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 strai