cecum and colon . Rectal administration of different Lactobacillus strains with and without arginine in an ALI model significantly modulates the extent of the liver failure and reduces bacterial translocation . Lb . plantarum DSM 9843 (= strain 299v) with or without arginine seemed superior to the other Lactobacillus strains . The beneficial effect of arginine administration alone indicates a possible role of nitric oxide and polyamines in this process, and the lactobacilli may execute their action via the same mechanisms or via bacterial antagonism and/or enhancement of systemic and intestinal mucosal immunity. J Bacteriol, 1997 Mar, 179(5), 1813 - 8 Coexpression of the long and short forms of CheA, the chemotaxis histidine kinase, by members of the family Enterobacteriaceae; McNamara BP et al.; CheA is the histidine protein kinase of a two-component signal transduction system required for bacterial chemotaxis . Motile cells of the enteric species Escherichia coli and Salmonella typhimurium synthesize two forms of CheA by utilizing in-frame initiation sites within the gene cheA . The full-length protein, CheAL, plays an essential role in the chemotactic signaling pathway . In contrast, the function of the short form, CheAs, remains elusive . Although CheAs lacks the histidine residue that becomes phosphorylated in CheAL, it exhibits both kinase activity and the ability to interact with and enhance the activity of CheZ, a chemotaxis protein that accelerates dephosphorylation of the two-component response regulator CheY . To determine whether other members of the family Enterobacteriaceae express CheAs and CheZ, we analyzed immunoblots of proteins from clinical isolates of a variety of enteric species . All motile, chemotactic isolates that we tested coexpressed CheAL, CheAs, and CheZ . The only exceptions were closely related plant pathogens of the genus Erwinia, which expressed CheAL and CheZ but not CheAs . We also analyzed nucleotide sequences of the cheA loci from isolates of Serratia marcescens and Enterobacter cloacae, demonstrating the presence of in-frame translation initiation sites similar to those observed in the cheA loci of E . coli and S . typhimurium . Since coexpression of CheAs and CheZ appears to be limited to motile, chemotactic enteric bacteria, we propose that CheAs may play an important role in chemotactic responses in some environmental niches encountered by enteric species. J Clin Microbiol, 1997 Mar, 35(3), 584 - 7 Detection and identification of two Bartonella henselae variants in domestic cats in Germany; Sander A et al.; To determine the prevalence of bacteremia caused by Bartonella henselae in domestic cats in the region of Freiburg, Germany, we investigated culture of blood from 100 cats from 89 different households over a 12-month period . B . henselae could be isolated from 13% (13 of 100) of these cats . In eight households with two cats each and in one household with three cats, B . henselae bacteremia was found either in all of the animals or in none of the animals . Positive cultures were more likely to be found for female, young (24 months of age or younger) cats than for male or older cats . Identification of the Bartonella isolates was made by colony morphology, by Gram staining, biochemically by RapID ANA II or Rapid ID 32 A systems, and by whole-cell fatty acid analysis . Differentiation between B . henselae and Bartonella quintana was only possible by 16S rRNA sequencing, enterobacterial repetitive intergenic consensus (ERIC)-PCR and sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Genomic fingerprinting of the B . henselae isolates by ERIC-PCR yielded two different patterns based on three distinct bands. Gene, 1997 Feb 28, 186(2), 201 - 5 Cloning and characterization of the exbB-exbD-tonB locus of Pasteurella haemolytica A1; Graham MR et al.; A recombinant plasmid (pMG1) carrying Pasteurella haemolytica A1 DNA which complements a tonB mutation of Escherichia coli has been isolated . E . coli tonB metE which carries pMG1 exhibits growth kinetics in the presence of vitamin B12 similar to that of the wild-type host . In addition, the complemented E . coli is susceptible to killing by bacteriophage phi 80 and colicin B . Analysis of the nucleotide sequence in the complementing DNA showed that it codes for three genes in the order of exbB-exbD-tonB . This genetic organization has been reported in Haemophilus influenzae, H . ducreyi, Pseudomonas putida and Vibrio cholerae, and may represent a separate lineage of evolution from that of the Enterobacteriaceae in which tonB is unlinked with the accessory genes exbB and exbD . A comparison of the DNA flanking the exbB-exbD-tonB locus in P . haemolytica A1 and H . influenzae showed that the flanking regions are completely different between the two organisms. Biochem Biophys Res Commun, 1997 Feb 24, 231(3), 692 - 5 Effect of glucose concentration on swimming motility in enterobacteria; Lai HC et al.; Since the observation that glucose prevents the synthesis of flagella in Escherichia coli was first reported in 1967, many studies have addressed the underlying mechanism . Currently, it is thought that an increase in glucose concentration decreases the intracellular CRP/cAMP concentration . This leads to an inhibitory effect on the expression of the flhD operon, the master operon for flagella synthesis . In our study on defining factors influencing the cell differentiation of Serratia marcescens, glucose catabolite repression of hag expression and swimming/swarming motility was not observed . Further experiments using a simple swimming motility assay extended this observation to other members of Enterobacteriaceae . Although the underlying mechanism is still uncharacterised, our results suggest that glucose catabolite repression of swimming motility may not be a common phenomenon in Enterobacteriaceae. FEMS Microbiol Lett, 1997 Feb 15, 147(2), 173 - 80 Acid stress responses in enterobacteria; Bearson S et al.; The enteric microogranisms Salmonella, Escherichia coli and Shigella flexneri prefer to grow in neutral pH environments . They nevertheless experience dramatic pH fluctuations in nature and during pathogenesis . In response to environmental encounters with acid, these organisms have evolved complex, inducible acid survival strategies . Regulatory features include an alternative factor (sigma S), 2- component signal transduction systems (PhoP/Q; MviA/?) and the major iron regulatory protein Fur . Specific survival mechanisms include emergency pH homeostasis by inducible amino acid decarboxylases and probable roles for DNA repair, chaparonins, membrane biogenesis as well as others that remain poorly defined . Continued study of acid survival in these organisms will provide insights regarding stress management and will have a direct impact on our understanding of pathogenesis. J Immunol, 1997 Feb 15, 158(4), 1976 - 83 Lipoprotein from Yersinia enterocolitica contains epitopes that cross-react with the human thyrotropin receptor; Zhang H et al.; Yersinia enterocolitica has recently been shown to produce a low molecular mass envelope protein that contains an epitope(s) that is cross-reactive with the extracellular domain of the human thyrotropin receptor (ETSHR) . In this study, we have generated mAb to this cross-reactive protein and have obtained amino acid sequences for peptide fragments obtained from Lys-c digestion of the protein . The amino acid sequences of these peptides were identical to sequences present in bacterial lipoprotein (LP) . All bacteria of the Enterobacteriaceae family produce LP as a major outer membrane protein . However, the ETSHR cross-reactive epitope(s) was shown to be unique to LP produced by Yersinia species . This was shown by Western blot analysis using a mAb specific for LP and with affinity-purified Ab specific for either LP or ETSHR and obtained from mouse antiserum generated to Y . enterocolitica . LPs from different Gram-negative bacteria were shown to be mitogenic for C3H/HeJ spleen cells and induced production and secretion of significant levels of Ig . Production of Ab that recognized the ETSHR was only induced in spleen cells stimulated with the LP obtained from Yersinia . In contrast, LP was not mitogenic for either human PBMC or human B cells . However, LP did induce IL6 and IL8 production in human monocytes at levels equivalent to that seen after LPS activation . These results identify, for the first time, the Yersinia envelope protein that is cross-reactive with the ETSHR and show that it can activate human monocytes . These findings are potentially important for advancing our understanding of the role molecular mimicry plays in the induction of autoimmunity to the thyrotropin receptor. Comp Immunol Microbiol Infect Dis, 1997 Feb, 20(2), 163 - 70 Non-O157 Vero cytotoxin producing Escherichia coli: aetiological agents of diarrhoea in children in Dunedin, New Zealand; Brooks HJ et al.; Strains of Escherichia coli that produce Vero cytotoxin (VTEC) commonly cause diarrhoea, haemorrhagic colitis and haemolytic-uraemic syndrome in many northern hemisphere countries . In these countries, serotype O157:H7/H-predominates and has caused large food-borne outbreaks of infection . In contrast, few cases of infection with this serotype have been reported in New Zealand . Over a 3-month period, 484 stool specimens submitted to medical laboratories in Dunedin were screened for E . coli O157:H7/H-using sorbitol MacConkey agar, Y1 and Vero cell assays . Where possible, Vero cytotoxin production was confirmed by an ELISA test . Specimens from children aged 12 years or less were additionally screened for non-O157 VTEC . In the specimens of the children tested, O157:H7/H-VTEC was not isolated, but VTEC belonging to other serogroups were isolated from the children . Of interest was the detection of other species of Enterobacteriaceae, which produced a cytopathic effect on Vero cells . This study confirms the low incidence of infection with O157:H7/H- VTEC in New Zealand and suggests that non-O157 VTEC is a more important cause of diarrhoeal disease. J Infect Dis, 1997 Feb, 175(2), 470 - 3 Clinical isolates of Shigella species induce apoptosis in macrophages; Guichon A et al.; Shigella species are invasive enterobacteria that cause dysentery, a severe form of diarrhea . The ability to invade epithelial cells and to kill macrophages is essential for virulence in a prototype Shigella flexneri strain . It is shown here that clinical isolates of both S . flexneri and Shigella sonnei invade epithelial cells and are cytotoxic to macrophages in vitro . Furthermore, clinical Shigella strains kill macrophages by inducing apoptosis . The conservation of the ability to induce macrophage apoptosis by clinical isolates suggests that this function plays a crucial role in the pathogenesis of Shigella species. Farmaco, 1997 Feb, 52(2), 99 - 103 Synthesis and structure-activity relationships of some 2,5-disubstituted benzoxazoles and benzimidazoles as antimicrobial agents; Sener E et al.; The synthesis of a new series of 2,5-disubstitutedbenzoxazoles 5a-e, and 2,5-disubstitutedbenzimidazoles 6a-h are described in order to determine their antimicrobial activities and feasible structure-activity relationships (SAR) . The synthesized compounds were tested in vitro against 3 Gram-positive, 3 Gram-negative, bacteria and a fungus Candida albicans . 5c, and 5e were found most active than the others against Bacillus subtilis at a MIC value of 3.12 micrograms/ml and the compounds 5e, 6a and 6e indicated significant antibacterial activity against the enterobacter Pseudomonas aeruginosae . 5a, 5c, 5d and 6d also exhibited antimycotic activity against C . albicans . The antibacterial and antimycotic activities of 5-6 are compared with several control drugs. Mol Microbiol, 1997 Feb, 23(4), 729 - 36 The type IC hsd loci of the enterobacteria are flanked by DNA with high homology to the phage P1 genome: implications for the evolution and spread of DNA restriction systems; Tyndall C et al.; EcoR124l, EcoDXXl and Ecoprrl are the known members of the type IC family of DNA restriction and modification systems . The first three are carried on large, conjugative plasmids, while Ecoprrl is chromosomally encoded . The enzymes are coded by three genes, hsdR, hsdM and hsdS . Analysis of the DNA sequences upstream and downstream of the type IC hsd loci shows that all are highly homologous to each other and also to sequences present in the bacteriophage P1 genome . The upstream sequences include functional phd and doc genes, which encode an addiction system that stabilizes the P1 prophage state, and extend to and beyond pac, the site at which phage DNA packaging begins . Downstream of the hsd loci, P1 DNA sequences begin at exactly the same place for all of the systems . For EcoDXXl and Ecoprrl the P1 homology extends for thousands of base pairs while for EcoR124l and IS1 insertion and an associated deletion have removed most of the P1-homologous sequences . The significance of these results for the evolution of DNA restriction and modification systems is discussed. Mol Microbiol, 1997 Feb, 23(4), 629 - 38 Modulation of the surface architecture of gram-negative bacteria by the action of surface polymer:lipid A-core ligase and by determinants of polymer chain length; Whitfield C et al.; Lipopolysaccharides (LPSs) are complex glycolipids found in the outer membrane of Gram-negative bacteria . The lipid A-core component of the LPS molecule provides a versatile anchor to which a surface polymer:lipid A-core ligase enzyme can attach one or more structurally distinct surface polymers in a single bacterial strain . In some cases the same polymer can be found on the cell surface in both lipid A-core-linked and -unlinked forms . Analysis by SDS-PAGE of populations of LPS molecules extracted from bacterial cells indicates that there is extensive heterogeneity in their size distribution . Much of the heterogeneity results from complex modal distributions in the chain length of the polymers which are attached to lipid A-core . This is the result of preferential ligation of polymers with specific degrees of polymerization during the assembly of the LPS molecule . The surface architecture of the Gram-negative bacterial cell is therefore profoundly affected by the activities of the surface polymer:lipid A-core ligase and by molecular determinants of polymer chain length . Because of the involvement of cell-surface polymers in interactions between pathogenic bacteria and their hosts, these enzymatic activities also have an important impact on virulence . In this review, the organization of LPSs and related surface polymers will be described and the current understanding of the molecular mechanisms involved in surface diversity will be discussed . Emphasis is placed on the Enterobacteriaceae, but similarities to other bacteria suggest that aspects of the enterobacterial system will have broader significance. Arch Microbiol, 1997 Feb-Mar, 167(2-3), 78 - 88 Anaerobic citrate metabolism and its regulation in enterobacteria; Bott M; Several species of enterobacteria are able to utilize citrate as carbon and energy source . Under oxic conditions in the presence of a functional tricarboxylic acid cycle, growth on this compound solely depends on an appropriate transport system . During anaerobiosis, when 2-oxoglutarate dehydrogenase is repressed, some species such as Klebsiella pneumoniae and Salmonella typhimurium, but not Escherichia coli, are capable of growth on citrate by a Na+-dependent pathway forming acetate, formate, and CO2 as products . During the last decade, several novel features associated with this type of fermentation have been discovered in K . pneumoniae . The biotin protein oxaloacetate decarboxylase, one of the key enzymes of the pathway besides citrate lyase, is a Na+ pump . Recently it has been shown that the proton required for the decarboxylation of carboxybiotin is taken up from the side to which Na+ ions are pumped, and a membrane-embedded aspartate residue that is probably involved both in Na+ and in H+ transport was identified . The Na+ gradient established by oxaloacetate decarboxylase drives citrate uptake via CitS, a homodimeric carrier protein with a simultaneous-type reaction mechanism, and NADH formation by reversed electron transfer involving formate dehydrogenase, quinone, and a Na+-dependent NADH:quinone oxidoreductase . All enzymes specifically required for citrate fermentation are induced under anoxic conditions in the presence of citrate and Na+ ions . The corresponding genes form a cluster on the chromosome and are organized as two divergently transcribed operons . Their co-ordinate expression is dependent on a two-component system consisting of the sensor kinase CitA and the response regulator CitB . The citAB genes are part of the cluster and are positively autoregulated . In addition to CitA/CitB, the cAMP receptor protein (Crp) is involved in the regulation of the citrate fermentation enzymes, subjecting them to catabolite repression. Clin Infect Dis, 1997 Feb, 24(2), 211 - 5 Antimicrobial resistance in isolates from inpatients and outpatients in the United States: increasing importance of the intensive care unit; Archibald L et al.; To compare the occurrence of antimicrobial resistance in hospitals with that in the community, we analyzed data for isolates collected from inpatients and outpatients in eight U.S . hospitals . The percentage of resistant isolates from inpatients was higher than that from outpatients for the following combinations of antimicrobials and organisms: methicillin/coagulase-negative Staphylococcus (49.0% vs . 36.0%, respectively; P < .01); methicillin/Staphylococcus aureus (33.0% vs . 14.5%, respectively; P < .01); ceftazidime/Enterobacter cloacae (26.0% vs . 12.0%, respectively; P < .01); imipenem/Pseudomonas aeruginosa (12.0% vs . 6.5%, respectively; P < .01); ceftazidime/P . aeruginosa (7.8% vs . 4.0%, respectively; P < .01); and vancomycin/Enterococcus species (6.3% vs . 1.4%, respectively; P < .01) . There was a significant stepwise decrease in the percentage of resistant organisms isolated from patients in the intensive care unit (ICU), non-ICU inpatients, and outpatients . These results suggest that resources allocated to control antimicrobial resistance should continue to be focused in the hospital, particularly in the ICU. Pathology, 1997 Feb, 29(1), 79 - 83 A national collaborative study of the in vitro activity of oral cephalosporins and loracarbef (LY 163892) . Australian Group for the Study of Antimicrobial Resistance (AGAR); Benn RA et al.; A national collaborative study involving the laboratories of 17 Australian hospitals examined the in vitro activity of loracarbef, cefaclor, cephalexin, amoxycillin and amoxycillin/clavulanate against 2661 recently isolated common bacterial pathogens . Loracarbef was the most active agent against Escherichia coli (MIC90 = 1 mg/l) and had activity comparable to other agents against Klebsiella pneumoniae and Proteus mirabilis . Like the oral cephalosporins, it had no activity against species of Enterobacter and Serratia . beta-lactamase-producing Staphylococcus aureus and Haemophilus influenzae were moderately sensitive to loracarbef (MIC90 = 8 mg/l for both species) . Streptococcus pneumoniae was moderately sensitive to loracarbef (MIC90 = 2 mg/l) but strains which were insensitive to penicillin were often highly resistant. J Antimicrob Chemother, 1997 Feb, 39(2), 177 - 87 Prevalence and mechanism of resistance to 'third-generation' cephalosporins in clinically relevant isolates of Enterobacteriaceae from 43 hospitals in the UK, 1990-1991; Piddock LJ et al.; In a UK survey of the occurrence of extended spectrum beta-lactamases, 96 hospitals submitted a total of 3951 non-selected, non-duplicate isolates of Enterobacteriaceae from 100 patients in each hospital, 206 of these cultures being mixed and, therefore, discarded . These isolates were initially screened for strains likely to produce extended-spectrum beta-lactamases (ESBLs) by MIC determination of beta-lactams followed by a bioassay, then disc approximation test and isoelectric focusing (IEF) . Isolates were further examined using two pairs of PCR primers for both blaTEM and blaSHV genes . The ability of isolates to transfer resistance to both cefotaxime and ceftazidime by conjugation and transformation were examined . Four hundred and nine cefotaxime/ceftazidime-resistant isolates (10.9%) were identified from the 3745 submitted isolates, of which 338 (9.0%) were Enterobacteriaceae, 29 Escherichia coli, 35 Klebsiella spp . and seven Hafnia alveii . IEF suggested that 17 isolates produced an ESBL, which was confirmed in most cases by PCR and hydrolysis, five isolates produced an SHV enzyme by IEF, but not confirmed by PCR, and 11 had isoelectric points in the range 8-9 suggesting a possible AmpC enzyme . Only two isolates transferred the determinants . In the case of the Klebsiella spp., 19 of the 24 ceftazidime-resistant/clavulanate-sensitive isolates were positive by PCR for a blaSHV gene . No isolates were identified as carrying blaTEM, although eight isolates had isoelectric points of 5-6.3, suggesting the presence of a possible TEM beta-lactamase . The results for the H . alveii isolates suggest that either an AmpC-like enzyme or a transferable beta-lactamase which is not TEM/SHV is present . This study shows that a wide range of genotypically and phenotypically different isolates of Enterobacteriaceae producing ESBL-like enzymes is present throughout the UK at a frequency of about 1% of unselected isolates . It is important that surveillance of resistance to these clinically important antibiotics is maintained as the occurrence of localized or more widespread outbreaks caused by bacteria producing ESBLs is to be expected. J Antimicrob Chemother, 1997 Feb, 39(2), 157 - 62 Bactericidal activity of cefodizime on Enterobacteriaceae in an in-vitro model simulating plasma pharmacokinetics in humans; Pechinot A et al.; An in-vitro dialysis model was employed to assess the feasibility of once-daily dosing of cefodizime in the treatment of infections caused by various Enterobacteriaceae: Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Serratia marcescens, Providencia stuartii and Enterobacter cloacae . This model simulated the concentrations of cefodizime detected in human blood after an intravenous (i.v.) bolus injection of 1 g or 2 g of the antibiotic . Validation of the model was undertaken to confirm its utility . Based on the data obtained with this model, once-daily dosing with 1 g cefodizime (i.v.) should be effective against infections due to the commonest Gram-negative bacteria (E . coli, K . pneumoniae, M . morganii) . For infections caused by Enterobacteriaceae strains that produce large quantities of Class I beta-lactamases, twice-daily (P . stuartii or S . marcescens) or four times daily (E . cloacae) administration of 1 g cefodizime may be required. Aust Vet J, 1997 Feb, 75(2), 126 - 31 Antibiotic prophylaxis of lower respiratory tract contamination in horses confined with head elevation for 24 or 48 hours; Raidal SL et al.; OBJECTIVE: To evaluate the administration of procaine penicillin prior to or during confinement with head elevation as a means of reducing the associated accumulation of inflammatory lower respiratory tract secretions and increased numbers of bacteria within the lower respiratory tract of confined horses . DESIGN AND PROCEDURE: Two experiments were conducted to evaluate the efficacy of different dose rates and dosing frequencies . In experiment A a single low dose (15,000 IU/kg) of procaine penicillin was administered to four horses immediately prior to confinement with head elevation for 48 hours . The systemic leucocyte response, gross and cytologic characteristics of transtracheal aspirate and bacterial numbers in lower respiratory tract samples were compared with corresponding samples from two horses confined with heads elevated but not given penicillin . The efficacy of higher dose rates (20,000 IU/kg and 40,000 IU/kg) given before and during confinement with heads elevated for 24 hours was evaluated in experiment B . RESULTS: Treatment with procaine penicillin had no effect on the systemic leucocyte response or on the accumulation of inflammatory lower respiratory tract secretions at any of the dosing schedules evaluated . The number of bacteria isolated from trans-tracheal samples was reduced at 12 hours for treated horses in experiment A and at 24 hours for experiment B . beta-haemolytic Streptococcus spp were not isolated from treated horses in either experiment . Bacterial species isolated from treated horses were predominantly Pasteurella and/or Actinobacillus spp, however, members of the family Enterobacteriaceae and a Staphylococcus sp were isolated from treated horses . One treated horse in experiment A developed clinically apparent pulmonary disease . CONCLUSIONS: The prophylactic administration of penicillin before or during confinement did not reliably reduce bacterial numbers or prevent the accumulation of purulent lower respiratory tract secretions in horses confined with their heads elevated . Numbers of beta-haemolytic Streptococcus spp were reduced following treatment, suggesting that the repeated administration of procaine penicillin may have some merit as part of a strategy to prevent transport-associated respiratory disease . However, methods directed at minimising the duration of confinement with head elevation, augmentation of the clearance of accumulated secretions and prompt identification of animals in which airway inflammation has extended to the pulmonary parenchyma remain the best ways of minimising transport-associated respiratory disease. Indian J Med Res, 1997 Feb, 105, 47 - 52 Isolation of Salmonella senftenberg bacteriophages; Kumar S et al.; A total of 61 bacteriophages were isolated from 100 strains of Salmonella senftenberg . Six bacteriophages were selected for typing purposes which were specific for S . senftenberg . Five phages, SasL1 to SasL5 were morphologically similar; phage SasL6 was morphologically different from the others . These phages fall into two morphological groups none of which correspond to the known tailed enterobacterial phage species . Hence, two new phage species represented by SasL1 and SasL6 are proposed. Microbiology, 1997 Feb, 143 ( Pt 2), 603 - 15 The nucleoside-specific Tsx channel from the outer membrane of Salmonella typhimurium, Klebsiella pneumoniae and Enterobacter aerogenes: functional characterization and DNA sequence analysis of the tsx genes; Nieweg A et al.; The Escherichia coli tsx gene encodes an integral outer-membrane protein (Tsx) that functions as a substrate-specific channel for deoxynucleosides and the antibiotic albicidin, and also serves as a receptor for bacteriophages and colicins . We cloned the structural genes of the Tsx proteins from Salmonella typhimurium, Klebsiella pneumoniae and Enterobacter aerogenes and expressed them in an E.coli tsx mutant . The heterologous Tsx proteins fully substituted the E.coli Tsx protein with respect to its function in deoxynucleoside and albicidin uptake, and as receptor for colicin K . The Tsx proteins from K . pneumoniae and Ent . aerogenes were also proficient as receptors for several Tsx-specific bacteriophages, whereas the corresponding protein from S . typhimurium did not confer sensitivity against these phages . The nucleotide sequence of the tsx genes from S . typhimurium, K . pneumoniae and Ent . aerogenes was established . Each of the Tsx proteins is initially synthesized with typical bacterial signal sequence peptides and the predicted mature forms of the Tsx proteins have a calculated M(r) of 30,567 (265 residues), 31,412 (272 residues) and 31,477 (272 residues), respectively . Multiple sequence alignments between the Tsx proteins showed a high degree of sequence identity and revealed the presence of four hypervariable regions, which are thought to constitute segments of the polypeptide chain exposed at the cell surface . Most notable was a deletion of 8 amino acids in one of these hypervariable domains in the S . typhimurium Tsx protein . When this deletion was introduced by site-directed mutagenesis into the corresponding region of the E.coli tsx gene, the mutant Tsx-515 protein lost its phage receptor function but still served as a colicin K receptor and as a substrate-specific channel, indicating that the region between residues 198 and 207 might be part of the bacteriophage receptor area . Multiple sequence alignments, structural predictions and the properties of previously characterized Tsx missense mutants were taken into account to develop a two-dimensional model for the topological organization of the Tsx protein within the outer membrane. Microbiology, 1997 Feb, 143 ( Pt 2), 505 - 12 Distribution of amine oxidases and amine dehydrogenases in bacteria grown on primary amines and characterization of the amine oxidase from Klebsiella oxytoca; Hacisalihoglu A et al.; The bacteria Klebsiella oxytoca LMD 72.65 (ATCC 8724), Arthrobacter P1 LMD 81.60 (NCIB 11625), Paracoccus versutus LMD 80.62 (ATCC 25364), Escherichia coli W LMD 50.28 (ATCC 9637), E . coli K12 LMD 93.68, Pseudomonas aeruginosa PAO1 LMD 89.1 (ATCC 17933) and Pseudomonas putida LMD 68.20 (ATCC 12633) utilized primary amines as a carbon and energy source, although the range of amines accepted varied from organism to organism . The Gram-negative bacteria K . oxytoca and E . coli as well as the Gram-positive methylotroph Arthrobacter P1 used an oxidase whereas the pseudomonads and the Gram-negative methylotroph Paracoccus versutus used a dehydrogenase for amine oxidation . K . oxytoca utilized several primary amines but showed a preference for those containing a phenyl group moiety . Only a single oxidase was used for oxidation of the amines . After purification, the following characteristics of the enzyme indicated that it belonged to the group of copper-quinoprotein amine oxidase (EC 1.4.3.6): the molecular mass (172,000 Da) of the homodimeric protein; the UV/visible and EPR spectra of isolated and p-nitrophenylhydrazine-inhibited enzyme; the presence and the content of copper and topaquinone (TPQ) . The amine oxidase appeared to be soluble and localized in the periplasm, but catalase and NAD-dependent aromatic aldehyde dehydrogenase, enzymes catalysing the conversion of its reaction products, were found in the cytoplasm . From the amino acid sequence of the N-terminal part as well as that of a purified peptide, it appears that K . oxytoca produces a copper-quinoprotein oxidase which is very similar to that found in other Enterobacteriaceae. Int J Food Microbiol, 1997 Feb, 34(2), 103 - 13 Enterobacter sakazakii: a review; Nazarowec-White M et al.; Enterobacter sakazakii, previously referred to as a yellow-pigmented Enterobacter cloacae was designated as a unique species in 1980 . This reclassification was based on differences from E . cloacae in DNA relatedness, pigment production and biochemical reactions . E . sakazakii has been implicated in a severe form of neonatal meningitis . Although studies have failed to identify an environmental source for the organism, dried-infant formula has been implicated in both outbreaks and sporadic cases of E . sakazakii meningitis . The high mortality rate (40-80%), the severity of the infection in infants, plus the scarcity of information on the ecology and pathogenicity of this organism warranted a review of the clinical and microbiological features of this putative foodborne pathogen. J Bacteriol, 1997 Feb, 179(4), 1354 - 61 Characterization of the rcsB gene from Erwinia amylovora and its influence on exoploysaccharide synthesis and virulence of the fire blight pathogen; Bereswill S et al.; RcsB belongs to a family of positive regulators of exopolysaccharide synthesis in various enterobacteria . The rcsB gene of the fire blight pathogen Erwinia amylovora was cloned by PCR amplification with consensus primers, and its role in exopolysaccharide (EPS) synthesis was investigated . Its overexpression from high-copy-number plasmids stimulated the synthesis of the acidic EPS amylovoran and suppressed expression of the levan-forming enzyme levansucrase . Inactivation of rcsB by site-directed mutagenesis created mutants that were deficient in amylovoran synthesis and avirulent on host plants . In addition, a cosmid which complemented rcsB mutants was selected from a genomic library . The spontaneous E . amylovora mutant E8 has a similar phenotype and was complemented by the cloned rcsB gene . The rcsB region of strain E8 was also amplified by PCR, and the mutation was characterized as a nine-nucleotide deletion at the start of the rcsB gene . Nucleotide sequence analysis of the E . amylovora rcsB region and the predicted amino acid sequence of RcsB revealed extensive homology to rcsB and the encoded protein of other bacteria such as Escherichia coli and Erwinia stewartii . In all three organisms, rcsB is localized adjacent to the rcsC gene, which is transcribed in the opposite direction of rcsB . The E . amylovora rcsB gene has now been shown to strongly affect the formation of disease symptoms of a plant pathogen. Antimicrob Agents Chemother, 1997 Feb, 41(2), 401 - 9 Differential distributions in tissues and efficacies of aztreonam and ceftazidime and in vivo bacterial morphological changes following treatment; Turcotte A et al.; The differential tissue distributions of aztreonam and ceftazidime within fibrin clots infected with Pseudomonas aeruginosa, Enterobacter cloacae, and Serratia marcescens, their efficacies, and the in vivo bacterial morphological changes induced by these drugs were evaluated . Rabbits were given intravenously a single dose of 100 mg of either agents/kg of body weight . In the cores of the clots, the peak levels of both drugs were much lower than those observed in the peripheries and in serum . Aztreonam's half-lives within the peripheries and in the cores of the fibrin clots were up to six times higher than observed in serum, while ceftazidime's half-lives in clots were twice that observed in serum . This resulted in a much greater penetration ratio for aztreonam than for ceftazidime . Both drugs controlled the growth of P . aeruginosa in vivo, but E . cloacae and S . marcescens responded better to ceftazidime . Morphological changes were more abundant in the peripheries than in the cores of the clots . In the control group, P . aeruginosa's morphology in the cores was different than that in the peripheries of the clots . Against P . aeruginosa, aztreonam did induce morphological changes in the cores while ceftazidime did not . Electron microscopic studies revealed that morphological changes associated with aztreonam seemed different than those of ceftazidime . Along with elongation of bacteria, more bow tie and herniated bacteria were observed with aztreonam . Though both agents selectively affect PBP 3, as manifested by elongated bacteria, they induce in the peripheries of the clots thickening, breaks, and detachment in bacterial cell walls, alterations which are generally associated with antibiotics affecting PBP 1a and 1b. Antimicrob Agents Chemother, 1997 Feb, 41(2), 298 - 307 In vitro and in vivo antibacterial activities of ER-35786, a new antipseudomonal carbapenem; Ohba F et al.; ER-35786 is a new parenteral 1 beta-methyl carbapenem with a broad antibacterial spectrum and a potent antipseudomonal activity . It showed high in vitro activity, comparable to those of meropenem and a new carbapenem, BO-2727, against methicillin-susceptible Staphylococcus aureus and streptococci, with MICs at which 90% of strains tested are inhibited (MIC90S) of < or = 0.39 microgram/ml . Against methicillin-resistant S . aureus, ER-35786 was the most active among the compounds tested, yet its MIC90 was 12.5 micrograms/ml . Against members of the family Enterobacteriaceae, Moraxella catarrhalis, and Haemophilus influenzae, ER-35786 inhibited 90% of strains tested at a concentration of < or = 1.56 micrograms/ml . The MIC90 of ER-35786 for Pseudomonas aeruginosa was 3.13 micrograms/ml, and the compound was more active than meropenem . In addition, the activity of ER-35786 against imipenem-, meropenem-, cefclidin-, or ceftazidime-resistant P . aeruginosa was equal to or higher than that of the most active reference compound . The in vivo activity of ER-35786 was consistent with this in vitro activity . The in vivo activity of ER-35786 was highest for systemic infection models with methicillin-resistant S . aureus and beta-lactam-resistant P . aeruginosa strains . In acute pneumonia caused by P . aeruginosa, ER-35786 produced a greater reduction in the viable cell count in the lungs than did imipenem-cilastatin or meropenem. Infect Immun, 1997 Feb, 65(2), 604 - 8 Helicobacter pylori lipopolysaccharide can activate 70Z/3 cells via CD14; Kirkland T et al.; Helicobacter pylori persistently colonizes the human gastrointestinal tract and is associated with chronic gastritis and, in some cases, peptic ulcer disease or gastric neoplasms . One factor in the persistence of this organism may be its inability to elicit a strong inflammatory response . Lipopolysaccharide (LPS) is a proinflammatory substance found in the cell walls of all gram-negative bacteria . H . pylori LPS has been found by several different measures to be less active than LPS from Enterobacteriaceae . This study addresses the role of CD14 and LPS-binding protein in the cellular response to H . pylori LPS . We report that H . pylori LPS activates mammalian cells expressing CD14 at much lower LPS concentrations than those for control cells not expressing CD14 . The maximal activation of CD14-70Z/3 cells by H . pylori LPS also requires LPS-binding protein . H . pylori LPS at concentrations as high as 30 microg/ml does not elicit an interleukin-8 (IL-8) response from the epithelial cell line SW620 in the presence of CD14; 10 ng of Escherichia coli LPS per ml elicits a maximal IL-8 response . Furthermore, in contrast to some other types of LPS with little activity, H . pylori LPS does not inhibit the CD14-70Z/3 cell response to E . coli LPS . From these studies, we conclude that H . pylori LPS, though much less active than E . coli LPS, stimulates cells via CD14. J Clin Microbiol, 1997 Feb, 35(2), 523 - 4 Response of enteric gram-negative bacteria to disks containing 20 micrograms each of ampicillin and sulbactam; Isenberg HD et al.; Ampicillin-sulbactam disks containing either 10 microg of each drug or 20 microg of each drug were tested against 138 recently, sequentially isolated members of the family Enterobacteriaceae . Results obtained with the higher-content disks corresponded more closely to the impressions of clinicians. J Clin Microbiol, 1997 Feb, 35(2), 508 - 10 Study of an outbreak of cefoxitin-resistant Klebsiella pneumoniae in a general hospital; Gazouli M et al.; During a 3-month period, six Klebsiella pneumoniae isolates resistant to cefoxitin and penicillin-inhibitor combinations were derived from patients in the intensive care unit of a hospital in Athens, Greece . Enterobacterial repetitive intergenic consensus PCR and pulsed-field gel electrophoresis provided evidence of the clonal origin of the isolates . Conventional techniques and ribotyping were inadequate in proving that the isolates were related . Resistance was due to a plasmidic class C beta-lactamase. Vestn Ross Akad Med Nauk, 1997, (6), 44 - 7 {Recombinant plasmids carrying yersinia pestis fra-operon: specific features of genetic transmission, inheritance and expression in attenuated enterobacterial cells}; Fursova NK et al.; The study was undertaken to study the specific features of transformation of E . coli strains having different R-chemotypes, Y . pestis, S . minnesota R595, and S . typhi Ty21a by plasmids carrying Yersinia pestis Fra-operon which controls the formation of a plague microbe capsular F1 antigen in this microorganism . Calcium transformation was shown to be rather effective for the plasmids constructed on the basis of a cosmid vector (pFS1), rather than those designed by using the Y . pestis plasmid pPst I (pFSK3, pP3) . The level of plasmid stability varied and failed to correlate with taxonomy fitting and the chemotype of a recipient strain . The cells of all recombinant strains produced F1 antigen, secreted it into the environment; the synthesis was temperature-regulated . F1 was identified both in the diffuse precipitation and serological tests . The levels of F1 antigen synthesis decreased whereas nutritious requirements for the maintenance of protein synthesis increased for bacterial strains with higher levels of LPS reduction. Microbiol Immunol, 1997, 41(7), 513 - 7 Effects of chronic isoproterenol treatment or submandibular and sublingual ablation on microflora of mouse tooth surfaces; Maeda N et al.; BALB/cA mice were examined for the effects of chronic isoproterenol treatment or submandibular-sublingual gland ablation on the natural patterns of oral bacterial colonization on tooth surfaces . Indigenous microflora on the tooth surfaces of BALB/cA mice was relatively simple . The predominant bacterial groups were Enterobacteriaceae (45.9%), enterococci (29.4%) and staphylococci (15.7%) . Isoproterenol, which resulted in the induced synthesis of proline-rich proteins, caused a decrease in the total cultivable bacteria on the tooth surfaces . The proportion of Enterobacteriaceae in the isoproterenol-treated mice decreased, although the proportion of other bacterial groups increased . Salivary gland ablation, which caused the loss of mucins in saliva, showed essentially the same number of total bacteria as the control . Salivary gland ablation resulted in a decrease in the proportion of Enterobacteriaceae, while the proportion of Gram-positive rods and staphylococci increased. Arch Virol, 1997, 142(7), 1381 - 90 Taxonomic changes in tailed phages of enterobacteria; Ackermann HW et al.; Out of 136 new phages, 80 (59%) are classified into 23 species according to morphology and physicochemical properties . Six new species are described and species beta 4, from a previous classification scheme, is renamed T1 . The morphology of 36 phage species is schematically represented. Bacteriol Virusol Parazitol Epidemiol, 1997 Jan-Jun, 42(1-2), 21 - 6 {Enterobacteriaceae isolated in eastern Romania: the evolution of ampicillin sensitivity in the 1970-1995 period}; Poiata A et al.; The activity of ampicillin against 3383 Enterobacteriaceae (community and clinical isolates), collected in Eastern Romania, during 25 years was tested . Data were prelucrated by the box-plot method proposed by Simpson and Donnelly . The resistance degree for all species tested has progressively increased . In the studied region Enterobacteriaceae strains maintain their natural sensitivity only exceptionally: e.g., S . typhi and S . java, with limited circulation . Enterobacteriaceae which have contact with the resistance genic reservoir of the colon microbiota during the justified or nonjustified antibiotic treatment development resistance to usual antibiotics in the same ratio as most existent commensals present in this habitat. Mol Gen Mikrobiol Virusol, 1997, (2), 36 - 40 {Prevalence of IS285 and IS100 in Yersinia pestis and Yersinia pseudotuberculosis genomes}; Bobrov AG et al.; Cell DNAs of various species of Enterobacteriaceae were hybridized with the probes based on IS285 and IS100, mobile genetic elements of Yersinia pestis . These IS elements are found only in the genomes of all tested Y . pestis strains and a number of strains of a related bacterium Y . pseudotuberculosis . Phylogenetic relations between the tested strains and correlation of fingerprints with the geographical origin of the strains were revealed by analysis of the hybridization profiles of Y . pestis and Y . pseudotuberculosis chromosomal DNAs with IS probes . Comparison of the chromosomal IS100 profiles of Y . pestis wild strain and its nonpigmented mutant helped us determine the minimal extension of the genetic rearrangement and detect at least three copies of the IS element in the mutant region. Adv Exp Med Biol, 1997, 412, 349 - 55 A novel regulatory mechanism for a novel phase-variable outer membrane protein of Escherichia coli; Henderson IR et al.; Antigen 43 (Ag43) is a prominent hetero-oligomeric protein complex in the outer membrane of Escherichia coli . It is composed of two subunits . alpha 43 (M(r) 60, 000) and beta 43 (M(r) 53, 000) in 1:1 stoichiometry . alpha 43 is surface expressed, extends beyond the O-side chains of smooth lipopolysaccharide and is bound to the cell surface through an interaction with beta 43, itself an integral outer membrane protein, alpha 43 shows limited sequence homology with some enterobacterial adhesins . Expression of Ag43 is subject to reversible phase variation, the rates of variation from the Ag43+ve to Ag43-ve states in liquid minimal medium being approximately 2.2 x 10(-3), the corresponding rates from Ag43-ve to Ag43+ve states being approximately 1 x 10(-3) . Phase switching of genes encoding Ag43 are transcriptionally regulated by DNA methylation (deoxyadenosine methylase {dam} mutants being "locked OFF") and by OxyR (oxyR mutants being "locked ON") . It is proposed that OxyR acts as a repressor of Ag43 transcription by binding to unmethylated GATC sites in the regulatory region of the gene . Sequencing and mapping has identified Ag43 as the likely product of the metastable flu gene first described in 1980 by Diderichsen and responsible for colony form variation in E . coli. Mikrobiologiia, 1997 Jan-Feb, 66(1), 54 - 9 {Features of metabolism of Klebsiella genus bacteria}; Pishchik VN et al.; Some metabolic peculiarities of bacteria of the genus Klebsiella were investigated . The bacteria under study were isolated from different sources and varied in virulence . The pathogenic and saprotrophic enterobacteria were discriminated based on their response to the addition of carbohydrates or nitrate to the medium . Pathogenic Klebsiella spp . exhibited mainly the mixed formic-acid type of fermentation and were more resistant to nitrates than saprotrophic bacteria with the butanediol type of fermentation . The bacteria Klebsiella pneumoniae subsp . pneumoniae isolated from different sources, such as patients, healthy persons, or the environment, exhibited no substantial differences in metabolism and virulence . It was inferred that these bacteria themselves cannot cause disease, and their isolation in morbid states is an indirect result of dysbacteriosis. Diagn Microbiol Infect Dis, 1997 Jan-Feb, 27(1-2), 7 - 12 Antimicrobial activity of RU-66647, a new ketolide; Jones RN et al.; A new macrolide subclass called ketolides, possess a mode of action similar to the macrolide-lincosamide-streptogramin (MLS) compounds . Utilizing reference in vitro tests, the in vitro activity of RU-66647 (a ketolide) was compared to other MLS compounds against 376 Gram-positive organisms and over 400 representative strains of Gram-negative bacilli . The ketolide's spectrum was most similar to clindamycin and an earlier drug in the series (RU-64004 or RU-004) against staphylococci and streptococci . However, RU-66647 was more active than erythromycin and azithromycin against oxacillin-resistant Staphylococcus spp . and vancomycin-resistant enterococci . Ketolide activity was more potent than other MLS drugs against vancomycin-susceptible enterococci (MIC90, 0.25-4 micrograms/ml) and all streptococci (MICs, < or = 0.25 microgram/ml) . Erythromycin-resistant (constitutive) strains were generally inhibited by < or = 2 micrograms RU-66647/ml (staphylococci, 31 to 36%; streptococci, 100%; enterococci, 72%) . RU-66647 was active against Haemophilus influenzae (MIC90, 2 micrograms/ml), Moraxella catarrhalis (MIC90, 0.12 microgram/ml), and pathogenic Neisseria spp . (MIC90 0.5 microgram/ml) . The ketolide failed to inhibit Enterobacteriaceae, nonfermentative Gram-negative bacilli, and Bacteriodes fragilis group strains . RU-66647 was observed to be a promising new compound directed toward some organisms resistant to other MLS-class drugs. Antibiot Khimioter, 1997, 42(2), 26 - 32 {Use of piperacillin-tazobactam in abdominal surgery}; Savov AM et al.; Piperacillin/tazobactam (P/T) was used in the monotherapy of 40 patients with various inflammatory diseases of the abdominal cavity organs . P/T was administered as dropwise intravenous infusions in a single dose of 4/0.5 g 3 times a day for 5 to 17 days . In 82.5 per cent of the patients with infection of the abdominal cavity: severe postoperative purulent wounds, peritonitis of various etiology (biliary, serous-fibrinous, hemorrhagic fibrinous), postnecrotic cyst of the pancrease, abscesses of the liver and subhepatic space P/T proved to be highly efficient . The P/T monotherapy resulted in practically complete eradication of anaerobic microbes, coagulase negative staphylococci, enterobacteria and nonfermenting bacteria except for Pseudomonas aeruginosa in the inflammation foci. Salud Publica Mex, 1997 Jan-Feb, 39(1), 25 - 31 {Epidemiology of nosocomial infections in a second level hospital}; Tinoco JC et al.; OBJECTIVE: To determine the incidence, specific rates, areas of greatest risk and causal agents of nosocomial infections at the Hospital General de Durango, of the Secretaria de Salud, Mexico . MATERIAL AND METHODS: Prospective study of nosocomial infection vigilance during one year including all patients discharged during this period . RESULTS: An overall rate of 9 infections per 100 discharged patients was found, the higher specific rates were in the areas of intensive pediatric care and births and the lowest were in the surgery, pediatric and gynecology and obstetrics departments . Infections were most frequent in urinary tract and surgical wounds as well as pneumonia among adults; among children, the most frequent were bacteremias and an epidemic outbreak with predominating Serratia marscecens was observed . Most patients presented one only infectious process and E coli, Klebsiello and Enterobacter sp . were the most frequently isolated microorganisms . CONCLUSIONS: The nosocomial infection rate observed in this study is higher than the average in Mexico for similar institutions . The most affected areas were those of critical patients and new births with urinary tract and surgical wound infections, and pneumonia, and the most frequent causal agents were enteric Gram-negative bacilli . These findings suggest guide lines for the design of a nosocomial infection control program, adjusted to the particular features of each institution. J Antimicrob Chemother, 1997 Jan, 39(1), 103 - 6 Reduced susceptibility to co-amoxiclav in Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae isolated in Romania between 1985 and 1993; Espinasse F et al.; By determining the beta-lactam susceptibility of Enterobacteriaceae isolated in Eastern Romania from 1985 to 1993, three Escherichia coli, three Salmonella typhimurium and one Klebsiella pneumoniae isolates with reduced susceptibility to co-amoxiclav were found . The antibiotic susceptibility of the isolates and their E . coli derivatives, and kinetic values suggested the following resistance mechanisms: hyperproduction of TEM in S . typhimurium, limited antibiotic uptake in K . pneumoniae and OXA production in one strain of E . coli . Despite a normal beta-lactamase activity, the two remaining E . coli strains and their derivatives were less susceptible to co-amoxiclav. Proteins, 1997 Jan, 27(1), 47 - 58 A disulfide bridge near the active site of carbapenem-hydrolyzing class A beta-lactamases might explain their unusual substrate profile; Raquet X et al.; Bacterial resistance to beta-lactam antibiotics, a clinically worrying and recurrent problem, is often due to the production of beta-lactamases, enzymes that efficiently hydrolyze the amide bond of the beta-lactam nucleus . Imipenem and other carbapenems escape the activity of most active site serine beta-lactamases and have therefore become very popular drugs for antibacterial chemotherapy in the hospital environment . Their usefulness is, however, threatened by the appearance of new beta-lactamases that efficiently hydrolyze them . This study is focused on the structure and properties of two recently described class A carbapenemases, produced by Serratia marcescens and Enterobacter cloacae strains and leads to a better understanding of the specificity of beta-lactamases . In turn, this will contribute to the design of better antibacterial drugs . Three-dimensional models of the two class A carbapenemases were constructed by homology modeling . They suggested the presence, near the active site of the enzymes, of a disulfide bridge (C69-C238) whose existence was experimentally confirmed . Kinetic parameters were measured with the purified Sme-1 carbapenemase, and an attempt was made to explain its specific substrate profile by analyzing the structures of minimized Henri-Michaelis complexes and comparing them to those obtained for the "classical" TEM-1 beta-lactamase . The peculiar substrate profile of the carbapenemases appears to be strongly correlated with the presence of the disulfide bridge between C69 and C238. Lett Appl Microbiol, 1997 Jan, 24(1), 9 - 13 Thermal resistance of Enterobacter sakazakii in reconstituted dried-infant formula; Nazarowec-White M et al.; Enterobacter sakazakii, designated a unique species in 1980, has been implicated in a rare but severe form of neonatal meningitis, with dried-infant formula being implicated as the mode of transmission . The high mortality rate (40-80%) and the lack of information about this organism led to a study of the heat resistance of Ent . sakazakii in reconstituted dried-infant formula . Ten Canadian Ent . sakazakii strains (5 clinical and 5 food isolates) were used to determine the heat resistance of this organism at 52, 54, 56, 58 and 60 degrees C in reconstituted dried-infant formula . D-values of 54.8, 23.7, 10.3, 4.2 and 2.5 min were obtained for each temperature, respectively . The overall calculated z-value was 5.82 degrees C . In a comparison of the D-values of several members of the Enterobacteriaceae in dairy products, Ent . sakazakii appeared to be one of the most thermotolerant organisms . The importance of process control during manufacture and the use of aseptic procedures during the preparation, use and storage of dried-infant formula is discussed. Clin Nephrol, 1997 Jan, 47(1), 13 - 8 Pathogenetic aspects of uncomplicated urinary tract infection: recent advances; Funfstuck R et al.; Urinary tract infections mostly are caused by Enterobacteriaceae; E . coli dominating in 80-90% for uncomplicated diseases . Microorganisms possessing the ability to colonize the uroepithelium (fimbriae/pili) and to cytotoxically damage cells and tissue (hemolysin) may initiate acute infection . Properties such as serum resistance, iron sequesteration, hydroxamate production and the presence of K-antigen are found in strains which persist in the host without initiating clinical symptoms . The ability of bacteria to adhere to cells of the epithelial boundary layer of the host organisms is of initial importance in the origin and progress of an infection . A variety of specific factors, e.g . glycolipids on the surface of the uroepithelium as well as cellular and humoral disorders of immunoreactions in the host determine the course of a disease . The immune response may ameliorate clinical symptoms and select urovirulent characteristics of the causative microorganism in recurrent diseases. Otolaryngol Head Neck Surg, 1997 Jan, 116(1), 16 - 22 Contemporary management of deep neck space infections; Gidley PW et al.; Deep neck infections continue to be seen despite the wide use of antibiotics . These infections follow along fascial planes to create deep neck space abscesses . The clinical presentation often points to the space involved . Understanding the regional anatomy gives the surgeon the ability to treat these grave infections . The records of 24 patients with a diagnosis of deep neck space abscess admitted to Hermann Hospital between 1988 and 1993 were reviewed . Fifty percent of the patients had received antibiotics for an infection of the ear, nose, or throat before the development of a neck space abscess . Ten patients had parapharyngeal abscesses, seven had retropharyngeal abscesses, six had submandibular space abscesses, and one had parotid space abscess . Thirty-five organisms were isolated in 18 cases (1.9 isolates per patient) . The most common organism cultured was Streptococcus (13 of 18), followed by Staphylococcus (6 of 18), Bacteroides (5 of 18), Micrococcus (2 of 18), and Neisseria (2 of 18) . One case each of Candida, Enterobacter, Enterococcus, Peptostreptococcus, Proteus, Proprionobacter, and Pseudomonas was cultured . Six patients had no growth on culture but did have organisms found on Gram's stain . The operative techniques and antibiotics used are discussed . The main complications of jugular vein thrombosis, carotid artery rupture, and mediastinitis are described, as well as an unusual case of meningitis from a large retropharyngeal-parapharyngeal abscess. Biol Pharm Bull, 1997 Jan, 20(1), 110 - 2 Molecular cloning of the nemA gene encoding N-ethylmaleimide reductase from Escherichia coli; Miura K et al.; Using the gene mapping membrane technique, we identified a gene (nemA) that encodes N-ethylmaleimide reductase in Escherichia coli . The open reading frame encodes a polypeptide of 365 amino acids with a molecular mass of 39,514 Da . The deduced amino acid sequence showed a high degree of homology (87% identical) with the pentaerythritol tetranitrate reductase of Enterobacter cloacae and the morphinone reductase of Pseudomonas putida (52% identical). Chemotherapy, 1997 Jan-Feb, 43(1), 69 - 76 Changing patterns of bacterial nosocomial infections: a nine-year study in a general hospital; Maniatis AN et al.; Surveillance data on 12,944 bacterial isolates derived from nosocomial infections, reported to the Department of Microbiology and Infectious Diseases of the Hellenic Air Force and VA General Hospital over a 9-year period (1986-1994), were analyzed by the use of a microbial infection control software system . Overall, the isolation rate of Escherichia coli decreased from 25.2% in 1986 to 18.2% in 1994 and Proteus spp . from 5.3 to 2.6% . Remarkably, Pseudomonas spp . increased from 7.2 to 11.3%, Enterobacter spp . from 1.6 to 5.1%, Klebsiella spp . from 5.9 to 7.8% and Enterococcus spp . from 3 to 7.4% . Interestingly, the above phenomenon was paralleled by a significant increase in resistance rate to various antibiotics . Specifically, Staphylococcus aureus and coagulase-negative staphylococci, though they did not display any significant variation in isolation rates, showed an alarming increase in resistance rate to oxacillin, from 11 and 21% in 1986 to 51 and 75% in 1994, respectively . Enterococcus spp . sensitivity to vancomycin remained unlatered at 90% . The above-mentioned serious shift towards more resistant bacteria should be a matter of consideration. Chest, 1997 Jan, 111(1), 194 - 7 Heterogeneous Serratia marcescens genotypes from a nosocomial pediatric outbreak; Cimolai N et al.; OBJECTIVE: Define the applicability of a rapid molecular typing scheme to study the epidemiology of a Serratia marcescens outbreak . DESIGN: With the assistance of a simple bacterial lysis technique, isolates of S marcescens from a putative outbreak were genotyped with the polymerase chain reaction technology for which primers were chosen on the basis of previously defined enterobacterial repetitive intergenic consensus sequences . SETTING: Pediatric ICU . PATIENTS: Intensively monitored patients who were found to yield S marcescens from any body site during the epidemic period . RESULTS: Over an 8-month period, 12 ICU patients were either infected or colonized with S marcescens . All of these patients were transiently supported by artificial ventilation . During the epidemiologic investigation, a dilution error in a high-level glutaraldehyde disinfectant, which was being used for some ventilator components, was observed . Rectification of the error was associated with an abrupt termination of the outbreak . Enterobacterial repetitive intergenic consensus polymerase chain reaction was easily applicable to this setting and it defined 4 distinct genotypes among the 12 isolates . CONCLUSION: The typing method is easily implemented and offers great promise as an epidemiologic tool . The associated investigation served to emphasize that an outbreak may occur with more than one epidemic strain and that strain heterogeneity itself does not exclude an outbreak. Am J Gastroenterol, 1997 Jan, 92(1), 47 - 51 Small intestinal bacterial overgrowth in the symptomatic elderly; Riordan SM et al.; OBJECTIVE: 1) To determine the prevalence of small intestinal overgrowth with colonic-type bacteria in symptomatic elderly subjects, particularly those without important "clues" such as clinically apparent predisposition or vitamin B12 deficiency, and 2) to investigate defense mechanisms such as gastric acidity, small intestinal motility, and luminal IgA in this setting . METHODS: Fifty-two symptomatic subjects without vitamin B12 deficiency or clinically apparent predisposition to bacterial overgrowth or disturbed mucosal immunity, including 22 subjects > or = 75 yr old, underwent culture of small intestinal luminal secretions . Indicator paper was used to measure fasting gastric pH . The presence of bacteria of confirmed nonsalivary origin in small intestinal secretions served as an index of small intestinal dysmotility . Small intestinal luminal IgA concentrations were measured by radial immunodiffusion . RESULTS: Small intestinal overgrowth with colonic-type flora was not present in any subject investigated for dyspepsia, irrespective of age . In subjects with chronic diarrhea, anorexia, or nausea, overgrowth with colonic-type flora (Enterobacteriaceae) was present in 0/12 (0%), 1/10 (10.0%), and 9/14 (64.3%) subjects aged < 50 yr, 50-74 yr, and > or = 75 yr, respectively . Enterobacteriaceae were not concurrently recovered from saliva of any subject > or = 75 yr old with small intestinal overgrowth with these bacteria . Fasting hypochlorhydria was present in only 1/9 (11.1%) such subjects . Luminal IgA concentrations were significantly greater in subjects > or = 75 yr old with bacterial overgrowth than in culture-negative subjects (p < or = 0.003) . CONCLUSIONS: Small intestinal overgrowth with colonic-type bacterial should be considered in subjects > or = 75 yr old with chronic diarrhea, anorexia, or nausea, even in the absence of clues such as clinically apparent predisposition or vitamin B12 deficiency . Small intestinal dysmotility, rather than fasting hypochlorhydria or mucosal immunosenescence, probably is responsible for the prevalence of bacterial overgrowth in this group. Crit Care Med, 1997 Jan, 25(1), 63 - 71 Randomized, controlled trial of selective digestive decontamination in 600 mechanically ventilated patients in a multidisciplinary intensive care unit; Verwaest C et al.; OBJECTIVE: To evaluate the efficacy of two regimens of selective decontamination of the digestive tract in mechanically ventilated patients . DESIGN: Prospective, randomized, concurrent trial . SETTING: Multidisciplinary intensive care unit (ICU) in a 1,800-bed university hospital . PATIENTS: Consecutive patients (n = 660) who were likely to require mechanical ventilation for at least 48 hrs were randomized to one of three groups: conventional antibiotic regimen (control group A); oral and enteral ofloxacin-amphotericin B (group B); and oral and enteral polymyxin E-tobramycin-amphotericin B (group C) . Both treatment groups received systemic antibiotics for 4 days (ofloxacin in group B and cefotaxime in group C) . INTERVENTIONS: Patients were randomized to receive standard treatment (control group A, n = 220), selective decontamination regimen B (group B, n = 220), and selective decontamination regimen C (group C, n = 220) . After early deaths and exclusions from the study, 185 controls (group A) and 193 (group B)/200 (group C) selective decontamination regimen patients were available for analysis . MEASUREMENTS AND MAIN RESULTS: Measurements included colonization and primary/secondary infection rate, ICU mortality rate, emergence of antibiotic resistance, length of ICU stay, and antimicrobial agent costs . The study duration was 19 months . The patient groups were fully comparable for age, diagnostic category, and severity of illness . One third of patients in each group suffered a nosocomial infection at the time of admission . There was a significant difference between treatment group B and control group A in the number of infected patients (odds ratio of 0.42, 95% confidence interval of 0.27 to 0.64), secondary lower respiratory tract infection (odds ratio of 0.47, 95% confidence interval of 0.26 to 0.82), and urinary tract infection (odds ratio of 0.47, 95% confidence interval of 0.27 to 0.81) . Significantly more Gram-positive bacteremias occurred in treatment group C vs . group A (odds ratio of 1.22, 95% confidence interval 0.72 to 2.08) . Infection at the time of admission proved to be the most significant risk factor for subsequent infection in control and both treatment groups . ICU mortality rate was almost identical (group A 16.8%, group B 17.6%, and group C 15.5%) and was not significantly related to primary or secondary infection . Increased antimicrobial resistance was recorded in both treatment groups: tobramycin-resistant enterobacteriaceae (group C 48% vs . group A 14%, p < .01), ofloxacin-resistant enterobacteriaceae (group B 50% vs . group A 11%, p < .02), ofloxacin-resistant nonfermenters (group B 81% vs . group A 52%, p < .02), and methicillin-resistant Staphylococcus aureus (group C 83% vs . group A 55%, p < .05) . Antimicrobial agent costs were comparable in control and group C patients; one third less was spent for group B patients . CONCLUSIONS: In cases of high colonization and infection rates at the time of ICU admission, the preventive benefit of selective decontamination is highly debatable . Emergence of multiple antibiotic-resistant microorganisms creates a clinical problem and a definite change in the ecology of environmental, colonizing, and infecting bacteria . The selection of multiple antibiotic-resistant Gram-positive cocci is particularly hazardous . No beneficial effect on survival is observed . Moreover, selective decontamination adds substantially to the cost of ICU care. Antimicrob Agents Chemother, 1997 Jan, 41(1), 204 - 11 Antimicrobial activity and spectrum of LB20304, a novel fluoronaphthyridone; Cormican MG et al.; Compound LB20304 is a fluoronaphthyridone carboxylic acid with a novel pyrrolidine substituent . This drug was compared with ciprofloxacin, levofloxacin, ofloxacin, and trovafloxacin against over 800 pathogens, most from blood stream infections, by National Committee for Clinical Laboratory Standards reference methods . LB20304 was the most active agent against gram-positive species including strains observed to be resistant to other fluoroquinolones and glycopeptides . The potency of LB20304 (MIC50, 0.03 micrograms/ml) against the Enterobacteriaceae was exceeded only by that of ciprofloxacin (0.015 micrograms/ml) . It has limited activity against gram-negative anaerobes. Antimicrob Agents Chemother, 1997 Jan, 41(1), 35 - 9 Beta-lactamases and detection of beta-lactam resistance in Enterobacter spp; Pitout JD et al.; Enterobacter spp . are becoming increasingly frequent nosocomial pathogens, and beta-lactam-resistant strains are on the increase, especially among isolates recovered from intensive care units . Therefore, a study was designed to characterize the beta-lactamases produced by 80 isolates of E . cloacae, E . aerogenes, E . taylorae, E . gergoviae, E . sakazakii, E . asburiae, and E . agglomerans by induction studies, spectrophotometric hydrolysis assays, and isoelectric focusing . The ability of broth microdilution and disk diffusion susceptibility tests to detect resistance to 16 beta-lactam antibiotics among these species was also assessed . All species except E . agglomerans, E . gergoviae, and some isolates of E . sakazakii were found to produce a Bush group 1 cephalosporinase that was expressed inducibly or constitutively at high levels . In addition, some strains also produced a Bush group 2 beta-lactamase . In comparisons of broth microdilution and disk diffusion tests, disk diffusion tests failed to detect resistance in 1 of 25 isolates resistant to aztreonam and 2 of 30 isolates resistant to ceftazidime . These results indicate that species of Enterobacter can possess a variety of beta-lactamases that are responsible for beta-lactam resistance in this genus and that the disk diffusion test may occasionally miss resistance in some strains. J Am Vet Med Assoc, 1997 Jan 1, 210(1), 55 - 8 Microbiological study of transtracheal aspirates from dogs with suspected lower respiratory tract disease: 264 cases (1989-1995); Angus JC et al.; OBJECTIVE: To determine the most commonly isolated bacterial species associated with lower respiratory tract disease of dogs and to determine susceptibility of these isolates to antimicrobial agents . DESIGN: Retrospective case series . SAMPLE POPULATION: Transtracheal aspirates from 264 dogs with clinical evidence of lower respiratory tract disease . PROCEDURE: Records of microbiological analyses of transtracheal aspirates obtained from dogs with clinical evidence of lower respiratory tract disease were reviewed . Analyses performed included bacterial culture (anaerobic and aerobic organisms) and susceptibility testing (aerobic organisms) . The medical record of each affected dog was evaluated to determine signalment and underlying condition . RESULTS: Bacteria were isolated from 116 of 264 (44%) samples, and 203 bacterial species were identified . Most (57%) of the samples from which bacteria could be isolated contained a single species, whereas 43% yielded cultures of mixed species . Bacterial species belonging to the family Enterobacteriaceae (particularly Escherichia coli) were isolated most commonly (45.7% of samples contained members of this group), followed by members of the genus Pasteurella (22.4%), obligate anaerobes (21.6%), beta-hemolytic Streptococcus (12.1%), Bordetella bronchiseptica (12.1%), nonhemolytic Streptococcus/Enterococcus sp group (12.1%), coagulase-positive Staphylococcus (9.5%), and Pseudomonas sp (7.8%) . The most active antimicrobial drugs (inhibiting > 90% of the isolates) for aerobic microorganisms encountered most often (E . coli and Pasteurella sp) included amikacin, ceftizoxime sodium, enrofloxacin, and gentamicin sulfate . CLINICAL IMPLICATIONS: Amikacin, ceftizoxime, enrofloxacin, and gentamicin may be rational choices for treatment of suspected infectious lower respiratory tract disease of dogs, before identification of the causative agent(s) and before results of susceptibility tests become available. J Clin Microbiol, 1997 Jan, 35(1), 288 - 91 Genomic fingerprinting of Haemophilus somnus by a combination of PCR methods; Appuhamy S et al.; Twenty-three isolates of Haemophilus somnus were typed by repetitive extragenic palindromic (REP) element-based PCR, enterobacterial repetitive intergenic consensus (ERIC)-based PCR, and PCR ribotyping . A total of 11 types were distinguished by REP-PCR, 13 types were distinguished by ERIC-PCR, and 5 types were distinguished by PCR ribotyping . PCR ribotyping produced a relatively simple pattern and a small number of distinct types, whereas REP- and ERIC-PCR both produced more complex banding patterns but increased the discrimination between strains . Clearly distinguishable profiles were obtained for respiratory and genital isolates of H . somnus by all three typing methods . The results suggest that a combination of all three primer sets provides a high-resolution fingerprinting method for epidemiological studies of H . somnus and for its differentiation from related species. J Clin Microbiol, 1997 Jan, 35(1), 152 - 60 Molecular epidemiology of an outbreak of multidrug-resistant Enterobacter aerogenes infections and in vivo emergence of imipenem resistance; De Gheldre Y et al.; Molecular typing was used to investigate an outbreak of infection caused by multidrug-resistant Enterobacter aerogenes (MREA) susceptible only to gentamicin and imipenem in an intensive care unit (ICU) . Over a 9-month period, ciprofloxacin-resistant E . aerogenes isolates were isolated from 34 patients, or 4.1% of ICU admissions, compared with a baseline rate of 0.1% in the previous period (P < 0.001) . Infection developed in 15 (44%) patients . In vivo emergence of imipenem resistance (MIC, 32 micrograms/ml) of organisms causing deep-seated infection was observed in two (13%) of these patients following prolonged therapy with imipenem and gentamicin . Arbitrarily primed PCR (AP-PCR) analysis with ERIC1R and ERIC2 primers and pulsed-field gel electrophoresis (PFGE) analysis of XbaI macrorestriction patterns concordantly showed that outbreak-associated MREA isolates were clonally related and distinct from epidemiologically unrelated strains . AP-PCR and PFGE showed discrimination indices of 0.88 and 0.98, respectively . Space-time clustering of cases within units suggests that the epidemic-related MREA isolates were transmitted on the hands of the health care personnel . A case-control study and repeated environmental culture surveys failed to identify a common source or procedure associated with transmission . In spite of the early implementation of isolation measures, the incidence of MREA colonization remained stable until all colonized patients were discharged . This study confirms the usefulness of AP-PCR and PFGE analyses for the epidemiological study of E . aerogenes and underscores the difficulty of controlling the spread of multiresistant clones of this organism in the ICU setting . The emergence of imipenem resistance represents a threat because virtually no therapeutic option is available for such strains. DNA Res, 1996 Dec 31, 3(6), 415 - 9 Structure of the dnaA region of the endosymbiont, Buchnera aphidicola, of aphid Schizaphis graminum; Hassan AK et al.; Buchnera aphidicola is an intracellular prokaryote (endosymbiont) that lives in the body cavity of the aphid . Phylogenetic studies indicated that it is closely related to Escherichia coli and members of Enterobacteria . The gene order of the region containing the dnaA gene is well conserved in many bacteria . Seven genes of the endosymbiont of the aphid Schizaphis graminum, gyrB, dnaN, dnaA, rpmH, rnpA, yidD, and 60K . were found to be homologous in sequence and relative location to those of E . coli . We have further sequenced the region downstream of the 60K gene to elucidate the boundary of the conserved region, and found that one more gene, thdF, is conserved . The comparison of gene organizations of the dnaA region of the related bacteria supported the close phylogenetic relationship of B . aphidicola to E . coli . In addition, we have identified groES and groEL genes next to the thdF gene . GroEL protein was reported to be expressed at an elevated level in the endosymbionts of aphids, and is considered to play an important role in their association with the aphid host . Comparison of the structure of the groE operon with that of the endosymbiont of the aphid Acyrthosiphon pisum revealed the conservation of a sequence resembling the E . coli consensus heat shock promoter, and this sequence may be responsible for the high expression of the groEL gene in aphid endosymbionts. Gene, 1996 Dec 12, 183(1-2), 243 - 53 Cloning and nucleotide sequence of a flagellin encoding genetic locus from Xenorhabdus nematophilus: phase variation leads to differential transcription of two flagellar genes (fliCD); Givaudan A et al.; The insect-pathogenic bacterium Xenorhabdus undergoes spontaneous phase variation involving a large number of phenotypes . Our previous study indicated that phase I variants were motile, whereas phase II variants of X . nematophilus F1 were nonflagellated cells which did not synthesize flagellin {Givaudan A., Baghdiguian, S., Lanois, A . and Boemare, N . (1995) Appl . Environ . Microbiol . 61, 1408-1413} . In order to approach the study of the flagellar switching, a locus containing two ORFs from X . nematophilus F1 (phase I) was identified by using functional complementation of flagellin-negative E . coli . The sequence analysis revealed that the first ORF corresponds to the fliC gene coding for flagellin, and showed a high degree of homology between the N-terminal and C-terminal of Xenorhabdus FliC and flagellins from other bacteria . The second identified ORF in the opposite orientation encodes a homologue of the enterobacterial hook-associated protein 2, FliD . Both Xenorhabdus fliCD genes were required for the entire restoration of E . coli motility . A sequence highly homologous to the sigma 28 consensus promoter was identified upstream from the coding sequences from both genes . The structure of the fliC gene and its surrounding region was shown to be the same in both phase variants, but Northern blot analysis revealed that fliC and fliD were, respectively, not and weakly transcribed in phase II variants . In addition, complementation experiments showed that motility and flagellin synthesis of phase II cannot be recovered by placing in trans fliCD genes from phase I . These latter results suggest that a gene(s) higher in the transcriptional hierarchy of the flagellar regulon is switched off in Xenorhabdus phase II variants. Biochemistry, 1996 Dec 3, 35(48), 15143 - 8 The central domain of colicin N possesses the receptor recognition site but not the binding affinity of the whole toxin; Evans LJ et al.; Colicin N is a three-domain pore-forming colicin which kills enterobacterial cells following an initial binding to its receptor, the outer membrane porin OmpF . The receptor-binding domain of colicin N alone, and attached to the translocation domain, was overexpressed and purified using a hexahistidine tag . The receptor domain attached to the pore-forming domain was obtained by enzymatic digestion . Circular dichroism spectroscopy showed that the domains have structure in keeping with the known structure of colicin N . The receptor domain was stable, retaining both secondary and tertiary structure in 2 M guanidine hydrochloride and at low pH . It bound to both OmpF and PhoE porin-producing Escherichia coli with no toxicity and protected sensitive E . coli against intact colicin N toxicity at high domain/ colicin N ratios . Its in vitro affinity for OmpF, as determined by isothermal titration microcalorimetry, was found to be approximately 50-fold weaker than that of native colicin N . The receptor domain was readily out-competed by native colicin N in in vivo fluorescence assays which, coupled with its structural stability, suggests that its interaction with OmpF is one of weak, reversible binding . Since neither of the double domain constructs shows wild-type binding affinity either, it appears that the molecular recognition is a property of the receptor domain but that affinity is influenced by the entire molecule. Cent Afr J Med, 1996 Dec, 42(12), 332 - 6 Aerobic bacteria isolated from blood cultures of patients and their antibiotic susceptibilities in Harare, Zimbabwe; Obi CL et al.; OBJECTIVE: To assess the extent of involvement of different types of gram positive and gram negative bacteria and incidence of monomicrobial and polymicrobial cases in patients with bacteremia but without a record of the underlying clinical conditions of the patients . Antibiotic susceptibility patterns of isolates were also determined to guide clinicians in the management of such bacteremic cases especially where routine sensitivity testing is not performed . DESIGN: Case series . SETTING: The study comprised patients attending different clinics in Parirenyatwa Hospital, Harare . SUBJECTS: A total of 817 blood cultures from patients, comprising 469 and 348 males and females respectively . There were no records of the underlying clinical conditions of the patients . MAIN OUTCOME MEASURES: Prevalence rates of organisms and their antibiograms using standard techniques and Kirby-Bauer disc diffusion method . RESULTS: Results obtained revealed that only 303(37.1%) of the 817 total samples screened were positive for either monomicrobial or polymicrobial bacteremia . Two hundred and eighteen (71.9%) and 85 of positive cultures were Gram positive and Gram negative bacteria respectively . Coagulase negative staphylococci (CNS) strains were the predominant organisms isolated (42.9%) . Other organisms isolated were Staphylococcus aureus (11.6%), Escherichia coli (6.9%), Salmonella spp . (8.3%), Klebsiella spp . (5.3%), whereas Pseudomonas aeruginosa, Haemophilus influenzae, Enterobacter and Micrococcus species each accounted for less than 4% . Antibiogram patterns showed multiple resistance of S . aureus and CNS to Penicillin, Erythromycin and Methicillin . All isolates of S . pyogenes (10), S . pneumoniae (18) and Micrococcus spp (10) . were susceptible to penicillin . Ciprofloxacin, Clindamycin, Fusidic acid and Gentamycin were highly active against gram positive organisms except that Gentamycin was inactive against S . pneumoniae . Ceforoxime, Erythromycin and Ceftriazone also showed good activities against Gram positive organisms . All (10) isolates of P . aeruginosa were susceptible to Polymyxin B, Carbenicillin and Ciprofloxacin . Ciprofloxacin, Norfloxacin and Gentamycin were highly active against all Gram negative bacteria . CONCLUSION: For infections due to both Gram positive and Gram negative bacteria, Ciprofloxacin and Gentamycin would be appropriate for therapy whereas Fusidic acid and Clindamycin may, in addition, be recommended for Gram positive organisms . It is also concluded that a prevalence rate of 37.1% of bacteremic cases existed in the sampled population and that monomicrobial cases were more predominant. Antimicrob Agents Chemother, 1996 Dec, 40(12), 2854 - 8 Prevalence of outer membrane porin alteration in beta-lactam-antibiotic-resistant Enterobacter aerogenes; Charrel RN et al.; We evaluated the prevalence of impermeability as a mechanism associated with resistance against beta-lactam antibiotics in members of the family Enterobacteriaceae . During a 1-year period, 80 strains were selected from 3,110 routinely isolated strains according to their noticeable cross-resistance pattern to cephalosporins . They were tested for (i) outer membrane nonspecific porins involved in the entry of small hydrophilic molecules; (ii) the MICs of cefepime, cefotaxime, imipenem, and moxalactam; and (iii) beta-lactamase production . Immunological investigations using specific probes showed that 23 of 80 strains presented an alteration of the porin content, most of them expressing an additional resistance mechanism . The prevalence of this porin-deficient phenotype is especially high in Enterobacter aerogenes and concerns 6.4% of the clinical isolates. Antimicrob Agents Chemother, 1996 Dec, 40(12), 2792 - 5 Inexpensive 4-hour micro-agar dilution susceptibility determination method; Holloway Y et al.; Using a micro-agar dilution (MAD) method in which microscope slides are covered with a thin film of agar, and MICs are read microscopically after a 4-h incubation, 18 antibiotics were tested against 29 to 32 microorganisms each . Identical MICs were obtained for microscopic MAD MICs performed in duplicate in 87.1% of the antibiotic-microorganism combinations, and 97.9% were identical within one dilution . When read macroscopically after an 18-h incubation, identical duplicate MICs were obtained in 86.8% of the cases, and 98.4% were identical within one dilution . Using agar dilution as the "gold standard," the correlation obtained with MAD slides read microscopically at 4 h was 94.3%, and macroscopic correlation at 18 h was 97.6% . The correlation of MAD slides with agar dilution for the groups of microorganisms most frequently used was as follows (microscopic/macroscopic): Staphylococcus aureus 96%/98%; Streptococcaceae 97%/98%; Enterobacteriaceae 98%/99%; and Pseudomonadaceae 95%/98% . At the present rate of exchange (fl 1.60 = $1.00f1p4he cost of a MAD slide, including labor, is $1.28 (20 microorganisms tested) or $0.06 per microorganism-antibiotic combination tested . This method is easy to perform, rapid, and inexpensive . It is suitable for use in routine and research laboratories. Arch Microbiol, 1996 Dec, 166(6), 388 - 93 Ammonia-excreting mutants of Klebsiella pneumoniae with a pleiotropic defect in nitrogen metabolism; Kuczius T et al.; Enterobacterial mutants defective in the nitrogen control regulatory system (Ntr) generally display a pleiotropic phenotype with regard to expression and regulation of several enzymes and transport systems involved in the assimilation of N sources . This report describes the isolation and characterization of similar pleiotropic mutants of Klebsiella pneumoniae that cannot be complemented by ntr genes . The strains excreted ammonia, were unable to grow on a number of N sources, and contained low glutamine:2-oxoglutarate amino transferase and normal, but unmodifiable glutamine synthetase activities and a nitrogenase level largely unaffected by ammonium, but still repressible by an amino acid mixture . Genetic studies suggested that this phenotype is due to overexpression of an unknown regulatory protein. Am J Trop Med Hyg, 1996 Dec, 55(6), 610 - 6 Growth promotion of Mycobacterium avium-M . intracellulare complex by enterobacterial acetate; Gomez-Flores R et al.; A mycobacterial growth factor was present in the conditioned media of Escherichia coli and Enterobacter cloacae cultures, but not in Pseudomonas aeruginosa culture . This factor potentiated the growth of Mycobacterium avium-M . intracellulare complex (MAC), a patient isolate, and well-established strains of M . avium and M . intracellulare . The growth factor was not a polypeptide; it was heat-stable and possessed a molecular weight < 500 D . Acetate production by enterobacteria was responsible for the biological activities observed . Acetate promoted mycobacterial growth at concentrations up to 3 mM; higher levels were toxic . The effects of acetate on MAC growth were not influenced by the pH of the media . Our data suggest that production of acetate by enterobacteria may regulate mycobacterial growth, and therefore, intestinal acetate might be a cofactor in the pathogenicity of MAC. Arch Bronconeumol, 1996 Dec, 32(10), 541 - 3 {Surgical treatment of sternoclavicular osteomyelitis}; Gonzalez Munoz JI et al.; Osteomyelitis of the sternocosto-clavicular (SCC) articulation is a rare infection usually caused by Staphylococcus aureus and enterobacteria . It usually occurs in individuals with osteoarticular disease or predisposing factors . Prolonged antibiotic treatment and articular puncture are generally accepted . Authors do not agree on an established protocol . We report three cases of SCC septic arthritis in two previously healthy patients with two foci of infection (one perianal abscess and one dental extraction) and in one adult patient with Still's disease . Pain and intense inflammation was referred to the shoulder, with scarce leukocytosis and fever reaching 38 degrees C . The germs responsible were S . aureus, Bacteroides fragilis and B . oralis . Two of the patients had local, regional abscesses . Long-term antibiotic treatment failed in all cases and surgery for SCC resection and myoplasty of the pectoralis major muscle was required . Recovery was good and shoulder and arm mobility was excellent . We propose medical treatment and articular diagnostic-therapeutic puncture as the first line of therapy for this disease . When evolution is poor or when complications appear, such as abscesses or mediastinitis, we conclude that radical debridement and myoplasty of the pectoralis major muscle are indicated. Arzneimittelforschung, 1996 Dec, 46(12), 1169 - 73 Therapeutic effect of the quinolone prodrug prulifloxacin against experimental urinary tract infections in mice; Tomii Y et al.; The in vitro antibacterial activity of prulifloxacin (CAS 123447-62-1, NM441), a new quinoline prodrug, against clinical isolates from urinary tract infections was investigated . In addition, it was compared with ofloxacin (CAS 82419-36-1), levofloxacin (CAS 100986-85-4), ciprofloxacin urinary tract infections in mice, as well as its pharmacokinetics . 1 . The antibacterial activity of NM394 (6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H-{1,3}thiazeto{3,2- a}quinoline-3-carboxylic acid), an active metabolite of prulifloxacin, against gram-positive clinical isolates was inferior to that of levofloxacin and tosufloxacin, and equal to that of ofloxacin and ciprofloxacin . Against gram-negative clinical isolates, the activity of NM394 was superior to that of the reference drugs . 2 . The therapeutic effect of prulifloxacin on experimental urinary tract infection with Escherichia coli in mice was equal to that of tosufloxacin and ciprofloxacin and superior to that of ofloxacin and levofloxacin . Its therapeutic effect on Pseudomonas aeruginosa infection was equal to that of tosufloxacin and ciprofloxacin, and superior to that of ofloxacin . Against urinary tract infection with olfloxacin-resistant Enterobacter cloacae, prulifloxacin was the most effective of all the drugs tested . 3 . The maximal serum concentration of prulifloxacin was slightly higher than that of ciprofloxacin, and the area under the curve (AUC) for prulifloxacin was 1/4 that of ofloxacin, levofloxacin and tosufloxacin . The maximal concentration and AUC of prulifloxacin in lung and kidney were slightly higher than the corresponding values for ciprofloxacin but only 1/2 to 1/4 of the values for ofloxacin, levofloxacin and tosufloxacin . In conclusion, prulifloxacin (NM394) showed potent antibacterial activity against clinical isolates and potent therapeutic efficacy against experimental infection in spite of its lower AUCs compared with the reference drugs . These findings suggest that prulifloxacin may be a useful drug in the treatment of urinary tract infections. Am J Surg, 1996 Dec, 172(6A), 1S - 6S Antimicrobial therapy for intraabdominal infection; Nathens AB et al.; Timely and appropriate antimicrobial therapy is an essential component of the management of intraabdominal infection . Over the past three decades, our ability to treat these infections optimally has been enhanced by an increased understanding of the underlying microbial pathogens, by the development of new antimicrobial agents, and by the completion of several well-controlled clinical trials that guide treatment . This article provides an overview of the approach to antimicrobial therapy in patients with intraabdominal infection . A literature review was performed to collect the information used in this article . Data were derived from experimental and clinical studies evaluating the microbiology and treatment of intraabdominal infections . Evidence from both animal studies and clinical trials supports the initiation of empiric antimicrobial therapy directed against Escherichia coli and other common members of the family Enterobacteriaceae, as well as the anaerobe Bacteroides fragilis . Based on this premise, the clinician is faced with a broad selection of possible single agents, as well as combinations of agents that fulfill these criteria . The factors involved in selecting a specific regimen include consideration of the antimicrobial spectrum of various agents, experimental animal studies evaluating their efficacy, and, importantly, efficacy in well-designed clinical trials . In addition, consideration of safety profiles, pharmacokinetics, and cost of specific pharmaceutical agents should be made when selecting a regimen . Antimicrobial therapy is an important component of the management of intraabdominal infection . The results of well-designed clinical trials evaluating various aspects of therapy should serve to guide treatment. Int J Clin Pharmacol Ther, 1996 Dec, 34(12), 550 - 4 Perioperative pharmacokinetics of piperacillin during liver transplantation; Bourget P et al.; There have been few evaluations of the perioperative pharmacokinetics of antibiotics . Piperacillin (PPR) is a widely prescribed ureidopenicillin of established efficacy against enterobacteria and P . aeruginosa . The serum pharmacokinetics and perioperative safety of PPR were evaluated in 8 patients hospitalized for an orthotopic liver transplantation . The subjects were given a 60 mg/kg infusion of PPR once every 8 hours . PPR was assayed by HPLC and data were analyzed by a noncompartmental method . There were no adverse events during surgery . It seems that kinetics of PPR showed no variation during the anhepatic period . However, transplants notably modified the kinetics of PPR in comparison with data previously published in healthy volunteers . Trends were as follows: flattening of Cmax and prolongation of T1/2 (2.2 h vs 0.92 h) . This phenomenon seems to be due to a marked increase in V(area) (44.0 1 vs 16.2 1) while C1 were similar . The increase in V(area) is probably the combined results of multiple factors including blood loss, vascular filling, combined prescription of vasoactive drugs, and, obviously, the surgical procedure itself . Concentrations of PPR were after 4 hours below (i.e . 5/8 patients) the MIC of P . aeruginosa (i.e . < or = 16 micrograms/ml) . From 6 hours onwards antibacterial cover was insufficient against the majority of enterobacteria (i.e . < or = 8 micrograms/ml) . This inadequate protection included the critical anhepatic period . Measured concentrations achieved by the initial dosage regimen were compared to those obtained by simulation using modified dosing pattern in order to ensure circulating levels constantly of 16 micrograms/ml or more . This leads to a suggested modified dosage pattern in which PPR would be given as 1 dose of 60 mg/kg every 4 hours . Under these conditions the expected concentrations should be constantly over 16 micrograms/ml and any risk of systemic accumulation is excluded. FEMS Immunol Med Microbiol, 1996 Dec 1, 16(2), 63 - 76 Phase-variable outer membrane proteins in Escherichia coli; Owen P et al.; Escherichia coli contains at least two phase-variable proteins in its outer membrane . One, termed antigen 43 (Ag43), is the product of the metastable flu gene located at min 43.6 on the E . coli chromosome and is responsible for colony form variation and for autoaggregation in liquid media . Ag43 is composed of two proteinaceous subunits, alpha 43 and beta 43 in 1:1 stoichiometry . alpha 43 (apparent M(r) 60,000) is surface expressed, extends beyond the O-side chains of smooth lipopolysaccharide and is bound to the cell surface through an interaction with beta 43 (apparent M(r) 53,000), itself an integral, heat-modifiable, outer membrane protein . alpha 43 shows limited N-terminal sequence homology with certain enterobacterial adhesins, and notable sequence homology with AIDA-1, an adhesin of diffuse-adhering E . coli . In addition, alpha 43 contains an RGD motif and a consensus sequence for an (autoproteolytic?) aspartyl protease active site . Expression of Ag43 is subject to reversible phase variation-in liquid minimal medium, the rates of variation from Ag43+ to Ag43- states and from Ag43- to Ag43+ states being approximately 2.2 x 10(-3) and approximately 1 x 10(-3), respectively . Phase switching of Ag43 is regulated by DNA methylation (deoxyadenosine methylase (dam) mutants being 'locked OFF') and by OxyR (oxyR mutants being 'locked ON') . It is proposed that OxyR acts as a repressor of Ag43 transcription by binding to unmethylated GATC sites in the regulatory region of the gene . In some strains, Ag43 may also undergo antigenic variation . A 94 kDa immunocrossreactive outer membrane protein, showing similar rates of phase variation, has additionally been detected for some enteropathogenic and uropathogenic strains of E . coli . This 94 kDa protein can be proteolytically cleaved in situ with trypsin to yield two membrane-bound products with M(r)s and properties similar to those of alpha 43 and beta 43 . Results suggest that Ag43 may represent one of a family of antigenically-related high-M(r) adhesins which are synthesized as polyprotein precursors . Some members may be processed and presented on the cell surface as bipartite protein complexes (as Ag43) . Others can remain uncleaved. Yeast, 1996 Dec, 12(15), 1511 - 8 Functional analysis of YCL09C: evidence for a role as the regulatory subunit of acetolactate synthase; Cullin C et al.; We have analysed the function of the open reading frame (ORF) YCL09C . The deletion of this ORF from chromosome III does not affect the physiology of the corresponding yeast strain enough to give a distinct phenotype . Nevertheless a computational analysis reveals high homology between this ORF and the enterobacterial genes encoding the regulatory subunit of acetolactate synthase . We have therefore tested the possibility that yc109cp is the regulatory subunit of yeast acetolactate synthase by in vitro enzymatic analysis . The acetolactate synthase was previously shown to be retroinhibited by its final product valine . In Escherichia coli this retro-control is assured by the regulatory subunit . Using a yeast strain carrying a complete deletion of YCL09C, we have observed the loss of such retro-inhibition . These results together with the computational predictions show that YCL09C encodes the regulatory subunit of yeast acetolactate synthase. Mol Microbiol, 1996 Dec, 22(5), 789 - 800 Streptomyces linear plasmids that contain a phage-like, centrally located, replication origin; Chang PC et al.; Unlike previously studied linear replicons containing 5' DNA termini covalently bound to protein, pSLA2, a 17 kb linear plasmid of Streptomyces rochei, initiates replication internally rather than at the telomeres (Chang and Cohen, 1994) . Here we identify and characterize the replication origin of pSLA2, showing that it contains a series of direct repeats (iterons) within a centrally located gene encoding an essential DNA-binding protein (Rep1); a second essential protein (Rep2), which resembles prokaryotic DNA helicases and has ATPase activity stimulated by single-stranded DNA, is expressed from the same transcript . A 430 bp locus separated by almost 2 kb from the iterons of the origin specifies an as yet undefined additional function required in cis for plasmid replication . pSCL, a 12 kb linear plasmid of Streptomyces clavuligerus, contains, near the centre of the plasmid, a region configured like the pSLA2 origin . The replication regions of pSLA2 and pSCL, which are capable of propagating plasmid DNA in either a circular or linear form (Shiffman and Cohen, 1992; Chang and Cohen, 1994) resemble those of temperate bacteriophages of the Enterobacteriacae and Bacillus . Our observations suggest that Streptomyces linear plasmids may occupy an evolutionarily intermediate position between circular plasmids and linear phage replicons. Pediatr Infect Dis J, 1996 Dec, 15(12), 1092 - 7 Community-acquired bacteremia in human immunodeficiency virus-infected children in Harare, Zimbabwe; Nathoo KJ et al.; BACKGROUND: HIV infection is common in mothers and their children in Zimbabwe, and HIV-infected children are particularly susceptible to bacterial infections . There is little information on the etiology and outcome of HIV-related bacteremia in African children . METHODS: Blood cultures from 309 hospitalized children in Zimbabwe, of whom 168 were diagnosed as having HIV, were examined for pathogens . The association among significant bacteremia, HIV infection and mortality was assessed in these children . RESULTS: The most common isolates were coagulase-negative staphylococci (31 children, 25 clinically significant), Staphylococcus aureus (22 children) and Streptococcus pneumoniae (20 children) . Nontyphoidal Salmonella (10 children), Escherichia coli (4 children) and Klebsiella sp . (4 children) were the most frequent Gram-negative bacteria . Two children had Rhodococcus equi pneumonia . HIV-infected children showed increased risk of bacteremia (odds ratio (OR) = 2.68), especially if younger than 18 months of age (OR = 2.94), and high risk of enterobacteremia (OR = 15.76) . There was no significant association of bacteremia with nutritional status . Mortality was 17% overall but was higher in HIV-infected children up to 6 months of age (OR = 2.81) and in bacteremic children of any age (OR = 2.03) . CONCLUSIONS: Prompt recognition of pathogens and early administration of appropriate antimicrobials is important in reducing the morbidity and mortality associated with bacteremia in HIV-infected children in AfricaPIP: Researchers compared data on 168 HIV-positive pediatric patients with data on 141 HIV-negative pediatric patients to examine the etiology and outcome of HIV-related bacterial infections in a pediatric population admitted to Harare Hospital in Zimbabwe during June 1993 to December 1994 . The age of the children ranged from less than 1 month to 96 months . 72% were less than 12 months old . 54% of all pediatric patients tested were HIV-infected . HIV-infected children were more likely to have a bacterial infection than HIV-negative children (40% vs . 20%; odds ratio {OR} = 2.68; p 0.001) . The difference in the bacterial infection rate was only significant for children aged less than 18 months (41% vs . 19%; OR = 2.94; p 0.001), however . 14% of the children suffered from severe malnutrition . Nutritional status was not significantly associated with bacterial infection . In both HIV-positive and HIV-negative children, Staphylococcus aureus was the most frequent bacterial pathogen (29% for HIV-positive and 18% for HIV-negative children) . Many Gram-positive and Gram-negative isolates were resistant to the combination therapy of trimethoprim-sulfamethoxazole . Only 1 child, who was HIV-positive, had more than one bacterial infection (both Streptococcus pneumoniae and Actinomyces israelii) . HIV-positive children were more likely to have an enterobacterial infection than HIV-negative children (10% vs . 0.7%; p 0.001) . Mortality was significantly higher among HIV-infected children aged less than 6 months old than their HIV-negative counterparts (28% vs . 12%; OR = 2.81; p 0.05) . Even though it was also higher among HIV-positive children aged more than 6 months (17% vs . 7%), the difference was not significant . Regardless of HIV status, children with bacteremia were more likely to die than those without bacteremia (24% vs . 14%; OR = 2.03; p 0.05) . These findings stress the importance of early and effective antibiotic therapy . This therapy will reduce the morbidity and mortality associated with bacteriemia in HIV-infected children in Africa . J Med Microbiol, 1996 Dec, 45(6), 445 - 51 Adherence of Aeromonas caviae to human cell lines Hep-2 and Caco-2; Thornley JP et al.; Adherence of Aeromonas caviae to HEp-2 and Caco-2 cell monolayers was investigated with 24 clinical isolates . Growth phase, temperature, multiplicity of infection and length of incubation affected adherence . Treatment of the bacteria with trypsin, sodium metaperiodate, mechanical shearing and the addition of cytochalasin B and cycloheximide to the monolayer significantly reduced the adherence capabilities of the strains investigated . The use of chloramphenicol to inhibit protein synthesis reduced the adhesive capabilities of bacteria grown in liquid medium and those subjected to mechanical shearing . Light microscopy, scanning and transmission electron microscopy were employed in the investigation of bacteria-bacteria and bacteria-monolayer interactions and indicated similarities with the aggregative adherence patterns of the Enterobacteriaceae . The presence of extracellular bacterial appendages and their correlation with increased adhesive capacity may indicate a role in the process of adherence. J Bacteriol, 1996 Dec, 178(24), 7187 - 96 Regulation of pelZ, a gene of the pelB-pelC cluster encoding a new pectate lyase of Erwinia chrysanthemi 3937; Pissavin C et al.; The phytopathogenic enterobacterium Erwinia chrysanthemi 3937 produces five major and several secondary endo-pectate lyases encoded by the pel genes . Most of these genes are arranged in clusters on the bacterial chromosome . The genomic region surrounding the pelB-pelC cluster was supposed to be involved in the regulation of PelB and PelC synthesis . We demonstrated that the variation of pelB expression resulted from the titration of a regulatory protein by the gene adjacent to pelC . This gene was renamed pelZ since it encodes a protein of 420 amino acids with an endo-pectate lyase activity . Regulation of pelZ expression was investigated by using transcriptional fusions and a study of mRNA synthesis . Its transcription depends on different environmental conditions . It is induced in planta and in the presence of pectic catabolite products . This induction seems to be partially mediated by the KdgR protein but does not result from a direct interaction of KdgR with the pelZ 5' region . The transcription of pelZ leads to the synthesis of a monocistronic mRNA . However, the synthesis of a polycistronic mRNA from the pelC promoter, regulated by KdgR, is responsible for increased production of PelZ under inducing conditions . pelZ transcription is also controlled by pecT, which regulates some other pel genes, but it is independent of the pecS regulatory locus . The pelZ gene appears to be widespread in different strains of E . chrysanthemi . Moreover, a gene homologous to pelZ exists in Erwinia carotovora subsp . atroseptica adjacent to the cluster containing the pectate lyase-encoding genes pel1, pel2, and pel3 . This conservation could reflect a significant role of PelZ in the pectinolytic system of Erwiniae . We showed pelZ is not a predominant virulence factor of E . chrysanthemi but is involved in host specificity. Appl Environ Microbiol, 1996 Dec, 62(12), 4303 - 8 PCR amplification of the fimA gene sequence of Salmonella typhimurium, a specific method for detection of Salmonella spp; Cohen HJ et al.; The goal of this study was to evaluate the suitability of the fimA gene amplification by PCR as a specific method for detection of Salmonella strains . Salmonella typhimurium and other pathogenic members of the family Enterobacteriaceae produce morphologically and antigenically related, thin, aggregative, type 1 fimbriae . A single gene, fimA, encodes the major fimbrial unit . In order to obtain higher specificity, we have selected a series of primers internal to the fimA gene sequence and have developed a PCR method for detecting Salmonella strains . A collection of 376 strains of Salmonella comprising over 80 serovars, isolated from animals and humans in Canada, have been used to evaluate this PCR method . Forty non-Salmonella strains were also tested by the same procedure . Cultures were screened by inoculating a single colony of bacteria directly into a PCR mixture containing a pair of primers specific for the fimA gene . The specific PCR product is an 85-bp fragment which was visualized by polyacrylamide gel electrophoresis and ethidium bromide staining . All Salmonella strains gave positive results by the PCR . Feed and milk samples contaminated by Salmonella strains were also detected by this procedure . The detection of all Salmonella strains tested and the failure to amplify the fragment from non-Salmonella strains confirm that the fimA gene contains sequences unique to Salmonella strains and demonstrate that this gene is a suitable PCR target for detection of Salmonella strains in food samples. J Clin Microbiol, 1996 Dec, 34(12), 3190 - 5 Comparative typing of Pseudomonas aeruginosa by random amplification of polymorphic DNA or pulsed-field gel electrophoresis of DNA macrorestriction fragments; Renders N et al.; Eighty-seven strains of Pseudomonas aeruginosa were typed by random amplification of polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) of macrorestriction fragments . Stains were clustered on the basis of interpretative criteria as presented previously for the PFGE analysis . Clusters of strains were also defined on the basis of epidemiological data and subsequently reanalyzed by RAPD . It was found that in an RAPD assay employing the enterobacterial repetitive intergenic consensus sequence ERIC2 as a primer, single band differences can be ignored; in this case, clonally related strains could be grouped as effectively and reliably as with PFGE . These data could be corroborated by the use of other primer species . However, some primers either showed reduced resolution or, in contrast, identified DNA polymorphisms beyond epidemiologically and PFGE-defined limits . Apparently, different primers define different windows of genetic variation . It is suggested that criteria for interpretation of the ERIC2 PCR fingerprints can be simple and straightforward: when single band differences are ignored, RAPD-determined grouping of P . aeruginosa is congruent with that obtained by PFGE . Consequently, this implies that RAPD can be used with trust as a first screen in epidemiological characterization of P . aeruginosa . The ability to measure the rate of molecular evolution of the P . aeruginosa genome clearly depends on the choice of restriction enzyme or primer when RAPD or PFGE, respectively, is applied for the detection of DNA polymorphisms. J Clin Microbiol, 1996 Dec, 34(12), 2997 - 3001 Detection of extended-spectrum-beta-lactamase-producing members of the family Enterobacteriaceae with Vitek ESBL test; Sanders CC et al.; A three-phase analysis of the Vitek ESBL test and a double-disk (2 disk) test was performed to assess their ability to detect extended-spectrum beta-lactamases (ESBLs) in members of the family Enterobacteriaceae . In the first two phases involving detection of ESBLs in 157 stains processing well-characterized beta-lactamases, sensitivity and specificity were found to be 99.5 and 100%, respectively, for the Vitek ESBl test and 98.1 and 99.4%, respectively, for the 2-disk test . In the third phase, in which the ability of each test to detect ESBLs in 295 clinical isolates was assessed, there was only one false positive (Vitek ESBL test) . Across all three phases, the Vitek ESBL test was found to be much easier to perform than the 2-disk test . The latter also involved subjective interpretation of results . There were a total of 176 Escherichia coli and 157 Klebsiella pneumoniae isolates and less than 40 isolates of each of 14 other species evaluated . In a supplemental study of Klebsiella oxytoca, an organism possessing a chromosomal beta-lactamase similar to an ESBL, the Vitek ESBL test was found to be capable of detecting hyperproduction of this enzyme in strains of this species as well . These data indicate that the Vitek ESBL test is reliable for the detection of ESBLs in E . coli and K . pneumoniae, the two species in which ESBLs are most common, and of hyperproduction of the K . oxytoca beta-lactamase, a situation which engenders a level of resistance to this species similar to that seen with ESBLs. Int J Food Microbiol, 1996 Dec, 33(2-3), 301 - 6 Characterization and extracellular activity of psychrotrophic bacteria isolated from Villalón cheese (fresh variety of Spanish sheep's milk cheese); Santos JA et al.; The incidence of psychrotrophic bacteria was investigated in a Spanish fresh ewes' cheese (Villalon) . Counts of mesophiles and psychrotrophs were (log cfu/g) 5.72 +/- 1.10 and 3.90 +/- 1.01, respectively, for factory cheeses made from pasteurized-milk . Figures for hand-made cheeses made from raw-milk were 7.35 +/- 0.48 and 6.94 +/- 0.65, respectively . A total of 59 representative psychrotrophic isolates were characterized and tested for protease and lipase production at 7 and 30 degrees C . The strains were assigned to Enterobacteriaceae (predominant in raw-milk cheese), heterofermentative lactic acid bacteria (dominant in pasteurized-milk cheese and absent in raw-milk cheese) and Pseudomonas . More than 73% of the Enterobacteriaceae produced both proteolytic and lipolytic enzymes at either 30 or 7 degrees C . This percentage is considerably higher than those previously reported . The seven isolates of pseudomonads investigated produced proteases at 7 degrees C and six were positive at 30 degrees C; lipolytic activity was shown by five of the isolates at both temperatures . Among the heterofermentative lactic acid bacteria seven of the ten isolates were proteolytic at 30 degrees C. Bratisl Lek Listy, 1996 Nov, 97(11), 684 - 7 Bacteremia in cancer patients with solid tumors undergoing chemotherapy versus surgery: risk factors, etiology and outcome in 276 patients; Grausova S et al.; Risk factors, etiology, symptomatology and outcome of bacteremia in 276 patients with solid tumors were evaluated . A group of 78 patients with solid tumors and surgical therapy was compared with 172 patients with solid tumors but treated solely by chemotherapy . The most frequently observed risk factors of bacteremia in patients after surgery were the vascular and urinary catheter insertions, wound as source of bacteremia, staphylococci, enterococci and Enterobacteriaceae as etiologic agents . Comparing the group of therapeutically treated patients with solid tumors, with the group of those treated only by chemotherapy, a statistically significant difference in risk factors between both groups was observed only in the incidence of catheter insertion (more frequently in surgically treated patients), neutropenia (more frequently in those treated by chemotherapy) . Wound as source of bacteremia was more frequently observed in those after surgery . Enterobacteriaceae and enterococci were significantly more frequently observed in patients with solid tumors treated by surgery . Surprisingly, patients after surgery the mortality due to septic shock was lower in (6.4% vs 16.9%, p < 0.03) than in the control group of patients with solid tumors treated solely by chemotherapy . (Tab . 1, Ref . 5.).
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