A multiplex PCR for the simultaneous detection of five virulence genes (asa1, gelE, cylA, esp, and hyl) in enterococci was developed. The presence of these genes was investigated in 153 clinical and 118 fecal Enterococcus faecium isolates from inpatients at an increased risk of developing infections (such as patients in intensive care units and hematology wards) from 13 hospitals in eight European countries. Of the 271 E. faecium isolates, 135 were vancomycin resistant E. faecium (VREF) isolates and 136 were vancomycin susceptible E. faecium (VSEF) isolates. Susceptibilities to ampicillin, gentamicin, streptomycin, vancomycin, teicoplanin, ramoplanin, quinupristin-dalfopristin, and linezolid were tested by the microdilution method. Overall, the prevalence of esp was significantly higher (P ؍ 0.03) in clinical VREF isolates (92%) than in fecal VREF isolates (73%). In Italy, the prevalence of esp was significantly higher (P ؍ 0.02) in VREF isolates (91%) than in VSEF isolates (68%), whereas in the United Kingdom, hyl was significantly more prevalent (P ؍ 0.01) in VREF isolates (71%) than in VSEF isolates (29%). No significant differences were found for the other countries. Pulsed-field gel electrophoresis was used to check the clonality among the strains tested and showed the spread of two center-specific (esp-positive) VREF clones in Italy and one center-specific (hyl-positive) clone in the United Kingdom. These clones were resistant to ampicillin, gentamicin, and streptomycin. The multiplex PCR reported in this study is a convenient and rapid method for the simultaneous detection of the virulence genes asa1, gelE, cylA, esp, and hyl in enterococci. Molecular analysis showed the intrahospital spread of esp-positive VREF clones (in Italy) and hyl-positive VREF clones (in the United Kingdom); the role of hyl remains to be elucidated.Enterococci form part of the normal flora of both the human and the animal gastrointestinal tract. However, vancomycinresistant enterococci have emerged as a major cause of nosocomial infections (28). Several virulence factors have been described in enterococci, for instance, aggregation substance (14), gelatinase (39), cytolysin (4), enterococcal surface protein (38), and, very recently, hyaluronidase (35). The first four virulence factors are found in Enterococcus faecalis, while the fourth and fifth virulence factors are specific for Enterococcus faecium.
BackgroundAn altered gut microbiota composition has recently been linked to obesity. The principal aim of this study is to investigate and compare the gut microbiota composition in obese and lean children. Secondly, associations between analysed gut bacterial species, dietary compounds, energy intake and biochemical blood parameters are evaluated.MethodsIn this prospective cross-sectional study, 26 overweight/obese (mean BMI: 28.7 ± 6.5) and 27 lean (mean BMI: 16.5 ± 2.1) children aged 6 to 16 were included. Faecal samples were collected and subjected to selective plating and quantitative real-time PCR (qPCR) in order to determine the concentrations of bacterial species belonging to the genera: Bacteroides, Bifidobacterium, Clostridium, Staphylococcus and Lactobacillus. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was applied for an in-depth identification of species of Bacteroides fragilis group. Differences in the concentrations of gut bacterial species between obese and lean children were statistically analysed using Mann Whitney U test. Subsequently, random forest analysis and multiple linear regression analysis were performed in order to test associations between gut bacterial species, dietary compounds and blood parameters.ResultsObese children showed an elevated Firmicutes-to-Bacteroidetes ratio compared with lean children. Furthermore, low relative proportions of B. vulgatus and high concentrations of Lactobacillus spp. were observed in the obese microbiota. In all children, Staphylococcus spp. were positively associated with energy intake. Additionally, in obese children, Lactobacillus spp. were positively associated with plasma hs-CRP.ConclusionsOur findings corroborate a significant difference in the gut microbiota composition of important bacterial species between obese and lean children. In future, non-invasive manipulation of gut microbiota composition in early infancy could offer a new approach to manage childhood obesity and associated disorders.
An open reading frame (hyl(Efm)) with homologies to previously described hyaluronidase genes has been identified in nonstool isolates of Enterococcus faecium. E. faecium isolates (n=577) from diverse sources were screened for the presence of hyl(Efm) and esp(Efm), a putative virulence gene associated with epidemic E. faecium strains. The presence of esp(Efm) was roughly twice that of hyl(Efm), but both were found primarily in vancomycin-resistant E. faecium isolates in nonstool cultures obtained from patients hospitalized in the United States. These data suggest that specific E. faecium strains may be enriched in determinants that make them more likely to cause clinical infections. Differences in the prevalence of these strains may help explain variations in the clinical importance of multiresistant E. faecium across different continents.
ObjectiveWe investigated the association between body mass index (BMI) standard deviation score (SDS) and prenatal exposure to hexachlorobenzene, dichlorodiphenyldichloroethylene (DDE), dioxin-like compounds, and polychlorinated biphenyls (PCBs).MethodsIn this prospective birth cohort study, we assessed a random sample of mother–infant pairs (n = 138) living in Flanders, Belgium, with follow-up until the children were 3 years of age. We measured body mass index as standard deviation scores (BMI SDS) of children 1–3 years of age as well as pollutants measured in cord blood.ResultsDDE correlated with BMI SDS, with effect modification by maternal smoking and the child’s age. At 1 year, children of smoking mothers had higher BMI SDS than did children of nonsmoking mothers. At 3 years, this difference was reduced because of the faster rate of decline in BMI SDS in the former group. This relationship held except for children with high levels of DDE. DDE had a small effect on BMI SDS at 3 years of age in children of nonsmoking mothers (difference in BMI SDS for DDE concentrations between the 90th and 10th percentiles = 0.13). On the other hand, smoking enhanced the relation between DDE and BMI SDS at 3 years (difference in BMI SDS for DDE concentrations between the 90th and 10th percentiles = 0.76). Increasing concentrations of PCBs were associated with higher BMI SDS values at all ages (parameter estimate = 0.003 ± 0.001; p = 0.03).ConclusionIn this study we demonstrated that intrauterine exposure to DDE and PCBs is associated with BMI during early childhood. Future studies are warranted to confirm our findings and to assess possible mechanisms by which these pollutants could alter energy metabolism.
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