Enterobacteriacea

Clin Infect Dis, 2005 Jan 15, 40(2), 251 - 7 Epub 2004 Dec 22.
Possible animal origin of human-associated, multidrug-resistant, uropathogenic Escherichia coli; Ramchandani M et al.; BACKGROUND: The multistate occurrence of cases of urinary tract infection (UTI) caused by trimethoprim-sulfamethoxazole (TMP-SMZ)-resistant Escherichia coli strains belonging to a single clonal group (designated as clonal group A {CgA}) in the United States has raised an intriguing hypothesis that these infections may have been spread by contaminated food products . The present study attempted to determine if CgA strains could be traced to food animals . METHODS: A total of 495 animal and environmental E . coli isolates, which belonged to serogroups O11, O17, O73, and O77 and were collected between 1965 and 2002 by the Gastroenteric Disease Center at Pennsylvania State University (University Park, PA), were further subtyped by antimicrobial drug susceptibility, enterobacterial repetitive intergenic consensus (ERIC2) PCR, random amplified polymorphic DNA analysis, pulsed-field gel electrophoresis (PFGE), and virulence profile pattern . RESULTS: Of 495 isolates, 128 (26%) had an ERIC2 PCR electrophoretic pattern indistinguishable from that of the human prototype CgA strain, and 14 CgA isolates were resistant to TMP-SMZ . Cluster analysis of PFGE patterns showed that 1 of these 14 isolates, obtained from a cow in 1988, was 94% similar to a CgA uropathogenic human-associated E . coli strain . The pattern for this isolate was included among a cluster of PFGE patterns for 5 human-associated UTI isolates that were >80% similar to each other . CONCLUSIONS: These observations suggest that drug-resistant, uropathogenic human-associated E . coli strains potentially have an animal origin . The possibility that human drug-resistant UTI could be a foodborne illness has serious public health implications.

Clin Infect Dis, 2005 Jan 15, 40(2), 218 - 24 Epub 2004 Dec 17.
Pathogen-specific early mortality in very low birth weight infants with late-onset sepsis: a national survey; Makhoul IR et al.; BACKGROUND: Late-onset sepsis (LOS) is an important cause of mortality among very low birth weight (VLBW) infants, and deaths occurring within 3 days after the onset of sepsis can probably be ascribed to sepsis . We examined the association of sepsis due to specific pathogens with the risk for early mortality after the onset of LOS, adjusted for perinatal and neonatal risk factors . METHODS: From 1995 through 2001, information about 10,215 infants was gathered and deposited in the Israel National VLBW Infant Database . The study population was composed of 2644 infants, of which each had >or=1 events of LOS (totalling 3462 events) . Logistic regression models were used to calculate the crude and adjusted risk for early mortality . RESULTS: Early mortality was associated with 179 LOS events (5.2% of 3,462); the range of pathogens associated with these events included coagulase-negative staphylococci (CoNS), which were the cause of 1.8% of LOS events associated with early mortality, and Pseudomonas species, which were the cause of 22.6% of such events . Early mortality after LOS, adjusted for neonatal risk factors, was significantly associated with sepsis due to certain pathogens: Pseudomonas species (odds ratio {OR}, 12.3); Klebsiella species (OR, 6.3); Serratia species (OR, 6.2); Escherichia species (OR, 4.3); Enterobacter species (OR, 4.1); and Candida species (OR, 3.2), compared with sepsis due to CoNS . In addition, lower gestational age, lower chronological age, small size for gestational age, and grade 3-4 intraventricular hemorrhage, each had an independent association with early mortality . CONCLUSIONS: Klebsiella sepsis and Pseudomonas sepsis were associated with a 6.3-fold and 12.3-fold increased risk of early mortality, respectively, and accounted for 41.9% of all early deaths associated with LOS . Considering the aggressive nature of sepsis caused by these pathogens, empiric antibiotic therapy active against these organisms is worth consideration for VLBW infants with presumed LOS.

Chest, 2005 Jan, 127(1), 213 - 9
Multicenter Study of Hospital-Acquired Pneumonia in Non-ICU Patients; Sopena N et al.; STUDY OBJECTIVE: To know the incidence, epidemiology, etiology, and outcome of hospital-acquired pneumonia (HAP) in non-ICUs adult patients . SETTING: Twelve Spanish teaching hospitals . INTERVENTIONS: From April 1999 to November 2000, non-ICU HAP was prospectively studied by active, bimonthly 1-week surveillance . Epidemiologic data, etiology, and evolution of pneumonia were recorded . Blood and sputum cultures and Legionella pneumophila and Streptococcus pneumoniae urinary antigen tests were performed . RESULTS: We included 186 patients, with complete data available in 165 patients (70.3% male gender; mean age, 63.7 +/- 16.9 years { +/- SD}) The mean incidence of HAP was 3 +/- 1.4 cases/1,000 hospital admissions . Most patients (64.2%) were in medical wards, had severe underlying diseases (66.6%), and had a hospital stay > 5 days (76.4%) . Blood cultures were performed in 139 patients (84.2%), sputum cultures were performed in 89 patients (53.9%), and urinary antigen detection was performed in 123 patients (74.5%) . An etiologic diagnosis was obtained in 60 cases (36.4%), and 31 were definitive . The most frequent etiologies were S pneumoniae (16 cases, 14 definitive), L pneumophila (7 cases, 7 definitive), Aspergillus sp (7 cases, 3 definitive), Pseudomonas aeruginosa (7 cases, 2 definitive), and several Enterobacteriaceae (8 cases, 4 definitive) . Clinical complications occurred in 52.1% of the cases, and mortality was 26% (13.9% attributed to pneumonia) . CONCLUSIONS: Non-ICU HAP is an important cause of hospital morbidity, observed most frequently in medical wards and elderly patients with severe underlying diseases . In this setting, S pneumoniae and Legionella sp should be considered in addition to other nosocomial pathogens; urinary antigen detection is useful in determining the prevalence of these microorganisms.

Int J Syst Evol Microbiol, 2005 Jan, 55(Pt 1), 437 - 42
Phylogenetic relationships of the genus Kluyvera: transfer of Enterobacter intermedius Izard et al . 1980 to the genus Kluyvera as Kluyvera intermedia comb . nov . and reclassification of Kluyvera cochleae as a later synonym of K . intermedia; Pavan ME et al.; In order to assess the relationship between the genus Kluyvera and other members of the family Enterobacteriaceae, the 16S rRNA genes of type strains of the recognized Kluyvera species, Kluyvera georgiana, Kluyvera cochleae, Kluyvera ascorbata and Kluyvera cryocrescens, were sequenced . A comparative phylogenetic analysis based on these 16S rRNA gene sequences and those available for strains belonging to several genera of the family Enterobacteriaceae showed that members of the genus Kluyvera form a cluster that contains all the known Kluyvera species . However, the type strain of Enterobacter intermedius (ATCC 33110(T)) was included within this cluster in a very close relationship with the type strain of K . cochleae (ATCC 51609(T)) . In addition to the phylogenetic evidence, biochemical and DNA-DNA hybridization analyses of species within this cluster indicated that the type strain of E . intermedius is in fact a member of the genus Kluyvera and, within it, of the species Kluyvera cochleae . Therefore, following the current rules for bacterial nomenclature and classification, the transfer of E . intermedius to the genus Kluyvera as Kluyvera intermedia comb . nov . is proposed (type strain, ATCC 33110(T)=CIP 79.27(T)=LMG 2785(T)=CCUG 14183(T)) . Biochemical analysis of four E . intermedius strains and one K . cochleae strain independent of the respective type strains further indicated that E . intermedius and K . cochleae represent the same species and are therefore heterotypic synonyms . Nomenclatural priority goes to the oldest legitimate epithet . Consequently, Kluyvera cochleae Muller et al . 1996 is a later synonym of Kluyvera intermedia (Izard et al . 1980) Pavan et al . 2005.

Clin Microbiol Rev, 2005 Jan, 18(1), 147 - 62
Manual and automated instrumentation for identification of enterobacteriaceae and other aerobic gram-negative bacilli; O'hara CM; Identification of gram-negative bacilli, both enteric and nonenteric, by conventional methods is not realistic for clinical microbiology laboratories performing routine cultures in today's world . The use of commercial kits, either manual or automated, to identify these organisms is a common practice . The advent of rapid or "spot" testing has eliminated the need for some commonly isolated organisms to be identified with the systems approach . Commercially available systems provide more in-depth identification to the species level as well as detect new and unusual strains . The answers obtained from these systems may not always be correct and must be interpreted with caution . The patient demographics, laboratory workload and work flow, and technologist's skill levels should dictate the system of choice . Cost considerations introduce another variable into the equation affecting choice . Each system has its own strengths and weaknesses, and each laboratory must decide on the level of sophistication that fulfills its particular needs.

Eur J Orthod, 2004 Dec, 26(6), 623 - 9
The effect of fixed orthodontic appliances on the oral carriage of Candida species and Enterobacteriaceae; Hagg U et al.; The aim of this investigation was to evaluate the prevalence of Candida and Enterobacteriaceae in a group of adolescents during fixed orthodontic appliance (FOA) therapy . The experimental group was recruited from a larger sample of orthodontic patients who were clinically examined once to obtain baseline data before active treatment . The group comprised 27 subjects; 13 males, 14 females (mean age 15.5 +/- 2.3 years) . Thereafter, the experimental group was examined three times during a 3 month follow-up period after insertion of the FOA . The whole mouth plaque score was obtained, and the oral cavity was then sampled for Candida species and Enterobacteriaceae using three different microbiological culture techniques, namely the oral rinse, pooled plaque and the imprint culture.A significant increase in candidal numbers was observed after FOA insertion when the imprint technique was used (P < 0.001), although the overall candidal prevalence rates obtained using the oral rinse and pooled plaque techniques did not demonstrate such a change . The predominant Candida species isolated was C . albicans and the number of coliform carriers significantly increased after the insertion of a FOA, as detected by the oral rinse (P < 0.05) and the pooled plaque (P < 0.05) techniques . In total, eight coliform species were isolated following FOA therapy compared with the three species isolated before insertion of the appliance . The results also revealed a significant increase in plaque index due to the introduction of a FOA . Taken together, these data imply that insertion of a FOA is likely to promote oral carriage of Candida and coliform species . Furthermore, it appears that routine oral hygiene instruction and information on appliance hygiene given to these patients may not necessarily reduce plaque accumulation and possible attendant effects . Further work with a larger cohort is required to confirm these findings.

Can J Microbiol, 2004 Oct, 50(10), 877 - 81
Role of glutamine synthetase in phenazine antibiotic production by Pantoea agglomerans Eh1087; Galbraith MD et al.; Pantoea agglomerans strain Eh1087 produces the phenazine antibiotic D-alanylgriseoluteic acid . A glutamine auxotroph harboring an insertion in a putative glnA gene was obtained by transposon-mutagenesis of Eh1087 that produced less D-alanylgriseoluteic acid than the parental strain (strain Eh7.1) . Cosmids encoding the Eh1087 glnA were isolated by their ability to complement the mutant for prototrophy . The role of the Eh1087 glnA locus was functionally confirmed by complementation of an Escherichia coli glnA mutant . Analysis of the nucleotide and deduced amino acid sequences of the Eh1087 glnA gene indicated a high degree of similarity to the glnA genes and glutamine synthetase enzymes of other Enterobacteriaceae . Isotopic labelling experiments with 15N-labelled ammonium sulfate demonstrated that wild-type Eh1087 incorporated 15N into griseoluteic acid more readily than the glnA mutant Eh7.1 . We conclude that the 2 nitrogens in the phenazine nucleus originate from glutamine and the intracellular glutamine synthesized by Eh1087 is a source of the phenazine nucleus nitrogens even in glutamine-rich environments.

Can J Microbiol, 2004 Oct, 50(10), 873 - 5
Morphology of Salmonella enterica serovar Heidelberg typing phages; Demczuk W et al.; Eleven tailed phages are described . They belong to the Myoviridae, Siphoviridae, or Podoviridae families and represent the ViI, T1, T5, Jersey, N4, and P22 species of enterobacterial phages . Morphology is correlated with host range.

FEBS Lett, 2005 Jan 17, 579(2), 373 - 8
2-Aminoperimidine, a specific inhibitor of bacterial NhaA Na(+)/H(+) antiporters; Dibrov P et al.; The diuretic drug amiloride and its numerous derivatives are competitive inhibitors of mammalian Na(+)/H(+) antiporters and other eukaryotic antiporters . Most prokaryotic antiporters, including the major NhaA family of enterobacteria, are resistant to these compounds . We show that 2-aminoperimidine (AP), a guanidine-containing naphthalene derivative with some similarity to amiloride, acts as a specific inhibitor of NhaA from Escherichia coli . Similar concentrations (IC(50) of 0.9 muM) inhibit the proton motive force dependent Na(+)(Li(+))/H(+) exchange reaction in inside-out sub-bacterial vesicles (at 10 mM NaCl, pH 8) as well as the initial rate of (22)Na(+)/Na(+) exchange mediated by pure NhaA in proteoliposomes . The inhibitor is specific to NhaA type antiporters, so AP is a new tool to study the mechanism and roles of NhaA antiporters of enterobacteria as well as the molecular basis of inhibition by an amiloride-like compound.

Arq Bras Endocrinol Metabol, 2004 Jun, 48(3), 406 - 13 Epub 2004 Aug 26.
{Diabetic foot infection: bacteriologic analysis of 141 patients.}; Carvalho CB et al.; Diabetes mellitus (DM) is a progressive disease with chronic complications . Feet problems represent one of the most important complications . In a prospective study, we analyzed 298 species of bacteria isolated from 141 patients with community-acquired diabetic foot ulcers . The study was undertaken at a diabetic center and at the Federal University of Ceara, Brazil, from March/2000 to November/2001 . The majority of patients had mild to moderate infections and was classified as Wagner's grades I and II . The samples were cultured using selective media . The identification and the susceptibility tests were done by conventional and automated methods . The most frequently occurring pathogens were Enterobacteriaceae (83.7%), Staphylococcus aureus (43.3%) and anaerobic bacteria (17%) . Streptococcus pyogenes was recovered from 7.8% of the patients . ESBL producing strains were detected in 6% and methicillin resistant Staphylococcus aureus strains were recovered from 11.6% of the patients . Resistance among bacteria has increased largely, and became common even in community-acquired infections . Improvements in the routine etiologic diagnostics and antibiotic use strategies are required to avoid inadequate treatment and its well known dramatic consequences.

Appl Environ Microbiol, 2005 Jan, 71(1), 538 - 41
First Record of the Rare Species Aeromonas culicicola from a Drinking Water Supply; Figueras MJ et al.; We describe the recovery of the rare species Aeromonas culicicola, so far known only in mosquitoes in India, from a drinking water supply in Spain . Typing, using enterobacterial repetitive intergenic consensus-PCR, revealed that the 27 new isolates belonged to 3 very closely related strains . These strains were genetically identified by 16S rRNA gene sequencing . Spanish strains differed from the mosquito strains in three nucleotide positions . The AHCYTOEN gene was present in these water strains, which may have a public health significance.

Res Microbiol, 2005 Jan-Feb, 156(1), 104 - 6
Microbiological carcass sampling methods to achieve compliance with 2001/471/EC and new hygiene regulations; Byrne B et al.; The aim of this research was to evaluate the effectiveness of excision versus swabbing as methods for the assessment of bovine and ovine carcass hygiene . Microbiological evaluation of bovine and ovine carcasses was performed by obtaining total viable counts (TVCs) and total Enterobacteriaceae counts (TECs) using excision and a swab (polyurethane) sampling method . Four anatomical locations were sampled on 30 bovine and 30 ovine carcasses, processed in four small (<10 animals per week) abattoirs . Excision and swab TVC were statistically similar (P<0.05) at all sites . The corresponding TECs were also statistically the same (P<0.05) . Swabbing with the polyurethane sponge was therefore as effective as excision sampling for the determination of TVCs and TECs on bovine and ovine carcasses and may be used instead of excision sampling when assessing bovine and ovine carcass hygiene as per 2001/471/EC.

J Food Prot, 2004 Dec, 67(12), 2850 - 7
Microbiological, epidemiological, and food safety aspects of Enterobacter sakazakii; Lehner A et al.; Enterobacter sakazakii is considered to be an opportunistic pathogen and has been implicated in foodborne diseases causing meningitis or enteritis, especially in neonates and infants . The U.S FoodNet 2002 survey rate of invasive infections with this organism in infants under 1 year of age was 1 per 100,000 infants . Severity of the disease is a matter of concern . In a recent study on the occurrence of E . sakazakii in production environments from food (milk powder, chocolate, cereal, potato, and pasta) factories and households, this organism was isolated with varying frequency from nearly all environments examined, strongly indicating that it is widespread . Stationary phase E . sakazakii cells are remarkably resistant to osmotic and drying stresses compared with other species of the Enterobacteriacae . In this article, we review the literature on this organism with special respect to the information relevant for food safety.

J Food Prot, 2004 Dec, 67(12), 2815 - 9
Inactivation of Enterobacter sakazakii in reconstituted infant formula by monocaprylin; Nair MK et al.; Enterobacter sakazakii is an emerging pathogen that causes meningitis, bacteremia, sepsis, and necrotizing enterocolitis in neonates and children, with a mortality rate of 14% . Epidemiological studies have implicated dried infant formula as the principal source of the pathogen . Caprylic acid is a natural eight-carbon fatty acid present in breast milk and bovine milk and is approved as generally recognizable as safe by the U.S . Food and Drug Administration . The objective of this study was to determine the antibacterial effect of monocaprylin (monoglyceride ester of caprylic acid) on E . sakazakii in reconstituted infant formula . A five-strain mixture of E . sakazakii was inoculated into 10-ml samples of reconstituted infant formula (at 6.0 log CFU/ml) followed by 0, 25, or 50 mM (1%) monocaprylin . The samples were incubated at 37 or 23 degrees C for 0, 1, 6, and 24 h and at 8 or 4 degrees C for 0, 6, 24, and 48 h, and the surviving populations of E . sakazakii at each sampling time were counted . The treatments containing monocaprylin significantly reduced the population of E . sakazakii (P < 0.05) compared with the controls . Monocaprylin (50 mM) reduced the pathogen by >5 log CFU/ml by 1 h of incubation at 37 or 23 degrees C and by 24 h of incubation at 8 or 4 degrees C . Results indicate that monocaprylin could potentially be used to inactivate E . sakazakii in reconstituted infant formula; however, sensory studies are warranted before its use can be recommended.

J Food Prot, 2004 Dec, 67(12), 2812 - 4
Occurrence and behavior of Enterobacteriaceae and enterococci in mediterranean dry sausages during ripening in a Pilot-Scale chamber; Lopez C et al.; The occurrence and evolution of Enterobacteriaceae, coliforms, Escherichia coli, and enterococci in 252 samples of six types of Mediterranean dry-ripened sausages during maturation was investigated . The changes of the pH values were also recorded . Samples were analyzed in three steps of the ripening process: fresh product, first drying stage, and finished product . In all six sausages, Enterobacteriaceae, coliforms, and E . coli counts were characterized by high initial concentrations that significantly decreased during ripening . However, the initial counts of enterococci remained stable throughout the experiments in all sausages types . The average pH values of finished sausages ranged from 4.54 to 5.31.

J Food Prot, 2004 Dec, 67(12), 2801 - 4
Survey of shell egg processing plant sanitation programs: effects on non-egg-contact surfaces; Musgrove MT et al.; To successfully implement a hazard analysis critical control point plan, prerequisite programs are essential . Sanitation standard operating procedures are an important part of such a plan and can reduce contamination levels so that food safety and quality are not adversely affected . Noncontact surfaces in the shell egg processing plants can serve as a reservoir of cross-contamination . The objective of this study was to assess the efficacy of sanitation programs used in a variety of shell egg processing facilities (in-line, off-line, and mixed operations) . Fourteen different noncontact surfaces were sampled in nine commercial facilities across the southeastern United States . Non-egg-contact surfaces were defined as those where the shell egg does not come into direct contact with the surface or with the fluid from that surface . Gauze pads soaked in sterile phosphate-buffered saline were used for sampling at the end of a processing day (POST) and again the next morning prior to operations (PRE) . Aerobic plate counts (APCs) and numbers of Enterobacteriaceae were determined . No significant differences (P > 0.05) were found between POST and PRE counts for either population recovered from the 14 sampling sites . Only samples from the floor under the farm belts, nest-run loader, washers, and packer heads were reduced by 1 log CFU/ml of rinsate for APCs or Enterobacteriaceae counts . APCs of more than 10(4) CFU/ml of rinsate were recovered from many samples . Highest APCs were found on the floor under the farm belt and on shelves of the nest-run carts . High APCs were found on the wheel surface for off-line carts and on the loading dock floor . Highest Enterobacteriaceae counts were found in samples from the floor, drain, and nest-run egg cart shelves . A lack of significant difference between POST and PRE counts indicates that current sanitation programs could be improved . These data suggest that traffic patterns for the movement of eggs and materials through the plant should be reevaluated so that cross-contamination is reduced.

J Food Prot, 2004 Dec, 67(12), 2703 - 11
Effect of single or sequential hot water and lactic acid decontamination treatments on the survival and growth of listeria monocytogenes and spoilage microflora during aerobic storage of fresh beef at 4, 10, and 25 degrees C; Koutsoumanis KP et al.; The survival and growth of Listeria monocytogenes and spoilage microflora during storage of fresh beef subjected to different decontamination treatments was studied . Fresh beef inoculated with a five-strain mixture of L . monocytogenes (5.18 log CFU/cm2) was left untreated (control) or was immersed (30 s) in hot water (HW; 75 degrees C), 2% lactic acid (LA; 55 degrees C), hot water followed by lactic acid (HW-LA), or lactic acid followed by hot water (LA-HW) and then stored aerobically at 4, 10, and 25 degrees C for 25, 17, and 5 days, respectively . Initial populations of L . monocytogenes were reduced by 0.82 (HW), 1.43 (LA), 2.73 (HW-LA), and 2.68 (LA-HW) log CFU/cm2 . During storage, the pathogen grew at higher rates in HW than in control samples at all storage temperatures . Acid decontamination treatments (LA . HW-LA, and LA-HW) resulted in a weaker inhibition of L . monocytogenes (P < 0.05) at 25 degrees C than at 4 and 10 degrees C . In general, the order of effectiveness of treatments was HW-LA > LA > LA-HW > HW > control at all storage temperatures tested . In untreated samples, the spoilage microflora was dominated by pseudomonads, while lactic acid bacteria, Enterobacteriaceae, and yeasts remained at lower concentrations during storage . Brochothrix thermosphacta was detected periodically in only a limited number of samples . Although decontamination with HW did not affect the above spoilage microbial profile, acid treatments shifted the predominant microflora in the direction of yeasts and gram-positive bacteria (lactic acid bacteria) . Overall, the results of the present study indicate that decontamination with LA and combinations of LA and HW could limit growth of L . monocytogenes and inhibit pseudomonads, which are the main spoilage bacteria of fresh beef stored under aerobic conditions . However, to optimize the efficacy of such treatments, they must be applied in the appropriate sequence and followed by effective temperature control.

J Food Prot, 2004 Dec, 67(12), 2657 - 60
Variations in external and internal microbial populations in shell eggs during extended storage; Jones DR et al.; The current project was conducted to determine the microbial quality of commercially processed shell eggs during extended storage . Unwashed eggs were collected at the accumulator before entering the processing line . Washed eggs were retrieved after placement in flats . All eggs were stored on pulp flats at 4 degrees C for 10 weeks . Twelve eggs from each treatment were rinsed on the day of collection and during each week of storage . After rinsing, eggs were sanitized in ethanol, and contents were aseptically collected . Total aerobes, yeasts and molds, Enterobacteriaceae, and pseudomonads were enumerated from shell rinses and pooled egg contents . During storage, no differences were found between unwashed and washed eggs for Enterobacteriaceae and pseudomonads in either shell rinses or contents . No differences were found between treatments for population levels of total aerobes or yeasts and molds in the egg contents throughout the storage period . Significant differences between treatments were found at each week of storage for external shell contamination by total aerobes . The highest unwashed egg contamination occurred at week 8 of storage and the lowest was at weeks 0 and 1 of storage . The highest shell contamination with aerobic bacteria on the washed eggs was found at week 0 of storage and the lowest was at week 7 . Yeast and mold contamination determined by shell rinses was also significantly different between treatments at each week of storage . Commercially washed eggs were significantly less contaminated than were unwashed eggs for the populations monitored.

Eur J Pediatr Surg, 2004 Dec, 14(6), 422 - 6
Prophylactic antibiotic use in pediatric burn units*; Ergun O et al.; Prophylactic antibiotic use in childhood burns is controversial . The efficiency of antibiotic prophylaxis in 77 pediatric burn patients was evaluated . Forty-seven patients received prophylactic antibiotics (Group AP), while 30 patients received no prophylaxis (Group NP) . Age, wound depth, day of admission, mechanism of burn injury, type of dressings were similar for both groups (p > 0.05) . Wound infection rates were 21.3 % in Group AP and 16.7 % in Group NP (p > 0.05) . S . aureus, Enterobacter spp., P . aeruginosa, and E . coli were the most common microorganisms . Patients with wound colonization and infection had a larger burned total body surface area (BTBSA) in both groups (p < 0.01) . Eight patients had clinical sepsis . All but one of the septic patients were from Group AP . Associated infections of the upper and lower respiratory tract (16), urinary tract (7), and otitis media (2) were more common in Group AP . One patient died from sepsis in Group AP . Hospital stays were longer in Group AP (21.7 +/- 16.4 vs . 13.5 +/- 10 days; p < 0.05) . Antibiotic prophylaxis in childhood burns does not reduce the rate of wound infection . Age, wound depth and BTBSA are not critical variables for prophylaxis . Reinforcing the use of culture-specific antibiotics for more beneficial and cost-effective results in the treatment of childhood burns is recommended.

Acta Biochim Pol, 2004, 51(4), 1081 - 6
Enzymatic redox reactions of the explosive 4,6-dinitrobenzofuroxan (DNBF): implications for its toxic action; Nemeikaite-Ceniene A et al.; With an aim to understand the toxicity mechanisms of the explosive 4,6-dinitro- benzofuroxan (DNBF), we studied its single-electron reduction by NADPH:cytochrome P450 reductase and ferredoxin:NADP(+) reductase, and two- electron reduction by DT-diaphorase and Enterobacter cloacae nitroreductase . The enzymatic reactivities of DNBF and another explosive 2,4,6-trinitrotoluene (TNT) were similar, except for the much lower reactivity of DNBF towards nitroreductase . DNBF was less cytotoxic in FLK cells than TNT . However, their action shared the same mechanisms, oxidative stress and activation by DT-diaphorase . The lower cytotoxicity of DNBF may be explained by the negative electrostatic charge of its adduct with water which may impede cellular membrane penetration, and by the formation of its less reactive adducts with intracellular reduced glutathione.

FEMS Microbiol Lett, 2005 Jan 15, 242(2), 231 - 240
Aeromonas hydrophila clinical and environmental ecotypes as revealed by genetic diversity and virulence genes; Aguilera-Arreola MG et al.; Aeromonas hydrophila strains recovered from clinical samples and ambient sources were phenotypically and genetically identified . In addition, the distribution of putative virulence factors was assayed . To determine the genetic diversity of these strains, random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC)-PCR markers were used . The discriminatory ability of the techniques, using Simpson's index, was 0.96 for both methods . The most consistent dendrogram was obtained when RAPD and ERIC data were combined . The genetic diversity revealed a high intra-specific genetic diversity (h=0.364+/-0.024 and I=0.538+/-0.030) . The strains showed a tendency to cluster according to their origin of isolation (best-cut test 0.80 and bootstrap values >50%) . The present study demonstrates and quantifies the high intra-specific diversity within this species and reveals a clear differentiation of strains according to their ecological origin . The distribution of virulence-related genes confirm that A . hydrophila is a genetically heterogeneous species that harbour ecotypes which have different pathogenic potential to human and other animals.

Med Mal Infect, 2004 Feb, 34(2), 70 - 5
{Surveillance of multi-resistant bacteria in Lorraine: a three-year multicentre incidence study}; Ducki S et al.; OBJECTIVE: Controlling outbreaks of nosocomial infections is a priority for public healthcare in France . This study concerned the incidence of multidrug-resistant bacteria (MDRB) in Lorraine and the impact of the national guidelines for the prevention of MDRB . METHODS: A multicenter incidence study was conducted for 5 months, in volunteer hospitals . Samples collected for the clinical diagnostic were included . The bacteria studied were: methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella sp., Enterobacter sp., and other Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBL), and vancomycin resistant Enterococci sp . RESULTS: A total of 30 hospitals were included in the surveillance of MDRB . During the study period (2001-2003), 17874 strains were identified . MRSA reached 29.3% of the 4038 strains of S . aureus, 20.9%, 1.23% and 1.21% of ESBL, respectively, for Enterobacter sp., Klebsiella sp., and other Enterobacteriaceae (for 895, 1061 and 9419 strains) . Overall, the incidence of MRSA reached 0.55 per 1000 hospital-days and 0.087 for Enterobacter sp . The incidence increased during the 3 years, from 3.36 to 4.84 per 1000 new patients for MRSA, and from 0.43 to 0.90 for Enterobacter sp . CONCLUSION: Despite guidelines on isolation, MRSA remains poorly controlled and requires more efficient measures . Surveillance of ESBL should be improved.

Med Mal Infect, 2004 Apr, 34(4), 166 - 70
{Outbreak of Enterobacter aerogenes in paediatric unit}; Burnichon G et al.; Within the framework of breast milk control the hygiene laboratory of Brest hospital isolates, on 3 January 1996 a strain of Enterobacter aerogenes secretory of cephalosporinase in the breast milk of a mother whose child was hospitalized in neonatalogy . On 15 April 1996 a new strain of E . aerogenes is isolated from another mother's breast milk . Until 18 August 1997, 21 samples of breast milk were tested positive to this bacteria . During the same period, E . aerogenes was isolated in 26 children under 1 year of age, 11 of which were infected and 15 colonized . The breast milk did not correspond to those of the mothers of the infected or colonized children . All the strains presented the same antibioresistance . The pulsed-field gel electrophoresis showed that the children's strains, those colonized or infected as well as those isolated in breast milk had the same restriction profile . The epidemiological study concerned the biberonnery-lactarium . The biberonnery's staff is the same as the staff of the lactarium . A portage was searched for among the members of the staff of these units, but without success . The search for E . aerogenes in the environment and in baby-food, others than breast milk was negative . Finally, we did not find any source for these contagions . The only hypothesis we have retained is that of a common source from the biberonnery-lactarium, but without being able to bring any proof to it . Following this epidemic, we have revised all the working modalities and practices with the staff of the biberonnery-lactarium.

BMC Microbiol . 2004 Dec 24;4(1):49.
Extended-Spectrum beta-lactamase (ESBL) producing Enterobacter aerogenes phenotypically misidentified as Klebsiella pneumoniae or K . terrigena; Claeys G et al.; BACKGROUND: Enterobacter aerogenes and Klebsiella pneumoniae are common isolates in clinical microbiology and important as producers of extended spectrum beta-lactamases (ESBL) . The discrimination between both species, which is routinely based on biochemical characteristics, is generally accepted to be straightforward . Here we report that genotypically unrelated strains of E . aerogenes can be misidentified as K . pneumoniae by routine laboratories using standard biochemical identification and using identification automates . RESULTS: Ten clinical isolates, identified as K . pneumoniae or K . terrigena with the routinely used biochemical tests and with API-20E, were identified as E . aerogenes by tDNA-PCR - an identification that was confirmed by 16S rRNA gene sequencing for five of these isolates . Misidentification also occurred when using the automated identification systems Vitek 2 and Phoenix, and was due to delayed positivity for ornithine decarboxylase and motility . Subculture and prolonged incubation resulted in positive results for ornithine decarboxylase and for motility . It could be shown by RAPD-analysis that the E . aerogenes strains belonged to different genotypes . CONCLUSIONS: Clinical E . aerogenes isolates can be easily misidentified as Klebsiella due to delayed positivity for ornithine decarboxylase and motility . The phenomenon may be widespread, since it was shown to occur among genotypically unrelated strains from different hospitals and different isolation dates . A useful clue for correct identification is the presence of an inducible beta-lactamase, which is highly unusual for K . pneumoniae . In several instances, the use of genotypic techniques like tDNA-PCR may circumvent problems of phenotypic identification.

J Biol Chem . 2004 Dec 22; {Epub ahead of print}
A small bacterial RNA regulates a putative ABC transporter; Antal M et al.; A small non coding bacterial ribonucleic acid of 62 to 64 nucleotides, RydC, was identified in the genomes of Escherichia coli, Salmonella and Shigella . In vivo, RydC binds to the RNA binding protein Hfq, and it is unstable when Hfq is absent . Mobility assays reveal that complex formation between RydC and Hfq is specific, with an apparent binding constant of ~300nM . Sequence alignments combined with structural probing demonstrate that RydC folds as a pseudoknot . Hfq binds the loops crossing the deep and shallow grooves of the pseudoknotted RNA and reorganizes its overall conformation . An interaction with a polycistronic mRNA, yejABEF, that encode a putative ABC transporter, was detected by affinity purification of immobilized "RNA-Hfq" complexes . In vivo, the yejABEF operon is expressed on minimal medium . Remarkably, its expression is reduced when RydC is absent and the operon is degraded when RydC expression is stimulated . This observation correlates with the growth defects associated with a stimulation of its expression in vivo, generating a thermosensitive phenotype that affect growth on minimal media supplemented with glycerol, maltose or ribose . We conclude that RydC regulates the yejABEF encoded ABC permease at the mRNA level . This sRNA may contribute to optimal adaptation of some Enterobacteria to environmental conditions.

Antimicrob Agents Chemother, 2005 Jan, 49(1), 447 - 50
ISEcp1B-mediated transposition of blaCTX-M in Escherichia coli; Poirel L et al.; Several expanded-spectrum beta-lactamase bla(CTX-M) genes are associated with ISEcp1-like elements in Enterobacteriaceae . We found that ISEcp1B was able to mobilize the adjacent bla(CTX-M-19) gene by a transpositional mechanism in Escherichia coli by recognizing a variety of DNA sequences as right inverted repeats.

Antimicrob Agents Chemother, 2005 Jan, 49(1), 441 - 3
Emergence of CTX-M-15-producing enterobacteria in Cameroon and characterization of a blaCTX-M-15-carrying element; Gangoue-Pieboji J et al.; CTX-M-15-producing Klebsiella pneumoniae and Escherichia coli emerged recently in Cameroon . CTX-M-15 was encoded by two different multiresistance plasmids, of which one carried an ISEcp1-bla(CTX-M-15) element flanked by a 5-bp target site duplication and inserted within a Tn2-derived sequence . A truncated form of this element in the second plasmid was identified.

Antimicrob Agents Chemother, 2005 Jan, 49(1), 269 - 75
Antibacterial activity and specificity of the six human {alpha}-defensins; Ericksen B et al.; We developed a kinetic, 96-well turbidimetric procedure that is capable of testing the antimicrobial properties of six human alpha-defensins concurrently on a single microplate . The defensins were prepared by solid-phase peptide synthesis and tested against gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and gram-negative bacteria (Enterobacter aerogenes and Escherichia coli) . Analysis of the growth curves provided virtual lethal doses (vLDs) equivalent to conventional 50% lethal doses (LD(50)s), LD(90)s, LD(99)s, and LD(99.9)s obtained from colony counts . On the basis of their respective vLD(90)s and vLD(99)s, the relative potencies of human myeloid alpha-defensins against S . aureus were HNP2 > HNP1 > HNP3 > HNP4 . In contrast, their relative potencies against E . coli and E . aerogenes were HNP4 > HNP2 > HNP1 = HNP3 . HD5 was as effective as HNP2 against S . aureus and as effective as HNP4 against the gram-negative bacteria in our panel . HD6 showed little or no activity against any of the bacteria in our panel, including B . cereus, which was highly susceptible to the other five alpha-defensins . The assay described provides a quantitative, precise, and economical way to study the antimicrobial activities of host-defense peptides . Its use has clarified the relative potencies of human alpha-defensins and raised intriguing questions about the in vivo function(s) of HD6.

Antimicrob Agents Chemother, 2005 Jan, 49(1), 71 - 6
Emergence of plasmid-mediated quinolone resistance in Escherichia coli in Europe; Mammeri H et al.; Although quinolone resistance results mostly from chromosomal mutations, it may also be mediated by a plasmid-encoded qnr gene in members of the family Enterobacteriaceae . Thus, 297 nalidixic-acid resistant strains of 2,700 Escherichia coli strains that had been isolated at the Bicetre Hospital (Le Kremlin-Bicetre, France) in 2003 were screened for qnr by PCR . A single E . coli isolate that carried a ca . 180-kb conjugative plasmid encoding a qnr determinant was identified . It conferred low-level resistance to quinolones and was associated with a chromosomal mutation in subunit A of the topoisomerase II gene . The qnr gene was located on a sul1-type class 1 integron just downstream of a conserved region (CR) element (CR1) comprising the Orf513 recombinase . Promoter sequences for qnr expression overlapped the extremity of CR1, indicating the role of CR1 in the expression of antibiotic resistance genes . This integron was different from other qnr-positive sul1-type integrons identified in American and Chinese enterobacterial isolates . In addition, plasmid pQR1 carried another class 1 integron that was identical to In53 from E . coli . The latter integron possessed a series of gene cassettes, including those coding for the extended-spectrum beta-lactamase VEB-1, the rifampin ADP ribosyltransferase ARR-2, and several aminoglycoside resistance markers . This is the first report of plasmid-mediated quinolone resistance in Europe associated with an unknown level of plasmid-mediated multidrug resistance in Enterobacteriaceae.

Med Trop (Mars), 2004, 64(4), 359 - 62
{Orbital cellulitis in children: a 33-case series}; Ailal F et al.; Orbital cellulitis is rare . However the high risk of severe ocular and neurological complications make early diagnosis and adequate therapy essential . The purpose of this retrospective study is to describe 33 cases observed in the pediatric infectious disease department of the Casablanca Children's Hospital in Morocco from 1994 to 2000 . Orbital cellulitis was preseptal in 24 patients and retroseptal in 9 . Infection occurred in relation with sinusitis in 10 cases, polydermitis in 8, wound infection in 6, ocular infection in 2, and dental abscess in 2 . Ages ranged from 40 days to 15 years with a mean age of 5 years . Infants accounted for 25% of cases and always presented preseptal cellulitis . Fever and local edema were noted in all patients . Exophthalmia occurred in six patients and seizures in 2 . The 9 cases of retroseptal cellulitis were complicated by empyema in 2 cases, meningitis in 1 case and thrombophlebitis of cavernous sinus with cerebromalacia in 1 case . Bacteriological testing identified micro-organisms in 10 cases, i.e., Staphylococcus aureus in 6 cases, Streptococcus B in 1, Streptococcus pyogenes in 1, Enterobacter Cloacae in land Acinitobacter jejuni in 1 case . Therapy was based on broad-spectrum antibiotics in association with surgery in the patient presenting in intracranial abscess . Ophthalmoplegia-like sequels including blindness, aphasia, and motor deficit occurred in 2 patients . Orbital cellulitis in children are usually preseptal and have a favorable prognosis . However prompt and adequate antibiotherapy is essential due to the risk of retroseptal involvement with inflammatory palpberal edema and possible cerebral extension.

Mol Microbiol, 2005 Jan, 55(1), 261 - 75
Erwinia chrysanthemi requires a second iron transport route dependent of the siderophore achromobactin for extracellular growth and plant infection; Franza T et al.; Summary Full virulence of the pectinolytic enterobacterium Erwinia chrysanthemi strain 3937 depends on the production in planta of the catechol-type siderophore chrysobactin . Under iron-limited conditions, E . chrysanthemi synthesizes a second siderophore called achromobactin belonging to the hydroxy/carboxylate class of siderophore . In this study, we cloned and functionally characterized a 13 kb long operon comprising seven genes required for the biosynthesis (acs) and extracellular release (yhcA) of achromobactin, as well as the gene encoding the specific outer membrane receptor for its ferric complex (acr) . The promoter of this operon was negatively regulated by iron . In a fur null mutant, transcriptional fusions to the acsD and acsA genes were constitutively expressed . Band shift assays showed that the purified E . chrysanthemi Fur repressor protein specifically binds in vitro to the promoter region of the acsF gene confirming that the metalloregulation of the achromobactin operon is achieved directly by Fur . The temporal production of achromobactin in iron-depleted bacterial cultures was determined: achromobactin is produced before chrysobactin and its production decreases as that of chrysobactin increases . Pathogenicity tests performed on African violets showed that achromobactin production contributes to the virulence of E . chrysanthemi . Thus, during infection, synthesis of these two different siderophores allows E . chrysanthemi cells to cope with the fluctuations of iron availability encountered within plant tissues . Interestingly, iron transport mediated by achromobactin or a closely related siderophore probably exists in other phytopathogenic bacterial species such as Pseudomonas syringae.

Syst Appl Microbiol, 2004 Nov, 27(6), 689 - 95
Development of a fast DNA-DNA hybridization method based on melting profiles in microplates; Mehlen A et al.; DNA-DNA hybridization is still the "gold standard" for the genotypic delineation of bacterial species . However, it is not widely used because traditional DNA-DNA hybridization techniques are rather time-consuming and not easy to perform in routine laboratories . In the present study, DNA of reference strains was digested with Sau3A, ligated with linker oligonucleotides S1/2 and in vitro amplified . The amplified DNA fragments were immobilized on MaxiSorb 96-well plates . DNA isolated from target strains was also digested with Sau3A, ligated with linker oligonuleotides P1/2 and in vitro amplified in the presence of digoxygenin modified dUTP . The labeled amplificate was hybridized to the immobilized reference DNA under isothermal conditions . Thermal denaturation curves of the DNA-DNA hybrids were obtained by using washing solutions of increasing stringency . Remaining hybrids were colorimetrically detected with anti-digoxygenin-horseradish peroxidase anti-bodies . The new method was validated with strains of the genus Pedioccocus for which DNA-DNA similarities have also been determined by the filter hybridization method . In addition, DNA-DNA hybridizations were performed with genotypically defined Enterobacter species.

FEMS Immunol Med Microbiol, 2005 Jan 1, 43(1), 1 - 11
Towards more virulent and antibiotic-resistant Salmonella?
Fluit AC.
Salmonella are well-known pathogens . Virulence determinants can be present on the chromosome, usually encoded on pathogenicity islands, or on plasmids and bacteriophages . Antibiotic resistance determinants usually are encoded on plasmids, but can also be present on the multidrug resistance region of Salmonella Genomic Island 1 (SGI1) . Virulence plasmids show a remarkable diversity in the combination of virulence factors they encode, which appears to adapt them to specific hosts and the ability to cause gastroenteritidis or systemic disease . The appearance of plasmids with two replicons may help to extend the host range of these plasmids and thereby increase the virulence of previously non- or low pathogenic serovars . Antibiotic resistance among Salmonella is also increasing . This increase is not only in the percentage isolates resistant to a particular antibiotic, but also the development of resistance against newer antibiotics . The increased occurrence of integrons is particularly worrying . Integrons can harbour a varying set of antibiotic resistance encoding gene cassettes . Gene cassettes can be exchanged between integrons . Although the gene cassettes currently present in Salmonella integrons encode for older antibiotics (however, some still frequently used) gene cassettes encoding resistance against the newest antibiotics has been documented in Enterobacteriaceae . Furthermore, beta-lactamases with activity against broad-spectrum cephalosporins, which are often used in empiric therapy, have been found associated with integrons . So, empiric treatment of Salmonella infections becomes increasingly more difficult . The most worrisome finding is that virulence and resistance plasmids form cointegrates . These newly formed plasmids can be selected by antibiotic pressure and thereby for virulence factors . Taken together these trends may lead to more virulent and antibiotic-resistant Salmonella.

Di Yi Jun Yi Da Xue Xue Bao, 2004 Dec, 24(12), 1441 - 3
{Investigation of pathogenic bacteria for pulmonary infections and their drug resistance in neurological intensive care unit.}; Shi MY et al.; OBJECTIVE: To investigate the pathogenic bacterial spectrum responsible for pulmonary infections and their drug resistance in patients admitted to neurological care unit . METHODS: Sputum specimens were obtained from patients who developed pulmonary infections in neurological intensive care unit between January, 2001 and June, 2002 for bacterial culture and isolation . K-B paper disc method was employed for determination of the drug sensitivity of the bacterial isolates . RESULTS: In the 207 strains obtained from the patients, the majority (68.51%) were Gram-negative and 30.91/ Gram-positive bacteria, with fungi detected in one case (0.48%) . The major pathogenic bacteria for pulmonary infection were, in the order of frequency, Staphylococcus aureus(14.49%), Pseudomonas aeruginosa (14.49%), Klebsiella pneumoniae (8.7%), Enterobacter cloacae (6.76%), and Enterobacter aerogenes (6.28%) . Drug sensitivity tests showed increased drug resistance of the bacteria, but Staphylococcus aureus still remained sensitive to vancomycin and most of the Gram-negative bacillus sensitive to imipenem . CONCLUSION: The major pathogenic bacteria causing pulmonary infections in neurological intensive care unit are Staphylococcus aureus and Pseudomonas aeruginosa, and their drug resistance is obviously increased, suggesting the necessity of strengthening bacterial surveillance and more adequate clinical use of antibiotics.

J Bacteriol, 2005 Jan, 187(1), 77 - 84
The pbgPE operon in Photorhabdus luminescens is required for pathogenicity and symbiosis; Bennett HP et al.; Photorhabdus is a genus of gram-negative Enterobacteriaceae that is pathogenic to insect larvae while also maintaining a mutualistic relationship with nematodes from the family Heterorhabditis, where the bacteria occupy the gut of the infective juvenile (IJ) stage of the nematode . In this study we describe the identification and characterization of a mutation in the pbgE1 gene of Photorhabdus luminescens TT01, predicted to be the fifth gene in the pbgPE operon . We show that this mutant, BMM305, is strongly attenuated in virulence against larvae of the greater wax moth, Galleria mellonella, and we report that BMM305 is more sensitive to the cationic antimicrobial peptide, polymyxin B, and growth in mildly acidic pH than the parental strain of P . luminescens . Moreover, we also show that the lipopolysaccharide (LPS) present on the surface of BMM305 does not appear to contain any O antigen . Complementation studies reveal that the increased sensitivity to polymyxin B and growth in mildly acidic pH can be rescued by the in trans expression of pbgE1, while the defects in O-antigen assembly and pathogenicity require the in trans expression of pbgE1 and the downstream genes pbgE2 and pbgE3 . Finally, we show that BMM305 is defective in symbiosis as this mutant is unable to colonize the gut of the IJ stage of the nematode . Therefore, we conclude that the pbgPE operon is required for both pathogenicity and symbiosis in P . luminescens.

Crit Care Med, 2004 Dec, 32(12), 2450 - 6
Cycling empirical antimicrobial agents to prevent emergence of antimicrobial-resistant Gram-negative bacteria among intensive care unit patients; Warren DK et al.; OBJECTIVE: To determine the impact of the rotation of antimicrobial agents on the rates of infection, intestinal colonization, and acquisition with antimicrobial-resistant Gram-negative bacteria . DESIGN: Pre- and postintervention design . SETTING: A 19-bed, medical intensive care unit . PATIENTS: Individuals admitted to the study unit for >48 hrs . INTERVENTIONS: After a 5-month baseline observation period, four classes of antimicrobial agents with Gram-negative activity were cycled at 3- to 4-month intervals for 24 months . MEASUREMENTS AND MAIN RESULTS: The primary outcome was the acquisition rate of antimicrobial resistance among Enterobacteriaceae and Pseudomonas aeruginosa obtained from rectal swab cultures performed on admission, weekly during the patients' stay, and at discharge . Rates and microbiology of nosocomial bloodstream infections and ventilator-associated pneumonia were also compared between baseline and cycling periods . The cycling program resulted in a significant change in prescribing practices; the predominant agent used changed with each cycle . Among study patients who were not already colonized with a resistant organism, the rate of acquisition of enteric colonization with bacteria resistant to any of the target drugs remained stable during the cycling period for P . aeruginosa (relative rate, 0.96; 95% confidence Interval, 0.47-2.16) and Enterobacteriaceae (relative rate, 1.57; 95% confidence interval, 0.80-3.43) . Hospital-wide, P . aeruginosa from routine clinical cultures resistant to the target drugs increased during the cycling period . The proportion of Gram-negative bacteria isolated from cases of nosocomial bloodstream infection (29% baseline vs . 26% cycling; p = .11) and ventilator-associated pneumonia (80% vs . 41%; p = .06) did not significantly differ . CONCLUSIONS: In this study, antimicrobial cycling did not result in a significant change in enteric acquisition of resistant Gram-negative bacteria among intensive care unit patients.

Phytother Res, 2004 Nov, 18(11), 911 - 4
Piperitone from Mentha longifolia var . chorodictya Rech F . reduces the nitrofurantoin resistance of strains of enterobacteriaceae; Shahverdi AR et al.; The diluted essential oil of Mentha longifolia (L.) var . chlorodictya Rech F . foliage enhanced the bactericidal activity of nitrofurantoin decreasing the minimum inhibitory concentration (MIC) of nitrofurantoin for nitrofurantoin-resistant strains of Enterobacteriaceae . Thin-layer chromatography (TLC) analysis of the essential oil detected a fraction (R(f) = 0.35, UV lambda(max) of 232.5), which was the most effective in enhancement of nitrofurantoin activity . Using gas liquid chromatography and known standards, the active fraction was identified as piperitone . 1 microl of the piperitone fraction decreased the MIC of nitrofurantoin 3-20 fold for the different strains of Enterobacteriaceae tested .

Pathol Biol (Paris), 2004 Dec, 52(10), 602 - 606

Lawrence C, Ohana S, Ronco E, Dizien O, Denys P, Laffont I, Lortat-Jacob S, Vezant P, Doussin F, Gaillard JL.
Objectives . - The objective of this study was to evaluate the epidemiology of antibiotic-resistant bacteria among motor impaired patients admitted to an acute rehabilitation unit . Methods . - From January 2000 to December 2002, the acute rehabilitation units of R . Poincare Hospital have screened patients for methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase enterobacteria (ESBL-EB) carriage by nasal and rectal swab at admission, every month and exit . Results . - Finally, MRSA was isolated form screening or diagnosis samples of 360 patients and ESBL-EB from screening or diagnosis samples of 170 patients, corresponding respectively to an incidence of 3.6 for 1000 days of hospitalization (DH) and 1.7 for 1000 DH . 66% (236/360) of MRSA carriers and 58% of ESBL-EB carriers were identified only by screening samples . Carriage origin was identified for year 2002: Cases were imported for 40% (26/65) of MRSA carriers and 43% (18/42) of ESBL-EB carriers . The median acquisition delays were of 31 days {3-154} for MRSA and 19 days {3-317} for ESBL-EB . Conclusion . - This allowed to set up contact precautions for more than 2 fold patients that would have allowed diagnosis samples alone.

Int J Med Microbiol, 2004 Oct, 294(6), 373 - 81
OmpA of a septicemic Escherichia coli O78--secretion and convergent evolution; Gophna U et al.; OmpA is an important constituent of the outer membrane of Gram-negative bacteria . OmpA is involved in a variety of host-bacteria interactions, including crossing of the blood-brain barrier by E . coli strains causing newborn meningitis, and elicits a significant response by the immune system of the host . The bactericidal effect of neutrophil elastase (NE) is also attributed to degradation of the bacterial OmpA . Here we examined the OmpA of septicemic E . coli 078 strains and show that two surface-exposed loops are conserved among invasive strains of E . coli and other pathogenic Enterobacteriaceae . In addition, there is evidence for convergent evolution, implying the existence of selective pressure . Our results also indicate that large quantities of OmpA are secreted into the medium during all phases of growth, where it is present both in secreted vesicles and as a soluble secreted protein . We assume that secreted OmpA can play a role in protection of bacteria from NE by competitive inhibition . Support for this assumption was obtained from experiments indicating that addition of exogenous, purified OmpA reduces killing of bacteria by NE.

J Zhejiang Univ Sci, 2005 Jan, 6B(1), 53 - 56
The binding of MBL to common bacteria in infectious diseases of children; Shang SQ et al.; Objective: To purify Mannan-binding lectin (MBL) from human serum and detect its binding ability to several kinds of bacteria common in infectious diseases of children . Methods: MBL was purified from human serum by affinity chromatography on mannan-Sepharose 4B column . Its binding ability to eight species, 97 strains of bacteria was detected by enzyme-linked lectin assay (ELLA) . Results: MBL has different binding ability to bacteria and shows strong binding ability to Klebsiella ornithinolytica and Escherichia coli, but shows relatively lower binding ability to Staphylococcus haemolyticus, Enterobacter cloacae and Staphylococcus epidermidis . To different isolates of Klebsiella pneumoniae, Haemophilus influenzae and Staphylococcus aureus, MBL shows quite different binding ability . Conclusions: MBL has different binding ability to different bacteria, and has relatively stronger binding ability to Gram-negative bacteria . Its binding ability to different isolates of certain kinds of bacteria is quite different.

Pharmazie, 2004 Nov, 59(11), 854 - 8
In vitro activity of cefepime and cefpirome compared to other third-generation cephem antibiotics against gram-negative nosocomial pathogens; Tumah HN; The in vitro activities of new expanded spectrum of fourth-generation cephalosporins, cefepime and cefpirome, were compared with those of three third-generation cephalosporins, cefoperazone, ceftazidime, and ceftriaxone, that are commonly used in the treatment of serious infections caused by aerobic gram-negative bacteria . The agar dilution method described by the US National Committee for Clinical Laboratory Standards was used to determine the minimum inhibitory concentrations of antibiotics tested . 302 clinical isolates, representing a cross-section of Klebsiella and Enterobacter species and Pseudomonas aeruginosa were tested . Cefepime was considerably more active than other antibiotics tested, against Klebsiella species and Enterobacter species, and demonstrated activity similar to ceftazidime against Pseudomonas aeruginosa . Ceftazidime was active against Pseudomonas aeruginosa but was less potent against Enterobacter species . Cefoperazone and ceftriaxone were less active than ceftazidime against Pseudomonas aeruginosa . Cefepime had slightly greater activity than cefpirome against the gram-negative bacteria tested . However, cefepime and cefpirome were found to be highly active against many resistant organisms that traditionally have been difficult to treat.

Vox Sang, 2004 Nov, 87(4), 241 - 9
Influence of blood prestorage conditions and white blood cell filtration on the bacterial load of blood deliberately inoculated with Gram-positive and Gram-negative pathogens; Siblini L et al.; BACKGROUND AND OBJECTIVES: Currently, the bacterial contamination of blood constitutes one of the major infectious risks of transfusion . The aim of this study was to evaluate the bactericidal effect of blood on various bacterial species and to determine the influence of prestorage conditions and white blood cell (WBC) filtration on the reduction of the bacterial load in isolated red blood cells (RBCs) . MATERIALS AND METHODS: The growth kinetics of eight different species of bacteria were studied at 20 degrees C in deliberately contaminated RBC units . Further experiments evaluated the effect of prestorage conditions and WBC filtration on the viability of two model bacteria (Klebsiella oxytoca and Staphylococcus epidermidis) in comparison to previous results obtained with Yersinia enterocolitica . RESULTS: For bacteria susceptible to the bactericidal effect of blood (mainly Gram-negative rods), a reduction of the bacterial load was obtained within 2 h of prestorage at 20 degrees C . When the prestorage period was prolonged beyond 3 h at 20 degrees C, rapid growth was observed with some Enterobacteriaceae . Whereas WBC filtration reduced dramatically the viability of Y . enterocolitica, it had only a minimal effect on the viability of S . epidermidis and K . oxytoca . However, the two latter species of bacteria did not survive prolonged storage at 4 degrees C . CONCLUSIONS: Experiments conducted under realistic conditions are needed to determine whether it would be worthwhile recommending the rapid storage of RBCs at 4 degrees C after WBC reduction of the blood product.

Int J Food Microbiol, 2005 Jan 1, 97(3), 259 - 65
Sequencing of an internal transcribed spacer region of 16S-23S rRNA gene and designing of PCR primers for the detection of Salmonella spp . in food; Chiu TH et al.; DNA sequences of an internal transcribed spacer (ITS) region for 40 Salmonella serovars were determined and compared with ITS sequences of Salmonella spp., and non-Salmonella spp . already available on the GenBank database . From such comparison, two Salmonella-specific ITS based PCR primers, ITSF and ITSR, were designed . When Salmonella strains with various serotypes were PCR assayed with primers ITSF/ITSR, all generated PCR products with molecular weight bands equal to 312 bp . On the other hand, 48 non-Salmonella isolates, including strains of Enterobacteriaceae and other food pathogens generated negative results . Detection limits of this PCR method was 1-9 CFU per assay . These PCR primers were used for the detection of Salmonella cells in artificially contaminated foods, including chicken meat and whole milk . The detection limit was 1-9x10(3) CFU per assay . With an 8-h enrichment step performed prior to the PCR assay, however, the detection limit became 1-9 CFU per gram of the food sample.

Diagn Microbiol Infect Dis, 2004 Dec, 50(4), 291 - 3
Susceptibility of meropenem and comparators tested against 30,634 enterobacteriaceae isolated in the MYSTIC programme (1997-2003); Turner PJ; A total of 30,634 global Enterobacteriaceae isolates collected from the MYSTIC (Meropenem Yearly Surveillance Test Information Collection) Programme were tested using a reference methodology against meropenem and seven other broad-spectrum agents commonly used in the hospital setting (1997-2003) . The most active compound was meropenem (99.6% susceptible), followed by imipenem (98.4%), cefepime (94.0%), gentamicin (86.8%), piperacillin/tazobactam (85.8%), ceftazidime (85.0%), ciprofloxacin (84.6%), and tobramycin (84.5%) . Continued surveillance of antimicrobial compounds' in vitro activity is necessary to recommend regimens that are likely to be effective in clinical practice.

Chemosphere, 2005 Jan, 58(3), 263 - 70
Enhanced bioavailability of sorbed 2,4,6-trinitrotoluene (TNT) by a bacterial consortium; Robertson BK et al.; Large quantities of trinitrotoluene (TNT) have been associated with past and present military activities worldwide . Because this contaminant is highly toxic and strongly sorbs to soil particles, bacteria that are able to transform it have had very little success, if any . This study was conducted to evaluate the bioavailability of (14)C-labeled TNT in soil for microbial mineralization . Sorption-desorption experiments indicated that a Kendaia loam soil effectively adsorbs this explosive compound, with approximately 30-45% of the added TNT remaining sorbed to the soil after a total of 10 washings . A bacterial consortium isolated from explosive-contaminated sites was prepared in liquid medium and then tested in a TNT-spiked Kendaia loam soil . The concentration of TNT in the soil that was inoculated with the bacterial consortium was reduced by more than 30% of the initial concentration compared to the soil that did not contain the bacterial consortium within a period of 20weeks . Nearly half of the TNT was mineralized as determined by the percentage of (14)CO(2) produced . Only one member of the consortium (i.e., Enterobacter sp.) significantly mineralized 25% of TNT although the extent of mineralization was significantly enhanced to 35% in the presence of the other two members of the consortium . The data suggest that some of the strongly adsorbed TNT may be accessible for metabolism if conditions for the right combination of microorganisms with specialized capabilities are optimized . The remaining sorbed fraction of substrate is presumably sequestered and thus unavailable to the microorganisms.

Ying Yong Sheng Tai Xue Bao, 2004 Aug, 15(8), 1344 - 8
{Population of entophytic bacteria in maize roots and its dynamic analysis}; Gao Z et al.; In 2001-2002, 14 maize cultivars in Liaoning Province were used for the analysis of their entophytic bacteria population . The entophytic bacteria strains with a higher frequency in maize roots were Bacillus spp., Enterobacter spp., Serratia spp., Pseudomonas spp., Xanthomonas spp., Clavibacter spp., Bacillus spp., Enterobacter spp . and Serratia spp . Comparatively, Bacillus spp . was the most prevalent entophytic bacterium, including 8 species, B . subtilis, B . megaterium, B . cereus, B . licheniformis, B . anthracis, B . mycoides, B . pumilus and B . circulans, and with an average isolation frequency of 75.5% at seedling stage and 77.6% at adult stage . There existed significant differences in the population and dynamics of endophytic bacteria among maize cultivars and growth periods, and a significant correlation was found between maize genetic background and entophytic bacteria population.

J Econ Entomol, 2004 Oct, 97(5), 1570 - 80
Effect of probiotic adult diets on fitness components of sterile male Mediterranean fruit flies (Diptera: Tephritidae) under laboratory and field cage conditions; Niyazi N et al.; The aim of the current study was to investigate the effect of probiotic adult diets, i.e., adult diets containing viable symbiotic intestinal bacteria, on the pheromone-calling activity, mating success, life expectancy, and survival of mass-reared male Mediterranean fruit flies, Ceratitis capitata (Wiedemann), as an avenue for improving the field performance of sterile males in release programs to eradicate, suppress, or prevent spread of wild populations . The effect of inoculation of two standard adult diets (sugar-yeast granulate {SY} and sugar agar {s}) and two experimental formulations (yeast-reduced granulate {Sy} and yeast-enhanced sugar agar {sy}) with Enterobacter agglomerans and Klebsiella pneumoniae (typically occurring in the gut of wild flies) on the different fitness components was assessed in the laboratory and on field-caged host trees . We found that, in the laboratory, males reared on the probiotic yeast-enhanced agar, sy, had a significant mating advantage over competitors fed the standard s agar (probiotic and control) or noninoculated sy agar; no effect of probiotic enrichment (or lowering the yeast content) was found with the granular diets . Mating test results obtained in the field were inconsistent with laboratory data in that no differences in the numbers of matings were observed between males reared on any of the probiotic and control agar diets (or the SY granulate), whereas males feeding on the probiotic modified granulate, Sy, scored significantly more matings than their control competitors . The pheromone-calling activity of males maintained on the granular diets was not affected by probiotic enrichment on any of the seven observation days . Agar-fed males, however, "called" more frequently on days 6 and 7 (but not on days 1-5) when their diet contained the probiotic load . Laboratory survival of granulate-fed males was found to be significantly prolonged with probiotic inoculation and lowering the yeast content of the standard SY granulate (but not with probiotic inoculation of sy) . Similarly, males reared on the probiotic and control modified agars (sy) survived significantly longer than those feeding on the standard s agars (inoculated and control) . Again, the results obtained in the field were inconsistent, because no differences between treated and control males were found for any of the diets . The findings are discussed in the light of other published studies on adult nutrition and behavioral ecology in C . capitata.

Asian J Surg, 2004 Jul, 27(3), 227 - 35
Randomized comparison of piperacillin/tazobactam versus imipenem/cilastatin in the treatment of patients with intra-abdominal infection; Erasmo AA et al.; OBJECTIVES: Treatment of intra-abdominal infections remains a challenge because of their polymicrobial nature and associated mortality risk . Broad-spectrum empiric coverage is usually required . This randomized study compared the efficacy and safety of intravenous piperacillin/tazobactam with those of intravenous imipenem/cilastatin in the treatment of 293 hospitalized patients with intra-abdominal infection . METHODS: A total of 149 patients received piperacillin/tazobactam 4 g/500 mg every 8 hours, and 144 patients received imipenem/cilastatin 500 mg/500 mg every 6 hours . Efficacy was evaluated by clinical and bacteriological response . Safety was evaluated by analysis of adverse events and physical and laboratory examinations . RESULTS: Clinical and bacteriological responses in both evaluable treatment groups were equivalent . The clinical success was 97% (108/111) for piperacillin/tazobactam and 97% (100/103) for imipenem/cilastatin . Bacteriological success was 97% (67/69) for piperacillin/tazobactam and 95% (61/64) for imipenem/cilastatin . The most common pathogens were Escherichia coli, Klebsiella pneumoniae, Enterobacter species and Pseudomonas aeruginosa . The frequencies of treatment-related adverse events were similar (16 with piperacillin/tazobactam and 19 with imipenem/cilastatin) . CONCLUSIONS: These results suggest that the safety and efficacy of piperacillin/tazobactam administered every 8 hours are equivalent to those of imipenem/cilastatin administered every 6 hours for the treatment of intra-abdominal infections.

BMC Microbiol . 2004 Nov 25;4(1):43.
16S rRNA gene based analysis of Enterobacter sakazakii strains from different sources and development of a PCR assay for identification; Lehner A et al.; BACKGROUND: E . sakazakii is considered to be an opportunistic pathogen, implicated in food borne diseases causing meningitis or enteritis especially in neonates and infants . Cultural standard identification procedures for E . sakazakii include the observation of yellow pigmentation of colonies and a positive glucosidase activity . Up to now, only one PCR system based on a single available 16S rRNA gene sequence has been published for E . sakazakii identification . However, in our hands a preliminary evaluation of this system to a number of target and non-target strains showed significant specificity problems of this system . In this study full-length 16S rRNA genes of thirteen E . sakazakii strains from food, environment and human origin as well as the type strain ATCC 51329 were sequenced . Based on this sequence data a new specific PCR system for E . sakazakii was developed and evaluated . RESULTS: By phylogenetic analysis of the new full-length 16S rRNA gene sequence data obtained we could show the presence of a second phylogenetic distinct lineage within the E . sakazakii species . The newly developed 16S rRNA gene targeting PCR system allows identification of E . sakazakii strains from both lineages . The assay's ability to correctly identify different E . sakazakii isolates as well as to differentiate E . sakazakii from other closely related Enterobacteriaceae species and other microorganisms was shown on 75 target and non-target strains . CONCLUSION: By this study we are presenting a specific and reliable PCR identification system, which is able to correctly identify E . sakazakii isolates from both phylogenetic distinct lines within the E . sakazakii species . The impact of this second newly described phylogenetic line within the E . sakazakii species in view of clinical and food safety aspects need further investigation.

Mol Biol Evol . 2004 Nov 24; {Epub ahead of print}
Lack of Evidence for Horizontal Transfer of the lac Operon into Escherichia coli; Stoebel DM; The idea that Escherichia coli gained the lac operon via horizontal transfer, allowing it to invade a new niche and form a new species, has become a paradigmatic example of bacterial non-pathogenic adaptation and speciation catalyzed by horizontal transfer . Surprisingly, empirical evidence for this event is essentially nonexistant . To see whether horizontal transfer occurred, I compared a phylogeny of 14 Enterobacteriaceae based on two housekeeping genes to a phylogeny of a part of their lac operon . While several species in this clade appear to have acquired some or all of the operon via horizontal transfer, there is no evidence of horizontal transfer into E . coli . It is not clear whether the horizontal transfer events for which there is evidence were adaptive because those species which have acquired the operon are not thought to live in high lactose environments . I propose that vertical transmission from the common ancestor of the Enterobacteriacea, with subsequent loss of these genes in many species can explain much of the patchy distribution of lactose use in this clade . Finally, I argue that we need new, well-supported examples of horizontal transfer spurring niche expansion and speciation, particularly in non-pathogenic cases, before we can accept claims that horizontal transfer is a hallmark of bacterial adaptation.

Antimicrob Agents Chemother, 2004 Dec, 48(12), 4793 - 9
Outbreak of Klebsiella pneumoniae producing a new carbapenem-hydrolyzing class A beta-lactamase, KPC-3, in a New York Medical Center; Woodford N et al.; From April 2000 to April 2001, 24 patients in intensive care units at Tisch Hospital, New York, N.Y., were infected or colonized by carbapenem-resistant Klebsiella pneumoniae . Pulsed-field gel electrophoresis identified a predominant outbreak strain, but other resistant strains were also recovered . Three representatives of the outbreak strain from separate patients were studied in detail . All were resistant or had reduced susceptibility to imipenem, meropenem, ceftazidime, piperacillin-tazobactam, and gentamicin but remained fully susceptible to tetracycline . PCR amplified a blaKPC allele encoding a novel variant, KPC-3, with a His(272)-->Tyr substitution not found in KPC-2; other carbapenemase genes were absent . In the outbreak strain, KPC-3 was encoded by a 75-kb plasmid, which was transferred in vitro by electroporation and conjugation . The isolates lacked the OmpK35 porin but expressed OmpK36, implying reduced permeability as a cofactor in resistance . This is the third KPC carbapenem-hydrolyzing beta-lactamase variant to have been reported in members of the Enterobacteriaceae, with others reported from the East Coast of the United States . Although producers of these enzymes remain rare, the progress of this enzyme group merits monitoring.

Antimicrob Agents Chemother, 2004 Dec, 48(12), 4528 - 31
TEM-121, a novel complex mutant of TEM-type beta-lactamase from Enterobacter aerogenes; Poirel L et al.; Enterobacter aerogenes clinical isolate LOR was resistant to penicillins and ceftazidime but susceptible to cefuroxime, cephalothin, cefoxitin, cefotaxime, ceftriaxone, and cefepime . PCR and cloning experiments from this strain identified a novel TEM-type beta-lactamase (TEM-121) differing by five amino acid substitutions from beta-lactamase TEM-2 (Glu104Lys, Arg164Ser, Ala237Thr, Glu240Lys, and Arg244Ser) and by only one amino acid change from the extended-spectrum beta-lactamase (ESBL) TEM-24 (Arg244Ser), with the last substitution also being identified in the inhibitor-resistant beta-lactamase IRT-2 . Kinetic parameters indicated that TEM-121 hydrolyzed ceftazidime and aztreonam (like TEM-24) and was inhibited weakly by clavulanic acid and strongly by tazobactam . Thus, TEM-121 is a novel complex mutant TEM beta-lactamase (CMT-4) combining the kinetic properties of an ESBL and an inhibitor-resistant TEM enzyme.

Tuberk Toraks, 2004, 52(4), 333 - 340
{The pathogens and their antibiotic sensitivities in hospital-acquired pneumonia cases.}; Kaynar H et al.; Dynamic precautions in the early diagnosis and treatment of hospital acquired pneumonias are necessary because of their high mortality . In these patients, invasive diagnostic approaches may be needed since clinical and radiological findings and other non-invasive approaches frequently fail to establish the diagnosis . Thirty eight patients were prospectively included in the study . Average age of patients was 45.5 +/- 16.4 years; 31 were males (81.6%) and 7 (18.4%) were females . Pneumonia was detected in 9 (23.7%) cases during the first five days and in 29 (76.3%) cases after the fifth day of admission to the hospital . Bronchoscopic interventions diagnostic purpose were carried out in 25 (65.8%) patients . The culture results were negative in 7 (18.4%) cases . While more than one pathogen was determined on the cultures of 16 (42.1%) patients only one pathogen was isolated in the cultures of 15 (39.4%) cases . The frequently isolated pathogen on cultures was Staphylococci (45.4%) . Other pathogens were Enterobacter spp., Pseudomonas spp., Escherichia coli, Serratia and Streptococcus pneumoniae according to their frequency on cultures . High resistance rates to the third generation cephalosporins were determined . Eleven of 17 deaths in 38 pneumonia cases were attributable to pneumonia . As a conclusion, isolation of pathogen and antibiotic resitance should be determined in the cases with hospital acquired pneumonia . Invasive diagnostic interventions were not avoided when necessary . Although pro-BAL and PSB methods were expensive, their use in selected cases may prevent unnecessary antibiotic use and contribute to a decrease in mortality rate.

J Ind Microbiol Biotechnol . 2004 Nov 19; {Epub ahead of print}
Antifungal and sprout regulatory bioactivities of phenylacetic acid, indole-3-acetic acid, and tyrosol isolated from the potato dry rot suppressive bacterium Enterobacter cloacae S11:T:07; Slininger PJ et al.; Enterobacter cloacae S11: T:07 (NRRL B-21050) is a promising biological control agent that has significantly reduced both fungal dry rot disease and sprouting in laboratory and pilot potato storages . The metabolites phenylacetic acid (PAA), indole-3-acetic acid (IAA), and tyrosol (TSL) were isolated from S11:T:07 liquid cultures provided with three different growth media . The bioactivities of these metabolites were investigated via thin-layer chromatography bioautography of antifungal activity, wounded potato assays of dry rot suppressiveness, and cored potato eye assays of sprout inhibition . Relative accumulations of PAA, IAA, and TSL in cultures were nutrient dependent . For the first time, IAA, TSL, and PAA were shown to have antifungal activity against the dry rot causative pathogen Gibberella pulicaris, and to suppress dry rot infection of wounded potatoes . Disease suppression was optimal when all three metabolites were applied in combination . Dosages of IAA that resulted in disease suppression also resulted in sprout inhibition . These results suggest the potential for designing culture production and formulation conditions to achieve a dual purpose biological control agent able to suppress both dry rot and sprouting of stored potatoes.

Mar Pollut Bull, 2004 Dec, 49(11-12), 974 - 7
Accumulation of hexavalent chromium by an exopolysaccharide producing marine Enterobacter cloaceae; Iyer A et al.; An exopolysaccharide producing Enterobacter cloaceae (AK-I-MB-71a) was tested for its Cr (VI) tolerance . This isolate was not only resistant to this heavy metal but also showed enhanced growth and exopolysaccharide production in the presence of Cr (VI) at 25, 50 and 100 ppm concentrations . XRF analysis of both the biomass as well as the exopolysaccharide revealed that a sum total of about 60-70% chromium was accumulated by this bacterium . This indicated that this organism could prove to be a potential candidate in the field of bioremediation with respect to chromium removal.

Int J Antimicrob Agents, 2004 Dec, 24(6), 585 - 91
Beta-lactam susceptibilities and prevalence of ESBL-producing isolates among more than 5000 European Enterobacteriaceae isolates; Nijssen S et al.; In vitro susceptibility to 15 beta-lactam antibiotics was evaluated using Enterobacteriaceae isolated during the SENTRY Antimicrobial Surveillance Program . Piperacillin/tazobactam was the most active penicillin against Escherichia coli, Proteus mirabilis, Klebsiella oxytoca and Klebsiella pneumoniae (94.9%, 98.3%, 87.4% and 82.9% of isolates susceptible) . Of the cephalosporins, cefepime was most effective against Escherichia coli, Proteus mirabilis and Enterobacter cloacae (99.2%, 96.3% and 95.2% of isolates susceptible, respectively) and cefoxitin against Klebsiella oxytoca and Klebsiella pneumoniae (98.6% and 95.6% of isolates susceptible) . Carbapenems had excellent activity (> or =99.5% of all isolates) . ESBL-production was confirmed with the ESBL-Etest and disk diffusion test in 1.3% of Escherichia coli isolates, 18.4% of Klebsiella pneumoniae, 12.6% of Klebsiella oxytoca and 5.3% of Proteus mirabilis isolates.

Immunology, 2004 Dec, 113(4), 499 - 508
Characterization of T-regulatory cells, induced by immature dendritic cells, which inhibit enteroantigen-reactive colitis-inducing T-cell responses in vitro and in vivo; Gad M et al.; Regulatory T (Treg) cells, derived from co-cultures of unfractionated CD4(+) T cells and immature dendritic cells (DC), suppress enteroantigen-induced proliferation of CD4(+) CD25(-) T cells . The DC-induced Treg cells are a mixture of CD25(+) (10-20%) and CD25(-) (80-90%) T cells . However, all the suppressor activity in vitro and in vivo resides in the CD25(+) T-cell subset . The CD25(+) DC-induced Treg cells can inhibit enteroantigen-induced proliferation in vitro through a transwell membrane, and their function does not appear to depend on previous activation . DC-induced CD25(+) Treg cells display a naive phenotype, expressing high levels of CD45RB and l-selectin (CD62L) . In addition, the DC-induced Treg cells mediate a stronger suppressive activity than prototype CD25(+) regulatory T cells . The DC-induced Treg cells, and hereof purified CD25(+) and CD25(-) T-cell fractions, were co-injected into severe combined immunodeficiency (SCID) mice with colitis-inducing CD4(+) CD25(-) T cells . Both unfractionated CD4(+) and purified CD25(+) Treg cells fully protected the recipients against the development of colitis . In contrast, co-transfer of fractionated CD25(-) T cells offered no protection against disease development . Enterobacterial antigen-exposed CD4(+) T cells of the protected mice secreted higher levels of interleukin-10 and lower levels of interferon-gamma than the unprotected mice . The present data demonstrate DC-induced CD4(+) CD25(+) Treg cells, which phenotypically and functionally differ from the generally accepted prototype of CD25(+) Treg cells . These data may initiate new procedures for the expansion of Treg cells for clinical use.

Rinsho Biseibutshu Jinsoku Shindan Kenkyukai Shi, 2003, 14(2), 143 - 9
{A case of inactive Escherichia coli isolated from feces initially suspected to be Shigella boydii subgroup C serotype 14 by conventional biochemical tests in tubes}; Yamamoto S et al.; A small number of colorless colonies grew from DHL agar of feces culture taken as part of a complete physical for a 42 year-old woman who had lived in Singapore for several years . When cultured for first-stage identification using conventional biochemical tests in tubes for Enterobacteriaceae, such as TSI agar slant and SIM medium, the results for lactose reaction (-), saccharose reaction (-), gas (very weak +) and motility (-) were obtained, and Shigella spp . was suspected . Serological tests (by serotype) for Shigella spp . were then conducted . As a result, clear C14 agglutination was observed . Based on these results, the isolate was strongly suspected to be Shigella boydii serotype 14, but since the woman had no symptoms of abdominal pain, diarrhea or fever, such identification was still questionable . When further identification test was carried out using Walk-Away 96 and VITEK 2, non-Shigella spp . identification results were obtained . In second-stage identification, xylolytic activity, acetate salt utilization and use of carbon sources in CA (citrate-acetate) medium were checked, all results were positive, and the isolate was ultimately identified as Inactive Escherichia coli . While Shigella spp . and E . coli are taxonomically similar, they are quite different from each other in terms of pathogenicity . Accurate and rapid identification of Shigella spp . is therefore important.

J Antimicrob Chemother, 2004 Dec, 54(6), 1144 - 1147 Epub 2004 Nov 16.
Nosocomial outbreak by Proteus mirabilis producing extended-spectrum {beta}-lactamase VEB-1 in a Korean university hospital; Kim JY et al.; OBJECTIVES: To examine the molecular mechanisms involved in the beta-lactam resistance of multidrug-resistant Proteus mirabilis isolates that showed an unusual synergy between imipenem and ceftazidime in a Korean hospital . METHODS: Over an 11 month period, a total of 12 P . mirabilis isolates showing resistance to ampicillin, gentamicin, ceftazidime, cefotaxime, cefuroxime, cefalothin, cefepime, piperacillin, trimethoprim/sulfamethoxazole and ciprofloxacin, were recovered from the sputum and urine specimens of nine patients who were hospitalized in the neurosurgery ward . The extended-spectrum beta-lactamases were screened with a double disc synergy test using ceftazidime, cefotaxime, aztreonam, cefepime and clavulanate . The ESBL types were determined by PCR using specific primers for bla(TEM-1), bla(SHV-1), bla(CTX-M-1), bla(CTX-M-2), bla(CTX-M-8), bla(CTX-M-9), bla(PER-1), bla(GES-1), bla(VEB-1), bla(OXA-10) and bla(OXA-13) followed by sequencing . All the isolates underwent molecular typing by PFGE . The transferability was examined by conjugation . RESULTS AND CONCLUSIONS: All the isolates showed a marked synergy between the extended-spectrum cephalosporins and clavulanate together with an unusual synergy between cefoxitin and the cephalosporins (cefalothin, cefuroxime, ceftazidime, cefotaxime) and between imipenem, and ceftazidime and cefotaxime . Isoelectric focusing of the crude bacterial extracts showed a beta-lactamase band with a pI value of 5.4, which was inhibited by clavulanate . PCR and sequencing identified the gene to be bla(VEB-1) . In addition, the aadB gene was detected, conferring aminoglycoside resistance . The resistance was not transferred by conjugation . The outbreak was of a clonal origin as shown by PFGE demonstrating an identical banding pattern . This is the first report of VEB-1-producing Enterobacteriaceae in Korea.

Int J Syst Evol Microbiol . 2004 Nov;54(Pt 6):2437.
Proposal to acknowledge Beijerinck as the original author of the species Pantoea agglomerans . Request for an opinion; Edwards J et al.; The name 'Bacillus agglomerans' was first published by Beijerinck in 1888 . Ewing and Fife changed the name to Enterobacter agglomerans in 1972 as a new combination, acknowledging that Beijerinck had been the original author and making the new full name Enterobacter agglomerans (Beijerinck 1888) Ewing and Fife 1972 . Beijerinck's name was omitted from the Approved Lists of Bacterial Names in 1980, which listed only Ewing and Fife as the authors . The current listings in the List of Bacterial Names with Standing in Nomenclature follow the Approved Lists and omit Beijerinck from the names for both Enterobacter agglomerans and Pantoea agglomerans . It is proposed that Beijerinck be acknowledged as the original author of this species by having his name reinstated in its full name, Pantoea agglomerans (Beijerinck 1888) Gavini et al . 1989, and a Request for an Opinion is put forward to the Judicial Commission.

Int J Syst Evol Microbiol, 2004 Nov, 54(Pt 6), 2217 - 22
Erwinia toletana sp . nov., associated with Pseudomonas savastanoi-induced tree knots; Rojas AM et al.; Gram-negative bacteria were isolated from knots induced by Pseudomonas savastanoi in olive trees (Olea europaea L.) . A total of nine endophytic bacterial strains were isolated, each from inside a different tree knot . Biochemical characterization indicated that all the strains belong to the family Enterobacteriaceae . Phylogenetic analyses of the 16S rRNA genes of these novel isolates revealed that they formed a homogeneous cluster within Erwinia species . DNA signatures of these isolates were identical to those described for the genus Erwinia . The strains formed a homogeneous group as shown by DNA-DNA hybridization analysis and numerical analysis of phenotypic data, clearly differentiated from all species of Erwinia with validly published names . The data provide strong evidence of the differentiation of these strains from the most closely related species . Therefore, these isolates represent a novel species, for which the name Erwinia toletana sp . nov . is proposed . The isolates are available at CFBP, CECT and ATCC . The G+C content is 52+/-0.5 mol% . The type strain is CFBP 6631(T) (=A37(T)=ATCC 700880(T)=CECT 5263(T)).

Regul Pept, 2005 Jan 15, 124(1-3), 173 - 8
An antimicrobial peptide from the skin secretions of the mountain chicken frog Leptodactylus fallax (Anura:Leptodactylidae); Rollins-Smith LA et al.; A 25 amino-acid-residue, C-terminally alpha-amidated peptide with antimicrobial activity, which has been termed fallaxin, was isolated in high yield from the norepinephrine-stimulated skin secretions of the mountain chicken frog Leptodactylus fallax (Anura:Leptodactylidae) . The amino acid sequence of the peptide (Gly-Val-Val-Asp-Ile-Leu-Lys-Gly-Ala-Ala-Lys-Asp-Ile-Ala-Gly-His-Leu-Ala-Ser-Lys-Val-Met-Asn-Lys-Leu.NH2) shows structural similarity with members of the ranatuerin-2 family previously isolated from the skins of frogs of the genus Rana that are only distantly related to the Leptodactylidae . This observation is consistent with the hypothesis that many frog skin antimicrobial peptides are related evolutionarily, having arisen from multiple duplications of an ancestral gene that existed before the radiation of the different families . Fallaxin inhibited the growth of reference strains of Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae) but with relatively low potency (MIC> or =20 microM) and was inactive against the Gram-positive bacterium (Staphylococcus aureus) and the yeast Candida albicans . The hemolytic activity of fallaxin was very low (HC50>200 microM) . A second peptide, comprising residues (1-22) of fallaxin, was also isolated from the skin secretions but this component was inactive against the microorganisms tested.

Arq Gastroenterol, 2004 Apr-Jun, 41(2), 100 - 3 Epub 2004 Oct 27.
The influence of endoscopic procedures upon the contamination of Helicobacter pylori cultures; Ribeiro ML et al.; BACKGROUND: Among the various diagnostic methods for the detection of Helicobacter pylori infection, histological examination and microbiological processing of gastric biopsy samples are assumed to be the gold standard techniques . AIMS: Since H . pylori culture can be affected by the presence of non-H . pylori bacteria, we evaluated the efficacy of endoscope disinfection and the influence of endoscopic procedures on culture contamination . PATIENTS AND METHODS: The procedures used during the first two routine endoscopies were evaluated during 28 consecutive days . Endoscopy room, forceps and endoscopic channel were analyzed before and after the beginning of normal procedures . After disinfection, a biopsy simulation was performed to verify the gastric bacteria . RESULTS: Endoscope disinfection removed all organisms from forceps and endoscopic channel with 100% efficacy . The most frequent non-H . pylori bacteria detected were Streptococcus bovis, Enterobacter hormaechei, and Staphylococcus aureus . The sensibility of the H . pylori culture was affected by the presence of non-H . pylori bacteria . CONCLUSION:The risk of transmission of microorganisms was not detectable when sterilized biopsy forceps and stringent disinfection standards were employed . Whilst S . bovis and E . hormaechei may be common in gastric microbial flora, the presence of P . aeruginosa and S . aureus indicated that the manipulation of biopsies could be responsible for culture contamination with these bacteria.

J Anim Sci, 2004 Nov, 82(11), 3210 - 8
Effect of plant extracts and formic acid on the intestinal equilibrium of early-weaned pigs; Manzanilla EG et al.; We evaluated the effects of a plant extracts mixture (XT) standardized in 5% (wt/wt) carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin (oregano, cinnamon and Mexican pepper), alone or in combination with formic acid (FA), on the productive performance and the intestinal ecosystem of the early-weaned pig . Pigs weaned at 20 +/- 1 d of age (n = 216) were allocated in 24 pens and fed a standard medicated prestarter diet for 12 d . Twelve days after weaning, a stress management system based on social and dietary stress factors was applied to the animals, after which, each group was allocated to one of six dietary treatments, which followed a factorial arrangement, with three levels (as-fed basis) of the XT (0, 150, and 300 mg/kg) and two levels of FA (0 and 0.5%) . On d 24 and 25 after the stress episode, eight pigs per treatment were killed to examine variables describing some aspects of the gastrointestinal ecology . Two days after the stress episode, an Escherichia coli K88 diarrhea episode occurred, and five casualties were registered . Four of the five deaths occurred in pens of pigs not fed the XT . The FA resulted in better G:F (P = 0.040) in coincidence with shorter villous height (P = 0.073) and lower rectal total microbial mass (P = 0.078) . Both XT and FA addition increased stomach content (P = 0.006 and 0.003, respectively) and percentage of DM (P = 0.089 and 0.010, respectively), suggesting an increased gastric retention time; consequently, pH was also increased (P = 0.005 and 0.060, respectively) . The XT decreased ileum total microbial mass (P = 0.025) and increased the lactobacilli:enterobacteria ratio (P = 0.002) . The VFA profile in the cecum and colon was modified by XT inclusion, increasing the proportion of acetate (P = 0.018 and 0.025, respectively) and diminishing the proportion of butyrate (P = 0.096 and 0.040, respectively) and valerate (P = 0.001 and 0.039, respectively) . Both XT and FA were shown to be effective in modifying the gastrointestinal ecosystem, stomach contents, and stomach emptying rate, which are proposed as important aspects in the mechanisms of action for these additives.

Int J Food Microbiol, 2004 Dec 15, 97(2), 209 - 14
Effects of modified atmosphere and vacuum packaging on microbiological and chemical properties of rainbow trout (Oncorynchus mykiss) fillets; Arashisar S et al.; Microbial (psychrotrophic, mesophilic aerobic bacteria and Enterobacteriacae counts), and chemical analysis {pH, total volatile bases nitrogen (TVB-N), lipid oxidation (Thiobarbituric acid reactive substance, TBARS)} of rainbow trout (Oncorynchus mykiss) fillets in air (control), vacuum and modified atmosphere packaging (MAP) with various gas mixtures conditions at 4+/-1 degrees C were determined . The gas mixtures evaluated were 100% CO2, 2.5% O2+7.5% N2+90% CO2 and 30% O2+30% N2+40% CO2 . Psychrotrophic bacteria count was above 1 x 10(7) cfu/g on the 12th day in 100% CO2 . However; mesophilic bacteria count was below 1 x 10(6) cfu/g at the end of the 14-day storage period . Enterobacteriaceae count was significantly lower in samples packaged with MAP . Lipid oxidation increased rapidly after 6 days of storage in the samples containing 30% O2 . While minimum TBARS values were recorded in fillets containing 100% CO2 and vacuumed fillets, the lowest TVB-N values were obtained in fillets with 100% CO2.

Intensive Care Med, 2004 Dec, 30(12), 2263 - 70 Epub 2004 Nov 04.
Influence of positive end-expiratory pressure (PEEP) on histopathological and bacteriological aspects of pneumonia during low tidal volume mechanical ventilation; Charles PE et al.; OBJECTIVE: Ventilatory strategies combining low tidal volume (V(T)) with positive end-expiratory pressure (PEEP) are considered to be lung protective . The influence of the PEEP level was investigated on bacteriology and histology in a model of ventilator-associated pneumonia.SUBJECTS: Nineteen New Zealand rabbits.INTERVENTIONS: The animals were mechanically ventilated with a positive inspiratory pressure of 15 cmH(2)O and received either a zero end-expiratory pressure (ZEEP, n=6), a 5 cmH(2)O PEEP (n=5) or a 10 cmH(2)O PEEP (n=4) . An inoculum of Enterobacter aerogenes was then instilled intrabronchially . The non-ventilated pneumonia group (n=4) was composed of spontaneously breathing animals which received the same inoculum . Pneumonia was assessed 24 h later.MAIN RESULTS: The lung bacterial burden was higher in mechanically ventilated animals compared with spontaneously breathing animals . All animals from the latter group had negative spleen cultures . The spleen bacterial concentration was found to be lower in the 5 cmH(2)O PEEP group when compared to the ZEEP and 10 cmH(2)O PEEP groups (3.1+/-1.5 vs 4.9+/-1.1 and 5.0+/-1.3 log(10) cfu/g, respectively; p<0.05) . Lung weight and histological score values were lower in the spontaneously breathing animals as well as in the 5 cmH(2)O PEEP group compared with the ZEEP and 10 cmH(2)O groups.CONCLUSIONS: Mechanical ventilation substantially increased the lung bacterial burden and worsened the histological aspects of pneumonia in this rabbit model . Variations in terms of lung injury and systemic spreading of infection were noted with respect to the ventilatory strategy.

J Biol Chem . 2004 Nov 5; {Epub ahead of print}
Evidence that the fosfomycin target Cys115 in UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is essential for product release; Eschenburg S et al.; MurA (UDP-N-acetylglucosamine enolpyruvyl transferase, EC 2.5.1.7) is an essential enzyme in the biosynthesis of the peptidoglycan layer of the bacterial cell . It provides an attractive template for the design of novel antibiotic drugs and is the target of the naturally occurring antibiotic fosfomycin, which covalently attaches to Cys115 in the active site of the enzyme . Mutations of Cys115 to Asp exist in pathogens such as Mycobacteria or Chlamydia rendering these organisms resistant to fosfomycin . Thus, there is a need for the elucidation of the role of this cysteine in the MurA reaction . We determined the X-ray structure of the Cys115Ser mutant of Enterobacter cloacae MurA, which was crystallized in the presence of MurA's substrates . The structure depicts the product state of the enzyme with enolpyruvyl-UDP-N-acetylglucosamine and inorganic phosphate trapped in the active site . Kinetic analysis revealed that the Cys-to-Ser mutation results in an enzyme that appears to perform a single-turnover of the reaction . Opposing the common view of Cys115 as a key residue in the chemical reaction of enolpyruvyl transfer, we now conclude that the wild-type cysteine is essential for product release only . On the basis of a detailed comparison of the product state with the intermediate state and an unliganded state of MurA we propose that dissociation of the products is an ordered event with inorganic phosphate leaving first . Phosphate departure appears to trigger a suite of conformational changes, which finally leads to opening of MurA's two-domain structure and release of the second product enolpyruvyl-UDP-N-acetylglucosamine.

Folia Microbiol (Praha), 2004, 49(4), 457 - 64
Occurrence of endemic plasmids causing beta-lactam resistance in Enterobacteriaceae in children's university hospital in Munich; Benczeova S et al.; Susceptibility of 62 clinical isolates of Enterobacteriaceae to 15 aminoglycosides, beta-lactams and fluoroquinolones was determined . The isolates originating from 3 intensive care units (neonatal, pediatric, and surgical) and the Department of Infant Internal Medicine of the Children's University Hospital City Center in Munich (Germany) were collected in August 1999, and March and October 2000 . Transferability of antibiotic resistance from donors to their E . coli transconjugants was also demonstrated . The majority of isolates were resistant to ampicillin, cefoxitin, ceftriaxone, cefotaxime, ceftazidime and azthreonam but they were susceptible to cefepime, meropenem, aminoglycosides and fluoroquinolones . The occurrence of beta-lactamases and extended-spectrum beta-lactamases (ESBL) was also shown . In August 1999 75% of isolates produced beta-lactamases and 15% ESBL, in March 2000 95% of isolates produced beta-lactamases and 9% ESBL; in October 2000 all isolates produced beta-lactamases and only 5% produced ESBL . Plasmid DNA analysis in randomly chosen isolates and their transconjugants revealed the presence of plasmids ranging from 19 to 136 kb; in the majority of isolates a 120-kb plasmid was observed . Further analysis using restriction endonuclease suggested a dissemination and persistence of an endemic plasmid at all 4 wards of the large pediatric hospital in the City Center of Munich which may be responsible for resistance to beta-lactams among Enterobacteriaceae isolates.

Folia Microbiol (Praha), 2004, 49(4), 452 - 6
Detection of cefotaxime-resistant CTX-M-3 in clinical isolates of Serratia marcescens; Tsou MF et al.; Strains of Serratia marcescens (isolated in a hospital during April and August 2000) resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, streptomycin, tetracycline, and gentamicin were characterized . Out of a total of 34 clinical isolates 6 (17.6 %) exhibited the extended spectrum beta-lactamases (ESBL) resistance; they were also resistant to cefotaxime (minimum inhibitory concentration, MIC > or = 128 microg/mL) but susceptible to imipenem (MIC < or = 0.5 microg/mL) . This multidrug resistance was shown to be transferred by a conjugative plasmid . Transconjugants revealed similar MIC profiles when compared to the parental strains . Isoelectric focusing revealed one major transferable beta-lactamase (pI 8.4) which was further identified as CTX-M-3 by PCR and gene sequencing . The presence of strains with this type of ESBL showed the evolution of bla genes and their dissemination among at least three species of the family Enterobacteriaceae isolated within a single hospital . The predominance of CTX-M type enzymes found in this area of Taiwan appeared to be similar to that described in Poland.

Avian Dis, 2004 Sep, 48(3), 716 - 22
Bacteriologic findings in ostrich (Struthio camelus) eggs from farms with reproductive failures; Cabassi CS et al.; From January 2001 to December 2002, 543 ostrich eggs were submitted for bacteriologic investigation . The eggs were laid by 387 domesticated ostriches that suffered fertility disorders and that came from 44 farms located in different areas of Northern and Central Italy . Microbiologic investigations showed bacterial isolation in 105 (19.3%) of 543 eggs examined, with a high prevalence of enterobacteria from albumen and yolk . In only a few cases did bacterial isolation result from yolk or albumen alone . An antibiotic sensitivity test was conducted on isolates by the Kirby-Bauer disc diffusion method . This is the first report regarding the microbiologic status of eggs from ostrich farms located in different Italian regions.

J Vet Med Sci, 2004 Oct, 66(10), 1283 - 6
Intestinal microflora in 45 crows in Ueno Zoo and the in vitro susceptibilities of 29 Escherichia coli isolates to 14 antimicrobial agents; Aruji Y et al.; Microorganisms from 45 jungle crows (Corvus macrorhynchos) captured from July to December 2002 at Ueno Zoo, Tokyo were identified as Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Enterobacter agglomerans, Pseudomonas maltophila, Staphylococcus spp., Micrococcus spp., and Streptococcus spp . E . coli showed the highest rate of isolation (21.6%) . In an in vitro susceptibility test for 29 isolates of E . coli to 14 antimicrobial agents, all the isolates were resistant to penicillin G, vancomycin, erythromycin, lincomycin, bicozamycin, sulfadimethoxine, and olaquindox . Several isolates of them were also resistant to tetracycline, oxytetracycline, streptomycin, chloramphenicol, and ampicillin . Twenty-nine isolates were divided into 19 serogroups and the most frequently identified serogroups were O8, O114 and O144, which showed the same multidrug-resistant patterns.

Microbiology, 2004 Nov, 150(Pt 11), 3571 - 90
Comparative genomics of the KdgR regulon in Erwinia chrysanthemi 3937 and other gamma-proteobacteria; Rodionov DA et al.; In the plant-pathogenic enterobacterium Erwinia chrysanthemi, almost all known genes involved in pectin catabolism are controlled by the transcriptional regulator KdgR . In this study, the comparative genomics approach was used to analyse the KdgR regulon in completely sequenced genomes of eight enterobacteria, including Erw . chrysanthemi, and two Vibrio species . Application of a signal recognition procedure complemented by operon structure and protein sequence analysis allowed identification of new candidate genes of the KdgR regulon . Most of these genes were found to be controlled by the cAMP-receptor protein, a global regulator of catabolic genes . At the next step, regulation of these genes in Erw . chrysanthemi was experimentally verified using in vivo transcriptional fusions and an attempt was made to clarify the functional role of the predicted genes in pectin catabolism . Interestingly, it was found that the KdgR protein, previously known as a repressor, positively regulates expression of two new members of the regulon, phosphoenolpyruvate synthase gene ppsA and an adjacent gene, ydiA, of unknown function . Other predicted regulon members, namely chmX, dhfX, gntB, pykF, spiX, sotA, tpfX, yeeO and yjgK, were found to be subject to classical negative regulation by KdgR . Possible roles of newly identified members of the Erw . chrysanthemi KdgR regulon, chmX, dhfX, gntDBMNAC, spiX, tpfX, ydiA, yeeO, ygjV and yjgK, in pectin catabolism are discussed . Finally, complete reconstruction of the KdgR regulons in various gamma-proteobacteria yielded a metabolic map reflecting a globally conserved pathway for the catabolism of pectin and its derivatives with variability in transport and enzymic capabilities among species . In particular, possible non-orthologous substitutes of isomerase KduI and a new oligogalacturonide transporter in the Vibrio species were detected.

Int J Food Microbiol, 2004 Dec 1, 97(1), 53 - 62
Microbial profiles of commercial, vacuum-packaged, fresh pork of normal or short storage life; Holley RA et al.; The microbial ecology of fresh vacuum-packed pork cuts during storage at -1.5 degrees C for up to 45 days was examined to characterize rates of microbial growth and pH changes in commercially prepared products of normal storage quality . Pork loins in commercial distribution with odour defects were also studied to determine a possible cause of the defects and avoid future problems . In addition, microbial profiles of pork cuts from two plants were compared, after storage for 25 days at -1.5 degrees C, to identify possible reasons for differences in the storage life of product from the plants . The effects of a change in sanitation procedures on the microbial populations of products stored for 25 days were also studied . With normal product, microbial growth in different packages progressed at different rates, reflecting differences in initial levels of bacterial contamination . All samples in the study reached 8 weeks without apparent organoleptic change and samples carried 5.8+/-1.2 log bacteria cm(-2) (mean+/-S.D.) . The flora of loins with the odour defect were predominately lactic acid bacteria (LAB) and carnobacteria, but they contained large fractions of Enterobacteriaceae <35 days after packaging . Aeromonas spp . and Shewanella spp . were likely responsible for the sulfide-putrid smell of these spoiled products, but species of Enterobacteriaceae and lactic acid bacteria could have contributed to spoilage . Comparison of microbial groups present in 16 other cuts, half from each of two commercial plants, which were stored for 25 days at -1.5 degrees C, showed that larger fractions of Enterobacteriaceae were present in samples from the plant having difficulty achieving the desired storage life . Additional bacterial samples from 12 cuts supplied by the latter plant obtained after adoption of an acid sanitizer step in the plant cleaning regimen, and also stored for 25 days at -1.5 degrees C, yielded few Enterobacteriaceae, Aeromonas or Shewanella . Use of an acid sanitizer in plant cleaning may be a means of controlling alkali-tolerant bacteria such as Aeromonas or Shewanella which can contaminate pork cuts and spoil vacuum-packaged product . The fraction of Enterobacteriaceae in bacteria populations on fresh pork stored for 25 days at -1.5 degrees C may be a useful indicator of the effectiveness of plant sanitation.

Mol Biol Evol . 2004 Nov 3; {Epub ahead of print}
Non-Homogeneous Model of Sequence Evolution Indicates Independent Origins of Primary Endosymbionts within the Enterobacteriales ({gamma}-Proteobacteria); Herbeck JT et al.; Standard methods of phylogenetic reconstruction are based on models that assume homogeneity of nucleotide composition among taxa . However, this assumption is often violated in biological data sets . In this study, we examine possible effects of nucleotide heterogeneity among lineages on the phylogenetic reconstruction of a bacterial group that spans a wide range of genomic nucleotide contents: obligately endosymbiotic bacteria and free-living or commensal species in the gamma-Proteobacteria . We focus on AT-rich primary endosymbionts to better understand the origins of obligately intracellular lifestyles . Previous phylogenetic analysis of this bacterial group point to the importance of accounting for base compositional variation in estimating relationships, particularly between endosymbiotic and free-living taxa . Here, we develop an approach to compare susceptibility of various phylogenetic reconstruction methods to the effects of nucleotide heterogeneity . First, we identify candidate trees of gamma-Proteobacteria groEL and 16S rRNA using approaches that assume homogeneous and stationary base composition, including Bayesian, maximum likelihood, parsimony, and distance methods . We then create permutations of the resulting candidate trees by varying the placement of the AT-rich endosymbiont Buchnera . These permutations are evaluated under the non-homogeneous and non-stationary maximum likelihood model of Galtier and Gouy, which allows equilibrium base content to vary among examined lineages . Our results show that commonly used phylogenetic methods produce incongruent trees of the Enterobacteriales, and that the placement of Buchnera is especially unstable . However, under a non-homogeneous model, various groEL and 16S rRNA phylogenies that separate Buchnera from other AT-rich endosymbionts (Blochmannia and Wigglesworthia) have consistently and significantly higher likelihood scores . Blochmannia and Wigglesworthia appear to have evolved from secondary endosymbionts, and represent an origin of primary endosymbiosis that is independent from Buchnera . This new application of a non-homogeneous model (namely, to evaluate alternative trees developed under homogeneous models) offers a computationally feasible way to test specific phylogenetic hypotheses for taxa with heterogeneous and non-stationary base composition.

Med Dosw Mikrobiol, 2004, 56(1), 57 - 65
{Hydrophobic properties of gram-negative rods colonizing upper respiratory tract of healthy people}; Los R et al.; The cell surface hydrophobicity is one of the non specific factors of adhesion influencing the ability of microorganisms to colonize nasopharynx . The aim of this paper was to evaluate via salt aggregation test (SAT) the cell surface hydrophobicity of 150 strains of gram-negative rods isolated from the throat or/and nasal specimens of healthy people . It has been found that among the nonfermenting rods hydrophobic strains were predominant . In contrast, the isolates of Enterobacteriaceae family were characterized by the distinctive features of the cell surface within particular genera or even species . The obtained results show that, despite differences in cell surface hydrophobicity, numerous species of gram-negative rods have the ability to colonize the mucous membrane of upper respiratory tract . This suggests that the cell surface hydrophobicity is rather a feature of species or genus, but it is not related to the ecological niche of microorganisms in human body.

Indian Pediatr, 2004 Oct 7, 41(10), 1001 - 1007
Multiple Dose Pharmacokinetics of Ciprofloxacin in Preterm Babies; Aggarwal P et al.; BACKGROUND: Ciprofloxacin is increasingly used in preterm neonates to treat multi-drug resistant infections, however the pharmacokinetics of this drug in preterm newborns is not well studied . OBJECTIVE: To determine the multi-dose pharmacokinetics of intravenous ciprofloxacin in pre-term infants . DESIGN: Prospective, cohort study . SETTING: Level III Neonatal Intensive Care Unit in a tertiary Care hospital in North India . METHODS: 24 preterm neonates with age less than 28 days, who received intravenous ciprofloxacin 10 mg/kg/dose 12 hourly for clinical and/or culture proven sepsis, were enrolled . Serum levels of ciprofloxacin were analyzed after first dose on day 1 and at the end of days 3 and 7 . RESULTS: Of 24 babies included in the study {mean gestation (SD) 32 wks (2.4 wks)}, 3 died and 1 dropped out in the initial few days, leaving 20 patients whose data on serum ciprofloxacin were available . Peak values on days 1, 3 and 7 were 2.3, 3.0 and 2.7 micrograms/mL respectively . Trough values on these days were 0.7, 0.8 and 1.0 micrograms/mL respectively . There were no differences between the less than 1500 g and greater than 1500 g sub-groups and the less than 7 days and greater than 7 days sub-groups with respect to the corresponding peak and trough values on days 1, 3 and 7 . The 95 percent C.I . of serum concentrations were above the MIC90 for most Enterobacteriaceae species, however the lower bound of the 95 percent C.I . of the mean trough levels was lower than MIC90 for Pseudomonas aeruginosa and Staphylococcus aureus . No adverse effects were observed . CONCLUSION: Intravenous ciprofloxacin in a dose of 10 mg/kg/dose 12 hourly is an effective treatment of neonatal sepsis, but higher doses may be required for treating Staphylococcus aureus and Pseudomonas.

Infect Control Hosp Epidemiol, 2004 Oct, 25(10), 873 - 7
Incidence of urinary tract infection following transrectal ultrasound guided prostate biopsy at a tertiary-care medical center in Lebanon; Otrock ZK et al.; OBJECTIVE: To determine the incidence of urinary tract infections (UTIs) following transrectal ultrasound guided needle biopsy of the prostate (TRUBP) and the bacteriology of these infections . DESIGN: Retrospective evaluation of the charts and records of all patients who underwent TRUBP between June 1, 2002, and August 31, 2003 . SETTING: American University of Beirut Medical Center, a tertiary-care center in Lebanon . PATIENTS: Two hundred seven patients underwent TRUBP . All received prophylactic antibiotics . One hundred twenty (58%) received ciprofloxacin alone, whereas 87 (42%) received both ciprofloxacin and gentamicin . Sixty-one patients (29.5%) had an enema prior to the procedure, whereas 146 (70.5%) did not . RESULTS: Thirteen patients (6.3%) were admitted with UTI . All had rigors and fever on admission . Symptoms appeared at a mean of 2.7 days and the mean hospital stay was 9.2 days . The mean duration of antibiotic treatment was 23.2 days . Ten (77%) of the patients had positive bacteriology . Urine cultures were positive in 8 (61.5%) of the patients and blood cultures in 6 (46.2%) . All positive cultures grew Escherichia coli resistant to ciprofloxacin, with 5 isolates producing extended-spectrum betalactamases . CONCLUSIONS: TRUBP continues to be associated with significant infectious complications, especially UTI . Given the increasing incidence of antibiotic resistance mainly among the Enterobacteriaceae, antimicrobial prophylaxis practices should be reevaluated and the universal administration of quinolones alone or in combination with aminoglycosides should be reconsidered.

Infect Control Hosp Epidemiol, 2004 Oct, 25(10), 852 - 5
Molecular epidemiology of extended-spectrum beta-lactamase-producing Enterobacteriaceae isolated from environmental and clinical specimens in a cardiac surgery intensive care unit; Kac G et al.; OBJECTIVES: To investigate environmental contamination by extended-spectrum beta-lactamase-producing Enterobacteriaceae and to perform a comparative molecular analysis of clinical and environmental strains . SETTING: A 17-bed cardiac surgery intensive care unit of a 480-bed university teaching hospital . METHODS: Following an outbreak of extended-spectrum beta-lactamase-producing Enterobacteriaceae, an environmental survey revealed extensive contamination of the environment (particularly faucets, sink drains, and the joints of the countertops) by extended-spectrum beta-lactamase-producing Enterobacteriaceae . Environmental strains were compared with clinical strains by pulsed-field gel electrophoresis and randomly amplified polymorphic DNA . RESULTS: A total of 62 environmental strains belonging to 4 species of extended-spectrum beta-lactamase-producing Enterobacteriaceae were analyzed and compared with 43 clinical strains obtained from 34 patients . Comparative molecular analysis revealed 4 identical or closely related patterns (3 from Klebsiella oxytoca and 1 from Enterobacter cloacae) between environmental and clinical strains . CONCLUSIONS: Moist surfaces may serve as sources of multiply resistant Enterobacteriaceae in the intensive care unit . Identification and disinfection of such sources may therefore be helpful in prevention and control of outbreaks.

Infect Control Hosp Epidemiol, 2004 Oct, 25(10), 842 - 6
Rapidly rising prevalence of nosocomial multidrug-resistant, Gram-negative bacilli: a 9-year surveillance study; D'Agata EM; OBJECTIVE: To examine and quantify the temporal trends of nosocomial multidrug-resistant, gram-negative bacilli . DESIGN: A 9-year surveillance study was conducted . Multidrug resistance was defined as resistance to 3 or more antimicrobial classes . SETTING: Tertiary-care institution . RESULTS: From 1994 to 2002, multidrug-resistant, gram-negative bacilli increased from 1% to 16% for multidrug-resistant Pseudomonas aeruginosa, 4% to 13% for multidrug-resistant Enterobacter species, 0.5% to 17% for multidrug-resistant Klebsiella species, 0% to 9% for multidrug-resistant Proteus species, and 0.2% to 4% for multidrug-resistant Escherichia coli (P < or = .05) . The most common pattern of multidrug resistance was co-resistance to quinolones, third-generation cephalosporins, and aminoglycosides . CONCLUSION: The rapid rise of multidrug-resistant, gram-negative bacilli may warrant infection control programs to include these pathogens in strategies aimed at limiting the emergence and spread of antimicrobial-resistant pathogens.

Infect Control Hosp Epidemiol, 2004 Oct, 25(10), 838 - 41
Control of Enterobacteriaceae producing extended-spectrum beta-lactamase in intensive care units: rectal screening may not be needed in non-epidemic situations; Thouverez M et al.; OBJECTIVE: To evaluate the usefulness of screening cultures in the control of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in intensive care units (ICUs) . DESIGN: A 4-year retrospective study . SETTING: Two adult ICUs of a university-affiliated public hospital in France . RESULTS: A total of 7,777 specimens were analyzed and 28 (0.97%) of 2,883 screened patients had a positive result on a screening test, among the 3,678 admitted patients . Thirteen of these 28 patients were only carriers; 4 were carriers and then were colonized or infected 2, 2, 3, and 8 days later, respectively; and 11 were colonized or infected before a screening test was positive . Cluster analysis showed that the occurrence of ESBL-producing Enterobacteriaceae cross-transmission within both ICUs was limited to 9 cases . Thus, most cases (19 of 28) were probably imported . Surveillance cultures failed to detect 9 of the 19 cases . CONCLUSION: The low prevalence of ESBL-producing Enterobacteriaceae carriers on admission (0.45%) and the relative ineffectiveness of our screening test to detect imported cases suggest that systematic detection of ESBL-producing Enterobacteriaceae in ICU patients is not cost-effective and that the use of clinical cultures may be sufficient to control ESBL-producing Enterobacteriaceae in non-epidemic situations.

J Biol Chem, 2005 Jan 14, 280(2), 974 - 83 Epub 2004 Oct 28.
Depletion of Apolipoprotein N-Acyltransferase Causes Mislocalization of Outer Membrane Lipoproteins in Escherichia coli; Robichon C et al.; Lipoproteins in Gram-negative Enterobacteriaceae carry three fatty acids on the N-terminal cysteine residue, two as a diacylglyceride and one through an N-linkage following signal peptide cleavage . Most lipoproteins are anchored in the outer membrane, facing the periplasm, but some lipoproteins remain in the plasma membrane, depending on the amino acid at position +2, immediately after the fatty-acylated cysteine . In vitro, the last step in lipoprotein maturation, N-acylation of apolipoproteins by the plasma membrane apolipoprotein N-acyltransferase (Lnt), is necessary for efficient recognition of outer membrane lipoproteins by the Lol system, which transports them from the plasma to the outer membrane (Fukuda, A., Matsuyama, S.-I., Hara, T., Nakayama, J., Nagasawa, H., and Tokuda, H . (2002) J . Biol . Chem . 277, 43512-43518) . To study the role of Lnt in vivo, we constructed a conditional lnt mutant of Escherichia coli . The apo-form of peptidoglycan-anchored major lipoprotein (Lpp) and two other outer membrane lipoproteins accumulated in the plasma membrane when lnt expression was reduced . We also found that Lnt is an essential protein in E . coli and that the lethality is partially because of the retention of apoLpp in the plasma membrane . Topology mapping of Lnt with beta-galactosidase and alkaline phosphatase fusions indicated the presence of six membrane-spanning segments . The lnt gene in a mutant of Salmonella enterica displaying thermosensitive Lnt activity (Gupta, S . D., Gan, K., Schmid, M . B., and Wu, H . C . (1993) J . Biol . Chem . 268, 16551-16556) was found to carry a mutation causing a single glutamate to lysine substitution at a highly conserved position in the last predicted periplasmic loop of the protein.

Trop Doct, 2004 Oct, 34(4), 206 - 8
Other bacteria and HIV disease; Gray KJ et al.; HIV-infected individuals are predisposed to infection with bacteria, in particular Streptococcus pneumoniae and non-typhi Salmonella . Other bacteria also complicate HIV disease, either because they are inherently pathogenic--Staphylococcus aureus, Enterobacteraciae, bacterial agents of enteritis--or they take advantage of advanced immunosuppression--Rhodococcus spp, Nocardia spp . An understanding of the role of bacteria is essential to the care of HIV-infected patients.

J Food Prot, 2004 Oct, 67(10), 2248 - 54
Decreased dosage of acidified sodium chlorite reduces microbial contamination and maintains organoleptic qualities of ground beef products; Bosilevac JM et al.; Acidified sodium chlorite (ASC) spray was evaluated at decreased dosages and application rates to determine its efficacy for reducing bacterial contamination on boneless beef trimmings used for production of raw ground beef products while maintaining desirable consumer qualities in the finished ground beef products . Two different applications of ASC (600 ppm applied at a rate of 1.3 oz/lb and 300 ppm applied at a rate of 1 oz/lb) were used to treat boneless beef trimmings before grinding . The effect of ASC treatment on 50/50 lean beef trimmings was greater than on 90/10 trimmings . ASC at 600 ppm reduced both the aerobic plate counts (APC) and Enterobacteriaceae counts (EBC) by 2.3 log CFU/g on 50/50 trimmings, whereas treatment with 300 ppm ASC reduced APC and EBC of 50/50 trimmings by 1.1 and 0.7 log CFU/g, respectively . Ground beef formulations of 90/10 and 73/27 were produced from the treated boneless beef trim and packaged in chubs and in modified atmosphere packaging . The efficacy of ASC spray treatment to inhibit APC and EBC over the shelf life of each ground beef product was monitored . The APC and EBC in ground beef chubs were reduced by 1.0 to 1.5 log CFU/g until day 20 . The APC and EBC for products in modified atmosphere packaging were reduced 1.5 to 3.0 log CFU/g throughout their shelf life . Both decreased dosages of ASC were equally effective on 90/10 lean ground beef, but the 300 ppm ASC treatment was slightly better at reducing the EBC of 73/27 ground beef . The organoleptic qualities (color, odor, and taste) of the ground beef products treated with 300 ppm ASC were found to be superior to those treated with 600 ppm ASC . Our results indicated that decreased dosages of ASC reduce contamination and lengthen the shelf life of ground beef . Furthermore, the 300 ppm ASC treatment reduced bacterial counts while maintaining desirable organoleptic ground beef qualities.

Antimicrob Agents Chemother, 2004 Nov, 48(11), 4438 - 40
Plasmid-mediated carbapenem-hydrolyzing enzyme KPC-2 in an Enterobacter sp; Hossain A et al.; A strain of an Enterobacter sp . with reduced susceptibility to imipenem, which produced a plasmid-mediated class A carbapenem-hydrolyzing enzyme, KPC-2 beta-lactamase, was isolated from a patient with sepsis at a Boston hospital . This is the first report of the production of a plasmid-encoded KPC-2 beta-lactamase by an Enterobacter sp.

Antimicrob Agents Chemother, 2004 Nov, 48(11), 4177 - 82
Promoter sequences necessary for high-level expression of the plasmid-associated ampC beta-lactamase gene blaMIR-1; Reisbig MD et al.; Little is known about mechanisms involved in high-level expression of plasmid-associated ampC genes . The sequence for bla(MIR-1) has been elucidated, and the gene is not inducible . Although the sequence for the promoter (prA) that drives expression of Enterobacter cloacae chromosomal ampC is present upstream of bla(MIR-1), high-level expression from bla(MIR-1) is directed from a hybrid promoter (prB) located further upstream of prA . The purpose of this study was to determine the influence of each promoter on bla(MIR-1) expression and beta-lactam resistance . RNA expression by deletion clones with both promoters was measured and compared to that by clones in which -35 and/or -10 elements of prA and/or prB were altered . Primer extension revealed two start sites for bla(MIR-1) transcription . Expression of bla(MIR-1) in clones with both promoters was 171-fold higher than that in clones carrying only prA . In addition, bla(MIR-1) expression from prA increased 11-fold in the presence of the prB -10 element compared to expression driven from prA alone . Ceftazidime and cefotaxime MICs increased 42- and 64-fold, respectively, for the clone expressing bla(MIR-1) from both promoters compared to expression from prA alone . The upstream promoter prB of bla(MIR-1) is solely responsible for high-level expression required for cefotaxime and ceftazidime resistance . These data suggest that resistance to extended-spectrum cephalosporins mediated by noninducible plasmid-associated ampC genes requires the formation of novel promoter elements that are capable of increasing ampC expression.

J Chem Ecol, 2004 Jul, 30(7), 1329 - 47
Volatiles production and attractiveness to the Mexican fruit fly of Enterobacter agglomerans isolated from apple maggot and Mexican fruit flies; Robacker DC et al.; We investigated two strains of uricase (+) Enterobacter agglomerans, one isolated from the apple maggot fly (AMF) and one from the Mexican fruit fly (MFF), for 1) attractiveness to MFF, and 2) production of attractive chemicals . Regarding chemicals demonstrated attractive to the MFF, the MFF bacterial strain produced more 2,5-dimethylpyrazine, 2-phenylethanol, and indole than the AMF strain, whereas the AMF, but not the MFF strain, produced 3-hydroxybutanone . Cell types that predominated in plated subcultures varied from batch to batch resulting in variation in volatiles production, especially by the AMF strain where indole was sometimes a major component of the odor and at other times not detectable . Despite the greater production of attractive chemicals by the MFF strain, the AMF strain was consistently more attractive and the MFF strain was not different from uninoculated control plates . Statistical analyses indicated negative correlations of attractiveness with production of indole, 2,5-dimethylpyrazine, and 2-phenylethanol, and positive correlation with 3-hydroxybutanone . Results support previous findings with the Mexican fruit fly that showed combinations of attractive chemicals sometimes are not attractive.

J Vet Pharmacol Ther, 2004 Oct, 27(5), 283 - 8
Population pharmacokinetics of marbofloxacin in horses: preliminary analysis; Peyrou M et al.; Population pharmacokinetic of marbofloxacin was investigated on 21 healthy and 16 diseased horses to assess interindividual variability of drug exposure . Demographic, physiologic and disease covariables were tested using mixed effects models . As a preliminary analysis, this study has demonstrated that none of the tested covariables were significant in regression models for compartmental volumes or clearance of distribution, but the clinical status of the horse (healthy/diseased) was a significant covariable (P < 0.01) for systemic clearance . Clearance had a lower mean and a higher variance for diseased horses than healthy horses, with respectively a mean of 0.209 and 0.284 L/h/kg and a coefficient of variation of 52 and 15% . Consequently, variability of AUC was greater in diseased horses . Considering an AUC/MIC ratio below 60 h as a prediction of poor efficacy, a dosage regimen of 2 mg/kg intravenous was deemed to be inadequate for 19% of diseased horses if the MIC of the bacteria was 0.1 microg/mL . However 93% of diseased horses could achieve a ratio above 125 h, predicting a very good efficacy, for the MIC(90) of Enterobacteriacae (0.027 microg/mL).

J Am Diet Assoc, 2004 Nov, 104(11), 1722 - 4
Microbiological evaluation of foodservice contact surfaces in Iowa assisted-living facilities; Sneed J et al.; A study of 40 assisted-living facilities in Iowa was conducted to assess the microbiological quality of food-contact surfaces (work tables/counters, cooking equipment such as mixing bowls, and cutting boards) and a surface that could cross-contaminate food (refrigerator or freezer handles) to determine the effectiveness of cleaning and sanitation . Standards were set for foodservice for aerobic plate count, Enterobacteriaceae, and Staphylococcus aureus . Two facilities met standards for all five surfaces for each of the three tests . Fewer facilities met the standard for aerobic plate count than for the other two tests, and nearly three fourths of the facilities failed to meet the aerobic plate count for cutting boards . Critically, cross-contamination from these surfaces could result in contamination of food; thus, attention needs to be given to training and supervision to ensure proper hand washing and appropriate cleaning and sanitation procedures to reduce or eliminate cross-contamination.

J Med Microbiol, 2004 Nov, 53(Pt 11), 1119 - 22
Enhanced active efflux, repression of porin synthesis and development of Mar phenotype by diazepam in two enterobacteria strains; Tavio MM et al.; The aim of this work was to determine whether diazepam could induce the multiple antibiotic resistance (Mar) phenotype in Klebsiella pneumoniae and Escherichia coli strains . The Mar phenotype is characterized by decreased susceptibility to multiple antibiotics due to the loss of porins and/or increased expression of active efflux systems . The effect of subinhibitory concentrations of diazepam on the susceptibility of different antimicrobial agents, outer-membrane protein expression and norfloxacin intracellular accumulation was studied . The results revealed that diazepam concentrations equal or twice adult dosage induced the same Mar phenotype as two well known E . coli marRAB inducers, sodium salicylate and sodium benzoate . Susceptibility to norfloxacin in a K . pneumoniae clinical isolate and E . coli strain Ag100 decreased due to enhanced active efflux and loss of porin expression . A decreased susceptibility to chloramphenicol, tetracycline, nalidixic acid and beta-lactam antibiotics was also observed . In conclusion, like sodium salicylate or sodium benzoate, diazepam may induce the Mar phenotype.

J Med Microbiol, 2004 Nov, 53(Pt 11), 1089 - 96
Rapid genotyping of Pseudomonas aeruginosa isolates harboured by adult and paediatric patients with cystic fibrosis using repetitive-element-based PCR assays; Syrmis MW et al.; In this study, the suitability of two repetitive-element-based PCR (rep-PCR) assays, enterobacterial repetitive intergenic consensus (ERIC)-PCR and BOX-PCR, to rapidly characterize Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis (CF) was examined . ERIC-PCR utilizes paired sequence-specific primers and BOX-PCR a single primer that target highly conserved repetitive elements in the P . aeruginosa genome . Using these rep-PCR assays, 163 P . aeruginosa isolates cultured from sputa collected from 50 patients attending an adult CF clinic and 50 children attending a paediatric CF clinic were typed . The results of the rep-PCR assays were compared to the results of PFGE . All three assays revealed the presence of six major clonal groups shared by multiple patients attending either of the CF clinics, with the dominant clonal group infecting 38 % of all patients . This dominant clonal group was not related to the dominant clonal group detected in Sydney or Melbourne (pulsotype 1), nor was it related to the dominant groups detected in the UK . In all, PFGE and rep-PCR identified 58 distinct clonal groups, with only three of these shared between the two clinics . The results of this study showed that both ERIC-PCR and BOX-PCR are rapid, highly discriminatory and reproducible assays that proved to be powerful surveillance screening tools for the typing of clinical P . aeruginosa isolates recovered from patients with CF.

Biomedica, 2004 Jun, 24(2), 194 - 9
{Development and evaluation of a PCR method for diagnosis of Salmonella enteric fever, based on DNA sequences of the hilA gene}; Sanchez MM et al.; Typically, diagnosis of enteric fever due to Salmonella spp . is by bacterial isolation from blood culture; however, the blood culture method is slow, not always available, and not informative in patients with antibiotic treatment . Salmonella spp . uses the hilA gene (component of the pathogenicity island I) to invade epithelial cells and produce infection . Using the hilA gene sequence a PCR test was designed to detect Salmonella in blood samples . The sensitivity (S), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) of the PCR method were obtained by testing the blood samples from 34 patients with suspected of enteric fever . Presence of S . typhi was confirmed by blood culture . Blood samples were also tested from 35 patients with infections due to other non-Salmonella pathogens, again corroborated by blood culture (Klebsiella pneumoniae, 9; Serratia marcescens, 5; Escherichia coli, 4; Pseudomonas aeruginosa, 9; Providencia alcalifaciens, 4; Enterobacter cloacae, 4) . Control samples were obtained from 150 healthy volunteers . The S, SP, PPV and NPV for the PCR method were all 100% . The lowest number of colony forming units/ml detected by PCR in blood samples was 10.

Int J Med Microbiol, 2004 Sep, 294(2-3), 83 - 94
The Yersinia high-pathogenicity island (HPI): evolutionary and functional aspects; Schubert S et al.; The high-pathogenicity island (HPI) is a genomic island essential for the mouse-virulence phenotype in Yersinia and indispensable for pathogenicity of Yersinia and certain pathotypes of Escherichia coli . In contrast to most genomic islands, the HPI is a functional island widely disseminated among members of the family of Enterobacteriaceae . The HPI-encoded phage P4-like integrase together with excisionase and recombination sites make up the genetic mobility module of the island, while the siderophore yersiniabactin biosynthesis and uptake system comprises its functional part with respect to fitness and pathogenicity . The HPI-integrase promotes integration of the island into attB sites represented by three to four asn tDNAs in Yersinia pestis and E . coli . An additional enzyme, excisionase, is essential for efficient excision of the HPI from the initial site of integration . Furthermore a unique type of HPI has been characterized in the E . coli strain ECOR31 carrying a functional conjugative mating pair formation (Mpf) and a DNA-processing system, both of which are characteristic of integrative and conjugative elements (ICE) . A model of conjugative transfer for the dissemination of HPIs is proposed in which the excised HPI is mobilized to a new recipient either trapped by a transmissive asn tDNA-carrying plasmid or autonomously as an ICE named ICEEcl.

Mikrobiyol Bul, 2004 Jul, 38(3), 305 - 12
{Integrons}; Koseoglu O; The development of antimicrobial resistance has led to the discovery of many natural mobile elements like transposons and conjugative plasmids . Integrons are carried on plasmids and transposons that potentially increase the dissemination of antibiotic resistance genes among bacterial species . Integrons are genetic elements containing the determinants of a site-specific recombination system . These DNA elements mediate the integration of antibiotic resistance genes into bacteria through the site-specific recombination . Integrons consist of an integrase gene (intl), a recombination site (attl), and one or two promoters responsible for expression of the inserted gene cassettes . Class 1 integrons are the most commonly studied and largely implicated type in the dissemination of antibiotic resistance among clinical isolates . In the last few years, a variety of new gene cassettes coding antibiotic resistance have been described . Having the ability of horizontal transfer of antibiotic resistance genes between interspecies of bacteria, integrons play a dominant role in the development of multiresistance in Enterobacteriaceae . In this review article, classification, structure and expression, epidemiology and clinical importance of integrons, has been discussed.

J Antimicrob Chemother, 2004 Dec, 54(6), 1007 - 12 Epub 2004 Oct 14.
Plasmid-mediated 16S rRNA methylases conferring high-level aminoglycoside resistance in Escherichia coli and Klebsiella pneumoniae isolates from two Taiwanese hospitals; Yan JJ et al.; OBJECTIVES: This study was conducted to investigate the occurrence of 16S rRNA methylases that confer high-level aminoglycoside resistance in Klebsiella pneumoniae and Escherichia coli isolates from two Taiwanese hospitals and the characteristics of these isolates . METHODS: A total of 1624 K . pneumoniae and 2559 E . coli isolates consecutively collected over an 18 month period from a university hospital and seven E . coli and eight K . pneumoniae isolates that were resistant to amikacin from a district hospital were analysed . Two 16S rRNA methylase genes, armA and rmtB, were detected by PCR-based assays . beta-Lactamase characteristics were determined by phenotypic and genotypic methods . RESULTS: Overall, 28 armA-positive and seven rmtB-positive isolates were identified, and extended-spectrum beta-lactamases (ESBLs) were detected in 33 (94.3%) isolates . The prevalence rates of armA and rmtB at the university hospital were 0.9% (n=15) and 0.3% (n=5) in K . pneumoniae and 0.4% (n=10) and 0.04% (n=1) in E . coli . CTX-M-3, CTX-M-14, SHV-5-like ESBLs, and CMY-2 were detected alone or in combination in 21, 6, 11, and 2, respectively, of the 28 armA-positive isolates . CTX-M-14 was detected in six of the seven rmtB-positive isolates . Fingerprinting of conjugative plasmids revealed the dissemination of closely related plasmids containing both armA and bla(CTX-M-3) . PFGE suggests that armA and rmtB spread by both horizontal transfer and clonal spread . CONCLUSIONS: This is the first report of the emergence of 16S rRNA methylases in Enterobacteriaceae in Taiwan . The spread of the multidrug-resistant isolates producing both ESBLs and 16S rRNA methylases may become a clinical problem.

Infect Control Hosp Epidemiol, 2004 Sep, 25(9), 781 - 3
Risk factors for extended-spectrum beta-lactamase-producing Enterobacteriaceae in a neonatal intensive care unit; Linkin DR et al.; Risk factors for colonization or infection with extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae during an outbreak in a neonatal intensive care unit (NICU) included low gestational age and exposure to third-generation cephalosporins . We also reviewed the existing medical literature regarding the clinical epidemiology of ESBLs in NICUs .

Infect Control Hosp Epidemiol, 2004 Sep, 25(9), 772 - 7
Healthcare-associated infections among neonates in Brazil; Pessoa-Silva CL et al.; OBJECTIVE: To describe the epidemiology of healthcare-associated infections (HAIs) among neonates . DESIGN: Prospective surveillance of HAIs was conducted during 2 years . Infections beginning within 48 hours of birth were defined as HAIs of maternal origin . Death occurring during an active episode of HAI was considered related to HAI . SETTING: Seven neonatal units located in three Brazilian cities . PATIENTS: All admitted neonates were included and observed until discharge . RESULTS: Twenty-two percent of 4,878 neonates had at least one HAI . The overall incidence density was 24.9 per 1,000 patient-days, and 28.1% of all HAIs were maternally acquired . HAI rates ranged from 12.3% in the group with a birth weight (BW) of more than 2,500 g to 51.9% in the group with a BW of 1,000 g or less . The main HAIs were bloodstream infection (BSI) and pneumonia . Coagulase-negative staphylococci, Enterobacter species, Staphylococcus aureus, and Klebsiella pneumoniae were the main pathogens . Forty percent of all deaths were related to HAI . Central venous catheter (CVC)-associated BSIs per 1,000 CVC-days ranged from 17.3 (BW, 1,501 to 2,500 g; device utilization {DU}, 0.11) to 34.9 (BW, < or = 1,000 g; DU, 34.92) . Ventilator-associated pneumonia per 1,000 ventilator-days ranged from 7.0 (BW, < or = 1,000 g; DU, 0.34) to 9.2 (BW, 1,001 to 1,500 g; DU, 0.14) . CONCLUSIONS: The high proportion of HAIs of maternal origin highlights perinatal care issues in Brazil and the need to improve the diagnosis of neonatal HAIs . The very low BW group and device-associated infections should be priorities for prevention strategies in this population.

Infect Control Hosp Epidemiol, 2004 Sep, 25(9), 765 - 71
Prevalence of nosocomial infections in Swiss children's hospitals; Muhlemann K et al.; OBJECTIVE: To acquire data on pediatric nosocomial infections (NIs), which are associated with substantial morbidity and mortality and for which data are scarce . DESIGN: Prevalence survey and evaluation of a new comorbidity index . SETTING: Seven Swiss pediatric hospitals . PATIENTS: Those hospitalized for at least 24 hours in a medical, surgical, intensive care, or intermediate care ward . RESULTS: Thirty-five NIs were observed among 520 patients (6.7%; range per hospital, 1.4% to 11.8%) . Bacteremia was most frequent (2.5 per 100 patients), followed by urinary tract infection (1.3 per 100 patients) and surgical-site infection (1.1 per 100 patients; 3.2 per 100 patients undergoing surgery) . The median duration until the onset of infection was 19 days . Independent risk factors for NI were age between 1 and 12 months, a comorbidity score of 2 or greater, and a urinary catheter . Among surgical patients, an American Society of Anesthesiologists (ASA) score of 2 or greater was associated with any type of NI (P = .03) . Enterobacteriaceae were the most frequent cause of NI, followed by coagulase-negative staphylococci; viruses were rarely the cause . CONCLUSIONS: This national prevalence survey yielded valuable information about the rate and risk factors of pediatric NI . A new comorbidity score showed promising performance . ASA score may be a predictor of NI . The season in which a prevalence survey is conducted must be considered, as this determines whether seasonal viral infections are observed . Periodic prevalence surveys are a simple and cost-effective method for assessing NI and comparing rates among pediatric hospitals.

Lett Appl Microbiol, 2004, 39(5), 445 - 50
Incidence of antibiotic-resistant Klebsiella pneumoniae and Enterobacter species in freshwater wetlands; Halda-Alija L; AIMS: The aim of this study was to assess the incidence of Enterobacteriaceae (potential human and animal pathogens) in wetlands . METHODS: Enterobacteriaceae, selected from the sediments and rhizosphere of wetland plant Juncus effusus L., were analysed using classical microbiological methods, API20E, API20NE, fatty acid analyses, and 16S rRNA sequencing . Assessed virulence factors include antibiotic resistance, presence of plasmids and capsules . RESULTS: Klebsiella pneumoniae, Enterobacter cloacae and Enterobacter asburiae, known human pathogens, were identified . K . pneumoniae 16S rRNA gene sequence showed the significant hit (E < 0.001) with the unculturable bacteria obtained from faeces of elderly individuals (accession number AB099804) when Genbank database was used . Ent . asburiae 16S rRNA gene sequence showed the significant hit with (E < 0.001) with the unculturable bacteria obtained from the pig gastrointestinal tract (accession number AF371852) . The rate of antibiotic resistance (<50 microg ml(-1)) was high for ampicillin and cephalosporins for the most strains (75.7%) yet low (>10 to 20 microg ml(-1)) for kanamycin, tetracycline and chloramphenicol for all strains tested . Capsules were detected in all investigated strains . PCR detected membrane protein but not chromosomally encoded beta-lactamase . Significance and Impact of the Study: The antibiotic resistance of tested strains and presence of capsules (protect micro-organisms from phagocytosis) suggest that wetland sediments and rhizosphere present a potential reservoirs for enteric human and animal pathogens.

Expert Rev Anti Infect Ther, 2004 Apr, 2(2), 317 - 27
Global dissemination of beta-lactamases mediating resistance to cephalosporins and carbapenems; Gootz TD; While the main era of beta-lactam discovery programs is over, these agents continue to be the most widely prescribed antimicrobials in both community and hospital settings . This has led to considerable beta-lactam pressure on pathogens, resulting in a literal explosion of new beta-lactamase variants of existing enzyme classes . Recent advances in the molecular tools used to detect and characterize beta-lactamases and their genes has, in part, fueled the large increase in communications identifying novel beta-lactamases, particularly in Gram-negative bacilli . It now seems clear that the beta-lactams themselves have shaped the field of new enzymes, and the evolution of key amino acid substitutions around the active sites of beta-lactamases continues to drive resistance . Over 130 variants of TEM beta-lactamase now exist, and more are reported in the scientific literature each month . The most disturbing current trend is that many bla structural genes normally limited to the chromosome are now mobilized on plasmids and integrons, broadening the spread of resistance to include carbapenems and cephamycins . Furthermore, in some Enterobacteriaceae, concomitant loss of outer membrane porins act in concert with these transmissible beta-lactamase genes to confer resistance to the most potent beta-lactams and inhibitor combinations available . Continued reviews of the literature are necessary in order to keep abreast of the ingenuity with which bacteria are changing the current genetic landscape to confer resistance to this important class of antimicrobials.

Pol J Vet Sci, 2004, 7(3), 171 - 4
Influence of various treatment methods on bacteriological findings in cows with puerperal endometritis; Kaczmarowski M et al.; The aim of the study was to identify the species of microorganisms isolated from the uterus of healthy cows (control group) and cows affected with puerperal metritis (PM) before and after an experimental therapy with an immunomodulator and antibiotics versus commonly applied methods (antibiotic + beta-blocker or antibiotic + PGF2alpha) . Examinations were carried out on 110 cows with PM in three farms with similar system of rearing and nutrition . The control group consisted of 21 cows without postpartum disturbances . Smears from the uterus were taken before treatment and then at 21st day of observation . Escherichia coli and other species of Enterobacteriaceae family were isolated from 48.2% of PM cows and 47.6% of healthy cows . The degree of Arcanobacterium pyogenes infection was statistically lower in healthy than in sick cows (9.5% versus 30.0%) . Streptococcus sp . was isolated from 13.6% of PM cows and from 16% of control ones . Staphylococci were isolated from 10% of PM and from 30% of control cows . Other bacteria species were isolated from about 10% of the examined cows . The best elimination of infections (66%) was noted in cows treated with the intrauterine antibiotic in combination with PGF2alpha i.m . injection . Examination showed that species of bacteria in the postparturient uterus were similar in healthy and sick cows . However, Arcanobacterium pyogenes was isolated 3 times more often from the sick animals . This pathogen was identified in 11 cows out of 19 (57.9%) culled subsequently because of infertility after the metritis puerperalis was clinically cured.

Biochem Biophys Res Commun, 2004 Nov 12, 324(2), 679 - 85
Molecular cloning, characterization, and overexpression of a novel {Fe}-hydrogenase isolated from a high rate of hydrogen producing Enterobacter cloacae IIT-BT 08; Mishra J et al.; Degenerate primers were designed from the conserved zone of hydA structural gene encoding for catalytic subunit of {Fe}-hydrogenase of different hydrogen producing bacteria . A 750 bp of PCR product was amplified by using the above-mentioned degenerate primers and genomic DNA of Enterobacter cloacae IIT-BT 08 as template . The amplified PCR product was cloned and sequenced . The sequence showed the presence of an ORF of 450 bp with significant similarity (40%) with C-terminal end of the conserved zone (H-cluster) of {Fe}- hydrogenase . hydA ORF was then amplified and cloned in-frame with GST in pGEX4T-1 and overexpressed in a non-hydrogen producing Escherichia coli BL-21 to produce a GST-fusion protein of a calculated molecular mass of about 42.1 kDa . Recombinant protein was purified and specifically recognized by anti-GST monoclonal antibody through Western blot . Southern hybridization confirmed the presence of this gene in E . cloacae IIT-BT 08 genome . In vitro hydrogenase assay with the overexpressed hydrogenase enzyme showed that it is catalytically active upon anaerobic adaptation . In vivo hydrogenase assay confirmed the presence of H2 gas in the gas mixture obtained from the batch culture of recombinant E . coli BL-21 . A tentative molecular mechanism has been proposed about the transfer of electron from electron donor to H-cluster without the mediation of the F-cluster.

Clin Infect Dis, 2004 Sep 15, 39(6), 812 - 8 Epub 2004 Aug 25.
Bloodstream infections caused by Enterobacter species: predictors of 30-day mortality rate and impact of broad-spectrum cephalosporin resistance on outcome; Kang CI et al.; BACKGROUND: Enterobacter species have become increasingly important nosocomial pathogens . However, resistance to cephalosporins often complicates the treatment of Enterobacter infection . This study was conducted to evaluate the predictors of mortality and the impact of cephalosporin resistance on outcome in patients with Enterobacter bacteremia . METHODS: A total of 183 patients with Enterobacter bacteremia were retrospectively analyzed . Broad-spectrum cephalosporin resistance was defined as in vitro resistance to cefotaxime or ceftazidime . The main outcome measure was the 30-day mortality rate . RESULTS: Of 183 patients, 86 (47%) had bacteremia caused by broad-spectrum cephalosporin-resistant Enterobacter species, and their infections were classified as resistant . The 30-day mortality rate of patients with resistant infections (the resistant group) was significantly higher than that of patients with susceptible infections (the susceptible group) (33.7% vs . 18.6%; P=.021) . When the 30-day mortality rates were compared according to the primary sites of infection and underlying conditions, the 30-day mortality rates of the resistant group were significantly higher than those of the susceptible group, in patients with an unknown primary site of infection, or in patients with septic shock . Multivariate analysis showed that broad-spectrum cephalosporin resistance was one of the independent risk factors associated with 30-day mortality (odds ratio {OR}, 3.69; 95% confidence interval {CI}, 1.01-13.52; P=.049) . Presentation with septic shock and an increasing Acute Physiology and Chronic Health Evaluation II score were also independent risk factors for mortality (OR, 59.91 {95% CI, 14.93-240.15; P<.001} and 1.52 {95% CI, 1.24-1.86; P<.001}, respectively) . CONCLUSIONS: Broad-spectrum cephalosporin resistance adversely affects the outcome of patients with Enterobacter bacteremia, especially those with an unknown primary site of infection and those with septic shock.

J Clin Microbiol, 2004 Oct, 42(10), 4581 - 5
Controlled clinical comparison of the BacT/ALERT FN and the standard anaerobic SN blood culture medium; Mirrett S et al.; To determine the optimal anaerobic companion bottle to pair with the BacT/ALERT (bioMerieux, Durham, N.C.) nonvented aerobic FA (FA) medium for recovery of pathogenic microorganisms from adult patients with bacteremia and fungemia, we compared the BacT/ALERT FN (FN) anaerobic bottle with the standard BacT/ALERT SN (SN) anaerobic bottle . Each bottle, FA, FN, and SN, was filled with 8 to 12 ml of blood . Of 11,498 blood culture sets received in the clinical microbiology laboratories at two university medical centers, 7,945 sets had all three bottles filled adequately and 8,569 had both anaerobic bottles filled adequately . Of 686 clinically important (based on previously published criteria) isolates detected in one or both adequately filled anaerobic bottles, more staphylococci (P < 0.001), including Staphylococcus aureus (P < 0.001); members of the family Enterobacteriaceae (P < 0.001); and all microorganisms combined (P < 0.001) were detected in FN bottles . In contrast, more Pseudomonas aeruginosa isolates (P < 0.01) and yeasts (P < 0.001) were detected in SN bottles . More Bacteroides fragilis group bacteremias were detected only in the FN (six) than in the SN (one) anaerobic bottle (P = not significant) . Overall, the mean time to detection was shorter with FN (16.8 h) than with SN (18.2 h) . This difference in time to detection was greatest for the B . fragilis group: FN, 28 h, versus SN, 60.0 h . Many of the facultative microorganisms recovered in either FN or SN were also found in the companion FA . When microorganisms found in the companion FA bottle were omitted from the analysis, significantly more staphylococci (P < 0.001), including S . aureus (P < 0.001), and Enterobacteriaceae (P < 0.005) still were detected in FN bottles, whereas there were no significant differences for P . aeruginosa and yeasts, which were found as expected in FA bottles . We conclude that the companion anaerobic FN bottle detects more microorganisms than does the anaerobic SN bottle when used in conjunction with the nonvented aerobic FA bottle in the BacT/ALERT blood culture system.

J Clin Microbiol, 2004 Oct, 42(10), 4494 - 7
Genotyping of 44 isolates of Fusarium solani, the main agent of fungal keratitis in Brazil; Godoy P et al.; In a retrospective study performed over 6 years in Brazil, Fusarium solani was found to be the most common species causing mycotic keratitis . The genetic diversity of 44 isolates from 39 patients was assessed by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and PCR restriction fragment length polymorphism (PCR-RFLP) fingerprinting . ERIC-PCR was more discriminatory than PCR-RFLP for differentiating the strains . By combining of the results of both techniques, we identified 40 genotypes . Molecular typing revealed a high genomic heterogeneity of the strains of F . solani studied.

J Antimicrob Chemother, 2004 Nov, 54(5), 932 - 935 Epub 2004 Oct 7.
Identification of a chromosome-borne class C {beta}-lactamase from Erwinia rhapontici; Naas T et al.; OBJECTIVES: To characterize the beta-lactamase gene content of Erwinia rhapontici . METHODS: The beta-lactamase gene was cloned, sequenced and expressed in Escherichia coli . RESULTS: The cloned gene conferred a resistance pattern of an Ambler class C beta-lactamase in E . coli . The AmpC-type enzyme had a pI value of 8.6 and shared 62% amino acid sequence identity with that of Escherichia fergusonii . The ampC gene was associated with a regulatory ampR gene and beta-lactamase production was inducible . CONCLUSIONS: This work provides further evidence of the molecular heterogeneity of beta-lactamases in Erwinia spp . and that plant-pathogenic enterobacterial species may constitute a reservoir of antibiotic resistance genes.

Rev Esp Quimioter, 2004 Jun, 17(2), 169 - 76
{Evaluation of the Phoenix system for identifying and determining the susceptibility of clinical isolates . Comparative study with the Microscan system}; Marco F et al.; The Phoenix system (BD Diagnostic Systems), a rapid ID/AST system, was compared with the MicroScan WalkAway-40 system for accuracy of identification and antimicrobial susceptibility test results . The 327 bacterial isolates, were comprised of 191 Gram-negative bacilli (187 Enterobacteriaceae and 4 Aeromonas spp.) and 136 Gram-positive cocci (27 Staphylococcus aureus, 53 coagulase-negative staphylococci, 45 enterococci and 11 beta haemolytic streptococci) . The overall rate of agreement between the two systems for species level identification was 95.8% and 96.3% for Gram-negative bacilli and Gram-positive cocci, respectively . Enterococcus and Streptococcus species both achieved a 100% rate of species level agreement . The genus level agreement was >99% overall . Arbitration of the 8 Gram-negative bacilli disagreements resolved with 7 in agreement with the Phoenix identification . For the 5 Gram-positive cocci disagreements, 3 resolved in agreement with Phoenix . Overall, 3688 antimicrobial/organism combinations were evaluated in both systems . For Gram-negative isolates, the rate of essential agreement for the MICs was 98.5%, while the categorical agreement rate was 95.9% . Arbitration of 13 Gram-negative disagreements resolved with 11 in agreement with the Phoenix system . For Staphylococcus spp . and Enterococcus spp . isolates, the essential agreement rates were 96.4% and 99% respectively . Categorical agreement rates for both genera were 94.7% and 96.1%, respectively . Arbitration of 5 staphylococci disagreements resolved with 2 in agreement with Phoenix system . Our results show that the Phoenix system is a rapid and reliable system for both identification and antimicrobial susceptibility testing of common clinical isolates.

Med Princ Pract, 2004 Nov-Dec, 13(6), 334 - 9
Etiology and antibiotic susceptibility patterns of community-acquired urinary tract infections in a Kuwait hospital; Dimitrov TS et al.; OBJECTIVE: The aim of this study was to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from patients with community-acquired urinary tract infections (UTIs) at the Infectious Diseases Hospital, Kuwait . MATERIALS AND METHODS: The study was conducted over a 7-year period . Patient information was obtained from medical record files . Antibiotic-sensitivity testing was performed by disk diffusion . E test and double disk diffusion methods were used to study the production of extended spectrum beta-lactamases . RESULTS: Of the 14,042 urine samples processed, significant bacteriuria (>10(5) cfu/ml) was detected in 1,606 (11.4%) . The majority (74.5%) of the isolates were from women while the remaining 25.5% were from men . The majority of infections (75%) were due to Enterobacteriaceae, coagulase-negative staphylococci (10.3%) and group B streptococci (8.7%) . Among the gram-negative enteric bacilli high prevalence of resistance to ampicillin, amoxicillin/clavulanic acid, cephalothin, and trimethoprim/sulfamethoxazole was observed . Increasing resistance to ciprofloxacin and gentamicin was observed in E . coli isolates over the 7 years . Multiple resistance was detected in 53.8 and 41% of E . coli and Klebsiella spp . strains, respectively . No glycopeptide-resistant enterococci were isolated . CONCLUSION: This study revealed that Enterobacteriaceae were the predominant bacterial pathogen of community-acquired UTIs in Infectious Diseases Hospital, Kuwait . It also demonstrated an increasing resistance to ciprofloxacin, gentamicin and the production of extended spectrum beta-lactamase among UTI pathogens in the community.

Anim Health Res Rev, 2004 Jun, 5(1), 95 - 102
Molecular epidemiology of antimicrobial resistance in veterinary medicine: where do we go?
Boerlin P.
Molecular epidemiology allows us to trace specific microorganisms and mobile genetic elements and to assess their epidemiological and evolutionary relationships . Examples of molecular epidemiology investigations in veterinary hospitals are discussed . They demonstrate the great similarities with the situation in human medicine and the potential usefulness of molecular epidemiology in our fight against antimicrobial resistance and nosocomial infections in veterinary hospitals . A broad knowledge of the diversity of antimicrobial resistance determinants in some major groups of pathogens and commensals from animals such as Enterobacteriaceae, Pasteurellaceae, enterococci and staphylococci is emerging . However, there are important gaps in this knowledge, which are discussed here . Many more molecular epidemiology studies will be necessary to understand and follow the evolution of the problem in veterinary medicine and agriculture on a global scale . To be able to build useful surveillance programs and reliable epidemiological models, and to identify critical intervention points, we need to improve our understanding of antimicrobial resistance at the animal and farm levels . Studies assessing the dynamics of bacterial populations and of resistance determinants at these levels are desperately needed . Understanding the relationships between antimicrobial resistance, colonization factors, and virulence also represents a major issue for which molecular epidemiology investigations will be needed.

New Microbiol, 2004 Jul, 27(3), 249 - 53
Effect of cefoxitin and clindamycin on selection of derepressed mutants in Enterobacter cloacae; Saverino D et al.; The characteristics of an antibiotic that favor its ability to select for resistant bacteria are not completely understood . Otherwise, by the common use of broad-spectrum cephalosporins, resistant strains of several gram-negative species, especially Enterobacter cloacae, have been more frequently isolated . During our studies on beta-lactam resistance in E . cloacae, we observed that the addition of an inhibitor (clindamycin) to a potent inducer (cefoxitin) leads to an enhanced selection of resistant mutants . This could explain the emergence of beta-lactam resistant strains during antibiotic therapy.

Pediatr Surg Int, 2005 Jan, 21(1), 8 - 11
Bile infection contributes to intrahepatic calculi formation after excision of choledochal cysts; Kaneko K et al.; Intrahepatic calculi complicate choledochal cysts in 7-8% of patients . Although congenital stenoses and dilatation of the intrahepatic bile ducts are considered responsible for calculi formation, intrahepatic calculi are usually formed after cyst excision . In this study, bile specimens from patients with choledochal cysts were cultured for bacteria . Results were retrospectively analyzed among the following groups: the primary excision group, consisting of 97 patients undergoing cyst excision as a primary treatment (mean age 5.0 years), the internal drainage group, consisting of 13 patients who had previous cyst-enterostomy at cyst excision (mean age 20.2 years); and the hepatolithiasis group, consisting of 12 patients with postoperative hepatolithiasis (mean age 24.2 years) . Bacteria were present in the bile of 10 patients (76.9%) in the internal drainage group and in all patients (100%) in the hepatolithiasis group, but present in only 17 patients (17.5%) in the primary excision group (p<0.01) . Polymicrobial infection with Gram-negative enterobacteria such as Escherichia coli and Klebsiella species was predominant in the internal drainage and hepatolithiasis groups, while nonenteric bacteria were found in the primary excision group . Bile infection through bilioenterostomy may play an important role in intrahepatic calculus formation after excision of a choledochal cyst.

J Microbiol, 2004 Sep, 42(3), 216 - 22
PCR method based on the ogdH gene for the detection of Salmonella spp . from chicken meat samples; Jin UH et al.; In a previous paper, the ogdH gene that encodes 2-oxoglutarate dehydrogenase was isolated from Salmonella typhimurium . The catalytic N-terminal region in the enzyme was found to be very specific for the Salmonella species . Therefore, the aim of the present study was to detect S . typhimurium in food sources using primers designed for OGDH-1 and OGDH-2 which were based on the salmonella-specific region of the ogdH gene . A simple polymerase chain reaction (PCR) detection method was developed to detect low numbers of S . typhimurium in a chicken meat microbial consortium . Using the ogdH-specific primers under stringent amplification conditions and for gene probe analysis, fewer than 100 colony-forming units (CFUs) were detectable when pure cultures were employed . When the PCR assay was run on S . typhimurium-contaminated meat contents, only the positive meat samples containing as few as 200 CFUs reacted to the assay . The method employed for sample processing is simple and it was determined to provide a sensitive means of detecting trace amounts of S . typhimurium-specific sequences in the presence of mixed meat microbial populations . When compared with six representative intestinal gram-negative bacterial strains in foods, including Vibrio parahaemolyticus, V . vulnificus, Enterobacter cloacae, E . coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., S . typhimurium had a unique and distinct PCR product (796 bp) . In conclusion, the two OGDH primers were found to be rapid and sensitive detectors of Salmonella spp for the PCR method .

J Microbiol, 2004 Sep, 42(3), 169 - 73
Impact of genetically modified Enterobacter cloacae on indigenous endophytic community of Citrus sinensis seedlings; Andreote FD et al.; Enterobacter cloacae (strain PR2/7), a genetically modified endophyte (GME) in citrus plants, carrying different plasmids (pEC3.0/18, pCelE, pEglA and pGFP), was inoculated into Citrus sinensis seedlings under greenhouse conditions . The impact of this on the indigenous bacterial endophytic community was studied by analyses of 2 different morphologic groups . The germination rates of inoculated seeds were evaluated in greenhouse, and plasmid stability under in vitro conditions . Results demonstrated a great and diverse endophytic community inside plants, and specialization in tissue colonization by some bacterial groups, in different treatments . Shifts in seed germination rate were observed among treatments: in general, the PR2/7 harboring pEglA bacterial clone significantly reduced seed germination, compared to the PR2/7 harboring pEC3.0/18 clone . This suggests that the presence of the pEglA plasmid changes bacteria-seed interactions . The endophytic community of citrus seedlings changed according to treatment . In seedlings treated with the PR2/7 with pEglA clone, the population of group II decreased significantly, within the context of the total endophytic community . These results indicate that the application of GMEs induces shifts in the endophytic bacterial community of citrus seedlings .

Infect Genet Evol, 2004 Sep, 4(3), 187 - 91
International dissemination of antibiotic resistant strains of bacterial pathogens; Witte W; The increasing incidence of methicillin and multiple resistant Staphylococcus aureus (MRSA) in nosocomial infections is mainly associated with a wide, international dissemination of well defined clonal lineages (epidemic MRSA) which are clearly different from community acquired MRSA by molecular typing patterns and structure of the staphylococcal cassette chromosome containing the mecA gene . Although belonging to a definite subpopulation within the species Enterococcus faecium, hospital associated vancomycin resistant isolates also containing the esp gene have very likely evolved by acquisition of glycopeptide resistance gene clusters at different occasions and at different times by a susceptible already disseminated clonal lineage . There is obviously a continuous selection of new types of extended spectrum beta-lactamases in enterobacteriaceae and also horizontal spread of bla-genes . Intrahospital dissemination of particular strains has often been observed, however, an international dissemination until now has been described only for Salmonella enterica serovar Typhimurium producing the CTX-M-3 enzyme . Multiresistant isolates of Salmonella enterica serovar Typhimurium phage type DT104 harbour a multiresistant gene cluster with resistance genes from taxonomically more unrelated species (tetG, floR, bla(PSE1)) . Although in vitro transduction has been demonstrated, this gene cluster has only rarely been reported from isolates exhibiting other phage patterns of the same serovar or from other serovars of S . enterica.

J Pediatr Gastroenterol Nutr, 2004 Oct, 39(4), 320 - 322
Preparation and Handling of Powdered Infant Formula: A Commentary by the ESPGHAN Committee on Nutrition; Agostoni C et al.; Powdered infant formulae are not sterile and may contain pathogenic bacteria . In addition, milk products are excellent media for bacterial proliferation . Multiplication of Enterobacter sakazakii in prepared formula feeds can cause devastating sepsis, particularly in the first 2 months of life . In approximately 50 published case reports of severe infection, there are high rates of meningitis, brain abscesses and necrotizing enterocolitis, with an overall mortality from 33% to 80% . Breast feeding provides effective protection against infection, one of the many reasons why it deserves continued promotion and support . To minimize the risk of infection in infants not fully breastfed, recommendations are made for preparation and handling of powdered formulae for children younger than 2 months of age . In the home setting, powdered infant formulae should be freshly prepared for each feed . Any milk remaining should be discarded rather than used in the following feed . Infant feeds should never be kept warm in bottle heaters or thermoses . In hospitals and other institutions written guidelines for preparation and handling of infant formulae should be established and their implementation monitored . If formula needs to be prepared in advance, it should be prepared on a daily basis and kept at 4 degrees C or below . Manufacturers of infant formulae should make every effort to minimize bacterial contamination of powdered products.

Biosci Biotechnol Biochem, 2004 Sep, 68(9), 1882 - 7
Comparative effect of repeated ingestion of difructose anhydride III and palatinose on the induction of gastrointestinal symptoms in humans; Tamura A et al.; We evaluated the safety and change in fermentability from repeated ingestion of difructose anhydride III (DFAIII) in humans . A randomized controlled single-blind crossover study with thirteen subjects was conducted . Each subject ingested 5 g of DFAIII or palatinose daily for 12 days, before and after which the subject was loaded with 10 g of DFAIII and had breath hydrogen measured from 0 to 9 h (DL test) to evaluate the fermentability of DFAIII . The defecation frequency and abdominal symptom score were the same between each ingestion period . Moreover, DFAIII ingestion had no influence on blood test results . Only the breath hydrogen excretion in post-DFAIII ingestion was slightly higher at h 8 than the pre-ingestion . Consequently, repeated ingestion of DFAIII for 12 days was as safe as palatinose ingestion, especially with respect to abdominal symptoms and blood test results, and its high resistance to enterobacterial fermentation in humans was not impaired.

Mol Microbiol, 2004 Sep, 53(5), 1529 - 43
Functional domains of the IS1 transposase: analysis in vivo and in vitro; Ton-Hoang B et al.; The IS1 bacterial insertion sequence family, considered to be restricted to Enterobacteria, has now been extended to other Eubacteria and to Archaebacteria, reviving interest in its study . To analyse the functional domains of the InsAB' transposase of IS1A, a representative of this family, we used an in vivo system which measures IS1-promoted rescue of a temperature-sensitive pSC101 plasmid by fusion with a pBR322::IS1 derivative . We also describe the partial purification of the IS1 transposase and the development of several in vitro assays for transposase activity . These included a DNA band shift assay, a transposase-mediated cleavage assay and an integration assay . Alignments of IS family members not only confirmed the presence of an N-terminal helix-turn-helix and a C-terminal DDE motif in InsAB', but also revealed a putative N-terminal zinc finger . We have combined the in vitro and in vivo tests to carry out a functional analysis of InsAB' using a series of site-directed InsAB' mutants based on these alignments . The results demonstrate that appropriate mutations in the zinc finger and helix-turn-helix motifs result in loss of binding activity to the ends of IS1 whereas mutations in the DDE domain are affected in subsequent transposition steps but not in end binding .

Infect Immun, 2004 Oct, 72(10), 5548 - 54
Functional analysis of the Tsh autotransporter from an avian pathogenic Escherichia coli strain; Kostakioti M et al.; The temperature-sensitive hemagglutinin (Tsh) is an autotransporter protein secreted by avian-pathogenic Escherichia coli strains that colonize the respiratory tract and lead to airsacculitis, pericarditis, and colisepticemia . It is synthesized as a 140-kDa precursor protein, whose processing results in a 106-kDa passenger domain (Tshs) and a 33-kDa beta-domain (Tsh(beta)) . The presence of a conserved 7-amino-acid serine protease motif within Tshs classifies the protein in a subfamily of autotransporters, known as serine protease autotransporters of the Enterobacteriaceae . In this study, we report that purified Tshs is capable of adhering to red blood cells, hemoglobin, and the extracellular matrix proteins fibronectin and collagen IV . We also demonstrate that Tshs exerts proteolytic activity against casein, and we provide experimental evidence demonstrating that serine 259 is essential for the protease function . However, this residue is not required for adherence to substrates, and its replacement by an alanine does not abolish binding activity . In summary, our results demonstrate that Tsh is a bifunctional protein with both adhesive and proteolytic properties.

Sci China C Life Sci, 2004 Feb, 47(1), 44 - 51
Functional difference between Sinorhizobium meliloti NifA and Enterobacter cloacae NifA; Chengtao Y et al.; The nifA gene is an important regulatory gene and its product, NifA protein, regulates the expression of many nif genes involved in the nitrogen fixation process . We introduced multiple copies of the constitutively expressed Sinorhizobium meliloti (Sm) or Enterobacter cloacae (Ec) nifA gene into both the nifA mutant strain SmY and the wild-type strain Sm1021 . Root nodules produced by SmY containing a constitutively expressed Sm nifA gene were capable of fixing nitrogen, while nodules produced by SmY containing the Ec nifA gene remained unable to fix nitrogen, as is the case for SmY itself . However, transfer of an additional Sm nifA gene into Sm1021 improved the nitrogen-fixing efficiency of root nodules to a greater extent than that observed upon transfer of the Ec nifA gene into Sm1021 . Comparative analysis of amino acid sequences between Sm NifA and Ec NifA showed that the N-terminal domain was the least similar, but this domain is indispensable for complementation of the Fix- phenotype of SmY by Sm NifA . We conclude that more than one domain is involved in determining functional differences between Sm NifA and Ec NifA.

Microb Drug Resist, 2004 Fall, 10(3), 224 - 30
Dissemination of transferable AmpC-type beta-lactamase (CMY-10) in a Korean hospital; Lee JH et al.; To determine dissemination and genotype of AmpC beta-lactamases and an extended-spectrum beta-lactamase among clinical isolates of Enterobacteriaceae, we performed antibiotic susceptibility testing, pI determination, induction test, plasmid profiles, transconjugation test, enterobacterial repetitive consensus (ERIC)-PCR, and DNA sequencing . Among the 51 clinical isolates collected from a university hospital in Korea, six isolates were resistant to cephamycins . All six isolates produced a plasmid-encoded AmpC-type beta-lactamase, CMY-10 . Five strains also produced one or more other beta-lactamases: SHV-12, an extended-spectrum beta-lactamase (five isolates); TEM-1, a class A beta-lactamase (two isolates); and a chromosomal AmpC beta-lactamase (one isolate, a strain of Enterobacter aerogenes, which produced all four of the beta-lactamases that were identified) . One of six isolates produced only CMY-10 . ERIC-PCR analysis revealed that dissemination of CMY-10 and SHV-12 was due to a clonal outbreak of a resistant strain and to the interspecies spread of resistance to cephamycins and broad-spectrum beta-lactams in Korea . CMY-10 beta-lactamase genes that are responsible for the resistance to cephamycins (cefoxitin and cefotetan), amoxicillin, cephalothin, and amoxicillin-clavulanic acid were cloned and characterized from six clinical isolates . A sequence identical to the common regions in In6, In7, and a novel integron from pSAL-1 was found upstream from blaCMY-10 gene at nucleotides 1-71 . A total of 15 nucleotides (I-15) or 18 nucleotides (I-18) between position 71 and 72 were inserted into the blaCMY-10 gene . The blaCMY-10 gene might be inserted into a sul1-type complex integron by I-15 or I-18 . Copyright Mary Ann Liebert, Inc.

Water Res, 2004 Nov, 38(18), 3833 - 44
The use of microbial tracers to monitor seasonal variations in effluent retention in a constructed wetland; Hodgson CJ et al.; Effluent retention in a constructed wetland was determined using both microbial and chemical tracers . Seasonal variation in effluent retention was the main focus of the study . The biotracers used in the study were the coliphage MS2, a bacteriophage of Enterobacter cloacae and antibiotic resistant endospores of Bacillus globigii . Two separate tracer runs were conducted, Winter high flow (January 2002) and Summer low flow (June 2002) . The three biotracers were evaluated simultaneously on both occasions, with the commonly used chemical tracer, rhodamine WT, a bright red fluorescent dye, being evaluated during the final experiment . The Winter tracer run was conducted during a typical Winter storm, with a mean effluent discharge of 4.1 ls(-1) . Tracer recovery was 98% MS2, 91% Ent . cloacae phage and 2% endospore . Effluent retention was estimated at between 2 and 4 h at 90% phage tracer recovery . The Summer tracer run was conducted at a typical site operating discharge rate of 0.8 ls(-1) . Tracer recovery was 23% MS2, 36% Ent . cloacae phage, 8% rhodamine and 14% for the endospores . Effluent retention was estimated at between 11 and 18 h at 90% of phage tracer recovery . Initial results are encouraging and indicate bacteriophage to have further potential as tracing agents in wetlands.

Diagn Microbiol Infect Dis, 2004 Sep, 50(1), 73 - 5
Bactericidal activity of BAL9141, a novel parenteral cephalosporin against contemporary Gram-positive and Gram-negative isolates; Deshpande L et al.; BAL9141, the active principle of prodrug BAL5788, is a parenteral cephalosporin active against oxacillin-resistant Staphylococcus aureus . Previous studies have reported the cidal action of BAL9141 towards limited numbers of isolates by time-kill methods . We tested >100 staphylococci, streptococci, and Gram-negative isolates by broth microdilution methods to determine the antibacterial activity of BAL9141 and to compare minimum inhibitory concentrations (MICs) with minimum bactericidal concentrations (MBCs) . Among the 53 staphylococcal isolates, all but one (98%) had a, MBC:MIC ratio < or =2 . Forty-five percent (five strains) of the penicillin-nonsusceptible Streptococcus pneumoniae isolates had an MBC:MIC ratio >4 . Among 22 Enterobacteriaceae, 73% of isolates had MBC:MIC ratios of 2 or less; three strains with ratios greater than 4 were Serratia marcescens . BAL9141 displayed a predominant bactericidal activity against the majority of Gram-positive and -negative species, including resistant subsets, making it an attractive candidate for further development.

J Bacteriol, 2004 Oct, 186(19), 6671 - 7
Recent genetic transfer between Lactococcus lactis and enterobacteria; Bolotin A et al.; The genome sequence of Lactococcus lactis revealed that the ycdB gene was recently exchanged between lactococci and enterobacteria . The present study of ycdB orthologs suggests that L . lactis was probably the gene donor and reveals three instances of gene transfer to enterobacteria . Analysis of ycdB gene transfer between two L . lactis subspecies, L . lactis subsp . lactis and L . lactis subsp . cremoris, indicates that the gene can be mobilized, possibly by conjugation.

Transplantation, 2004 Sep 15, 78(5), 704 - 9
Surgical site infection in living-donor liver transplant recipients: a prospective study; Iinuma Y et al.; BACKGROUND: Infection is a constant threat for the living-donor liver transplantation (LDLT) recipients, although little information is available on the occurrence of infection in such patients . METHODS: One hundred and thirteen consecutive LDLT recipients were prospectively followed for the presence of surgical site infections (SSIs) defined by CDC from April 2001 to March 2002 . Risk factors for SSIs were evaluated by univariate and multivariate analysis . RESULTS: Of the 113 LDLT recipients, 42 (37%) developed 57 episodes of SSIs (21 intraabdominal abscess, 20 peritonitis, 8 cholangitis, and 9 wound) . Of the 57 episodes, 29 (51%) had secondary bacteremia in 19 patients . Causative pathogens, including 17 episodes of polymicrobial infections, were 37 gram-positive cocci (17 Staphylococcus aureus, 16 Enterococcus spp., and 4 others), 40 gram-negative rods (25 Enterobacteriaceae, 13 Pseudomonas aeruginosa, and 4 others), and 2 Candida albicans . Univariate analysis revealed that ABO incompatibility and repeat surgery were associated with the development of SSIs . Also, univariate analysis revealed that adult recipients, ABO incompatibility, total operation duration, repeat surgery, and NNIS risk index were associated with secondary bacteremia . Multivariate analysis revealed that ABO incompatibility (OR: 14.0; 95% CI, 2.52-77.2) and repeat surgery (OR: 9.29; 95% CI, 2.00-43.1) were independently associated with secondary bacteremia . Eleven of the 42 cases (26%) who developed SSIs died . Of these 11 cases, 5 (45%) developed secondary bacteremia within 30 days before death . CONCLUSION: SSIs occurred in 37% of LDLT recipients . ABO incompatibility and repeat surgery increased the risk of developing SSIs with secondary bacteremia, which correlated with poor prognosis.

Int J Food Sci Nutr, 2004 Jun, 55(4), 317 - 24
Microbiological quality of fermented cassava flour 'kpor umilin'; Tsav-Wua JA et al.; A study was conducted on the microbiological quality of traditionally fermented cassava flour 'kpor umilin' and a laboratory modification of the method developed with a view to upgrading the traditional process . Microbial analysis of samples from both processing methods was evaluated using standard microbiological methods . The bacterial count in the traditionally processed flours ranged from 2.7 x 10(3) to 1.2 x 10(7) cfu/g, while the modified sample had a count of 3.5 x 10(2) cfu/g . The predominant flora were Leuconostoc spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp., Bacillus spp., Streptococcus spp . and coliforms such as Escherichia coli . Other isolates were Enterobacter spp . and proteus spp . The sample from the modified method had a negligible (4 MPN/100 ml) coliform count . The yeast and mould count ranged from 1.9 x 10(3) cfu/g to 3.9 x 10(5) cfu/g in the traditionally processed samples as compared with 1.5 x 10(3) cfu/g in the sample from the modified process . Aspergillus spp., Penicillium spp., Saccharomyces spp . and Geotrichum candidum were the predominant fungi . The poor microbiological quality of 'kpor umilin', processed traditionally, calls for urgency in upgrading the processing and preservation methods as developed in this study as well as proper education of the local processors on good manufacturing practices.

Syst Appl Microbiol, 2004 Aug, 27(4), 462 - 8
Gamma proteobacteria can nodulate legumes of the genus Hedysarum; Benhizia Y et al.; The bacteria hosted in the root nodules of the three Mediterranean wild legume species Hedysarum carnosum, Hedysarum spinosissimum subsp . capitatum, and Hedysarum pallidum, growing in native stands in different habitats in Algeria were isolated . Bacteria were recovered on yeast-mannitol-agar or on minimal media from a total of 52 nodules . Isolates were analyzed by Amplified Ribosomal DNA Restriction Analysis (ARDRA) using the enzyme CfoI, and further sorted by RAPD fingerprinting . A total of ten different types were found and their amplified 16S rDNA was sequenced and compared to databases . The BLAST alignment indicates that all the species whose sequences share 98 to 100% identity to the bacteria found in these nodules belong to the class Gammaproteobacteria and include Pantoea agglomerans, Enterobacter kobei, Enterobacter cloacae, Leclercia adecarboxylata, Escherichia vulneris, and Pseudomonas sp . No evidence of any rhizobial-like sequence was found even upon amplifying from the bulk of microbial cells obtained from the squashed nodules, suggesting that the exclusive occupants of the nodules formed by the three plants tested are members of the orders Enterobacteriales or Pseudomonadales . This is the first report of Gammaproteobacteria associated with legume nodules . Despite the presence of the related crop plant Hedysarum coronarium, specifically nodulated by Rhizobium sullae, these three Hedysarum species demonstrate to have undergone a separate path in terms of endophytic interactions with bacteria . An hypothesis to account for differences between the symbiotic relationships engaged by man-managed legumes, and those found in plants whose ecology is independent from human action, is discussed.

J Clin Microbiol, 2004 Sep, 42(9), 4242 - 9
Risk factors for colonization and infection in a hospital outbreak caused by a strain of Klebsiella pneumoniae with reduced susceptibility to expanded-spectrum cephalosporins; Cartelle M et al.; Between February 2001 and January 2002, an increase in the number of Klebsiella pneumoniae isolates with reduced susceptibility to expanded-spectrum cephalosporins (RSKp) was detected in the neonatal unit of the Juan Canalejo Hospital, and 21 patients were either colonized or infected by the bacterial isolates . The current "gold standard" method for typing K . pneumoniae isolates is pulsed-field gel electrophoresis . However, this technique is expensive and time-consuming . In a search for faster and accurate alternatives to this method, we investigated PCR-based fingerprinting techniques (enterobacterial repetitive intergenic consensus sequence PCR {ERIC-PCR}, repetitive extragenic palindromic sequence-based PCR {REP-PCR}, and RAPD {randomly amplified polymorphic DNA}) for their ability to characterize K . pneumoniae isolates . The causal agent of the nosocomial outbreak was characterized by these techniques and was found to be a single epidemic strain (RSKp) . A multiple regression logistic model was developed to identify potential independent factors associated with colonization and/or infection by RSKp . Logistic regression analysis was applied to all significant variables (P < 0.05) in the univariate analysis, and it was revealed that intubation (odds ratio {OR}, 27.0; 95% confidence interval {95%CI}, 5.39 to 135.14) and prematurity (OR, 4.4; 95%CI, 0.89 to 21.89) were such independent factors . Moreover, oxime cephalosporins did not appear to be statistically significant . Overall, the results showed that PCR-based techniques are expeditious and useful methods for typing K . pneumoniae isolates . Of the techniques studied, ERIC-PCR showed the highest discriminatory index (D = 0.828), followed by RAPD (D = 0.826) and REP-PCR (D = 0.773)

Int J Antimicrob Agents, 2004 Sep, 24 Suppl 1, S61 - 4
Antimicrobial susceptibility of uropathogens causing acute uncomplicated cystitis in female outpatients in South Korea: a multicentre study in 2002; Lee SJ et al.; The objective of this study was to obtain data on the susceptibility of pathogens responsible for acute uncomplicated cystitis in South Korea to currently used antimicrobial agents . A total of 239 isolates were obtained from female outpatients with acute uncomplicated cystitis . The most prevalent causative organism was Escherichia coli (79.9%), followed by coagulase-negative staphylococci (CNS) (4.2%) and Enterobacteriaceae (8.2%) . The mean rates of susceptibility to commonly prescribed drugs are ampicillin 35.5%, cefazolin 89.1%, ciprofloxacin 85.7%, and trimethoprim/sulphamethoxazole (TMP/SMX) 62.1% . Regionally, resistance to TMP/SMX among E . coli now exceeds 30% in all regions . The high prevalence of resistance among uropathogens requires on going surveillance to ensure the provision of effective empirical therapy for acute uncomplicated cystitis.

J Struct Biol, 2004 Oct, 148(1), 22 - 33
Conformational epitope mapping of OmpC, a major cell surface antigen from Salmonella typhi; Arockiasamy A et al.; The outer membrane protein OmpC, a trimer made of 16 stranded beta-barrel monomers, is a major cell surface antigen from the human pathogen Salmonella typhi . The relative stability of the epitopes recognising a Salmonella specific MAb (referred as MPN5) and an Enterobacteria specific MAb (referred as P7D8) and the role of the trimeric organisation has been probed using gel electrophoresis and monoclonal antibodies . The assembly of the trimer and the stability of the beta-barrel are found to be important for epitope presentation . The Salmonella specific conformational epitope is found to be more stable than the Enterobacteria specific one . The important residues of the Salmonella specific (Asp 25 of loop 1, Asp 340 of loop 8, Lys 334 of loop 8, and Tyr 210 of loop 5) and the Enterobacteria specific (Asp 25 of loop 1, Tyr 210 of loop 5, and Lys 152 of loop 4) conformational epitope have been identified using monoclonal antibodies, chemical modification, and solid phase binding methods.

BMC Surg . 2004 Sep 13;4(1):10.
Radiation enteropathy and leucocyte-endothelial cell reactions in a refined small bowel model; Johnson LB et al.; BACKGROUND: Leucocyte recruitment and inflammation are key features of high dose radiation-induced tissue injury . The inflammatory response in the gut may be more pronounced following radiotherapy due to its high bacterial load in comparison to the response in other organs . We designed a model to enable us to study the effects of radiation on leucocyte-endothelium interactions and on intestinal microflora in the murine ileum . This model enables us to study specifically the local effects of radiation therapy . METHOD: A midline laparotomy was performed in male C57/Bl6 mice and a five-centimetre segment of ileum is irradiated using the chamber . Leucocyte responses (rolling and adhesion) were then analysed in ileal venules 2 - 48 hours after high dose irradiation, made possible by an inverted approach using intravital fluorescence microscopy . Furthermore, intestinal microflora, myeloperoxidase (MPO) and cell histology were analysed . RESULTS: The highest and most reproducible increase in leucocyte rolling was exhibited 2 hours after high dose irradiation whereas leucocyte adhesion was greatest after 16 hours . Radiation reduced the intestinal microflora count compared to sham animals with a significant decrease in the aerobic count after 2 hours of radiation . Further, the total aerobic counts, Enterobacteriaceae and Lactobacillus decreased significantly after 16 hours . In the radiation groups, the bacterial count showed a progressive increase from 2 to 24 hours after radiation . CONCLUSION: This study presents a refinement of a previous method of examining mechanisms of radiation enteropathy, and a new approach at investigating radiation induced leucocyte responses in the ileal microcirculation . Radiation induced maximum leucocyte rolling at 2 hours and adhesion peaked at 16 hours . It also reduces the microflora count, which then starts to increase steadily afterwards . This model may be instrumental in developing strategies against pathological recruitment of leucocytes and changes in intestinal microflora in the small bowel after radiotherapy.

Rev Inst Med Trop Sao Paulo, 2004 Jul-Aug, 46(4), 179 - 82 Epub 2004 Sep 03.
Vibrio spp . and Salmonella spp., presence and susceptibility in crabs Ucides cordatus; Vieira RH et al.; The presence of Vibrio spp . and Salmonella spp . in crabs marketed at the Bezerra de Menezes Ave., Fortaleza, State of Ceara, Brazil, was assessed between February and May, 2003 . The number of individuals sampled in each one of the fifteen weekly samplings ranged between four and eight . Seven strains of Salmonella, from four different samplings, were identified, being five of them identified as serotype S . Senftenberg and two as S . Poona . All strains of Salmonella were sensitive to the tested anti-microbial drugs, with the exception of tetracycline and nalidixic acid, for which an intermediary sensibility was found . The MPN's for Vibrio ranged between 110/g and 110,000/g . Of the forty five Vibrio strains isolated from the crab samples, only 10 were identified up to the species level: two V . alginolyticus and eight V . parahaemolyticus . Bacteria belonging to the Enterobacteriaceae and Pseudomonaceae families were also identified, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pantoea agglomerans and Pseudomonas aeruginosa . The proper cooking of the animals is recommended in order to avoid problems for the consumers of this crustacean.

Infect Control Hosp Epidemiol, 2004 Aug, 25(8), 685 - 9
Influence of selective bowel decontamination on the organisms recovered during bacteremia in neutropenic patients; Daxboeck F et al.; OBJECTIVE: To assess the influence of prophylactic selective bowel decontamination (SBD) on the spectrum of microbes causing bloodstream infection (BSI) . DESIGN: The microbes causing BSI in neutropenic patients of a hematologic ward (HW) and a bone marrow transplantation unit (BMTU), respectively, were compared by retrospective analysis of blood culture results from January 1996 to June 2003 . SETTING: A 30-bed HW (no SBD) and a BMTU including a 7-bed normal care ward and an 8-bed intensive care unit (SBD used) of a 2,200-bed university teaching hospital . RESULTS: The overall incidences of bacteremia in the HW and the BMTU were similar (72.6 vs 70.6 episodes per 1,000 admissions; P = .8) . Two hundred twenty episodes of BSI were recorded in 164 neutropenic patients of the HW and 153 episodes in 127 neutropenic patients of the BMTU . Enterobacteriaceae (OR, 3.14; CI95, 1.67-5.97; P= .0002) and Streptococcus species (OR, 2.04; CI95, 1.14-3.70; P = .015) were observed more frequently in HW patients and coagulase-negative staphylococci more frequently in BMTU patients (OR, 0.15; CI95, 0.09-0.26; P < .00001) . No statistically significant differences were found for gram-negative nonfermentative bacilli (P = .53), Staphylococcus aureus (P = .21), Enterococcus species (P = .48), anaerobic bacteria (P = .1), or fungi (P = .50) . CONCLUSIONS: SBD did not lead to a significant reduction in the incidence of bacteremia, but significant changes in microbes recovered from blood cultures were observed . SBD should be considered when empiric antimicrobial therapy is prescribed for suspected BSI.

Infect Control Hosp Epidemiol, 2004 Aug, 25(8), 675 - 7
Prevention of central venous catheter-related bloodstream infections using non-technologic strategies; Gnass SA et al.; OBJECTIVE: To evaluate the incidence of nosocomial bacteremias related to the use of non-impregnated central venous catheters (CVCs) when only non-technologic strategies were used to prevent them . DESIGN: This was a prospective study of infectious complications of CVCs placed in intensive care unit (ICU) patients from April 1997 to December 2001 . SETTING: The medical-surgical ICU of a tertiary-care, university-affiliated hospital in Argentina . METHODS: We studied all patients admitted to the ICU using non-impregnated CVCs . Maximal sterile barrier precautions (ie, use of cap, mask, sterile gown, sterile gloves, and large sterile drape), strict handwashing, preparation of the patients' skin with antiseptic solutions, insertion and management of catheters by trained personnel, and continuing quality improvement programs aimed at appropriate insertion and maintenance of catheters were employed . RESULTS: During the study period, 2,525 patients were admitted to the ICU . Eight hundred sixty-eight patients had 1,037 CVCs inserted . The number of CVC-related bloodstream infections (BSIs), acquired in the ICU, was 2.7 per 1,000 CVC-days (13 nosocomial CVC-related BSIs during 4,770 days of CVC use) . Microorganisms isolated included methicillin-susceptible Staphylococcus aureus (n = 6), methicillin-resistant S . aureus (n = 2), coagulase-negative methicillin-resistant Staphylococcus (n = 2), Escherichia coli (n = 1), Klebsiella pneumoniae (n = 1), and Enterobacter cloacae (n = 1) . CONCLUSIONS: A low rate of catheter-related BSI was achieved without antimicrobial-impregnated catheters . The incidence of CVC-associated bacteremias corresponded to the 10th to 20th percentile range of the National Nosocomial Infections Surveillance System hospitals for the same type of ICU.

J Eukaryot Microbiol, 2004 Jul-Aug, 51(4), 417 - 24
Co-infection of the macronucleus of Paramecium caudatum by free-living bacteria together with the infectious Holospora obtusa; Fokin SO et al.; Infection experiments were performed incubating Paramecium caudatum with non-infectious free-living bacteria or weakly infectious intracellular bacteria together with the infectious Holospora obtusa . Two of four non-infectious free-living bacteria (Enterobacter aerogenes and Klebsiella pneumoniae) were found to get into the nuclei when added to Paramecium together with H . obtusa . The endonuclear bacterium Nonospora macronucleata that is weakly infectious by itself increases its infectivity when presented together with the infectious holosporas . The results provide evidence that H . obtusa may facilitate entry of other, non-infectious bacteria into the nuclei of Paramecium.

J Hosp Infect, 2004 Sep, 58(1), 63 - 77
Nosocomial and community-acquired Enterobacter cloacae bloodstream infection: risk factors for and prevalence of SHV-12 in multiresistant isolates in a medical centre; Liu CP et al.; In a medical centre in northern Taiwan, 60 patients had bloodstream infection caused by Enterobacter cloacae from 1 January 2002 to 30 April 2003 . Forty (66.7%) were nosocomial and 26 were caused by multiresistant isolates . Twenty patients died due to the infection . Central venous catheterization and mechanical ventilation were relative risks for nosocomial E . cloacae infection . Age and mechanical ventilation were risk factors for multiresistant E . cloacae infection . Mortality was associated with multiresistant isolates and polymicrobial infection . Pulsed-field gel electrophoresis (PFGE) analysis showed, the 26 multiresistant isolates comprised 12 different types, with type A predominating (12 isolates) . Excluding the patients infected with PFGE type A, central venous catheterization was a relative risk for infection, and polymicrobial infection was a risk factor for mortality . All but one of the 26 multiresistant isolates had the extended-spectrum beta-lactamase SHV-12 . TEM-1 and ampC beta-lactamase genes were also detected in 25 of the 26 multiresistant isolates . Southern blotting indicated that the SHV-12 gene was located on plasmids . Eleven of the 26 multiresistant isolates had minimum inhibitory concentrations (MIC) > or =16 mg/L for cefepime, which was reduced by the addition of sulbactam for most isolates, resulting in susceptibility . The combination of cefepime and sulbactam may be effective in the treatment of multiresistant E . cloacae bloodstream infection.

Acta Orthop Traumatol Turc, 2004, 38(3), 195 - 9
{Necrotizing fasciitis in the lower extremity secondary to diabetic wounds}; Demirag B et al.; OBJECTIVES: The aim of this retrospective study was to evaluate patients who developed necrotizing fasciitis (NF) in the lower extremity secondary to diabetic wounds . METHODS: The study included sixteen patients (11 men, 5 women; mean age 63 years; range 50 to 82 years) who were treated for NF arising from diabetic wounds . Associated diseases were coronary heart disease in three patients, and chronic renal failure due to diabetic nephropathy in three patients . The patients were evaluated by physical examination, direct radiographs, blood pressure measurements, and cultures, and with respect to treatment methods and results . The mean hospitalization period was 26 days (range 5 to 59 days) . RESULTS: Necrotizing fasciitis was confined to the leg in four patients, extended to the thigh in 10 patients, and was bilateral in two patients . Pain was encountered in 10 patients (68.8%) . Fourteen patients (87.5%) had increased creatine kinase levels . Direct radiographs showed gas appearance in soft tissues in seven patients (43.8%) . Cultures showed a single microorganism in four patients (25%), and multiple microorganisms in five patients (31.3%) . Of seventeen microorganisms isolated, 10 (58.8%) were Enterobacter species . Eleven patients (68.8%) underwent above-the-knee, and three patients (18.8%) underwent below-the-knee amputations . Disarticulation of the hip was performed in four patients . The mean number of debridements was five (range 2 to 21) following the initial surgical intervention . Nine patients developed septic shock . Seven patients (43.8%) died due to multiple organ failure . Increased creatine kinase levels were significantly associated with mortality (p<0.05) . CONCLUSION: Early and accurate diagnosis and prompt surgical treatment may be life-saving in diabetic patients with NF of the lower extremity.

Microbiology, 2004 Sep, 150(Pt 9), 2947 - 58
Hypermutable Haemophilus influenzae with mutations in mutS are found in cystic fibrosis sputum; Watson ME Jr et al.; Hypermutable bacterial pathogens exist at surprisingly high prevalence and benefit bacterial populations by promoting adaptation to selective environments, including resistance to antibiotics . Five hundred Haemophilus influenzae isolates were screened for an increased frequency of mutation to resistance to rifampicin, nalidixic acid and spectinomycin: of the 14 hypermutable isolates identified, 12 were isolated from cystic fibrosis (CF) sputum . Analysis by enterobacterial repetitive intergenic consensus (ERIC)-PCR and ribotyping identified eight distinct genetic fingerprints . The hypermutable phenotype of seven of the eight unique isolates was associated with polymorphisms in conserved sites of mutS . Four of the mutant mutS alleles were cloned and failed to complement the mutator phenotype of a mutS : : TSTE mutant of H . influenzae strain Rd KW20 . Antibiotic susceptibility testing of the hypermutators identified one beta-lactamase-negative ampicillin-resistant (BLNAR) isolate with two isolates producing beta-lactamase . Six isolates from the same patient with CF, with the same genetic fingerprint, were clonal by multilocus sequence typing (MLST) . In this clone, there was an evolution to higher MIC values for the antibiotics administered to the patient during the period in which the strains were isolated . Hypermutable H . influenzae with mutations in mutS are prevalent, particularly in the CF lung environment, and may be selected for and maintained by antibiotic pressure.

Appl Environ Microbiol, 2004 Sep, 70(9), 5692 - 4
Fluorogenic selective and differential medium for isolation of Enterobacter sakazakii; Oh SW et al.; 4-Methylumbelliferyl-alpha-D-glucoside, the fluorogenic substrate of alpha-glucosidase, was used as a selective marker to develop a differential medium for Enterobacter sakazakii . This bacterium showed strong fluorogenic characteristics clearly distinguishable from other microorganisms . On the basis of reducing background noise, an optimum basal medium and nitrogen source were selected . Incubation conditions were optimized.

Appl Environ Microbiol, 2004 Sep, 70(9), 5628 - 43
Molecular fingerprinting of dairy microbial ecosystems by use of temporal temperature and denaturing gradient gel electrophoresis; Ogier JC et al.; Numerous microorganisms, including bacteria, yeasts, and molds, constitute the complex ecosystem present in milk and fermented dairy products . Our aim was to describe the bacterial ecosystem of various cheeses that differ by production technology and therefore by their bacterial content . For this purpose, we developed a rapid, semisystematic approach based on genetic profiling by temporal temperature gradient electrophoresis (TTGE) for bacteria with low-G+C-content genomes and denaturing gradient gel electrophoresis (DGGE) for those with medium- and high-G+C-content genomes . Bacteria in the unknown ecosystems were assigned an identity by comparison with a comprehensive bacterial reference database of approximately 150 species that included useful dairy microorganisms (lactic acid bacteria), spoilage bacteria (e.g., Pseudomonas and Enterobacteriaceae), and pathogenic bacteria (e.g., Listeria monocytogenes and Staphylococcus aureus) . Our analyses provide a high resolution of bacteria comprising the ecosystems of different commercial cheeses and identify species that could not be discerned by conventional methods; at least two species, belonging to the Halomonas and Pseudoalteromonas genera, are identified for the first time in a dairy ecosystem . Our analyses also reveal a surprising difference in ecosystems of the cheese surface versus those of the interior; the aerobic surface bacteria are generally G+C rich and represent diverse species, while the cheese interior comprises fewer species that are generally low in G+C content . TTGE and DGGE have proven here to be powerful methods to rapidly identify a broad range of bacterial species within dairy products.

Antibiot Khimioter, 2004, 49(3), 6 - 16
{Molecular mechanisms of cephalosporin resistance in Gram-negative bacteria of the Enterobacteriaceae family}; Sidorenko SV et al.; Extended spectrum beta lactamase genes were detected by the PCR in 87.6% of 231 Enterobacteriaceae strains isolated in medical institutions of Moscow, St . Petersburg, Tomsk and Nazran that showed a decrease in their susceptibility to 3rd generation cephalosporins . Alone or in various combinations TEM type beta lactamases were detected in 43.3% of the isolates, 46.8 and 51.2% of the isolates produced SHV type and CTX type beta lactamases respectively . Combinations of 2 and 3 different determinants were detected in 40 and 14% of the isolates respectively . Production of class C beta lactamases was suspected in 28% of the isolates by their resistance to cefoxitin . The gene of ACT type beta lactamase was detected in 1 strain of Klebsiella pneumoniae and the gene of CMY type beta lactamase was detected in 1 strain of Proteus mirabilis . By the NCCLS 100% of the isolates was susceptible to meropenem, 14% was susceptible to cefotaxime, 64% was susceptible to cefepime, 81% was susceptible to cefoperazone/sulbactam, 47% was susceptible to gentamicin, 57% was susceptible to amikacin and 36% was susceptible to ciprofloxacin.

Mar Pollut Bull, 2004 Aug, 49(4), 334 - 43
Bacteriological examination of ballast water in Singapore Harbour by flow cytometry with FISH; Joachimsthal EL et al.; In this study the concentrations of total bacteria, enterobacteria, Vibrio spp., and E . coli have been compared for ballast water samples taken from ships in Singapore Harbour . The cell concentrations were enumerated using FISH and flow cytometry . The data were highly variable, reflecting the many influences upon ballast water as it is utilized in the shipping industry . The concentration of bacterial species was determined as a proportion of the total concentration of cells for the ballast water sampled . For the ballast water sampled these concentrations were 0.67-39.55% for eubacteria, 0-2.46% for enterobacteria, 0.18-35.82% for Vibrio spp., and 0-2.46% for E . coli . Using FISH and flow cytometry, an informative determination of the bacterial hazards of ship ballast water can be made.

Bacteriol Virusol Parazitol Epidemiol, 2003 Apr-Sep, 48(2-3), 107 - 12
{Evaluation of the sensitivity to meropenem of some bacterial strains with nosocomial potential}; Dan L et al.; This study analyzes the sensitivity to meropenem of 880 bacterial strains isolated from hospitalized patients in various medical units of County Hospital No . 1 Timisoara . As a result, a high sensitivity of gram-negative pathogens to meropenem (82.01%) has been noticed . Among Enterobacteriaceae, 93.17% of Escherichia coli and 71% of Klebsiella sp . were susceptible to meropenem . For Pseudomonas aeruginosa strains, a high susceptibility was noticed to meropenem (91%), more than 70% to imipenem, but piperacillin + tazobactam had 42% resistance rates.

Ann Pharmacother, 2004 Oct, 38(10), 1692 - 701 Epub 2004 Aug 31.
Urinary tract infections during pregnancy; Le J et al.; OBJECTIVE: To provide a comprehensive review of urinary tract infections (UTIs) during pregnancy . All aspects of UTIs, including epidemiology, pathogenesis, resistance, clinical features, diagnosis, treatment, and prevention, were reviewed . DATA SOURCES: MEDLINE (1966-August 2003) and Cochrane Library searches were performed using the key search terms urinary tract infection, pyelonephritis, cystitis, asymptomatic bacteriuria, and resistance . STUDY SELECTION AND DATA EXTRACTION: All article abstracts were evaluated for relevance . Only articles pertaining to pregnancy were included . The majority of published literature were review articles; the number of original clinical studies was limited . DATA SYNTHESIS: UTIs are the most common bacterial infections during pregnancy . They are characterized by the presence of significant bacteria anywhere along the urinary tract . Pyelonephritis is the most common severe bacterial infection that can lead to perinatal and maternal complications including premature delivery, infants with low birth weight, fetal mortality, preeclampsia, pregnancy-induced hypertension, anemia, thrombocytopenia, and transient renal insufficiency . Enterobacteriaceae account for 90% of UTIs . The common antibiotics used are nitrofurantoin, cefazolin, cephalexin, ceftriaxone, and gentamicin . CONCLUSIONS: Therapeutic management of UTIs in pregnancy requires proper diagnostic workup and thorough understanding of antimicrobial agents to optimize maternal outcome, ensure safety to the fetus, and prevent complications that lead to significant morbidity and mortality in both the fetus and the mother.

Int Immunol, 2004 Oct, 16(10), 1467 - 75 Epub 2004 Aug 31.
Interaction of endotoxins with Toll-like receptor 4 correlates with their endotoxic potential and may explain the proinflammatory effect of Brucella spp . LPS; Duenas AI et al.; Endotoxins displaying differences in the chemical structure of their lipid A were used to induce the expression of chemokines in the human monocytic THP-1 cell line . LPS from two enterobacterial species such as Escherichia coli and Yersinia enterocolitica induced mRNA expression of IFN-gamma-inducible protein (IP)-10, macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta, monocyte chemoattractant protein (MCP)-1 and IL-8 . LPS from the non-enterobacterial genera Brucella and Ochrobactrum induced the expression of these chemokines to a lower extent . Attempts to address the signaling routes involved in these responses were carried out in transiently transfected HEK293 cells . Induction of kappaB-driven transcriptional activity by enterobacterial LPS was observed in cells transfected with TLR-4 alone, although co-transfection of TLR-4, MD-2 and CD14 provided optimal induction . The response to Brucella spp . and Ochrobactrum anthropi LPS was only significant at the concentration of 10 microg/ml . These data indicate that LPS from Brucella spp . and O . anthropi, which contain lipid A moieties with structural features different from those of Enterobacteriaceae elicit biochemical signaling via TLR-4 only at high concentrations . Neither TLR-1, TLR-2 and TLR-6 nor heterodimeric combinations of these receptor molecules are involved . Conversely, the ability of LPS to activate the TLR-4 route is a reliable molecular biomarker for endotoxicity.

Indian J Exp Biol, 2004 Jul, 42(7), 715 - 20
Isolation and identification of marine chitinolytic bacteria and their potential in antifungal biocontrol; Gohel V et al.; Chitinolytic marine bacterial strains (30) were isolated from the sea dumps at Bhavnagar, India . They were screened as chitinase producers on the basis of zone of clearance on chitin agar plates incorporated with calcofluor white M2R for the better resolution . Out of these, three strains namely, Pseudomonas sp., Pantoea dispersa and Enterobacter amnigenus showed high chitinase production . They were also found to produce proteases and therefore have a good potential for use as antifungal biocontrol agents for the control of fungal plant pathogens . These strains could degrade and utilize the mycelia of Macrophomina phaseoliena (Tassi) Goidanich and Fusarium sp . In vitro, these strains could inhibit the growth of Fusarium sp . and M . phaseolina . The culture filtrate inhibiting hyphal elongation was observed microscopically.

Poult Sci, 2004 Aug, 83(8), 1427 - 32
Microbiological quality of broiler carcasses during processing in two slaughterhouses in Turkey; Goksoy EO et al.; The effect of processing procedures on the microbial quality and safety of broiler carcasses was investigated in 2 processing plants . Neck skin samples were taken from broilers at the main stages of processing and changes in total viable count (TVC) and in the counts of Coliforms, Enterobacteriaceae, and Staphylococci/Micrococci were monitored . Processing reduced TVC more than 2 log cycles for the 2 processing plants investigated . The counts of Coliform bacteria decreased from 5.35 to 3.99 log cfu/g, Enterobacteriaceae from 5.36 to 3.81 log cfu/g, and Staphylococci/Micrococci from 6.90 to 4.11 log cfu/g for the first processing plant . The counts of Coliforms, Enterobacteriaceae, and Staphylococci/Micrococci were reduced from 5.67 to 3.92 log cfu/g, from 5.75 to 3.91 log cfu/g, and from 6.85 to 3.94 log cfu/g, respectively, by processing in the second plant . Cross-contamination with Salmonella spp . during processing was observed and the incidences of Salmonella spp . on the carcasses increased from 40 to 60% and from 33.3 to 40% during processing at plants 1 and 2, respectively . The incidences of Salmonella spp . in all broilers (n = 90 carcasses for each plant) were 36.6 and 31.1% at plants 1 and 2, respectively . Although a high proportion of microorganisms were removed from carcasses during processing, dissemination of Salmonella spp . was found to be unavoidable.

J Food Prot, 2004 Aug, 67(8), 1779 - 81
Microbiological quality of terrestrial gastropods prepared for human consumption; Serrano S et al.; Hygienic quality was investigated in 60 samples of ready-to-eat snails (Helix lactea, Helix nemoralis, and Helix hortensis) obtained from 30 in-season street stalls and 30 catering establishments (bars) in Cordoba . In accordance with Spanish legislation regarding hygiene in the preparation, distribution, and sale of prepared foods, counts were obtained for total mesophilic aerobic bacteria, coliforms, total Enterobacteriaceae, Escherichia coli, Salmonella, and Staphylococcus aureus . The results obtained showed that 33.3, 20.0, and 13.3% of the samples from stalls and 73.3, 53.3, and 6.7% of the samples from bars did not comply with the regulations with respect to the control of total mesophilic aerobic bacteria, Enterobacteriaceae, and Staphylococcus aureus, respectively . Coliforms were found in 53.3% of the samples from the bars (mean, 2.1 CFU/g) and in 33.3% of the stalls (mean, 1.1 CFU/g) . Salmonella was not detected.

Acta Microbiol Pol, 2004, 53(1), 27 - 34
Incidence of extended-spectrum beta-lactamases in clinical isolates of the family Enterobacteriaceae in a pediatric hospital; Halina RK et al.; The incidence of extended-spectrum beta-lactamases (ESBLs) was analyzed in Enterobacteriaceae population circulating in the Upper Silesian Child and Mother Health Center in Katowice (USC&MHC) . Altogether 1164 clinical specimens, collected from children hospitalized in 8 different hospital units of USC&MHC were investigated . Five hundred and eighty-five clinical isolates of the family Enterobacteriaceae were identified in specimens collected from 403 patients . Two hundred and twenty-nine Enterobacteriaceae strains (39%) isolated from 162 patients were found to be putative ESBL producers as revealed by double-disc synergy (DDS) test . ESBL activity was the most prevalent in the population of Klebsiella pneumoniae (77%), followed by Klebsiella oxytoca (50%), Serratia marcescens (43%), Escherichia coli (30%), Enterobacter spp . (18%) and Proteus mirabilis (12%) . ESBL producers demonstrated also wide resistance to the non-beta-lactam antimicrobial co-trimoxazole (93%) and the aminoglycosides netilmicin (88%), gentamicin (84%) and amikacin (79%).

Acta Microbiol Pol, 2004, 53(1), 23 - 6
Molecular epidemiology of antibiotic-resistant Escherichia coli isolated from hospitalized patients with urinary tract infections in Northern Palestine; Adwan K et al.; Eighty isolates of Escherichia coli were collected in Northern Palestine throughout the 1996 to 2000 period from hospitalized patients with urinary tract infections (UTIs) . Resistance rates were ampicillin, 65%; co-trimoxazole, 55%; cefuroxime, 10%; cefotaxime, 7.5%; ceftazidime, 2.5%; ciprofloxacin, 12.5%; gentamicin, 6.25% and amikacin, 1.25% . No imipenem-resistant isolates were identified . To determine whether this was due to intra-hospital transmission of resistant strains, clonal structure of 10 multiple-resistant isolates was examined by genomic DNA fingerprinting by enterobacterial repetitive intergenic concensus-polymerase chain reaction (ERIC-PCR) and all were clonally distinct . Thus, these strains are likely resistant due to convergent acquisition of resistance determinants by genetically unrelated uropathogenic strains rather than epidemic spread of resistant isolates.

Infez Med, 2004 Mar, 12(1), 60 - 4
{Epidemiology of salmonellosis in Caltagirone area (Sicily)}; Bellissima P et al.; The authors report the results of an epidemiological-clinical study concerning episodes of salmonellosis observed in Caltagirone (CT) from 1999 to 2002 and reported to the National Centre for Control of pathogen enterobacteria (enter-net Italy) . Overall, two hundred and forty strains of salmonella were isolated, typed and in vitro tested for susceptibility to eleven different antibiotics . Cases were evaluated according to patients' age, risk factors and clinical findings . Salmonella enteritidis (39%) was the most prevalent serovar followed by S . typhimurium (16%), S . newport (6%), S . salamae (5%) and others . The highest rate of antibiotic resistance was observed in S . typhimurium.

Jpn J Infect Dis, 2004 Aug, 57(4), 146 - 9
Prevalence of clinical strains resistant to various beta-lactams in a tertiary care hospital in India; Datta P et al.; The incidence of infection due to extended spectrum beta-lactamases (ESBLs) producing Enterobacteriaceae has markedly increased in recent years . The traditional susceptibility methods lack sensitivity and/or specificity and this issue has prompted the search for an accurate test to detect the presence of ESBL . The present study included 300 bacterial strains and was undertaken to determine the prevalence of ESBL-producing strains . Here, compared three tests: a double disk synergy test (DDS), a three-dimensional test (3-D), and an inhibitor potentiated disk diffusion test (IPT); each test employed three different antibiotic discs, i.e., ceftazidime, ceftriaxone, and cefotaxime, in order to screen for ESBL strains . A strain was said to be an ESBL producer if it showed positive result(s) on any one of the three tests . The prevalence rate of ESBL in our hospital was 12.6% (38/300) . IPT detected the most strains (34/38), followed by 3-D (23/38), and then DDS (15/38) . The ceftriaxone disc was found to detect more ESBLs than either the ceftazidime or the cefotaxime disc.

Antimicrob Agents Chemother, 2004 Sep, 48(9), 3621 - 4
The AcrAB-TolC pump is involved in macrolide resistance but not in telithromycin efflux in Enterobacter aerogenes and Escherichia coli; Chollet R et al.; The role of the AcrAB-TolC pump in macrolide and ketolide susceptibility in Escherichia coli and Enterobacter aerogenes was studied . Efflux pump inhibitor restored erythromycin, clarithromycin, and telithromycin susceptibilities to multidrug-resistant isolates . No modification of telithromycin accumulation was detected in E . aerogenes acrAB or tolC derivatives compared to that in the parental strain . Two independent efflux pumps, inhibited by phenylalanine arginine beta-naphthylamide, expel macrolides and telithromycin in E . aerogenes.

Antimicrob Agents Chemother, 2004 Sep, 48(9), 3419 - 24
Effect of ertapenem protein binding on killing of bacteria; Nix DE et al.; The effect of protein binding on the antimicrobial activity of ertapenem was evaluated using the bacterial kill rate and concentration-response studies . Various proportions of human serum were utilized to determine the total and free-drug concentrations using a validated high-performance liquid chromatography assay . The MICs and kill curves were determined for test isolates of Enterobacter cloacae and Staphylococcus aureus at various percentages of human serum . The killing of bacteria was analyzed in relation to the free and total concentrations of ertapenem at various proportions of human serum . It was determined that unbound ertapenem was responsible for the antimicrobial activity against the test isolates.

Arch Dis Child Fetal Neonatal Ed, 2004 Sep, 89(5), F440 - 1
Characteristics of breast milk and serology of women donating breast milk to a milk bank; Lindemann PC et al.; OBJECTIVE: Breast milk is the most important nutrient to all newborn babies . If the mother's milk production is insufficient, it is important to provide donor breast milk without reduction of its immunologic and antimicrobial properties . Early use of breast milk to preterm infants has shown a reduced incidence of necrotising enterocolitis, a faster tolerance of enteral feeding, and a reduced need of parenteral nutrition . It is important to have milk from a CMV-IgG negative donor to VLBW infants considered immunocompromised . METHODS: Between January 1st and December 31st 2001, 69 women delivered 1.973 litres (mean 28.6 litres/woman/year) . 73% had college education, were primipara, and with a mean age of 30.7 years . Those who smoked, used alcohol or any medications were refused as donors . They started to deliver approximately 7 weeks after having given birth and continued for a mean of 4 months . Each milk sample was tested for bacterial growth . Every donor was screened for HIV, CMV-IgG and hepatitis B/C before donating milk and thereafter every third month . RESULTS: 62.3% was CMV-IgG positive . Samples containing staphylococcus aureus, klebsialla-, enterobacter- and serratia-species or E . coli, and all samples containing > 10(4) cfu/ml were pasteurised . Overall, only 10.5% of the samples were pasteurised . CONCLUSION: It is possible and important to provide VLBW babies with fresh frozen unpasteurised CMV-IgG negative breast milk until their own mothers' milk production is sufficient.

FEMS Microbiol Lett, 2004 Aug 15, 237(2), 303 - 9
A novel glutamate-dependent acid resistance among strains belonging to the Proteeae tribe of Enterobacteriaceae; Park G et al.; Morganella, Providencia and Proteus strains were capable of surviving pH 2.0 for 1 h if glutamate was present . These strains did not have glutamic acid decarboxylase activity and the gadAB genes were not detected in any of these bacteria . When exposed to pH 2.0 acid shocks, the survival rate of these bacteria was significantly increased with glutamate concentrations as low as 0.3 mM in the acid media . Escherichia coli cells incubated at pH 3.4 consumed four times more glutamate and produced at least 7-fold more gamma-amino butyric acid than Morganella, Providencia and Proteus strains . These results indicate that strains belonging to the Proteeae tribe might have novel glutamate dependent acid-resistance mechanisms.

Med Princ Pract, 2004 Sep-Oct, 13(5), 286 - 9
Growth inhibition of enteric pathogens by zinc sulfate: an in vitro study; Surjawidjaja JE et al.; OBJECTIVE: To determine the inhibition effect of zinc sulfate on isolates of enteric bacteria . MATERIALS AND METHODS: Mueller-Hinton agar containing different concentrations of zinc sulfate was prepared . Isolates used in this study were obtained from local clinics . They were Salmonella typhi, Salmonella groups A, B, C, D and E, Escherichia coli, Enterobacter, Shigella and Vibrio cholerae . Overnight cultures of test organisms in brain-heart infusion broth were adjusted to 0.5 McFarland standard turbidity by adding normal saline with 1 microl of each adjusted broth culture inoculated onto zinc sulfate agar plates . The plates were incubated for 18-20 h at 37 degrees C . The inhibition concentration was recorded as the lowest concentration of zinc sulfate that completely inhibited growth . RESULTS: All enteric pathogens tested were inhibited by zinc sulfate . Of the isolates, S . typhi was most sensitive since 20% of the strains were inhibited by zinc sulfate of 0.8 mg/ml . Salmonella paratyphi A was inhibited at 1.2 mg/ml . Other Salmonella spp . were inhibited at concentrations between 1.4 and 2.0 mg/ml . V . cholerae O1 and Shigella flexneri demonstrated a similar pattern of inhibition as S . paratyphi A . A higher concentration of zinc sulfate (1.6 mg/ml) was required to completely inhibit Shigella sonnei . CONCLUSION: The findings indicate that zinc sulfate has an antimicrobial effect on enteric pathogens and may contribute to the treatment of diarrhea .

J Med Microbiol, 2004 Sep, 53(Pt 9), 875 - 8
Validation of a PCR for diagnosis of typhoid fever and salmonellosis by amplification of the hilA gene in clinical samples from Colombian patients; Sanchez-Jimenez MM et al.; Validation of a PCR test to detect hilA gene sequences of Salmonella spp . was performed in blood and faeces samples from typhoid fever and salmonellosis patients . Sensitivity (S), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) of the PCR in blood samples were performed by testing: 37 patients with clinical diagnosis of typhoid fever, 34 of them confirmed by isolation of S . Typhi from blood cultures; 35 patients infected with other pathogens corroborated by blood culture (Klebsiella pneumoniae, 9; Serratia marcescens, 5; Escherichia coli, 4; Pseudomonas aeruginosa, 9; Providencia alcalifaciens, 4 and Enterobacter cloacae, 4) and blood samples from 150 healthy volunteers . To evaluate S, SP, PPV and NPV of the PCR in faeces samples we studied: 34 patients with enteritis due Salmonella spp . (S . Typhimurium, 21; S . Enteritidis, 9; S . Choleraesuis, 3 and S . Agona, 1); faeces samples from 35 patients with enteric infection due to Shigella sonnei (8), Shigella flexneri (10), enteropathogenic E . coli (12), Aeromonas hydrophila (5) and faeces samples from 150 healthy volunteers . The S, SP, PPV and NPV of the PCR in blood samples were all 100 % . PCR detected three patients with clinical diagnosis of typhoid fever and negative blood cultures . In faeces samples, S was 97 %, SP 100 %, PPV 100 % and NPV 99 % . The lowest number of c.f.u . ml(-1) detected by PCR in blood samples was 1 x 10(1) and in faeces samples 4 x 10(2).

Diagn Microbiol Infect Dis, 2004 Aug, 49(4), 283 - 7
Potency and spectrum reevaluation of cefdinir tested against pathogens causing skin and soft tissue infections: a sample of North American isolates; Sader HS et al.; Cefdinir is a widely used orally administered cephalosporin for community-acquired respiratory tract infections and skin and soft tissue infections (SSTI) . A total of 415 nonduplicate isolates of community-acquired SSTI (CA-SSTI) were collected from medical centers in North America and susceptibility tested against cefdinir and various compounds indicated for the treatment of CA-SSTI . The cefdinir MIC(50/90) in microg/mL/% susceptible for strains of the 7 principal CA-SSTI pathogens were: oxacillin-susceptible Staphylococcus aureus (0.5/0.5/100%), oxacillin-susceptible coagulase-negative staphylococci (0.06/0.12/100%), group A streptococci (< or =0.03/< or =0.03/100%), group B streptococci (< or =0.03/0.06/100%), viridans group streptococci (0.25/2/88%), Klebsiella spp . (0.12/1/95%), and Escherichia coli (0.25/0.5/95%) . Cefdinir was the most potent oral cephalosporin tested against staphylococci and the Enterobacteriaceae species, and 8-fold to 64-fold more potent than cephalexin against these pathogens . Beta-Hemolytic streptococci was highly susceptible to cefdinir (MIC(90), < or =0.03-0.06 microg/mL), while viridans group streptococci showed slightly elevated MIC results . Cephalexin MIC values for streptococcal strains (MIC(90), 1-32 microg/mL) were 32-fold to 64-fold higher than those of cefdinir or other oral cephalosporins evaluated . Only 0.5% of all 415 recent CA-SSTI pathogens were resistant to cefdinir (MIC, > or = 4 mg/L) . Cefdinir showed a spectrum and potency comparable or superior to other orally administered beta-lactams (cephalexin).

Res Microbiol, 2004 Sep, 155(7), 535 - 42
Transcriptional analysis of the acid-inducible asr gene in enterobacteria; Seputiene V et al.; We show here that transcription of the asr gene in Escherichia coli, Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae and Enterobacter cloacae is strongly dependent on the acidification level of the growth medium, with maximal induction at pH 4.0-4.5 as determined by Northern hybridization analysis . Previous gene array analyses have also shown that asr is the most acid-induced gene in the E . coli genome . Sequence alignment of the asr promoters from different enterobacterial species identified a highly conserved region located at position -70 to -30 relative to the asr transcriptional start site . By deletion of various segments of this region in the E . coli asr promoter it was shown that sequences upstream from the -40 position were important for induction . Transcription from the E . coli asr promoter was demonstrated to be growth-phase-dependent and to require the alternative sigma factor RpoS (sigma(S)) in stationary phase . Transcription of the asr gene was also found to be subject to negative control by the nucleoid protein H-NS.

Bioprocess Biosyst Eng, 2004 Oct, 26(5), 325 - 30
Enhanced production of acetoin and butanediol in recombinant Enterobacter aerogenes carrying Vitreoscilla hemoglobin gene; Geckil H et al.; Microbial production of butanediol and acetoin has received increasing interest because of their diverse potential practical uses . Although both products are fermentative in nature, their optimal production requires a low level of oxygen . In this study, the use of a recombinant oxygen uptake system on production of these metabolites was investigated . Enterobacter aerogenes was transformed with a pUC8-based plasmid carrying the gene (vgb) encoding Vitreoscilla (bacterial)hemoglobin (VHb) . The presence of vgb and production of VHb by this strain resulted in an increase in viability from 72 to 96 h in culture, but no overall increase in cell mass . Accumulation of the fermentation products acetoin and butanediol were enhanced (up to 83%) by the presence of vgb/VHb . This vgb/VHb related effect appears to be due to an increase of flux through the acetoin/butanediol pathway, but not at the expense of acid production.

Zhonghua Xue Ye Xue Za Zhi, 2004 Jun, 25(6), 328 - 32
{Epidemiology and drug resistance of the pathogenic microbes in the complicated infection of hematological malignancies}; Shen Y et al.; OBJECTIVE: To investigate the epidemiological characteristics and drug resistance profile of the infection in patients with hematological malignancies . METHODS: All the microbe strains isolated from the department of hematology in Ruijin hospital between 1998 and 2002 were collected for the assessment of antimicrobial susceptibility and the results were analysed by WHONET5 software . RESULTS: Out of the 536 strains isolated in the department of hematology, 230 (42.9%) were Gram positive and 301 (56.2%) Gram negative organisms . The first 6 strains of Gram (-) microbes in frequent order were Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Escheriahia coli, Alinetobacter Baumannii and Stenotrophomonas (xantho) maltophi . The extended spectrum beta-lactamase (ESBLs) producing rates of Escheriahia coli and Klebsiella pneumoniae were 27.3% and 33.3%, respectively . Methylcillin resistant coagulase negative staphylococcus (MRCNS) was the most prevalent Gram (+) bacteria in the complicated infection patients with hematological malignancies, which accounted for 88.5% . Carbapenems were most sensitive for all of the gram negative bacteria, with a drug resistance rate of 11.4 (5.0% approximately 15.8%) of imipenem . For ESBLs strains, carbapenems and cefapime were the best choice, with the resistance rate of 46.4% approximately 94.4% and 50.0% approximately 75.9%, respectively . The drug resistance rate of Alinetobacter Baumannii was 25.0% approximately 41.3% for the third generation cephalosporin, 22.7% for the fourth generation cephalosporin and 12.7% for imipenem . Pseudomonas aeruginosa was resistant to carbapenems, with a resistance rate of 12.7% of imipenem; however, it was more sensitive to the third generation cephalosporin . CONCLUSION: Antibiotics should be rationally administrated with more considerations to the characteristics of epidemiology and drug resistance profile of the microbes in the given department of hematology.

Mol Plant Microbe Interact, 2004 Aug, 17(8), 865 - 71
Changes in gene expression in canola roots induced by ACC-deaminase-containing plant-growth-promoting bacteria; Hontzeas N et al.; The technique of RNA arbitrarily primed-polymerase chain reaction (RAP-PCR) was used to study changes in gene expression over time in canola roots treated with the 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing plant-growth-promoting bacterium Enterobacter cloacae UW4 and to compare the changes with those in a mutant of E . cloacae UW4 in which the ACC deaminase structural gene acdS was replaced by homologous recombination with acdS with an intentional knockout containing a tetracycline resistance gene . Genes that were either up- or down-regulated over a three-day period in canola plants treated with wild-type or mutant bacteria were isolated, cloned, and sequenced; all appeared to have high homology with Arabidopsis thaliana genes . The upregulated genes included a cell division cycle protein 48 homolog and a eukaryotic translation initiation factor 3 subunit 7 gene homolog . The downregulated genes included one encoding a glycine-rich RNA binding protein with a function in RNA processing or binding during ethylene-induced stress, which is expressed only in roots, and another gene thought to be involved in a defense signaling pathway . All RAP-PCR results were verified using Northern blotting . These data, indicate that roots isolated from canola seeds treated with the ACC deaminase-producing E . cloacae UW4 upregulate genes involved in cell division and proliferation but down-regulate stress genes . This data is in agreement with a model in which ACC deaminase-containing plant-growth-promoting bacteria reduce plant stress and induce root elongation and proliferation in plants, largely by lowering ethylene levels.

Biochem Biophys Res Commun, 2004 Aug 6, 320(4), 1365 - 73
Characterization of an Escherichia coli elaC deletion mutant; Schilling O et al.; The elaC gene of Escherichia coli encodes a binuclear zinc phosphodiesterase (ZiPD) . ZiPD homologs from various species act as3' tRNA processing endoribonucleases, and although the homologous gene in Bacillus subtilis is essential for viability {EMBO J . 22(2003) 4534}, the physiological function of E . coli ZiPD has remained enigmatic . In order to investigate the function of E . coli ZiPDwe generated and characterized an E . coli elaC deletion mutant . Surprisingly, the E . coli elaC deletion mutant was viable and had wild-type like growth properties . Microarray-based transcriptional analysis indicated expression of the E . coli elaC gene at basal levels during aerobic growth . The elaC gene deletion had no effect on the expression of genes coding for RNases or amino-acyl tRNA synthetases or any other gene among a total of > 1300 genes probed . 2D-PAGE analysis showed that the elaC mutation, like-wise, had no effect on the proteome . These results strengthen doubts about the involvement of E . coli ZiPD in tRNA maturation and suggest functional diversity within the ZiPD/ElaC1 protein family . In addition to these unexpected features of the E . coli elaC deletion mutant, a sequence comparison of ZiPD (ElaC1) proteins revealed specific regions for either enterobacterial or mammalian ZiPD (ElaC1) proteins.

Clin Microbiol Infect, 2004 Aug, 10(8), 752 - 5
Extended-spectrum beta-lactamase (ESBL) CTX-M-15-producing Escherichia coli and Klebsiella pneumoniae in Sofia, Bulgaria; Markovska R et al.; During a survey of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in Bulgaria in 2001-2002, three isolates from Sofia (two Escherichia coli, one Klebsiella pneumoniae) showed cefotaxime MICs that were decreased in the presence of clavulanate and were 2-8-fold higher than those of ceftazidime . Resistance was transferred to a sensitive recipient strain of E . coli . Both wild-type and transconjugant strains produced a cefotaxime-hydrolysing beta-lactamase of pI 8.8 . Sequencing of the PCR product obtained with oligonucleotide primers binding outside the coding region identified this beta-lactamase as CTX-M-15 . To our knowledge, this is the first report of CTX-M-15 in Bulgaria.

Clin Microbiol Infect, 2004 Aug, 10(8), 724 - 33
Natural antimicrobial susceptibility patterns and biochemical profiles of Leclercia adecarboxylata strains; Stock I et al.; Leclercia adecarboxylata is an opportunistic human pathogen that phenotypically resembles Escherichia coli . The natural susceptibilities of 101 Leclercia strains to 70 antimicrobial agents were investigated . MICs were determined with a microdilution procedure in cation-adjusted Mueller-Hinton broth (all strains) and IsoSensitest broth (some strains) . Natural susceptibility patterns were assessed using German (DIN) standards (when applicable) . In addition, biochemical properties recommended for the phenotypic identification of L . adecarboxylata were evaluated, applying two commercially available identification systems for Enterobacteriaceae and seven conventional tests . L . adecarboxylata strains were naturally sensitive to tetracyclines, aminoglycosides, all but two beta-lactams, quinolones, folate pathway inhibitors, chloramphenicol, nitrofurantoin and azithromycin . They were naturally resistant to penicillin G, oxacillin, erythromycin, roxithromycin, clarithromycin, ketolides, lincosamides, streptogramins, linezolid, glycopeptides, rifampicin, fusidic acid and fosfomycin . There were only minor medium-dependent differences in susceptibility to most antibiotics . Lysine decarboxylase, malonate assimilation and acid production from arabitol and cellobiose, but not from adonitol and sorbitol, allowed definitive separation of L . adecarboxylata from E . coli . The results of this study form a database that can be applied to validate forthcoming antibiotic susceptibility tests of L . adecarboxylata, and might contribute to its reliable identification . Susceptibility patterns did not indicate obvious therapeutic difficulties for treatment of Leclercia infections . Special attention should be paid to biochemically aberrant leclerciae . Apart from biochemical features, fosfomycin susceptibility might be useful to differentiate between L . adecarboxylata and E . coli.

Clin Microbiol Infect, 2004 Aug, 10(8), 709 - 17
Adult bacterial meningitis: aetiology, penicillin susceptibility, risk factors, prognostic factors and guidelines for empirical antibiotic treatment; Meyer CN et al.; Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System . Reduced penicillin susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p < 0.001) . Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases . The notification rate was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p < 0.001) . Cases involving staphylococci, Pseudomonas spp . and Enterobacteriaceae were under-reported . Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin-non-susceptible bacteria were community-acquired . Severe sequelae correlated independently with age, penicillin non-susceptibility, mechanical ventilation and non-transferral to a tertiary hospital (p < 0.05; logistic regression) . Other factors that correlated with severe sequelae by univariate analysis only were inappropriate clinical handling, abnormal consciousness, convulsions and nosocomial infection . Overall, the data indicated that neither age alone, community-acquired infection nor absence of identified risk factors can predict susceptibility to penicillin accurately . Recommendations for empirical antibiotic treatment for ABM should not be based exclusively on clinical notification systems with possible unbalanced under-reporting.

Curr Microbiol, 2004 Aug, 49(2), 84 - 8
Cloning and characterization of a mosquito larvicidal toxin produced during vegetative stage of Bacillus sphaericus 2297; Promdonkoy B et al.; The mosquitocidal toxin 1 (mtx1) gene from genomic DNA of B . sphaericus strain 2297 was cloned and expressed in E . coli . DNA sequencing analysis of the cloned gene revealed a single open reading frame encoding an 870-amino acid polypeptide . Expression level of the full-length gene in E . coli was very low even though strong promoter was used or the gene was expressed as a fusion protein . Expression level was highly improved after the putative leader sequence was deleted, and the truncated gene was expressed as a fusion protein with glutathione S-transferase (GST-tMtx1) . E . coli cells expressing GST-tMtx1 was highly toxic to Culex quinquefasciatus larvae and showed lower toxicity against Anopheles dirus and Aedes aegypti larvae . Enterobacter amnigenus An11, a mosquito larval gut colonizable bacteria, transformed with the cloned gene exhibited mosquito larvicidal activity . Result suggested that there is a potential to develop this protein to be used as an alternative mosquito control agent.

J Clin Microbiol, 2004 Aug, 42(8), 3795 - 8
Assessment of a new selective chromogenic Bacillus cereus group plating medium and use of enterobacterial autoinducer of growth for cultural identification of Bacillus species; Reissbrodt R et al.; A new chromogenic Bacillus cereus group plating medium permits differentiation of pathogenic Bacillus species by colony morphology and color . Probiotic B . cereus mutants were distinguished from wild-type strains by their susceptibilities to penicillin G or cefazolin . The enterobacterial autoinducer increased the sensitivity and the speed of enrichment of B . cereus and B . anthracis spores in serum-supplemented minimal salts medium (based on the standard American Petroleum Institute medium) and buffered peptone water.

J Clin Microbiol, 2004 Aug, 42(8), 3766 - 74
Use of DNA microarrays for rapid genotyping of TEM beta-lactamases that confer resistance; Grimm V et al.; Standard clinical procedures for pathogen resistance identification are laborious and usually require 2 days of cultivation before the resistance can be determined unequivocally . In contrast, clinicians and patients face increasing threats from antibiotic-resistant pathogenic bacteria in terms of their frequencies and levels of resistance . A major class of microbial resistance stems from the occurrence of beta-lactamases, which, if mutated, can cause the severe extended-spectrum beta-lactamase (ESBL) or inhibitor-resistant TEM (IRT) phenotype, which cause resistance to extended-spectrum cephalosporins, monobactams, and beta-lactamase inhibitors . We describe an oligonucleotide microarray for identification of the single nucleotide polymorphisms (SNPs) of 96% of the TEM beta-lactamase variants described to date which are related to the ESBL and/or IRT phenotype . The target DNA, originating from Escherichia coli, Enterobacter cloacae, and Klebsiella pneumoniae cells isolated from clinical samples, was amplified and fluorescently labeled by PCR with consensus primers in the presence of cyanine 5-labeled nucleotides . The total assay, including PCR, hybridization, and image analysis, could be performed in 3.5 h . The microarray results were validated by standard clinical procedures . The microarray outperformed the standard procedures in terms of assay time and the depth of information provided . In conclusion, this array offers an attractive option for the identification and epidemiologic monitoring of TEM beta-lactamases in the routine clinical diagnostic laboratory.

J Clin Microbiol, 2004 Aug, 42(8), 3665 - 9
Recommended test panel for differentiation of Klebsiella species on the basis of a trilateral interlaboratory evaluation of 18 biochemical tests; Hansen DS et al.; Klebsiella pneumoniae and Klebsiella oxytoca are the two most frequently encountered Klebsiella species giving rise to infections in humans, but other Klebsiella species can also be found in clinical specimens: Klebsiella ozaenae, Klebsiella rhinoscleromatis, Klebsiella terrigena, Klebsiella planticola, Klebsiella ornithinolytica, and Enterobacter aerogenes (Klebsiella mobilis) . However, many of these species are indistinguishable by the conventional methods employed routinely in the clinical microbiological laboratory . Several investigators have suggested various additional tests, but as yet there is no standardized test panel for identifying all Klebsiella species and subspecies . In the present study, performed in three national Klebsiella reference laboratories, we have evaluated a test panel consisting of 18 biochemical tests on 242 strains comprising all Klebsiella species and subspecies . The test panel was designed to identify organisms preliminarily identified as belonging to the genus Klebsiella on the basis of conventional methods or automated identification systems . With the described test panel it is possible to find one or more positive test results differentiating any Klebsiella species, except Klebsiella rhinoscleromatis, from its closest relative.

Pediatr Infect Dis J, 2004 Aug, 23(8), 739 - 47
Improvements in nutritional management as a determinant of reduced mortality from community-acquired lower respiratory tract infection in hospitalized children from rural central Africa; Bahwere P et al.; BACKGROUND: In-hospital mortality from lower respiratory tract infections (LTRI) is unacceptably high in developing countries where LTRI are still a leading cause of death . OBJECTIVE: To identify new approaches to reduce in-hospital mortality of LRTI through the improvement of its management . METHODS: The prospectively collected database of children admitted during an 11-year period with LRTI in a pediatric rural hospital in Central Africa was reviewed to determine the predictors of death and to evaluate the impact on mortality of 4 different protocols for the management of malnutrition . RESULTS: During the study period, 859 children were admitted with a nonmeasles severe LRTI . In the 3-year period during which blood cultures were obtained, 29.0% of the children with LRTI were bacteremic, and multiresistant Enterobacteriaceae were recovered in 81.4% of positive blood cultures . Independent predictors of death in children without edema were age <24 months, dehydration and hepatomegaly with adjusted odds ratios (numbers in parentheses, 95% confidence interval) of 3.47 (1.70-7.08), 4.24 (2.11-8.50) and 2.90 (1.43-5.85), respectively . In those with edema, a significantly increased risk of death was noted for girls {4.31 (1.71-10.90)}, in children with z-score of weight to height < or = -3 {5.45 (1.67-17.79)} and when the serum albumin was <16 g/l {2.58 (1.01-6.58)} . The improvement in the management of malnutrition was followed by a reduction of LRTI-related mortality in children with edema from 32.4 to 8.9% (P < 0.001) . In children without edema, the LRTI-related mortality decreased from approximately 12% to 3.5% when their diet was supplemented with micronutrients . CONCLUSION: This study indicates that the improvement of the management of underlying nutritional deficiencies is crucial for the reduction of the high in-hospital case fatality rate associated with severe nonmeasles LRTI . The empiric antibiotic regimen should be modified to cover for multiresistant Enterobacteriaceae.

Appl Environ Microbiol, 2004 Aug, 70(8), 4855 - 63
Biodegradation of chlorpyrifos by enterobacter strain B-14 and its use in bioremediation of contaminated soils; Singh BK et al.; Six chlorpyrifos-degrading bacteria were isolated from an Australian soil and compared by biochemical and molecular methods . The isolates were indistinguishable, and one (strain B-14) was selected for further analysis . This strain showed greatest similarity to members of the order Enterobacteriales and was closest to members of the Enterobacter asburiae group . The ability of the strain to mineralize chlorpyrifos was investigated under different culture conditions, and the strain utilized chlorpyrifos as the sole source of carbon and phosphorus . Studies with ring or uniformly labeled {(14)C}chlorpyrifos in liquid culture demonstrated that the isolate hydrolyzed chlorpyrifos to diethylthiophospshate (DETP) and 3, 5, 6-trichloro-2-pyridinol, and utilized DETP for growth and energy . The isolate was found to possess mono- and diphosphatase activities along with a phosphotriesterase activity . Addition of other sources of carbon (glucose and succinate) resulted in slowing down of the initial rate of degradation of chlorpyrifos . The isolate degraded the DETP-containing organophosphates parathion, diazinon, coumaphos, and isazofos when provided as the sole source of carbon and phosphorus, but not fenamiphos, fonofos, ethoprop, and cadusafos, which have different side chains . Studies of the molecular basis of degradation suggested that the degrading ability could be polygenic and chromosome based . Further studies revealed that the strain possessed a novel phosphotriesterase enzyme system, as the gene coding for this enzyme had a different sequence from the widely studied organophosphate-degrading gene (opd) . The addition of strain B-14 (10(6) cells g(-1)) to soil with a low indigenous population of chlorpyrifos-degrading bacteria treated with 35 mg of chlorpyrifos kg(-1) resulted in a higher degradation rate than was observed in noninoculated soils . These results highlight the potential of this bacterium to be used in the cleanup of contaminated pesticide waste in the environment.

Appl Environ Microbiol, 2004 Aug, 70(8), 4831 - 9
Ecological significance of microdiversity: identical 16S rRNA gene sequences can be found in bacteria with highly divergent genomes and ecophysiologies; Jaspers E et al.; A combination of cultivation-based methods with a molecular biological approach was used to investigate whether planktonic bacteria with identical 16S rRNA gene sequences can represent distinct eco- and genotypes . A set of 11 strains of Brevundimonas alba were isolated from a bacterial freshwater community by conventional plating or by using a liquid most-probable-number (MPN) dilution series . These strains had identical 16S rRNA gene sequences and represented the dominant phylotype in the plateable fraction, as well as in the highest positive dilutions of the MPN series . However, internally transcribed spacer and enterobacterial repetitive intergenic consensus PCR fingerprinting analyses, as well as DNA-DNA hybridization analyses, revealed great genetic diversity among the 11 strains . Each strain utilized a specific combination of 59 carbon substrates, and the niche overlap indices were low, suggesting that each strain occupied a different ecological niche . In dialysis cultures incubated in situ, each strain had a different growth rate and cell yield . We thus demonstrated that the B . alba strains represent distinct populations with genetically determined adaptations and probably occupy different ecological niches . Our results have implications for assessment of the diversity and biogeography of bacteria and increase the perception of natural diversity beyond the level of 16S rRNA gene sequences.

Mikrobiyol Bul, 2004 Jan-Apr, 38(1-2), 9 - 19
{Molecular epidemiology of Stenotrophomonas maltophilia strains isolated from paediatric patients}; Koseoglu O et al.; As alternative regimens in therapy of Stenotrophomonas maltophilia infections are limited, epidemiological investigation of S . maltophilia is necessary for developing new strategies in prophylaxis of these infections . "Enterobacterial repetetive intergenic consensus-polymerase chain reaction (ERIC-PCR)", is a simple and rapid method to detect the genomic polymorphism at the strain level in nosocomial outbreaks due to S . maltophilia . The aim of this study was to investigate the molecular epidemiology of S . maltophilia strains isolated from paediatric patients in a university hospital . A total of 40 clinical isolates one from each of 35 patients, two pairs from two patients and one from an environmental source, were collected between 1998-2001 period . Susceptibility to eleven antimicrobials was studied by agar dilution test according to NCCLS criteria . Resistance rates of the tested isolates against piperacillin, piperacillin-tazobactam, ceftriaxone, ceftazidime, cefepime, ciprofloxacin, imipenem, meropenem, amikacin, gentamicin and trimethoprim-sulfamethoxazole were 57.5%, 25%, 85%, 37.5%, 47.5%, 20%, 100%, 95%, 62.5%, 62.5% and 5%, respectively . Trimethoprim-sulfamethoxazole was the most active agent against the tested isolates . The isolates were analyzed by ERIC-PCR by using each of ERIC-I and ERIC-II primers . Genotypic analysis by ERIC-PCR identified 24 different major and 4 minor profiles . Three isolates from each of four different groups, two isolates from each of other four different groups were unique . The results of this study, revealing a great genomic diversity and low clonality within the strains of S . maltophilia strains suggest that patients may be colonized with the naturally occuring isolates in the hospital environment and then get infected with these strains under the selective antibiotic pressure, thus supporting the view that clonal spread of S . maltophilia strains between patients is of rather low possibility.

Int J Med Microbiol, 2004 Jul, 294(1), 7 - 14
The omptin family of enterobacterial surface proteases/adhesins: from housekeeping in Escherichia coli to systemic spread of Yersinia pestis; Kukkonen M et al.; The omptins are a family of enterobacterial surface proteases/adhesins that share high sequence identity and a conserved beta-barrel fold in the outer membrane . The omptins are multifunctional, and the individual omptins exhibit differing virulence-associated functions . The Pla plasminogen activator of Yersinia pestis contributes by several mechanisms to bacterial invasiveness and the systemic, uncontrolled proteolysis in plague . Pla proteolytically activates the human proenzyme plasminogen and inactivates the antiprotease alpha2-antiplasmin, and its binding to laminin localizes the uncontrolled plasmin activity onto basement membranes . These properties enhance bacterial migration through tissue barriers . Pla also degrades circulating complement proteins and functions in bacterial invasion into human epithelial cells . PgtE of Salmonella enterica and OmpT of Escherichia coli have been shown to degrade cationic antimicrobial peptides from epithelial cells or macrophages . PgtE and SopA of Shigella flexneri appear important in the intracellular phases of salmonellosis and shigellosis, whereas functions of OmpT have mainly been associated with protein degradation in E . coli cells . The differing virulence roles and functions have been attributed to minor sequence variations at the surface-exposed regions important for substrate recognition, to the dependence of omptin functions on lipopolysaccharide, and to the different regulation of omptin expression.

Int J Antimicrob Agents, 2004 Aug, 24(2), 130 - 4
Evaluation of genetic determinants involved in beta-lactam- and multiresistance in a surgical ICU; van Loon HJ et al.; Antibiotic resistance is a major and well-known problem in intensive care units (ICUs) world-wide and previously susceptible isolates become resistant through the acquisition of resistance determinants from other bacteria or the development of mutations, as is the case in beta-lactam resistance . We evaluated the presence of resistance determinants involved in beta-lactam resistance and multi-resistance in order to establish the contribution of horizontal gene transfer to the spread of resistance in a surgical ICU during an antibiotic rotation study . Pseudomonas aeruginosa and Enterobacteriaceae isolates were selected and iso-electric focusing (IEF), DNA-typing methods such as specific beta-lactamase and specific integron PCRs were performed to determine the presence of beta-lactamases . The PCRs specific for IMP-1, OXA-1, and VIM-type beta-lactamases performed on the selected P . aeruginosa and Enterobacteriaceae isolates with MICs for cephalosporins >1 mg/l did not demonstrate any of these beta-lactamases . IEF for 14 pseudomonads, representing 7 genotypes from 9 patients, showed a beta-lactamase with a pI larger than 8.5 in 13 of the isolates . The integrase PCR was positive for only five isolates from three patients and conserved segment PCR showed integrons of variable sizes (700, 900, 1,400 and 1,500 bp) . Each patient had its own integron types . It can be concluded that integrons and associated resistance determinants played only a minor role in the surgical ICU and beta-lactam resistance among P . aeruginosa isolates was most likely due to the derepression of its AmpC gene.

Int J Antimicrob Agents, 2004 Aug, 24(2), 119 - 24
Determining incidence of extended spectrum beta-lactamase producing Enterobacteriaceae, vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus in 38 centres from 17 countries: the PEARLS study 2001-2002; Bouchillon SK et al.; The PEARLS study prospectively monitored selected nosocomial pathogens from 38 centres in 13 European, three Middle Eastern countries and South Africa during 2001-2002 . Extended spectrum beta-lactamase (ESBL) production rates among Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp . were 5.4% (142/2609), 18.2% (401/2,206) and 8.8% (204/2,328), respectively, for all study sites . The overall ESBL production rate for the combined Enterobacteriaceae was 10.5% (747/7,143), highest in Egypt, 38.5%, and Greece, 27.4%, and lowest in The Netherlands, 2.0%, and Germany, 2.6% . IEF, PCR and DNA sequencing determined 10.7% false positives among Enterobacter spp . when using NCCLS guidelines to screen for ESBL production . The prevalence of nosocomial methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium was 32.4% (294/908) and 8.7% (83/949), respectively . PEARLS provides baseline data against which prospective changes in resistant determinants and outcomes can be measured in this ongoing study.

Int J Antimicrob Agents, 2004 Aug, 24(2), 111 - 8
Assessment of pathogen occurrences and resistance profiles among infected patients in the intensive care unit: report from the SENTRY Antimicrobial Surveillance Program (North America, 2001); Streit JM et al.; Originating from 25 selected intensive care units (ICUs) in North America, a total of 1,321 bacterial strains from blood, respiratory tract, urine and wound sites were processed at a central laboratory as part of the SENTRY Antimicrobial Surveillance Program (2001) to assess their occurrence rates and antimicrobial susceptibility profiles . The rank order of pathogens recovered was Staphylococcus aureus (24.1%), Pseudomonas aeruginosa (12.2%), Escherichia coli (10.1%), Klebsiella spp . (8.9%), Enterococcus spp . (7.2%), coagulase-negative staphylococci (7.0%) and Enterobacter spp . (7.0%) . Although oxacillin resistance among S . aureus was 51.4%, no resistance was detected to vancomycin, linezolid and quinupristin/dalfopristin . The most active agents tested against P . aeruginosa were amikacin, cefepime, tobramycin, meropenem and piperacillin/tazobactam (3.1-13.0% resistance) . Among agents tested against the Enterobacteriaceae, amikacin, cefepime, imipenem and meropenem showed greatest in vitro activity (0.0-3.4% resistance) . Extended-spectrum beta-lactamase-producing phenotype rates were 11.2 and 16.2% in E . coli and Klebsiella spp., respectively . Linezolid was most active against enterococci (1.1% resistance; G2576U ribosomal mutation) whereas 28.4% of isolates were resistant to vancomycin . Cefepime and the carbapenems (imipenem or meropenem) for Gram-negative isolates and linezolid for Gram-positive isolates, provided the broadest spectrum of in vitro activity against contemporary ICU pathogens in North America.

J AOAC Int, 2004 May-Jun, 87(3), 604 - 13
A medium for the presumptive detection of Enterobacter sakazakii in infant formula: interlaboratory study; Leuschner RG et al.; A standard method for the detection of Enterobacteriaceae was modified for the presumptive detection of Enterobacter sakazakii, and the modified method was validated in an interlaboratory trial with 16 laboratories from 8 European countries . The modification included a differential-elective medium for the isolation of E . sakazakii, consisting of nutrient agar (NA) supplemented with 4-methyl-umbelliferyl alpha-D-glucoside (alpha-MUG) . A 25 g sample was added to 225 mL buffered peptone water . After incubation at 35 degrees or 37 degrees C for 16 or 20 h, 10 mL nonselective enrichment was transferred into 90 mL selective enrichment . The selective enrichment was streaked on violet-red bile glucose agar (VRBGA) and incubated at 37 degrees C for 24 h . It was streaked in parallel on NA plates supplemented with alpha-MUG at 50 mg/L and incubated at 25 degrees C for 16 h, and afterwards for an additional 24 h at room temperature in the dark . E . sakazakii appeared as vivid yellow colonies under normal light and showed blue/violet fluorescence under UV light on NA + alpha-MUG plates . Validation samples represented powdered infant formula without E . sakazakii (blanks) and with low (1-10 colony-forming units {CFU}/25 g) and medium (1-10 CFU/g) contamination levels . All samples contained Pseudomonas aeruginosa and Lactobacillus spp . as background flora . The specificity for blank samples was 100% . The sensitivity of the low contamination level was similar for VRBGA and NA + alpha-MUG, i.e., 66.7% (66.7% accordance, 53.9% concordance) . For the medium level the sensitivities were 96.7% (93.3% accordance, 93.5% concordance) for VRBGA and 98.3% (96.9% accordance, 96.9% concordance) for NA + alpha-MUG.

Crit Rev Oral Biol Med, 2004 Jul 01, 15(4), 207 - 20
Chemotaxis-guided movements in bacteria; Lux R et al.; Motile bacteria often use sophisticated chemotaxis signaling systems to direct their movements . In general, bacterial chemotactic signal transduction pathways have three basic elements: (1) signal reception by bacterial chemoreceptors located on the membrane; (2) signal transduction to relay the signals from membrane receptors to the motor; and (3) signal adaptation to desensitize the initial signal input . The chemotaxis proteins involved in these signal transduction pathways have been identified and extensively studied, especially in the enterobacteria Escherichia coli and Salmonella enterica serovar typhimurium . Chemotaxis-guided bacterial movements enable bacteria to adapt better to their natural habitats via moving toward favorable conditions and away from hostile surroundings . A variety of oral microbes exhibits motility and chemotaxis, behaviors that may play important roles in bacterial survival and pathogenesis in the oral cavity.

Prikl Biokhim Mikrobiol, 2004 May-Jun, 40(3), 288 - 95
Cloning and expression of the Vitreoscilla hemoglobin gene in Enterobacter aerogenes: effect on cell growth and oxygen uptake; Erendler SO et al.; The hemoglobins found in unicellular organisms show a greater chemical reactivity, protect cells against oxidative stress and hence have been implicated in a wider variety of potential functions than those traditionally associated with animal and plant hemoglobins . There are well-documented studies showing that bacteria expressing Vitreoscilla hemoglobin (VHb), the first prokaryotic hemoglobin characterized, have better growth and oxygen uptake rates than VHb counterparts.

Biochemistry, 2004 Aug 3, 43(30), 9664 - 73
Thermodynamic evaluation of a covalently bonded transition state analogue inhibitor: inhibition of beta-lactamases by phosphonates; Nagarajan R et al.; Serine beta-lactamases are inhibited by phosphonate monoesters in a reaction that involves phosphonylation of the active site serine residue . This reaction is much more rapid than the hydrolysis of these inhibitors in solution under the same conditions . The beta-lactamase active site therefore must have the ability to stabilize not only the anionic tetrahedral transition states of the acyl transfer reactions of substrates but also the pentacoordinated transition state(s) of phosphyl transfer reactions . A series of p-nitrophenyl arylphosphonates have been synthesized and the rate constants for their inhibition of the class C beta-lactamase of Enterobacter cloacae P99 determined . There is no direct correlation between these rate constants and the dissociation constants of analogous aryl boronic acids, where the latter are believed to generate good tetrahedral transition state analogue structures . Thus, the mode of stabilization of pentacoordinated phosphorus transition states by the beta-lactamase active site is qualitatively different from that of tetrahedral transition states . Molecular modeling suggests that the difference arises from different positioning of the side chain and of one of the oxygen ligands . In principle, the quality of the stable tetrahedral phosphonate complex as a transition state analogue structure can be assessed from the effect of its formation on the stability of the protein . Phosphonylation of the P99 beta-lactamase, however, had little effect on the stability of the protein, as measured both by thermal and guanidine hydrochloride denaturation . Consideration of the results of similar experiments with the Staphylococcus aureus PC1 beta-lactamase, where considerable stabilization is observed in thermal melting and, to a lesser degree, in formation of the molten globule in guanidine hydrochloride, but not in the complete unfolding transition in guanidine, suggests that results from the method may be strongly influenced by the interactions of the ligand with its environment in the unfolded state of the protein . Thus, quantitative estimates of the quality of a covalently bonded transition state analogue cannot generally be achieved by this method.

Antimicrob Agents Chemother, 2004 Aug, 48(8), 3159 - 61
High prevalence of extended-spectrum beta-lactamase-producing strains among blood isolates of Enterobacter spp . collected in a tertiary hospital during an 8-year period and their antimicrobial susceptibility patterns; Pai H et al.; Of 72 blood isolates of Enterobacter spp . collected over an 8-year period, 50% (36 of 72) were derepressed or partially derepressed AmpC mutants . The extended-spectrum beta-lactamase (ESBL) production rate was 43% (31 of 72 isolates), and 67.3% (31 of 46) of extended-spectrum cephalosporin-resistant strains produced ESBLs . Thus, a confirmatory test for ESBL production is necessary for extended-spectrum cephalosporin-resistant Enterobacter spp.

J Med Microbiol, 2004 Aug, 53(Pt 8), 735 - 40
Lipopolysaccharides of Bacteroides fragilis, Chlamydia trachomatis and Pseudomonas aeruginosa signal via toll-like receptor 2; Erridge C et al.; Recognition of bacterial lipopolysaccharide (LPS) is critical in the host defence against Gram-negative infection . While enterobacterial LPS signals via Toll-like receptor 4 (TLR4), it has recently been reported that the LPS of Leptospira interrogans, Legionella pneumophila, Rhizobium species Sin-1 and at least one strain of Porphyromonas gingivalis are capable of signalling via TLR2 . Using a TLR transfection assay and measurement of an NF-kappaB-sensitive promoter region, the results show that the LPS of Bacteroides fragilis NCTC-9343, Chlamydia trachomatis LGV-1 and Pseudomonas aeruginosa PAC-611 also signal via TLR2 and it is pointed out that all TLR2-signalling LPS discovered to date demonstrate relatively weak endotoxicity in some models and structural features distinct from those LPS shown to signal via TLR4 .

J Food Prot, 2004 Jul, 67(7), 1494 - 6
Determination of the principal points of product contamination during beef carcass dressing processes in Northern Ireland; Madden RH et al.; To determine the principal points of microbial contamination of carcasses during beef carcass dressing in Northern Ireland, 190 carcasses were sampled by swabbing 1,000 cm2 of the brisket . A detailed survey of one abattoir was initially conducted, with sampling of a total of 100 carcasses immediately after hide removal (H), after carcass splitting (S), and immediately after washing (W) before dispatch to the chiller . The total bacterial counts after incubation at both 22 and 37 degrees C indicated that there was no significant increase in the numbers of bacteria after the first sampling point, H (P > 0.05) . To determine whether this was the case in the majority of Northern Ireland abattoirs, 15 carcasses were then sampled at each of an additional six abattoirs, at points H and W only . Total bacterial counts were significantly higher (P < 0.05) at H than at W, indicating that hide pulling was the major point of bacterial contamination of beef carcasses and hence a critical control point for the final microbiological quality of the carcasses . Mean counts of Enterobacteriaceae at both incubation temperatures were very low (< 10 CFU/cm2) but were higher at W than at H, probably indicating that washing was redistributing bacteria from the posterior to the anterior region.

Am J Ther, 2004 Jul-Aug, 11(4), 251 - 7
Bacteremia in veterans administration nursing home patients; Khayr WF et al.; The objective of this study was to identify differences between nursing home (NH) and nonnursing home (non-NH) patients with bacteremia regarding host risk factors, exposures, microbiology, and outcome . Between October 1995 and February 1998, 134 episodes of true bacteremia were identified at the North Chicago Veterans Administration Medical Center (NCVAMC) . Seventy-eight episodes of bacteremia occurred in NH patients who stayed for at least 3 months in the NH at the NCVAMC and developed bacteremia there or 48 hours after admission to the acute care hospital (ACH) . Fifty-six episodes occurred in the non-NH patients who developed bacteremia in the community or 48 hours after admission to the ACH . NH patients were more likely to be older than 65 years (88% vs . 71%, P = 0.0334) and to have pressure sores (25% vs . 5%, P = 0.005), urinary incontinence (42% vs . 27%, P = 0.0471), and mental illness (62% vs . 29%, P = 0.0001) than non-NH patients . Coagulase-negative Staphylococcus and Escherichia coli were the most common causes of bacteremia occurring as frequently in both groups . Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and enterococcal bacteremia were comparable, whereas vancomycin-resistant enterococci, ceftazidime-resistant E . coli, Klebsiella pneumoniae, and Enterobacter were rarely isolated . Twelve (15%) NH patients died within 2 weeks of acquiring bacteremia compared with 4 (7%) non-NH patients (P = 0.1176) . For ACH-acquired cases, 20 NH patients were similar to 26 non-NH patients with regard to hospital stay; exposure to antibiotics, steroids, intensive care setting, surgery, tube feeding, and urinary and vascular catheters prior to bacteremia . Although NH and non-NH patients with bacteremia have different host characteristics, they have similar in-hospital exposures, distribution of infecting organisms, and outcome.

Transfusion, 2004 Aug, 44(8), 1174 - 8
Validation of BacT/ALERT plastic culture bottles for use in testing of whole-blood-derived leukoreduced platelet-rich-plasma-derived platelets; Brecher ME et al.; BACKGROUND: Bacterial detection of platelet (PLT)-rich-plasma (PRP)-derived PLTs presents unique challenges for countries that do not allow pooling before storage . This study validated the BacT/ALERT for use in testing pooled PRP-derived PLTs with nine contaminating organisms . STUDY DESIGN AND METHODS: Isolates of Bacillus cereus, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, Streptococcus viridans, and Propionibacterium acnes were inoculated into two PRP-derived PLT pools (target, 10 and 100 colony-forming units {CFUs}/mL; actual recovered concentrations, 5 and 90 CFUs/mL) . Four milliliters of each postbacterial inoculation sample was inoculated into both plastic aerobic and anaerobic bottles and 0.5 mL was plated onto blood agar . RESULTS: All organisms (excluding P . acnes) were detected in 8.2 to 22.0 and 7.6 to 20.3 hours (10 and 100 CFUs/mL, respectively) and the mean time to detection was 15.0 and 13.1 hours (10 and 100 CFUs/mL, respective) . P . acnes was detected with the anaerobic bottles in a mean of 74.9 and 64.3 hours (10 and 100 CFUs/mL, respectively) . With E . cloacae, E . coli, K . pneumoniae, S . marcescens, and S . viridans detection with the anaerobic bottles was faster or equivalent to the detection with the aerobic bottles . This was most notable with S . viridans where the anaerobic bottle was reactive on average 21.6 and 10.8 hours (10 and 100 CFUs/mL, respectively) faster than the aerobic bottle . CONCLUSIONS: This study validates the use of the BacT/ALERT system for the detection of bacteria in PRP-derived PLTs in a pooled format . Overall, the use of the BacT/ALERT system allowed the detection of pooled PRP-derived PLTs inoculated with nine bacteria at 10 and 100 CFUs per mL in 7.6 to 22.0 hours (excluding P . acnes).

Proc Natl Acad Sci U S A, 2004 Jul 27, 101(30), 11105 - 10 Epub 2004 Jul 19.
Genome sequence of the enterobacterial phytopathogen Erwinia carotovora subsp . atroseptica and characterization of virulence factors; Bell KS et al.; The bacterial family Enterobacteriaceae is notable for its well studied human pathogens, including Salmonella, Yersinia, Shigella, and Escherichia spp . However, it also contains several plant pathogens . We report the genome sequence of a plant pathogenic enterobacterium, Erwinia carotovora subsp . atroseptica (Eca) strain SCRI1043, the causative agent of soft rot and blackleg potato diseases . Approximately 33% of Eca genes are not shared with sequenced enterobacterial human pathogens, including some predicted to facilitate unexpected metabolic traits, such as nitrogen fixation and opine catabolism . This proportion of genes also contains an overrepresentation of pathogenicity determinants, including possible horizontally acquired gene clusters for putative type IV secretion and polyketide phytotoxin synthesis . To investigate whether these gene clusters play a role in the disease process, an arrayed set of insertional mutants was generated, and mutations were identified . Plant bioassays showed that these mutants were significantly reduced in virulence, demonstrating both the presence of novel pathogenicity determinants in Eca, and the impact of functional genomics in expanding our understanding of phytopathogenicity in the Enterobacteriaceae.

J Bacteriol, 2004 Aug, 186(15), 5116 - 28
Cloning Serratia entomophila antifeeding genes--a putative defective prophage active against the grass grub Costelytra zealandica; Hurst MR et al.; Serratia entomophila and Serratia proteamaculans (Enterobacteriaceae) cause amber disease in the grass grub Costelytra zealandica (Coleoptera: Scarabaeidae), an important pasture pest in New Zealand . Larval disease symptoms include cessation of feeding, clearance of the gut, amber coloration, and eventual death . A 155-kb plasmid, pADAP, carries the genes sepA, sepB, and sepC, which are essential for production of amber disease symptoms . Transposon insertions in any of the sep genes in pADAP abolish gut clearance but not cessation of feeding, indicating the presence of an antifeeding gene(s) elsewhere on pADAP . Based on deletion analysis of pADAP and subsequent sequence data, a 47-kb clone was constructed, which when placed in either an Escherichia coli or a Serratia background exerted strong antifeeding activity and often led to rapid death of the infected grass grub larvae . Sequence data show that the antifeeding component is part of a large gene cluster that may form a defective prophage and that six potential members of this prophage are present in Photorhabdus luminescens subsp . laumondii TTO1, a species which also has sep gene homologues.

Mol Genet Genomics, 2004 Jul, 271(6), 717 - 28 Epub 2004 Jun 15.
The genes and enzymes for the catabolism of galactitol, D-tagatose, and related carbohydrates in Klebsiella oxytoca M5a1 and other enteric bacteria display convergent evolution; Shakeri-Garakani A et al.; Enteric bacteria (Enteriobacteriaceae) carry on their single chromosome about 4000 genes that all strains have in common (referred to here as "obligatory genes"), and up to 1300 "facultative" genes that vary from strain to strain and from species to species . In closely related species, obligatory and facultative genes are orthologous genes that are found at similar loci . We have analyzed a set of facultative genes involved in the degradation of the carbohydrates galactitol, D-tagatose, D-galactosamine and N-acetyl-galactosamine in various pathogenic and non-pathogenic strains of these bacteria . The four carbohydrates are transported into the cell by phosphotransferase (PTS) uptake systems, and are metabolized by closely related or even identical catabolic enzymes via pathways that share several intermediates . In about 60% of Escherichia coli strains the genes for galactitol degradation map to a gat operon at 46.8 min . In strains of Salmonella enterica, Klebsiella pneumoniae and K . oxytoca, the corresponding gat genes, although orthologous to their E . coli counterparts, are found at 70.7 min, clustered in a regulon together with three tag genes for the degradation of D-tagatose, an isomer of D-fructose . In contrast, in all the E . coli strains tested, this chromosomal site was found to be occupied by an aga/kba gene cluster for the degradation of D-galactosamine and N-acetyl-galactosamine . The aga/kba and the tag genes were paralogous either to the gat cluster or to the fru genes for degradation of D-fructose . Finally, in more then 90% of strains of both Klebsiella species, and in about 5% of the E . coli strains, two operons were found at 46.8 min that comprise paralogous genes for catabolism of the isomers D-arabinitol (genes atl or dal) and ribitol (genes rtl or rbt) . In these strains gat genes were invariably absent from this location, and they were totally absent in S . enterica . These results strongly indicate that these various gene clusters and metabolic pathways have been subject to convergent evolution among the Enterobacteriaceae . This apparently involved recent horizontal gene transfer and recombination events, as indicated by major chromosomal rearrangements found in their immediate vicinity.

Indian J Exp Biol, 2003 Apr, 41(4), 363 - 6
Antidiarrhoeal effects of methanolic root extract of Hemidesmus indicus (Indian sarsaparilla)--an in vitro and in vivo study; Das S et al.; Methanolic extract of H . indicus root (MHI) was screened for its antimicrobial activity against S . typhimurium, E . coli and S . flexneri, in vitro and in experimentally induced diarrhoea in albino rats, in vivo . MHI had an anti enterobacteriae effect as evident from agar well diffusion method and decrease in CFU/ml in MHI treated LB broth culture . MHI inhibited the castor oil induced diarrhoea in rats as judged by a decrease in the amount of wet faeces in MHI-pretreated rats at a dose of 500-1500 mg/kg . The results indicated that MHI was more active than standard antidiarrhoeal drug, lomotil . Phytochemical tests revealed the main constituents as tannins, steroids, triterpenoids and carbohydrates . Present findings suggested that MHI might elicit an antidiarrhoeal effect by inhibition of intestinal motility and by its bacteriocidal activity.

Bull Soc Pathol Exot, 2004 May, 97(2), 131 - 4
{Comparative study of neonatal bacterial meningitis in Lomé, Bobo-Dioulasso, Casablanca and Lyon}; Balaka B et al.; Bacterial meningitis in new-borns remains a serious event because of its high mortality and morbidity rates in Africa . OBJECTIVE: To identify the clinical and bacteriological epidemiology and the outcome of neonatal bacterial meningitis in three African cities . METHOD: We have analysed and compared three hospital studies done in humid tropical, Sahelian, and desert Africa with a European study . RESULTS: Compared with the European study this African study is characterized by a high mean frequency of neonatal meningitis (6 cases per year against 1.4), more important risk factors linked to pregnancy and childbirth (50% against 33%), high rates of death (61 to 68% against 5%) and sequelae (25 to 40% against 30%), rarity of Streptococcus agalactiae (7 to 15% against 38%) and absence of Listeria . Enterobacteriaceae were predominant both in African (50 to 68%) and European (43%) studies . E . coli appeared as the most frequent germ in both European and African studies and Salmonella as more frequent in Sub-Saharan Africa than in occidental countries . CONCLUSION: The epidemiological, bacteriological and evolutional aspects of the neonatal meningitis were identical in the three African cities . The African studies were different from the European only by their high incidence, the rarity of S . agalactiae and Listeria and the difficulties of bacterial diagnosis and management, all might explain the high rates of death and sequelae . An epidemiological survey and adequate antimicrobial therapy according to antibiotic susceptibility may improve the outcome.

Bull Soc Pathol Exot, 2004 May, 97(2), 97 - 9
{Neonatal septicaemia: bacteriological aspects and outcome in the university hospital center of Lome}; Balaka B et al.; Despite the progress in neonatal intensive care and antibiotics, the neonatal septicaemia remains very frequent and lethal in tropical areas . OBJECTIVE: To study the bacteriology and outcome of the neonatal septicaemia through an analysis of 50 confirmed cases . METHODS: Every child aged of less than 29 days, suspected of infection and with at least one positive blood culture has been included . His perinatal antecedents, clinical features, bacteriological findings, treatments and clinical outcome have been collected . The patients have been divided into 3 groups in regard to the postnatal age at the first positive blood culture: before 48 hours, between 3 and 7 days and after 7 days of life . RESULTS: The neonatal septicaemia occurred in 50% of the cases before 48 hours, 24% from the 2nd to the 7th day and 26% from the 8th to the 28th day of life . Enterobacteriaceae (54%) with E . coli predominant (30%) and S . aureus (28%) were the most frequent germs and particularly during the first week of life: 20/27 and 11/14 respectively . The resistance to the association of ampicillin or amoxicillin and gentamicin was 70% for Enterobacteriaceae and 71% for Staphylococci . The lethality was 36% with an excess of lethality for S . aureus (43%) . CONCLUSION: The high rates of frequency and lethality of the neonatal septicaemia in tropical areas require a perinatal care improvement to reduce its morbidity and mortality.

Res Microbiol, 2004 Jul-Aug, 155(6), 409 - 21
Characteristics, epidemiology and clinical importance of emerging strains of Gram-negative bacilli producing extended-spectrum beta-lactamases; Shah AA et al.; Beta-lactam antimicrobial agents represent the most common treatment for bacterial infections and continue to be the leading cause of resistance to beta-lactam antibiotics among Gram-negative bacteria worldwide . The persistent exposure of bacterial strains to a multitude of beta-lactams has induced dynamic and continuous production and mutation of beta-lactamases in these bacteria, expanding their activity even against the newly developed beta-lactam antibiotics . These enzymes are known as extended-spectrum beta-lactamases (ESBLs) . The majority of ESBLs are derived from the widespread broad-spectrum beta-lactamases TEM-1 and SHV-1 . There are also new families of ESBLs, including the CTX-M and OXA-type enzymes as well as novel unrelated beta-lactamases . In recent years, there has been an increased incidence and prevalence of ESBLs . ESBLs are mainly found in strains of Escherichia coli and Klebsiella pneumoniae but have also been reported in other Enterobacteriaceae strains and Pseudomonas aeruginosa . Infections with ESBL-producing bacterial strains are encountered singly or in outbreaks, especially in critical care units in hospitals, resulting in increasing cost of treatment and prolonged hospital stays . Not only may nursing home patients be an important reservoir of ESBL-containing multiple antibiotic-resistant organisms, but ambulatory patients with chronic conditions may also harbor ESBL-producing organisms.

Int J Food Microbiol, 2004 Aug 1, 94(3), 269 - 78
Isolation, identification and characterisation of the dominant microorganisms of kule naoto: the Maasai traditional fermented milk in Kenya; Mathara JM et al.; From 22 samples of kule naoto, the traditional fermented milk products of the Maasai in Kenya, 300 lactic acid bacterial strains were isolated and phenotypically characterised by their ability to ferment different carbohydrates and by additional biochemical tests . Lactic acid bacteria (LAB), especially the genus Lactobacillus, followed by Enterococcus, Lactococcus and Leuconostoc, dominated the microflora of these samples . The major Lactobacillus species was Lactobacillus plantarum (60%), with a lower frequency of isolation for Lactobacillus fermentum, Lactobacillus paracasei and Lactobacillus acidophilus . Most strains produced enzymes such as beta-galactosidase and peptidases, which are of relevance to cultured dairy product processing, and exhibited similar patterns of enzymatic activity between species . Enterobacteriaceae could not be detected in 15 out of 22 samples (detection level 10(2)/ml) . Conversely, yeasts (detection level 10(1)/ml) were detected in those samples in which Enterobacteriaceae were not found . The pH values of all these samples were < 4.5.

Acta Paediatr, 2004 Jun, 93(6), 825 - 9
Intestinal microflora in breastfed colicky and non-colicky infants; Savino F et al.; BACKGROUND: Infantile colics are a common problem in the first months of life . During this period, a process of intestinal colonization rapidly occurs . A difference in the gut microflora could play an important role in the pathogenesis of colics, changing the metabolism of carbohydrates and fatty acids . Actually, in the literature, only few data have been collected about this topic . In this study, we evaluated intestinal microflora in breastfed colicky and non-colicky infants . METHODS: Seventy-one breastfed infants, aged 3.2 +/- 0.6 wk, free from episodes of gastroenteritis and without previous assumption of antibiotic and probiotic drugs, were enrolled in the study . They were divided into two groups: colicky (42 cases) and non-colicky (29 cases), according to Wessel's criteria . Stool samples were collected, diluted and cultured on several selective media to detect lactobacilli, clostridia, gram-negative anaerobes and Enterobacteriaceae . Statistical analysis was performed using Student's t-test, chi2 test and a non-parametric test (Mann-Whitney U-test) . RESULTS: Differences in gut microflora were found among colicky and non-colicky infants: colicky infants were less frequently colonized by Lactobacillus spp., and more frequently by anaerobic gram-negative bacteria . CONCLUSION: Our study indicates that colicky infants have different patterns of gut microflora . Further studies are required to understand whether gut microflora is the primary cause of colics or its consequence.

J Clin Microbiol, 2004 Jul, 42(7), 3108 - 16
Molecular epidemiology of Serratia marcescens in two hospitals in Gdańsk, Poland, over a 5-year period; Naumiuk L et al.; The history of the Serratia marcescens population in two hospitals in Danzig, Poland, over a 5-year period was analyzed in a study that combined MIC evaluation, typing by randomly amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis, and analysis of extended-spectrum beta-lactamases (ESBLs) . We analyzed 354 isolates collected from 341 patients in two teaching hospitals in Danzig, Poland, from 1996 to 2000 . The antimicrobial susceptibility profiles varied greatly, and for resistance to newer beta-lactams, probable AmpC cephalosporinase derepression and ESBL production occurred in about 23 and 19% of the isolates, respectively . RAPD typing, by which 69 types were discerned altogether, revealed a high degree of clonal diversity among the populations . However, the four most prevalent types were highly predominant, grouping approximately 71% of the isolates studied . These clones were observed in the two hospitals and were strong contributors to both outbreaks and the background of endemicity of the S . marcescens infections . Some of the strains that were not so widely spread (12 RAPD types; approximately 14% of the isolates) were responsible for several smaller outbreaks, and the remaining isolates represented unique RAPD types (53 types; approximately 15% of the isolates) and were probably sporadic introductions from other environments . ESBLs were identified in several different clones, and some of these had most likely already been introduced into the hospitals as ESBL producers, whereas the others acquired the ESBL-encoding genes from other enterobacterial strains in these environments . The CTX-M-3 enzyme, which is widely observed in Poland, was the most common ESBL type among the S . marcescens isolates, followed by TEM-47 and SHV-5 . The complex epidemiology of ESBLs, especially in 1999 and 2000, must have arisen from the introduction of ESBL producers from other centers, their clonal dissemination, and the constant penetration of the S . marcescens populations with plasmids with ESBL genes . Multiple S . marcescens isolates were obtained from 11 patients, who probably represented both patients with recolonizations and reinfections and patients with recurrences of infections with the evolution of the strain's susceptibility.

Infect Control Hosp Epidemiol, 2004 Jun, 25(6), 472 - 6
Surgical-site infection rates and risk factor analysis in coronary artery bypass graft surgery; Harrington G et al.; BACKGROUND: The Victorian Infection Control Surveillance Project (VICSP) is a multicenter collaborative surveillance project established by infection control practitioners . Five public hospitals contributed data for patients undergoing coronary artery bypass graft (CABG) surgery . OBJECTIVE: To determine the aggregate and comparative interhospital surgical-site infection (SSI) rates for patients undergoing CABG surgery and the risk factors for SSI in this patient group . METHOD: Each institution used standardized definitions of SSI, risk adjustment, and reporting methodology according to the National Nosocomial Infections Surveillance System of the Centers for Disease Control and Prevention . Data on potential risk factors were prospectively collected . RESULTS: For 4,474 patients undergoing CABG surgery, the aggregate SSI rate was 7.8 infections per 100 procedures (95% confidence interval {CI95}, 7.0-8.5), with individual institutions ranging between 4.5 and 10.7 infections per 100 procedures . Multivariate risk factor analysis demonstrated age (odds ratio {OR}, 1.02; CI95, 1.01-1.04; P < .001), obesity (OR, 1.8; CI95, 1.4-2.3; P < .001), and diabetes mellitus (OR, 1.6; CI95, 1.2-2.1; P < .001) as independent predictors of SSI . Three hundred thirty-four organisms were isolated from 296 SSIs . Of the total SSIs, methicillin-resistant Staphylococcus aureus was isolated from 32%, methicillin-sensitive S . aureus from 24%, gram-negative bacilli (eg, Enterobacter and Escherichia coli) from 18%, and miscellaneous organisms from the remainder . CONCLUSION: We documented aggregate and comparative SSI rates among five Victorian public hospitals performing CABG surgery and defined specific independent risk factors for SSI . VICSP data offer opportunities for targeted interventions to reduce SSI following cardiac surgery.

Eur J Pediatr, 2004 Sep, 163(9), 530 - 5 Epub 2004 Jul 06.
A 7-year study of bloodstream infections in an English children's hospital; Gray JW; Knowledge of the pattern of bloodstream infection (BSI) can help determine antibiotic prescribing policy and infection control procedures . Data on 2364 consecutive episodes of BSI at Birmingham Children's Hospital over 7 years were collected prospectively . A total of 1224 (51.8%) episodes were community-acquired, but only 281 (11.9%) were in previously healthy children . Intravascular devices (IVDs) were the most common source of infection, accounting for 48.9% of episodes . Gram-positive, gram-negative and anaerobic bacteria accounted for 66.2%, 31.3% and 0.4% of isolates, and 2.2% were yeasts . Coagulase-negative staphylococci, Staphylococcus aureus and enterococci accounted for over 50% of all isolates . Of these, only enterococci were predominantly hospital-acquired . Neisseria meningitidis was the most common cause of community-acquired BSI in previously healthy children . Of cases of meningococcaemia, 55.6% were diagnosed by PCR alone . Antibiotic resistance, especially in Enterobacteriaceae, S . aureus and enterococci, was more common than in earlier studies of BSI in children, and varied between specialties . The overall mortality rate directly attributable to infection was 2.4%, but was higher in neonates (6.2%) and in previously healthy children with community-acquired infections (5.3%) . CONCLUSION: Intravascular devices have emerged as the commonest source of bloodstream infection in children, leading to marked similarities in the species distribution of blood culture isolates across specialties other than General Paediatrics, and explaining the low overall mortality rate . Antibiotic resistance was found frequently in most commonly isolated pathogens, but differences between specialties suggest the existence of local risk factors, some of which might be amenable to infection control interventions.

Appl Environ Microbiol, 2004 Jul, 70(7), 4293 - 302
Presence of acylated homoserine lactones (AHLs) and AHL-producing bacteria in meat and potential role of AHL in spoilage of meat; Bruhn JB et al.; Quorum-sensing (QS) signals (N-acyl homoserine lactones {AHLs}) were extracted and detected from five commercially produced vacuum-packed meat samples . Ninety-six AHL-producing bacteria were isolated, and 92 were identified as Enterobacteriaceae . Hafnia alvei was the most commonly identified AHL-producing bacterium . Thin-layer chromatographic profiles of supernatants from six H . alvei isolates and of extracts from spoiling meat revealed that the major AHL species had an R(f) value and shape similar to N-3-oxo-hexanoyl homoserine lactone (OHHL) . Liquid chromatography-mass spectrometry (MS) (high-resolution MS) analysis confirmed the presence of OHHL in pure cultures of H . alvei . Vacuum-packed meat spoiled at the same rate when inoculated with the H . alvei wild type compared to a corresponding AHL-lacking mutant . Addition of specific QS inhibitors to the AHL-producing H . alvei inoculated in meat or to naturally contaminated meat did not influence the spoilage of vacuum-packed meat . An extracellular protein of approximately 20 kDa produced by the H . alvei wild-type was not produced by the AHL-negative mutant but was restored in the mutant when complemented by OHHL, thus indicating that AHLs do have a regulatory role in H . alvei . Coinoculation of H . alvei wild-type with an AHL-deficient Serratia proteamaculans B5a, in which protease secretion is QS regulated, caused spoilage of liquid milk . By contrast, coinoculation of AHL-negative strains of H . alvei and S . proteamaculans B5a did not cause spoilage . In conclusion, AHL and AHL-producing bacteria are present in vacuum-packed meat during storage and spoilage, but AHL does not appear to influence the spoilage of this particular type of conserved meat . Our data indicate that AHL-producing H . alvei may induce food quality-relevant phenotypes in other bacterial species in the same environment . H . alvei may thus influence spoilage of food products in which Enterobacteriaceae participate in the spoilage process.

World J Gastroenterol, 2004 Jul 15, 10(14), 2087 - 90
Changes of gut flora and endotoxin in rats with D-galactosamine-induced acute liver failure; Li LJ et al.; AIM: To investigate the changes of gut microflora and endotoxin levels in rats with acute liver failure (ALF) induced by D-galactosamine (GalN) . METHODS: Flora and endotoxin levels in the jejunum, ileum and colon in normal rats (group A) and rats with GalN -induced ALF were determined at 24 h (group B) or 48 h (group C) after GalN injection, as well as the endotoxin level in portal venous blood (PVB) and right ventricle blood (RVB) were determined by chromogenic limulus amoebocyte assay . RESULTS: Intestinal (jejunum, ileum, colon) lactobacillus count was statistically reduced in group B compared with those in group A (3.4+/-0.3 vs 4.9+/-0.3, 6.1+/-0.4 vs 8.0+/-0.3, 8.1+/-0.2 vs 9.3+/-0.2, P<0.001, P<0.001 and P<0.001 respectively) and recovered partially in the group C compared with those in the group B, whereas the count of Enterobacteriaceae in the jejunum, ileum and colon in group B was increased markedly compared with those in the group A (5.1+/-0.3 vs 3.6+/-0.2, 6.9+/-0.5 vs 5.3+/-0.3, 8.7+/-0.2 vs 7.6+/-0.1, P<0.001, P<0.05 and P<0.05 respectively) and restored partially in the group C compared with those in the group B . The endotoxin level in ileum was increased in the group B compared with those in the group A (111.3+/-22.8 vs 51.5+/-8.9, P<0.05) . In addition, the endotoxin level in PVB was obviously increased in group B compared with that in the group A (76.8+/-9.1 vs 40.6+/-7.3, P<0.01) and reduced to the baseline at 48 h (group C) . CONCLUSION: Severely disturbed gut flora in rats with GalN-induced acute liver failure plays an important role in the elevation of endotoxin level in PVB.

Indian J Exp Biol, 2004 May, 42(5), 508 - 14
Characterization of outer membrane proteins of Yersinia pestis and Yersinia pseudotuberculosis strains isolated from India; Khushiramani R et al.; The majority of virulence factors including the 12 Yersinia outer membrane proteins (Yops), 29 Yop secretion proteins (Ysc) and few specific Yop chaperone (Syc) are contributed by the 70 kb LCR middle plasmid of Yersinia pestis . Yersinia pestis isolates recovered during 1994 plague outbreak and rodent surveillance samples of Southern states of India were studied for the presence of important Yops by the conventional procedure of partially purifying outer membrane proteins (Omps) after cultivation in calcium deficient media . Prominent bands numbering 4-5 between 34-42 kDa region corresponding to important Yops were seen in all the isolates as well as in other Yersinia and non-Yersinia species by SDS-PAGE . Western blotting with the polyclonal antisera raised against these Omp preparations revealed few immuno-reactive bands that appeared to be shared among Y . pestis, Y . pseudotruberculosis, Y . enterocolitica, Y . fredrocksenii, Y . intermedia, Y . kristensenii and E . coli . Three recombinant Yop proteins namely, YopM, YopB and LcrV were produced and antisera to these proteins could reveal presence of these Yops in the Y . pestis Omp preparations . In order to further characterize the important Yops among Omps, attempts were made to generate monoclonal antibodies against Omp preparation . Three of the 4 stable reactive clones that were obtained, when tested, had extensive cross-reactions among pathogenic Yersinia species, Y . pestis and Y . pseudotuberculosis isolates, other Yersinia species and the members of Enterobacteriaceae in dot-ELISA and Western blotting . One of the monoclonal antibodies, YP1, exhibited reaction to all the pathogenic Yersinia species and the isolates, with restricted cross-reactivity to Y . intermedia, Y . kristensenii, K . pneumoniae . None of the 4 monoclonal antibodies had reactions with the 3 recombinant Yop proteins . It appears that under low calcium response, the Y . pestis not only activates secretion of Yops but also a large number of other proteins, which as per the present observations are cross-reactive within the family Enterobacteriaceae.

Dtsch Tierarztl Wochenschr, 2004 May, 111(5), 201 - 4
{Test schemes for evaluation of the effect of a probiotic feed additive on the gut microflora of young calves and newly hatched turkeys}; Klein G et al.; Probiotic feed additives have to undergo a strict assessment according to EU regula-tions, including the evaluation of the influence on the gut microflora of the host animal . A probiotic strain of the genus Enterococcus faecium and two different host animal species, young calves and newly hatched turkeys, were chosen as a test model for the establishment of schemes for feeding trials . Investigations included faeces samples and pooled swab samples of faeces as well as samples from gut sections derived from diagnostic slaughtering . The samples were tested for aerobic total count, for enterococci count and for Enterobacteriaceae and E . coli . The test schemes were appropriate for the evaluation of the influence of the probiotic feed additive on the physiological gut microflora of the host animals . Additional information could be gathered concerning safety aspects and effectiveness.

Dtsch Tierarztl Wochenschr, 2004 May, 111(5), 181 - 4
{The use of neck skin for microbial process control of fresh poultry meat using the bioluminescence method}; Ellerbroek L et al.; In this study comparative investigations of the total viable counts of bacteria and viable counts of Enterobacteriaceae with the ATP content were carried out on 70 poultry carcasses and neck skins thereof . The results revealed a correlation of total viable counts on the neck skin and on the carcass sample . Therefore the examination on total viable counts of neck skin is able to give results on the respective load of the carcass (coefficient of correlation (r) = 0.85 and coefficient of determination (R2) = 0.71) . This only applies, however, to a slaughter technology at which the poultry hangs up site down with the neck skin to the bottom . The results of the ATP investigation expressed in Relative Light Units (RLU) in a bioluminescence method and total viable counts of neck skin samples are correlated (r = 0.85; R2 = 0.72) . Lower values for r and R2 were estimated for RLU/Enterobacteriaceae on neck skin (r = 0.64; R2 = 0.41), for RLU/total viable counts on the carcass (r = 0.66; R2 = 0.46) and for RLU/Enterobacteriaceae on the carcass (r = 0.33; R2 = 0.11) . To estimate the hygiene status in poultry slaughtery, sampling from the neck skin can replace the sampling on the whole carcass The bioluminescence method is suitable to replace the determination of total viable counts in the context of in-house hygiene supervision . However, this method seemed to be less reliable to predict the Enterobacteriaceae counts.

Genome Res, 2004 Jul, 14(7), 1394 - 403
Mauve: multiple alignment of conserved genomic sequence with rearrangements; Darling AC et al.; As genomes evolve, they undergo large-scale evolutionary processes that present a challenge to sequence comparison not posed by short sequences . Recombination causes frequent genome rearrangements, horizontal transfer introduces new sequences into bacterial chromosomes, and deletions remove segments of the genome . Consequently, each genome is a mosaic of unique lineage-specific segments, regions shared with a subset of other genomes and segments conserved among all the genomes under consideration . Furthermore, the linear order of these segments may be shuffled among genomes . We present methods for identification and alignment of conserved genomic DNA in the presence of rearrangements and horizontal transfer . Our methods have been implemented in a software package called Mauve . Mauve has been applied to align nine enterobacterial genomes and to determine global rearrangement structure in three mammalian genomes . We have evaluated the quality of Mauve alignments and drawn comparison to other methods through extensive simulations of genome evolution .

An Pediatr (Barc), 2004 Jul, 61(1), 32 - 6
{Bacterial conjunctivitis: most prevalent pathogens and their antibiotic sensitivity}; Orden Martinez B et al.; INTRODUCTION: Bacterial conjunctivitis is a self-limiting process, but topical antibiotic treatment is recommended to eradicate the pathogen and reduce symptom duration . Since this treatment is usually empirical and prior cultures are not normally taken, the etiological agents involved in the process are unknown . PATIENTS AND METHODS: A total of 596 conjunctival exudates from pediatric outpatients with a diagnosis of acute conjunctivitis in Medical Area 6 of Madrid, Spain, were studied over 3 years (from 2000 to 2002 inclusive) . The patients were divided into three age groups: group 1 (infants), group 2 (2- to 6-year-olds) and group 3 (7- to 14-year-olds) . RESULTS: A total of 428 bacteria were isolated . The most prevalent bacteria were Haemophilus influenzae (44.8 %) and Streptococcus pneumoniae (30.6 %) followed by Staphylococcus aureus (7.5 %), S . viridans (7.2 %), Moraxella catarrhalis (6.8 %) and Enterobacteriaceae (4.2 %) . In 56 exudates (15.1 %), two or more bacteria were isolated and S . pneumoniae 1 H . influenzae were found in 8.1 % of the cases . By age group, S . aureus was significantly more prevalent (p < 0.0001) in group 3 than in groups 1 and 2 . Isolation of Enterobacteriaceae, S . viridans and non-fermentative Gram negative bacilli was significantly more frequent (p < 0.05) in group 1 and isolation of S . pneumoniae (p < 0.05) was significantly more frequent in group 2 . S . pneumoniae showed the greatest level of resistance to antibiotics used in eye drops and ophthalmic ointments . Ciprofloxacin, chloramphenicol and rifampin were active in the most prevalent pathogens . CONCLUSIONS: The most prevalent bacteria were H . influenzae and S . pneumoniae . The most active antibiotics in these pathogens were ciprofloxacin, chloramphenicol and rifampin.

Clin Infect Dis, 2004 Jun 15, 38(12), 1682 - 7 Epub 2004 May 24.
Molecular epidemiology of gram-negative bacilli from infected neonates and health care workers' hands in neonatal intensive care units; Waters V et al.; We sought to characterize the molecular epidemiology of gram-negative bacilli (GNB) causing infections in infants and associated with carriage on nurses' hands after hand hygiene was performed . From March 2001 to January 2003, GNB caused 192 (34%) of 562 hospital-acquired infections in the 2 participating neonatal intensive care units (NICUs) and were isolated from the hands of 45 (38%) of 119 nurses . Five species--Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens and Enterobacter cloacae, all of which were typed by pulsed-field gel electrophoresis--caused 169 (88%) of 192 of GNB infections . Overall, 58% of infections were caused by unique strains not cultured from other infants or nurses, and 31% of infections were part of unrecognized molecular clusters . In contrast, only 9% of strains that caused infections were cultured from nurses' hands . These data suggest that practices in addition to hand hygiene are needed to prevent horizontal transmission of GNB in the NICU.

FEBS Lett, 2004 Jul 2, 569(1-3), 27 - 30
Enterobacter aerogenes OmpX, a cation-selective channel mar- and osmo-regulated; Dupont M et al.; The ompX gene of Enterobacter aerogenes was cloned . Its overexpression induced a decrease in the major porin Omp36 production and consequently a beta-lactam resistance was noted . Purified outer membrane protein X (OmpX) was reconstituted into artificial membranes and formed ion channels with a conductance of 20 pS in 1 M NaCl and a cationic selectivity . Both MarA expression and high osmolarity induced a noticeable increase of the OmpX synthesis in the E . aerogenes ATCC 13048 strain . In addition, OmpX synthesis increased under conditions in which the expression of the E . aerogenes major non-specific porins, Omp36 and Omp35, decreased.

Vet Res Commun, 2004 May, 28(4), 287 - 98
Molecular variability among strains of Pasteurella multocida isolated from an outbreak of haemorrhagic septicaemia in India; Biswas A et al.; The applicability of conventional and molecular methods for rapid detection and differentiation of Pasteurella multocida serogroup B isolates involved in an outbreak of haemorrhagic septicaemia affecting Indian buffaloes, was studied . Five isolates were obtained and were subjected to phenotypic and genotypic characterization . None of the five isolates could be differentiated on the basis of cultural, biochemical, pathogenicity and antimicrobial sensitivity patterns . Polymerase chain reaction (PCR)-based techniques were found to be specific and sensitive for rapid detection and differentiation of isolates . Repetitive extragenic palindromic (REP-) PCR, enterobacterial repetitive intergenic consensus (ERIC-) PCR and single-primer PCR differentiated all the five isolates into different profiles . All the isolates involved in the outbreak were found to have a genetic profile different from standard P . multocida strain (P52) . However, three isolates had similar profiles, whereas each of the remaining two had a different profile . The study indicates the involvement of multiple strains of P . multocida in a single outbreak of haemorrhagic septicaemia in buffaloes . The results also indicate that molecular methods of detection and typing are superior to conventional methods for rapid epidemiological investigations of haemorrhagic septicaemia.

J Food Prot, 2004 Jun, 67(6), 1267 - 70
A new protocol for the detection of Enterobacter sakazakii applied to environmental samples; Kandhai MC et al.; Enterobacter sakazakii is a motile, peritrichous, gram-negative rod that was previously known as a yellow pigmented Enterobacter cloacae . It is documented as a rare cause of outbreaks and sporadic cases of life-threatening neonatal meningitis, necrotizing enterocolitis, and sepsis . E . sakazakii has been isolated from milk powder-based formulas, and there is thus a need to investigate whether and where E . sakazakii occurs in these manufacturing environments . For this purpose, a simple detection method was developed based on two features of E . sakazakii: its yellow pigmented colonies when grown on tryptone soy agar and its constitutive alpha-glucosidase, which is detected in a 4-h colorimetric assay . Using this screening method, E . sakazakii strains were isolated from three individual factories from 18 of 152 environmental samples, such as scrapings from dust, vacuum cleaner bags, and spilled product near equipment . The method is useful for routine screening of environmental samples for the presence of E . sakazakii.

J Med Assoc Thai, 2004 May, 87(5), 464 - 72
Etiologies of acute undifferentiated febrile illness in Thailand; Leelarasamee A et al.; BACKGROUND: Acute pyrexia of unknown origin (Acute PUO) was reported to affect approximately 200,000-400,000 patients each year reported by the national Annual Epidemiological Surveillance Report . The patients usually present with fever of less than two-week duration and non-specific symptoms such as malaise, myalgia, headache and loss of appetite . Its mortality rate is less than 0.02 percent . It would be interesting to find the etiologies and propose a management plan if the etiologies are discovered . OBJECTIVE: This prospective epidemiologic study aimed to discover the etiologies of acute undifferentiated febrile illness in a tropical region like Thailand . SUBJECTS AND METHOD: Ten community-based hospitals were chosen as representatives in each part of Thailand to enroll patients into the study . Patients aged over two years old who presented with fever at the participating hospitals during year 1991-1993 were eligible for the study . Entry criteria of acute undifferentiated febrile illnesses (AUFI) included oral temperature over 38.3 degrees C within the last 24 hours, duration of fever ranging from 3-14 days, no specific single organ involvement by history taking and physical examination, normal or non-specific results of the following investigations: complete blood count, thick film for malaria, urinalysis and chest roentgenogram . The patients were hospitalized and a preset diagnostic protocol was performed . Other diagnostic procedures deemed necessary by attending physicians were perform . Patients were followed up within one month after hospital discharge . RESULTS: 1,240 patients were enrolled but only 1,137 case records and results of the serological tests were available for analysis . Etiologies could be found in 471 cases (38.7%) . Primary bacteremia was detected in 36 cases (3.2%) . E . coli, streptococci, salmonella, Enterobacter spp . and S . aureus were the five most common blood isolates . Serological studies revealed positive results for scrub typhus (7.5%), influenza (6.0%), dengue fever (5.7%), murine typhus (5.3%), enteric fever (1.9%), chikunkunya infection (1.1%), leptospirosis (1.1%) and melioidosis (0.9%) . Thirteen cases succumbed (1.1%) in this study . CONCLUSION: The etiologies in the majority (61.3%) of AUFI remained unknown . Rickettsial infection, influenza and dengue fever are the most common identifiable diseases in a tropical country like Thailand especially during the rainy season . A management guideline for diagnosis and treatment of the AUFI with emphasis on primary bacteremia and antimicrobial-treatable AUFI was proposed.

J Med Assoc Thai, 2004 Apr, 87(4), 382 - 5
Retropharyngeal space infection; Srirompotong S et al.; Retropharyngeal space infections are relatively rare since the widespread use of modern antibiotics . In children, retropharyngeal space infections usually occur following an upper respiratory tract infection, while in adults they are usually caused by trauma, foreign bodies or extension from adjacent spaces . The authors reviewed 12 patients with retropharyngeal space infection between July 1996 and June 2002 . Age, sex, duration of symptoms and hospitalization time, clinical presentation, etiology, underlying disease, bacteriology, treatment and complications were analyzed . Widening of the prevertebral soft tissue as seen on a plain film of the lateral neck was the most important diagnostic tool . Fever was the most common symptom (91.6%) and showed a high prevalence in adult populations (66.6%) . Half of the cases were caused by ingestion of a foreign body . Nine cases underwent surgical drainage which was positive in eight cases (88.8%) . Staph . aureus, K . pneumoniae and Enterobacter species were the predominant pathogens . Early diagnosis and appropriate use of antibiotics lessened morbidity . Only two cases had postoperative complications and both recovered.

J Chemother, 2004 Apr, 16(2), 145 - 50
Extended-spectrum beta-lactamase-producing Enterobacteriaceae in an Italian intensive care unit: clinical and therapeutical remarks; Carretto E et al.; In this study we evaluated the prevalence of Enterobacteriaceae and the epidemiology of ESBL+ microorganisms in an ICU of our Institution over a 5-year period and analyzed the clinical features and outcomes of the infections caused by these microorganisms . The most frequent ESBL+ isolate was Proteus mirabilis (69 isolates, 58%); a high rate of positive results in the double-disk synergy test (DDS) was also recognized for Klebsiella pneumoniae (52 isolates, 51%), whereas this phenomenon was observed less frequently in other species . In 312 cases the isolated microorganism was considered to be the cause of infection; we documented 103 wound infections, 89 UTIs, 62 LRTIs, 30 primary bacteremias, 27 infections of indwelling catheters and 1 CNS infection . The overall mortality rate due to ESBL+ strains was 1%, compared with 10.6% rate caused by ESBL-negative Enterobacteriaceae . This could be explained because ESBL+ strains caused mostly localized infections (wound infections and UTIs), whereas systemic or severe infections were sustained by ESBL-negative strains, and therapy with carbapenems was started promptly after ESBL+ isolation (always within 24h after strain isolation).

J Chemother, 2004 Apr, 16(2), 107 - 18
Evaluation of the Uro-Quick, a new rapid automated system, for the detection of well-characterized antibiotic-resistant bacteria; Roveta S et al.; The Uro-Quick system has been employed to detect antibiotic resistance in genotypically and/or phenotypically well-characterized bacterial species including those that might not be easily identified by routine procedure . In order to achieve full agreement between the antibiotic susceptibility results obtained by the reference method (NCCLS) and the Uro-Quick system, the optimal experimental conditions (inoculum size, time of incubation and antibiotic concentration) for each strain to be used by the automatic system were determined . The shorter time periods for generation of correct susceptibility results were 180 min for ampicillin- and ciprofloxacin-resistant Escherichia coli and for ESBL- and Inhibitor-resistant TEM (IRT)-producing E . coli; 360 min for penicillin-susceptible Streptococcus pneumoniae, as well as for strains with reduced susceptibility to this antibiotic (both intermediate, and resistant isolates) . The same time was required to detect erythromycin-resistant pneumococci irrespective of their mechanism of resistance (ribosomal methylation and efflux-mediated), Streptococcus pyogenes exhibiting the three erythromycin-resistance phenotypes (constitutive, inducible and M-type) and Klebsiella pneumoniae, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus mirabilis and Moraxella morganii refractory to third-generation cephalosporins, aminoglycosides, ciprofloxacin and other classes of antimicrobial agents; 480 min for penicillin-resistant, constitutive and inducible oxacillin-resistant (OXA-R) Staphylococcus aureus and OXA-R Staphylococcus epidermidis . The same period of time was also necessary to find the great majority of drug-resistance exhibited by Pseudomonas aeruginosa . Teicoplanin-resistant Staphylococcus haemolyticus, vancomycin-resistant (VanA, VanB, VanC) high-level aminoglycoside-resistant (HLAR) Enterococcus spp, and imipenem-resistant P . aeruginosa required longer incubation (24 h) to be detected . The results obtained indicate that Uro-Quick might be a reliable and promising instrument for the correct detection of the above antibiotic resistance markers.

Microbiol Immunol, 2004, 48(5), 389 - 98
Identification and characterization of two contiguous operons required for aerobactin transport and biosynthesis in Vibrio mimicus; Moon YH et al.; In response to iron deprivation, Vibrio mimicus produces aerobactin as a major siderophore . Application of the Fur titration assay to a V . mimicus genomic DNA library followed by further cloning of the surrounding regions led to the identification of two adjacent, iron-regulated operons . One contains three genes encoding homologs of the Escherichia coli FhuCDB and the other, five genes encoding homologs of the E . coli IucABCD IutA . Construction of the V . mimicus polar disruptants in the respective operons allowed us to confirm their functions . The genetic arrangement of the aerobactin-mediated iron acquisition system in V . mimicus is unique in that the aerobactin operon (iucABCD iutA ) is contiguous to the operon (matCDB ) encoding components of an ATP-binding cassette transport system for ferric aerobactin . This is the first report demonstrating that aerobactin transport and biosynthesis genes are present in a species outside the family Enterobacteriaceae.

Antimicrob Agents Chemother, 2004 Jul, 48(7), 2771 - 7
In vitro and bactericidal activities of ABT-492, a novel fluoroquinolone, against Gram-positive and Gram-negative organisms; Almer LS et al.; In vitro activities of ABT-492, ciprofloxacin, levofloxacin, trovafloxacin, moxifloxacin, gatifloxacin, and gemifloxacin were compared . ABT-492 was more potent against quinolone-susceptible and -resistant gram-positive organisms, had activity similar to that of ciprofloxacin against certain members of the family Enterobacteriaceae, and had comparable activity against quinolone-susceptible, nonfermentative, gram-negative organisms . Bactericidal activity of ABT-492 was also evaluated.

Antimicrob Agents Chemother, 2004 Jul, 48(7), 2518 - 23
RamA is an alternate activator of the multidrug resistance cascade in Enterobacter aerogenes; Chollet R et al.; Multidrug resistance (MDR) in Enterobacter aerogenes can be mediated by induction of MarA, which is triggered by certain antibiotics and phenolic compounds . In this study, we identified the gene encoding RamA, a 113-amino-acid regulatory protein belonging to the AraC-XylS transcriptional activator family, in the Enterobacter aerogenes ATCC 13048 type strain and in a clinical multiresistant isolate . Overexpression of RamA induced an MDR phenotype in drug-susceptible Escherichia coli JM109 and E . aerogenes ATCC 13048, as demonstrated by 2- to 16-fold-increased resistance to beta-lactams, tetracycline, chloramphenicol, and quinolones, a decrease in porin production, and increased production of AcrA, a component of the AcrAB-TolC drug efflux pump . We show that RamA enhances the transcription of the marRAB operon but is also able to induce an MDR phenotype in a mar-deleted strain . We demonstrate here that RamA is a transcriptional activator of the Mar regulon and is also a self-governing activator of the MDR cascade.

Clin Microbiol Infect, 2004 Jul, 10(7), 665 - 7
Evolution of acquired resistance to third-generation cephalosporins in Enterobacteriaceae in a Tunisian hospital 1993-2001; Boutiba-Ben Boubaker I et al.; Between January 1993 and December 2001, the overall frequency of resistance to third-generation cephalosporins in isolates of Enterobacteriaceae from Charles Nicolle Hospital, Tunis, rose from 2.4% to 7.4% . Klebsiella pneumoniae was the most prevalent species (56%), followed by Escherichia coli (15%) and Proteus mirabilis (9%) . A rate of 49% was observed among isolates from paediatric patients in 1999, caused mostly by outbreaks in the neonatal intensive care unit of K . pneumoniae and P . mirabilis isolates that produced extended-spectrum beta-lactamases.

Can J Microbiol, 2004 Apr, 50(4), 299 - 302
Deletion of the Escherichia coli O14:K7 O antigen gene cluster; Jensen SO et al.; Escherichia coli O14:K7 is a rough strain, lacking a typical O antigen, in which the enterobacterial common antigen is attached to the lipopolysaccharide core . The rough phenotype was previously mapped to the O antigen gene cluster; however, the nature of the nonfunctional locus was not defined . In this study, we have shown that the O antigen gene cluster of an O14:K7 type strain (Su4411/41) was most likely deleted via homologous recombination between the GDP-mannose pathway genes (manB and manC) of the colanic acid and O antigen gene clusters . A similar recombination event has previously been inferred for the deletion of E . coli Sonnei chromosomal O antigen genes . Therefore, recombination between the GDP-mannose pathway genes provides a convenient mechanism for the deletion of O antigen genes, which may occur if the typical O antigen becomes redundant.

Emerg Infect Dis, 2004 Jun, 10(6), 1050 - 5
Nursing home residents and Enterobacteriaceae resistant to third-generation cephalosporins; Sandoval C et al.; Limited data identify the risk factors for infection with Enterobacteriaceae resistant to third-generation cephalosporins among residents of long-term-care facilities . Using a nested case-control study design, nursing home residents with clinical isolates of Enterobacteriaceae resistant to third-generation cephalosporins were compared to residents with isolates of Enterobacteriaceae susceptible to third-generation cephalosporins . Data were collected on antimicrobial drug exposure 10 weeks before detection of the isolates, facility-level demographics, hygiene facilities, and staffing levels . Logistic regression models were built to adjust for confounding variables . Twenty-seven case-residents were identified and compared to 85 controls . Exposure to any cephalosporin (adjusted odds ratio {OR} 4.0, 95% confidence interval {CI} 1.2 to 13.6) and log percentage of residents using gastrostomy tubes within the nursing home (adjusted OR 3.9, 95% CI 1.3 to 12.0) were associated with having a clinical isolate resistant to third-generation cephalosporins.

West Indian Med J, 2004 Mar, 53(2), 104 - 8
Extended spectrum beta-lactamase producing organisms at the University Hospital of the West Indies; Nicholson AM et al.; Extended spectrum beta-lactamases (ESBL) represent a major group of beta-lactamases that have the ability to inactivate beta-lactam antibiotics containing an oxyimino group such as third generation cephalosporins and monobactams . These enzymes are produced by gram negative organisms, especially members of the Enterobacteriaceae family such as Klebsiella pneumoniae and Escherichia coli . The prevalence of these organisms varies widely internationally, as well as within the same country . This is the first study on ESBL production in K pneumoniae and E coli at the University Hospital of the West Indies, a tertiary care hospital in Jamaica . Two-hundred and sixty-four isolates of K pneumoniae and 300 isolates of E coli were collected over the study period January 2002 to December 2002 . Forty-eight (18.2%) K pneumoniae isolates were confirmed to be ESBL producers, while there was no ESBL producing E coli . Infections with ESBL producing organisms can pose a therapeutic challenge, leading to treatment failure if the wrong class of antibiotics is used . With increasing resistance to all classes of antibiotics, there is a narrowing of available treatment options . It is very important that these organisms be monitored and antibiotic policies as well as infection control policies be in place to curtail their spread.

J Am Chem Soc, 2004 Jun 23, 126(24), 7652 - 64
Mixed quantum mechanical/molecular mechanical (QM/MM) study of the deacylation reaction in a penicillin binding protein (PBP) versus in a class C beta-lactamase; Gherman BF et al.; The origin of the substantial difference in deacylation rates for acyl-enzyme intermediates in penicillin-binding proteins (PBPs) and beta-lactamases has remained an unsolved puzzle whose solution is of great importance to understanding bacterial antibiotic resistance . In this work, accurate, large-scale mixed ab initio quantum mechanical/molecular mechanical (QM/MM) calculations have been used to study the hydrolysis of acyl-enzyme intermediates formed between cephalothin and the dd-peptidase of Streptomyces sp . R61, a PBP, and the Enterobacter cloacae P99 cephalosporinase, a class C beta-lactamase . Qualitative and, in the case of P99, quantitative agreement was achieved with experimental kinetics . The faster rate of deacylation in the beta-lactamase is attributed to a more favorable electrostatic environment around Tyr150 in P99 (as compared to that for Tyr159 in R61) which facilitates this residue's function as the general base . This is found to be in large part accomplished by the ability of P99 to covalently bind the ligand without concurrent elimination of hydrogen bonds to Tyr150, which proves not to be the case with Tyr159 in R61 . This work provides an essential foundation for further work in this area, such as selecting mutations capable of converting the PBP into a beta-lactamase.

Mikrobiologiia, 2004 Mar-Apr, 73(2), 188 - 94
{Characterization of enterobacteria producing the low-molecular-weight antibiotics microcins}; Tarakanov BV et al.; A comparative study of the morphological, cultural, physiological, and biochemical properties of the microcinogenic strains EcS 5/98, EcS 6/98, and EcB 214/99 with the known microcin C51 producer Escherichia coli M17(p74) showed that these strains belong to the species E . coli . The strains produced microcins with molecular masses lower than 10 kDa . Microcin biosynthesis was stimulated by a deficiency of nutrients in the cultivation media . Microcins were found to be resistant to thermolysin, but were degraded by pronase, protolichetrem, and the Bacillus mesentericus metalloproteinase . This indicated that microcins are peptides or contain peptides in their molecules . The study of cross immunity to microcins and the sequence of their genetic determinants showed that the microcins of strains EcS 5/98 and EcS 6/98 are of B type, whereas the microcin of strain EcB 214/99 presumably belongs to another type, since it suppresses the growth of the producers of C-type and B-type microcins . The new microcin producers possess antibacterial activity against natural isolates belonging to the genera Escherichia and Salmonella, against a wide range of colicinogenic Escherichia strains, and against the collection Salmonella cultures.

Int J Antimicrob Agents, 2004 Jun, 23(6), 547 - 55
Expanded-spectrum cephalosporin resistance in non-typhoid Salmonella; Miriagou V et al.; Expanded-spectrum cephalosporins (ESCs) such as ceftriaxone, together with fluorinated quinolones, are the choice antibiotics in the treatment of invasive salmonella infections . Resistance to ESCs among non-typhoid salmonella has been recognised since the late 1980s . Currently, ESC-resistant salmonella strains are reported world-wide and in some areas their incidence is significant . Resistance is mainly due to acquisition of multi-resistant plasmids encoding a variety of extended-spectrum and AmpC-type beta-lactamases . The origins of ESC-resistant salmonellae are diverse . Exchange of resistance determinants between salmonellae and nosocomial enterobacteria seems to be frequent, at least in developing countries . Also, the use of newer beta-lactams in animal husbandry and veterinary medicine may have facilitated the spread of ESC-resistant salmonella strains in livestock .

J Pediatr, 2004 Jun, 144(6), 821 - 3
Enterobacter sakazakii is a rare cause of neonatal septicemia or meningitis in VLBW infants; Stoll BJ et al.; To determine the rates of Enterobacter sakazakii (ES) infections among very low birth weight infants, culture data from the National Institute of Child Health and Human Development Neonatal Research Network were reviewed . Only one case of ES sepsis was identified among 10660 neonates . These data suggest that outside of the epidemic situation, ES is very rare in very low birth weight infants.

J Dairy Res, 2004 May, 71(2), 245 - 52
Evaluation of biogenic amines and microbial counts throughout the ripening of goat cheeses from pasteurized and raw milk; Novella-Rodriguez S et al.; The effect of the hygienic quality of milk on changes in microbial counts and biogenic amine content was evaluated during ripening of goat cheeses manufactured from pasteurized and raw milks at 1, 14, 30, 60 and 90 d . The original milk, rennet, curd and whey were also included in the study . The pH, salt content and extent of proteolysis in the cheese were also evaluated . Spermidine and spermine were the main amines in raw milk, while they were minor amines in cheeses . Other amines increased markedly during ripening, tyramine being the main amine in cheese made from raw milk and cadaverine and putrescine in those produced from pasteurized milk . Enterobacteriaceae counts decreased during ripening whereas those of lactic acid bacteria increased, especially lactobacilli and enterococci . Cheese made from raw milk showed higher microbial counts during ripening than those made from pasteurized milk, especially for Enterobacteriaceae and enterococci, counts being 2 or 3 log units higher . Raw milk cheese showed remarkably higher biogenic amines compared with pasteurized milk cheeses . Therefore, pasteurization of milk causes a decrease in final biogenic amine content of cheese as a result of the reduction of its microbial counts.

Lett Appl Microbiol, 2004, 39(1), 41 - 7
Investigation of extended-spectrum beta-lactamases produced by clinical isolates of Klebsiella pneumoniae and Escherichia coli in Korea; Jeong SH et al.; AIMS: Isolates obtained from various regions in Korea in 2002 were identified and their susceptibility to extended-spectrum cephalosporins, monobactams and/or cephamycins was studied along with any production of extended-spectrum beta-lactamases (ESBLs) . METHODS AND RESULTS: Bacteria identified by the conventional techniques and Vitek GNI card were Klebsiella pneumoniae and Escherichia coli . Using disk diffusion and double-disk synergy tests, we found that 39.2% of strains produced ESBLs . About 52% of isolates transferred resistance to ceftazidime by conjugation . Banding patterns of PCR amplification with the designed primers showed that 837- and 259-bp fragments specific to bla(TEM) genes were amplified in 63.3% of strains . 929- and 231-bp fragments (bla(SHV)), 847- and 520-bp fragments (bla(CMY)), 597- and 858-bp fragments (bla(CTX-M)) were amplified in 61.5, 17.3 and 7.7% of strains respectively . About 51.9% of strains contained more than two types of beta-lactamase genes . Especially, one strain contained bla(TEM), bla(CMY) and bla(CTX-M) genes . SIGNIFICANCE: Resistance mechanisms to beta-lactams, comprising mostly ESBL production, lead to the resistance against even recently developed beta-lactams in enterobacteria, which is now a serious threat to antibiotic therapy . The high prevalence of bla(CMY) genes and multidrug-resistant genes may also make therapeutic failure and lack of eradiation of these strains by extended-spectrum cephalosporins or cephamycins.

Berl Munch Tierarztl Wochenschr, 2004 May-Jun, 117(5-6), 201 - 6
{The entry of bound residues of tetracyclines into the food chain--a contribution to hazard identification}; Kuhne M et al.; Actually, some 67% of therapeutical used antibiotics in livestock in the European Union are tetracyclines . Their use can result in unwanted residues in food of animal origin . Apart the risk of the possible development of resistances in enterobacteriaceae we have to keep in mind secondary circuits . This paper focuses on tetracycline residues in bones . Bones have been widely used as raw material for meat and bone meal and gelatine, and are also a frequent contamination of mechanical recovered meat . Bones contain tetracycline residues in concentrations up to 50 mg/kg . These bound tetracycline residues have ever been thought to be of no significance to health . Nevertheless, recent studies have shown that these tetracyclines could be released in vivo and re-obtain their bioavailability . Further, several toxic degradation products of tetracyclines could be formed during heating . Additionally, in acid solutions from the production of gelatine high tetracycline concentrations have been found . These solutions are processed to dicalciumphosphate, which is used as a feed supplement in animal husbandry and as fertilizer in agriculture.

Proteomics, 2004 May, 4(5), 1265 - 79
Effect of high concentration of Co (II) on Enterobacter liquefaciens strain C-1: a bacterium highly resistant to heavy metals with an unknown genome; Marrero J et al.; Heavy metals are required as nutrients for essential functions in microorganisms . However, higher concentrations of these cations are generally toxic and may produce contrasting effects on living organisms . Enterobacter liquefaciens strain C-1, a bacterium isolated from the Moa mine in Cuba, is able to survive in the presence of high concentrations of heavy metals . The proteomes of Enterobacter liquefaciens strain C-1, grown under aerobic conditions in the presence and absence of Co (II) were compared using two-dimensional gel electrophoresis analysis in the isoelectric point range of 4-7 and the mass range of 15-120 kDa . Significant changes in the expression level (> two-fold) were detected for 13 spots: seven and six were up- and down-regulated, respectively . Because the genome of this bacterium is unknown, identification by peptide mass fingerprinting only succeeded in four cases and most of the cross-species identifications were supported by de novo sequencing of tryptic peptides followed by sequence alignment using the MS BLAST program . Twelve different proteins were identified, ten are involved in cellular antioxidant defence probably induced by the presence of Co (II) . This is the first step towards understanding the role of proteins participating in the mechanism of resistance to heavy metals in this bacterium.

J Clin Microbiol, 2004 Jun, 42(6), 2372 - 8
Implications of molecular genotyping of Helicobacter pylori isolates from different human populations by genomic fingerprinting of enterobacterial repetitive intergenic consensus regions for strain identification and geographic evolution; Hussain MA et al.; Biogeographic partitioning of the genome is typical of the gastric pathogen Helicobacter pylori . Such population-specific evolution could serve as a model for understanding host-pathogen interaction and the impact of genetic drift and recombination on insular populations . With a total of 320 isolates from six geographic regions (Japan, India, England, Spain, Ireland, Africa, and Peru) analyzed by enterobacterial repetitive intergenic consensus (ERIC)-based genotyping, we examined genetic affinities among various H . pylori populations in the world . Several strain-specific and region-specific differences were observed by ERIC-based typing . Polymorphic ERIC patterns indicated that the ERIC sequences are in fact dispersed in the H . pylori chromosome at different locations separated by various distances . Phylogenetic analysis of 61 representative isolates revealed three distinct genetic clusters populated by isolates with shared ERIC types independent of the cag right-junction motif type and vacA allele status . Among the notable genetic relationships were the genotypic similarities between Irish and Japanese and between Peruvian and Japanese isolates . Insular genotypic characteristics of Irish isolates amid genetic similarity to East Asian, as well as North European, strains have been once again proved in this study . Peruvian genotypes were more similar to those of Japanese isolates than to those of Iberian or European isolates . Given the current debate on the origin and age of present-day H . pylori, this is a significant finding that supports the possibility of ancient colonization of Amerindians with East Asian strains . Genotypic data presented here will be additionally helpful in realizing the importance of H . pylori geographical genomics in the development of gastroduodenal pathology.

J Hosp Infect, 2004 Jun, 57(2), 119 - 25
Emergence of Enterobacter cloacae as a common pathogen in neonatal units: pulsed-field gel electrophoresis analysis; Talon D et al.; In the first week of December 2002, three infants hospitalized in the neonatal department of our hospital had blood cultures positive with Enterobacter cloacae . Screening cultures and genotyping showed that 10 of 25 screened patients also carried E . cloacae and that nine isolates belonged to the same clone as that responsible for all three bacteraemias . This epidemic cluster was limited to one of the two units of the department . Surveillance of both units continued until the end of March 2003; 51 of 159 neonates screened were colonized with E . cloacae, 38 out of 80 (47.5%) in the premature unit (PU) and 13 out of 79 (16.4%) in the paediatric intensive care unit (PICU) . Pulsed-field gel electrophoresis (PFGE) analysis of 130 available isolates revealed 30 different pulsotypes, including 24 unique pulsotypes from individual patients and six from multiple patients . Antibiotic (particularly beta-lactam) use did not significantly vary from 1999 to 2003 . The consumption of alcohol-based hand rub (four-fold higher in the PICU than in the PU) and nurse-to-patient ratio (1:2 in the PICU and 1:4 in the PU) might explain the higher cross-transmission rate in the PU . Finally, despite an epidemiological survey, we failed to identify the causes of the emergence of E . cloacae in our neonatology units . However, improved hygiene practices combined with restriction of admission led to the progressive disappearance of the epidemic strain . The increasing importance of this type of unit and the dramatic consequences of infections emphasize the need for additional research on the constitution of the flora of newborns and the mode of acquisition Gram-negative multi-resistant bacteria .

Ann Acad Med Singapore, 2004 May, 33(3), 302 - 6
Extended-spectrum beta-lactamases in clinical isolates of Escherichia coli and Klebsiella spp . in a Singapore hospital: clinical spectrum; Chlebicki MP et al.; INTRODUCTION: The rising prevalence of extended-spectrum beta-lactamases in gram-negative bacillary pathogens is an important clinical problem resulting from the extensive use of broad-spectrum antibiotics . The emergence of the extended-spectrum beta-lactamases increases the possibility that traditional, empiric antimicrobial regimens may be ineffective . The aims of this study are: to determine the epidemiologic characteristics and clinical outcome of patients diagnosed with infection caused by Klebsiella spp . and Escherichia coli producing extended-spectrum beta-lactamases; to define a subgroup of patients who may benefit from early, empiric therapy; and to determine the local antibiotic sensitivity pattern in order to improve antibiotic utilisation in our hospital . MATERIALS AND METHODS: A 4-month retrospective review of patients hospitalised in Changi General Hospital between November 2000 and February 2001 who were diagnosed with infection caused by isolates of Klebsiella spp . or Escherichia coli producing extended-spectrum beta-lactamases . RESULTS: During the study period, 44 % of Klebsiella spp . and 16.1 % of Escherichia coli isolates were reported as producers of the extended-spectrum beta-lactamases . Sixty-eight patients were assessed to have clinically significant infection caused by 75 isolates . Most of them were elderly, had multiple medical problems and were recently treated with beta-lactam antibiotics . There was a trend toward better outcome in patients who received adequate initial, empiric therapy . CONCLUSION: Patients with infections caused by extended-spectrum beta-lactamase producing Enterobacteriaceae have certain identifiable, common clinical characteristics . In our institution, only carbapenems remain effective against all isolates of Klebsiella spp . or Escherichia coli producing extended-spectrum beta-lactamases . Further research is necessary to define a group of patients who can benefit from an early, broad-spectrum, empiric therapy.

Am J Infect Control, 2004 Jun, 32(4), 189 - 95
Enteric gram-negative bacilli bloodstream infections: 17 years' experience in a neonatal intensive care unit; Cordero L et al.; OBJECTIVE: To assess the occurrence of enteric gram-negative bacilli (EGNB) bloodstream infections (BSI) in a neonatal intensive care setting during a 17-year period in which a consistent antibiotic treatment program was in place . To document infections, outbreaks, or epidemics, emergence of antibiotic resistance, clinical correlates, and outcomes of the most prevalent EGNB (Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae) . METHODS: This study analyzed demographic, clinical, and bacteriologic information from 360 infants born 1986-2002 who developed 633 blood culture-proven BSI . A total of 121 EGNB were isolated (E coli, K pneumoniae, and E cloacae) . Early-onset BSI were discovered within 48 hours from birth, and late-onset BSI were those that occurred thereafter . Suspected early-onset BSI were treated with ampicillin and gentamicin, suspected late-onset BSI with vancomycin and gentamicin . Antibiotics were changed on the basis of organism antimicrobial susceptibility . RESULTS: Early-onset BSI were noted in 52 of 21,336 (244/100,000) live births (1986-1991), 40 of 20,402 (196/100,000) live births (1992-1997), and 25 of 17,926 (139/100,000) live births (1998-2002) . Of these cases, 39 were caused by E coli and 4 by K pneumoniae . Antibiograms for E coli isolated during the last 5 years of the study showed an increase in antibiotic resistance that coincided with obstetric group B streptococcus antepartum antibiotic prophylaxis . Group B streptococcus declined from 41 to 4 cases from the first to the last period . Late-onset BSI increased from 111 to 230 cases from the first to the second 6-year study period and declined modestly (171 cases) during the last . Fifteen percent (78 cases) of late-onset BSI were caused by EGNB, 5% by other gram-negative bacilli, 67% primarily by coagulase-negative staphylococcus, and 13% by fungus . Nonspecific clinical and hematologic signs of late-onset BSI were similar across EGNB species, but necrotizing enterocolitis was often associated with E coli, whereas pneumonia and prolonged thrombocytopenia characterized K pneumoniae infections . No outbreaks or epidemics were observed, and strains of EGNB with evidence of extended spectrum beta-lactamase production were never isolated . CONCLUSION: Antepartum antibiotic prophylaxis may have increased antibiotic resistance in E coli isolates from early-onset BSI but has dramatically decreased group B streptococcus infections . Late-onset BSI caused by EGNB increased, but without changes in antibiotic susceptibility . In spite of medical advances, E coli, K pneumoniae, and E cloacae remain responsible for significant morbidity and mortality, especially in very low birth weight infants.

Int J Antimicrob Agents, 2004 Mar, 23(3), 240 - 6
Antibiotic susceptibility of bacteria most commonly isolated from bone related infections: the role of cephalosporins in antimicrobial therapy; Jones ME et al.; Bone infections, which can be acute or chronic, often require aggressive antibiotic therapy, whether treated at home or in the community . Surveillance programmes are essential tools in the monitoring of antimicrobial resistance and can act as a resource to maintain effective prescribing . The Surveillance Network (TSN), which collects organism and patient-specific data from a network of laboratories across the United States, was used to analyse susceptibility of common bacterial species isolated from bone infections during 2000-2002 . Narrow-spectrum antimicrobials such as vancomycin, quinupristin-dalfopristin and linezolid demonstrated good activity against Staphylococcus aureus and streptococci, and were active against 100% of isolates . However, Gram-negative species were also commonly isolated from these sites of infection . Later-generation cephalosporins, represented by ceftriaxone, cefotaxime and cefepime, exhibited a broad spectrum of activity including Enterobacteriaceae, streptococci and methicillin-susceptible S . aureus, but they were not active against methicillin-resistant S . aureus (MRSA) and showed variable activity against Pseudomonas aeruginosa . Using ceftazidime as a marker for extended spectrum beta-lactamase (ESBL) expression, less than 3% of Escherichia coli or Klebsiella pneumoniae expressed this phenotype . Based on current in vitro activity, the third-generation cephalosporins provide broad-spectrum coverage useful for the empirical therapy of suspected bone infections, especially for patients treated in the community or hospitalised with community-acquired infections.

BMC Biol . 2004 May 25;2(1):10.
Structure of GlgS from Escherichia coli suggests a role in protein-protein interactions; Kozlov G et al.; BACKGROUND: The Escherichia coli protein GlgS is up-regulated in response to starvation stress and its overexpression was shown to stimulate glycogen synthesis . RESULTS: We solved the structure of GlgS from E . coli, a member of an enterobacterial protein family . The protein structure represents a bundle of three alpha-helices with a short hydrophobic helix sandwiched between two long amphipathic helices . CONCLUSION: GlgS shows structural homology to Huntingtin, elongation factor 3, protein phosphatase 2A, TOR1 motif domains and tetratricopeptide repeats, suggesting a possible role in protein-protein interactions.

Shanghai Kou Qiang Yi Xue, 1992 Jun, 1(1), 37 - 9
{Chemical analysis of lipopolysac-charides derived from oral anacerobes}; Li DY et al.; Lipopolysaccharides were isolated from six oral anaerobes(Va.Bg.Bf.Fn.Aa.Co.)by the hot phenol-water procedure and purified by PCP method.The six species can be all extracted their LPS with different yields (from 0.70 to 2.83% of cell dried weight).Comparable of LPS with the enterobacteriaceae(Sm.),they were the constructed with hexosamine,fatty acids and phosphorus etc.On the other hand,they showed much distinct differences from the enterobacterial LPS structure as follow:(1) 2-keto-3-deoxy-D-mannooctonate(KDO) was not detected by routine procedure.(2)The amount of heptose is reltively lower.(3) Methylated and branched fatty acids were detected.These chemical characteristics may relate to biological activities and pathogenic potential of LPS and bacteria themselves.

Clin Infect Dis, 2004 Jun 1, 38(11), 1513 - 20 Epub 2004 May 12.
Use of pharmacodynamic end points in the evaluation of gatifloxacin for the treatment of acute maxillary sinusitis; Ambrose PG et al.; The relationship between drug exposure and the time course of antimicrobial effect at the primary infection site for acute maxillary sinusitis has not previously been explored . This single-center, open-label study quantified the time course of sinus sterilization, described gatifloxacin exposure at the infection site, and posed the hypothesis that the use of continuous and quantitative time-related end points may allow for better characterization of drug effect with fewer patients than traditional clinical trial approaches . Of the 12 enrolled patients, 10 were clinically evaluable, from whom 7 pathogens were isolated: 4 Streptococcus pneumoniae, 2 staphylococci, and 1 Enterobacter aerogenes . The median predicted 24-h area under the curve (AUC) in sinus aspirates and plasma samples was 54.7 mg x h/L and 30.1 mg x h/L, respectively . The median 24-h AUC ratio for sinus aspirates and plasma samples was 1.51 (range, 0.88-2.23) . For patients infected with pneumococci, the median time to sinus sterilization was 50 h . The use of quantitative time-related end points may be useful in evaluating the efficacy of antimicrobial agents with fewer patients.

Methods Mol Biol, 2004, 268, 79 - 88
Abundance in sewage of bacteriophages infecting Escherichia coli O157:H7; Muniesa M et al.; Bacterial virulence factors such as toxins are often encoded by bacteriophages . Among other examples, factors encoded by phages have been described in some of the emerging or re-emerging pathogens, including the pyrogenic exotoxin A production in group A streptococci, the cholera toxin in Vibrio cholerae, or enterotoxin production in enterohemorrhagic (EHEC) strains of E . coli.Most described virulence factors in Shiga toxin (Stx)-producing E . coli strains are located in mobile genetic elements such as plasmids and bacteriophages . Stx, which are one of the most important virulence elements in Shiga toxin-producing E . coli (STEC), are encoded in the genome of temperate bacteriophages infecting E . coli and other Enterobacteriaceae.Studies on Stx phages indicate that they are transmitted between different bacteria in vivo and in vitro . Phages could also be transmitted extraintestinally, hence the observed presence of infectious Shiga toxin phages in sewage and in fecally contaminated rivers . Stx phages also show a higher persistence under natural inactivation and disinfectant treatments in aquatic environments.This background shows that phages or lysogenic strains carrying Stx2 phages might be the natural reservoir of Stx2 genes and that lysogenization could be the main cause of the emergence of STEC strains, as suggested by several authors . It has also been suggested that lysogenization/conversion processes could take place in food and water and probably inside the human and animal gut . Ingestion of Stx2 phages could produce conversion of non-Stx2-E . coli strains, present inside the gut and producing new pathogenic strains . To control these phenomena, it is first necessary to gain more information about the distribution of Stx phages in the environment.For this purpose, a method of detecting Stx2 phages present in environmental water samples has been developed . The particularity of this method is that it allows detection of all (infectious and noninfectious) Stx2 phages in a water sample; in a second stage, the method allows detection of those phages able to infect and replicate on E . coli O157:H7 . Although this method has been applied to Stx2 phages able to infect E . coli O157:H7, it is also applicable to detection in the natural environment of other genes carried by other bacteriophages and other bacteria.

Infect Immun, 2004 Jun, 72(6), 3609 - 21
The serine protease motif of EspC from enteropathogenic Escherichia coli produces epithelial damage by a mechanism different from that of Pet toxin from enteroaggregative E . coli; Navarro-Garcia F et al.; EspC (Escherichia coli secreted protein C) of enteropathogenic E . coli (EPEC) shows the three classical domains of the autotransporter proteins and has a conserved serine protease motif belonging to the SPATE (serine protease autotransporters of Enterobacteriaceae) subfamily . EspC and its homolog Pet in enteroaggregative E . coli (EAEC) bear the same sequence within the serine protease motif, and both proteins produce enterotoxic effects, suggesting that like Pet, EspC could be internalized to reach and cleave the calmodulin-binding domain of fodrin, causing actin cytoskeleton disruption . Even though both proteins cause cytoskeleton damage by virtue of their serine protease motifs, the following evidence supports the hypothesis that the mechanisms are different . (i) To obtain similar cytotoxic and cytoskeletal effects, a threefold-higher EspC concentration and a twofold-higher exposure time are needed . (ii) EspC internalization into epithelial cells takes more time (6 h) than Pet internalization (30 min), and the distributions of the two proteins inside the cells are also different . (iii) Both proteins have affinity for fodrin and cleave it, but the cleavage sites are different; EspC produces two cleavages, while Pet produces just one . (iv) EspC does not cause fodrin redistribution within epithelial cells . (v) An EspC serine protease motif mutant, but not a Pet serine protease mutant, competes with EspC by blocking cytoskeletal damage . All these data suggest that the protein conformational structure is very important for the activity of the catalytic site, influencing its interaction with the target protein and its internalization . The differences between these proteins may explain the reduced ability of EspC to cause cytopathic effects . However, these differences may confer a specialized role on EspC in the pathogenesis of EPEC, which is different from that of Pet in EAEC pathogenesis.

Antimicrob Agents Chemother, 2004 Jun, 48(6), 2277 - 9
Nosocomial outbreak of extended-spectrum beta-lactamase SHV-5-producing isolates of Pseudomonas aeruginosa in Athens, Greece; Poirel L et al.; Seven nonrepetitive Pseudomonas aeruginosa isolates producing the clavulanic acid-inhibited extended-spectrum beta-lactamase SHV-5 were isolated in the same hospital in Athens, Greece, from 1998 to 2002 . All isolates except one were clonally related, and the bla(SHV-5) gene was chromosomally located . This study underlined that this gene, which is widespread in Enterobacteriaceae in Greece, may disseminate also in P . aeruginosa.

Antimicrob Agents Chemother, 2004 Jun, 48(6), 2153 - 8
Omp35, a new Enterobacter aerogenes porin involved in selective susceptibility to cephalosporins; Bornet C et al.; In Enterobacter aerogenes, beta-lactam resistance often involves a decrease in outer membrane permeability induced by modifications of porin synthesis . In ATCC 15038 strain, we observed a different pattern of porin production associated with a variable antibiotic susceptibility . We purified Omp35, which is expressed under conditions of low osmolality and analyzed its pore-forming properties in artificial membranes . This porin was found to be an OmpF-like protein with high conductance values . It showed a noticeably higher conductance compared to Omp36 and a specific location of WNYT residues in the L3 loop . The importance of the constriction region in the porin function suggests that this organization is involved in the level of susceptibility to negative large cephalosporins such as ceftriaxone by bacteria producing the Omp35 porin subfamily.

Antimicrob Agents Chemother, 2004 Jun, 48(6), 2049 - 55
Antimicrobial activities of garenoxacin (BMS 284756) against Asia-Pacific region clinical isolates from the SENTRY program, 1999 to 2001; Christiansen KJ et al.; Between 1999 and 2001, 16,731 isolates from the Asia-Pacific Region were tested in the SENTRY Program for susceptibility to six fluoroquinolones including garenoxacin . Garenoxacin was four- to eightfold less active against Enterobacteriaceae than ciprofloxacin, although both drugs inhibited similar percentages at 1 microg/ml . Garenoxacin was more active against gram-positive species than all other fluoroquinolones except gemifloxacin . For Staphylococcus aureus, oxacillin resistance was high in many participating countries (Japan, 67%; Taiwan, 60%; Hong Kong, 55%; Singapore, 52%), with corresponding high levels of ciprofloxacin resistance (57 to 99%) in oxacillin-resistant S . aureus (ORSA) . Of the ciprofloxacin-resistant ORSA isolates, the garenoxacin MIC was >4 microg/ml for only 9% of them . For Streptococcus pneumoniae, penicillin nonsusceptibility and macrolide resistance were high in many countries . No relationship was seen between penicillin and garenoxacin susceptibility, with all isolates being susceptible at <2 microg/ml . There was, however, a partial correlation between ciprofloxacin and garenoxacin MICs . For ciprofloxacin-resistant isolates for which garenoxacin MICs were 0.25 to 1 microg/liter, mutations in both the ParC and GyrA regions of the quinolone resistance-determining region could be demonstrated . No mutations conferring high-level resistance were detected . Garenoxacin shows useful activity against a wide range of organisms from the Asia-Pacific region . In particular, it has good activity against S . aureus and S . pneumoniae, although there is evidence that low-level resistance is present in those organisms with ciprofloxacin resistance.

Antimicrob Agents Chemother, 2004 Jun, 48(6), 1960 - 7
Nosocomial spread of ceftazidime-resistant Klebsiella pneumoniae strains producing a novel class a beta-lactamase, GES-3, in a neonatal intensive care unit in Japan; Wachino J et al.; Klebsiella pneumoniae strain KG525, which showed high-level resistance to broad-spectrum cephalosporins, was isolated from the neonatal intensive care unit (NICU) of a Japanese hospital in March 2002 . The ceftazidime resistance of strain KG525 was transferable to Escherichia coli CSH-2 by conjugation . Cloning and sequence analysis revealed that production of a novel extended-spectrum class A beta-lactamase (pI 7.0), designated GES-3, which had two amino acid substitutions of M62T and E104K on the basis of the sequence of GES-1, was responsible for resistance in strain KG525 and its transconjugant . The bla(GES-3) gene was located as the first gene cassette in a class 1 integron that also contained an aacA1-orfG fused gene cassette and one unique cassette that has not been described in other class 1 integrons and ended with a truncated 3' conserved segment by insertion of IS26 . Another five ceftazidime-resistant K . pneumoniae strains, strains KG914, KG1116, KG545, KG502, and KG827, which were isolated from different neonates during a 1-year period in the same NICU where strain KG525 had been isolated, were also positive for GES-type beta-lactamase genes by PCR . Pulsed-field gel electrophoresis and enterobacterial repetitive intergenic consensus-PCR analyses displayed genetic relatedness among the six K . pneumoniae strains . Southern hybridization analysis with a GES-type beta-lactamase gene-specific probe showed that the locations of bla(GES) were multiple and diverse among the six strains . These findings suggest that within the NICU setting genetically related K . pneumoniae strains carrying the bla(GES) gene were ambushed with genetic rearrangements that caused the multiplication and translocation of the bla(GES) gene.

Antimicrob Agents Chemother, 2004 Jun, 48(6), 1934 - 40
The magnitude of the association between fluoroquinolone use and quinolone-resistant Escherichia coli and Klebsiella pneumoniae may be lower than previously reported; Bolon MK et al.; Case-control analyses of resistant versus susceptible isolates have implicated fluoroquinolone exposure as a strong risk factor for fluoroquinolone-resistant isolates of Enterobacteriaceae . We suspect that such methodology may overestimate this association . A total of 84 cases with fluoroquinolone-resistant isolates and 578 cases with fluoroquinolone-susceptible isolates of Escherichia coli or Klebsiella pneumoniae were compared with 608 hospitalized controls in parallel multivariable analyses . For comparison of previous estimates, the results of 10 published case-control studies of risk for fluoroquinolone resistance in isolates of Enterobacteriaceae were pooled by using a random-effects model . Exposure to fluoroquinolones was significantly positively associated with fluoroquinolone resistance (odds ratio {OR}, 3.17) and negatively associated with fluoroquinolone susceptibility (OR, 0.18) . Multivariable analyses yielded similar estimates (ORs, 2.04 and 0.10, respectively) . As data on antibiotic exposure were limited to inpatient prescriptions, misclassification of fluoroquinolone exposure in persons who received fluoroquinolones as outpatients may have led to an underestimation of the true effect size . Pooling the results of previously published studies in which a direct comparison of fluoroquinolone-resistant and fluoroquinolone-susceptible cases was used resulted in a markedly higher effect estimate (OR, 18.7) . Had we directly compared resistant and susceptible cases, our univariate OR for the association between fluoroquinolone use and the isolation of resistant Enterobacteriaceae would have been 19.3, and the multivariate OR would have been 16.5 . Fluoroquinolone use is significantly associated with the isolation of fluoroquinolone-resistant Enterobacteriaceae; however, previous studies likely exaggerated the magnitude of this association.

Expert Opin Pharmacother, 2004 May, 5(5), 1117 - 52
Gemifloxacin: a new fluoroquinolone; Blondeau JM et al.; Gemifloxacin is a dual targeted fluoroquinolone with potent in vitro activity against Gram-positive, -negative and atypical human pathogens--pathogens considered to be important causes of community-acquired respiratory tract infections . Gemifloxacin demonstrates impressive minimal inhibitory concentrations (MIC 90 ) values against clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydia pneumoniae and Legionella spp., with MIC 90 values reported to be 0.016-0.06, < 0.0008-0.06, 0.008-0.3, 0.25, 0.125 and 0.016-0.07 microg/ml, respectively . Gemifloxacin is also active in vitro against a broad range of Gram-negative bacilli with MIC 90 values against the Enterobacteriaceae in the range of 0.016 to > 16 microg/ml ( Escherichia coli and Providencia stuartii, respectively), with the majority of the genus having MIC 90 drug concentrations < 0.5 microg/ml . The in vitro activity of gemifloxacin against anaerobic organisms is variable . The MIC values for gemifloxacin are not affected by beta-lactamase production nor by penicillin or macrolide resistance in S . pneumoniae . Gemifloxacin is approved by the FDA to be clinically efficacious against multi-drug resistant S . pneumoniae . The pharmacokinetics of gemifloxacin are such that the drug can be administered orally once-daily to yield or achieve sustainable drug concentrations exceeding the MIC values of clinically important organisms . Gemifloxacin has been shown to target both DNA gyrase (preferred target) and topoisomerase IV (secondary target) - enzymes critical for DNA replication and organism survival - against clinical isolates of S . pneumoniae . This dual targeting activity is thought to be important for reducing the likelihood for selecting for quinolone resistance . Gemifloxacin has been investigated and approved for therapy in patients with community-acquired pneumonia (CAP) and acute exacerbations of chronic bronchitis . In one study, more patients receiving gemifloxacin compared to clarithromycin remained free of exacerbations for longer periods of time (p < 0.016) and gemifloxacin had a shorter time to eradication of H . influenzae than did clarithromycin (p < 0.02) . From efficacy studies, gemifloxacin was found to have an adverse profile that was comparable with other compounds . The most frequent side effects were diarrhoea, abdominal pain and headache . Gemifloxacin is a welcomed addition to currently available agents for the treatment of community-acquired lower respiratory tract infections . Other potential indications appear to be within the spectrum of this compound.

J Biol Chem, 2004 Jul 23, 279(30), 31495 - 504 Epub 2004 May 19.
Hydrophobic residues of the autotransporter EspP linker domain are important for outer membrane translocation of its passenger; Velarde JJ et al.; The autotransporter family of proteins is an important class of Gram-negative secreted virulence factors . Their secretion mechanism comprises entry to the periplasm via the Sec apparatus, followed by formation of an outer membrane beta barrel, which allows the N-terminal passenger domain to pass to the extracellular space . Several groups have identified a region immediately upstream of the beta domain that is important for outer membrane translocation, the so-called linker region . Here we characterize this region in EspP, a prototype of the serine protease autotransporters of enterobacteriaceae . We hypothesized that the folding of this region would be important in the outer membrane translocation process . We tested this hypothesis using a mutagenesis approach in conjunction with a series of nested deletions and found that in the absence of a complete passenger, mutations to the C-terminal helix, but not the upstream linker, significantly decrease secretion efficiency . However, in the presence of the passenger mutations to the amino-terminal region of the linker decrease secretion efficiency . Moreover, amino acids of hydrophobic character play a crucial role in linker function, suggesting the existence of a hydrophobic core or hydrophobic interaction necessary for outer membrane translocation of autotransporter proteins.

J Food Prot, 2004 May, 67(5), 966 - 71
Microbiological quality of rabbit meat; Rodriguez-Calleja JM et al.; World rabbit meat production is estimated to be over 1 million tons, and Spain is the third largest producer . Although rabbit meat is marketed and consumed worldwide, information on microbiological quality is very scarce . Here, we report indicator organisms, spoilage flora, sensory quality, and some physicochemical traits of 24 h postmortem chilled rabbit carcasses and prepackaged rabbit meat stored chilled in air for 0 to 3 days at the retail level . The mean total bacterial count (4.01 +/- 0.48 log CFU/g) for carcasses dressed at a small abattoir by a manual process was significantly lower (P < 0.05) than that (4.96 +/- 0.90 log CFU/g) for carcasses dressed at a large abattoir in automated slaughter lines . Both groups of carcasses had mean pH values of 5.98 . The dominant contaminants on carcasses from the small abattoir were Pseudomonas, lactic acid bacteria, and yeasts . These microorganisms and Brochothrix thermosphacta were dominant on carcasses from the large abattoir . On prepacked hind legs (pH 6.26 +/- 0.18) stored at -1 to +1 degree C (supermarket 1), mean aerobic mesophilic count was 5.87 +/- 1.03 log CFU/g, and the major microbial groups were Pseudomonas, yeasts, lactic acid bacteria, and B . thermosphacta . On prepacked whole carcasses (pH 6.37 +/- 0.18) displayed at -1 to +5 degrees C (supermarket 2), mean aerobic mesophilic count was 6.60 +/- 1.18 and the same microbial groups were dominant . Relative Escherichia coli incidence was supermarket 2 > large abattoir > supermarket 1 > small abattoir . Overall, low numbers of coliforms, Enterobacteriaceae, psychrotrophic clostridia, coagulase-positive staphylococci, and molds were found . Sensory scores, pH values, and L-lactic acid content differentiated fresh carcasses from retail samples . Data obtained suggest that the microflora of chilled rabbit meat are different from those found on the meat of other animals.

J Food Prot, 2004 May, 67(5), 960 - 5
Relation of biogenic amines with microbial and sensory changes of whole and filleted freshwater rainbow trout (Onchorynchus mykiss) stored on ice; Chytiri S et al.; The biogenic amine (BA) content of whole and filleted rainbow trout was monitored during ice storage for a period of 18 days and related to respective microbial and sensorial changes occurring during the same period . Eight amines, namely, putrescine, cadaverine, tyramine, spermidine, tryptamine, beta-phenylethylamine, spermine, and histamine, were determined . Agmatine was not detected in any of the fish samples . In all cases, concentration of BAs was higher (P < 0.05) in filleted compared with whole trout samples . Pseudomonads, H2S-producing bacteria, and, to a lesser extent, Enterobacteriaceae were the dominant microorganisms in both whole and filleted trout . Higher populations (P < 0.05) of these microorganisms were present in filleted trout compared with whole fish samples . Of the BAs determined, concentration of putrescine, cadaverine, spermidine, tryptamine, and beta-phenylethylamine increased steeply in both whole and filleted trout between days 15 and 18 of storage when pseudomonads and H2S-producing bacteria reached approximately 10(6) to 10(7) CFU/g . For the rest of the BAs, including tyramine, histamine, and spermine, a stepwise increase was recorded throughout the entire storage period . Interestingly, Enterobacteriaceae counts remained below 10(6) throughout the entire storage period, accounting for the lower production of histamine . A putrescine value of 13 to 14 mg/kg and a spermidine value of approximately 7 mg/kg for both the whole and filleted trout obtained after 12 and 9 days, respectively, may be proposed as the upper limit for spoilage initiation (freshness indicator) of fresh rainbow trout based on sensorial and microbiological (total viable count of 10(6) to 10(7)) data . With respect to other amines determined, both tyramine and spermine may also be proposed as freshness indicators preferably for whole trout, whereas tryptamine, beta-phenylethylamine, histamine, and cadaverine produced only during later stages of storage are not suitable as freshness indicators of either whole or filleted trout.

J Antimicrob Chemother, 2004 Jul, 54(1), 134 - 8 Epub 2004 May 18.
Evaluation of a new cefepime-clavulanate ESBL Etest to detect extended-spectrum beta-lactamases in an Enterobacteriaceae strain collection; Sturenburg E et al.; OBJECTIVES: In this study, we evaluated the performance of a new ESBL Etest configuration based on clavulanate synergy with cefepime compared with cefotaxime-clavulanate and ceftazidime-clavulanate ESBL Etest strips for the detection of extended-spectrum beta-lactamases (ESBL) in an Enterobacteriaceae strain collection, with special focus on Enterobacter spp . METHODS: Overall, a total of 54 clinical isolates of ESBL-producing Enterobacteriaceae species were evaluated: Enterobacter aerogenes (n=3), Enterobacter cloacae (n=10), Escherichia coli (n=10), Klebsiella oxytoca (n=3), Klebsiella pneumoniae (n=25) and Proteus mirabilis (n=3) . To check Etest behaviour with resistance phenotypes similar to ESBL, our panel was expanded by six clinical isolates of K . oxytoca that were identified as putative producers of their chromosomal K1 beta-lactamase . RESULTS: With this panel, ESBL Etest was 98% sensitive with cefepime-clavulanate, 83% with cefotaxime-clavulanate, and 74% with ceftazidime-clavulanate strips . Concentrating on Enterobacter spp., reliable ESBL detection could only be achieved by the new cefepime-clavulanate strip since it confirmed ESBL production in all strains (100% sensitivity) whereas only 4/13 (31%) of Enterobacter strains were positive using cefotaxime-clavulanate or ceftazidime-clavulanate strips . A limitation of using the new cefepime strip was less than optimal specificity with K1 phenotypes of K . oxytoca: among six strains, four isolates were scored false-positive by Etest strips containing cefepime-clavulanate . CONCLUSION: The new Etest ESBL strip containing cefepime-clavulanate is a valuable supplement to current methods for detection of ESBLs . In our study collection, the cefepime-clavulanate strip was the best configuration for detection of ESBLs, particularly in Enterobacter spp.

J Antimicrob Chemother, 2004 Jul, 54(1), 173 - 7 Epub 2004 May 18.
Relationship between ceftriaxone use and resistance to third-generation cephalosporins among clinical strains of Enterobacter cloacae; Muller A et al.; OBJECTIVE: To investigate the potential correlation between the use of extended-spectrum cephalosporins (ESCs) and resistance to this antibiotic class among clinical isolates of Enterobacter cloacae in a university-affiliated hospital . MATERIALS AND METHODS: Data on antimicrobial resistance and antimicrobial use concerning E . cloacae and ESCs were collected over a 4 year period . Various statistical tools were used to explore the potential relationship . RESULTS: From 1999 to 2002, the proportion of E . cloacae isolates resistant to ESCs increased from 24.3% to 29.6% . (P=0.04), and the quantity of ESCs prescribed and given did not change . Within the subclass constituted by first-line ESCs, the proportion of ceftriaxone increased from 64.3% to 77.6% and the proportion of cefotaxime decreased accordingly, from 35.7% to 22.4% . Statistical analyses showed that E . cloacae resistance to ESCs correlated with ceftriaxone use regardless of the other ESCs . For every defined daily dose of ceftriaxone per 1000 patient days used in our hospital, resistance of E . cloacae isolates to ESCs increased by 1.36% . CONCLUSION: This study demonstrates a specific correlation between ceftriaxone use and the development of resistance in E . cloacae clinical isolates . The high biliary elimination of ceftriaxone compared with other ESCs may be responsible for a greater impact of this antibiotic on the digestive flora.

Eur J Clin Microbiol Infect Dis, 2004 Jun, 23(6), 456 - 62 Epub 2004 May 18.
Factors associated with antimicrobial resistance among clinical isolates of Klebsiella pneumoniae: 1-year survey in a French university hospital; De Champs C et al.; Klebsiella pneumoniae is an opportunistic pathogen responsible for nosocomial infections . Both resistance to multiple antibiotics and the expression of virulence factors are likely to be involved in the physiopathological process . In this study, 227 isolates of K . pneumoniae collected over a 1-year period in a teaching hospital in Clermont-Ferrand, France, were investigated for their antibiotic resistance pattern and the presence of several potential virulence traits . Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) indicated that most of the isolates were phylogenetically unrelated . When tested in an in vitro adhesion assay with Int-407 intestinal cells, the median adhesion index was 5.5x10(4) bacteria/cm(2) (range, 2.0x10(2)-3.4x10(5)) . Isolates resistant to cefoxitin, chloramphenicol, and quinolones showed significantly lower adhesion indexes . The frequency of mutagenesis conferring resistance to rifampicin was low for most of the isolates . The median mutagenesis frequency was 1.0x10(-8) (range, 2.5x10(-9)-3.2x10(-6)) at 24 h and 1.1x10(-8) (range, 1.8x10(-9)-1.2x10(-5)) at 7 days . In contrast, isolates resistant to cefoxitin, chloramphenicol, and tetracycline showed a significantly greater ability to mutate . These results suggest a link between adhesion capabilities and resistance to certain antibiotics . They furthermore indicate that strains with a high mutagenesis capacity are more likely to acquire antibiotic resistance genes . The high pathogenicity island of Yersinia was detected in 16.3% of the strains and was more often associated with isolates resistant to nalidixic acid and augmentin.

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