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Here we report the presence and expression levels of the vanC 1 and vanC 2/3 genes in vancomycin-susceptible strains of Enterococcus faecalis. The vanC 1 and vanC 2/3 genes were located in the plasmid DNA and on the chromosome, respectively. Specific mRNA of the vanC 1 gene was detected in one of these strains. Additionally, analysis of the vanC gene sequences showed that these genes are related to the vanC genes of Enterococcus gallinarum and Enterococcus casseliflavus. The presence of vanC genes is useful for the identification of E. gallinarum and E. casseliflavus. Moreover, this is the first report of vanC mRNA in E. faecalis.

Abstract: Aim of the study: The aim of this study was to evaluate the rate of glycopeptides-resistant enterococci (GRE) fecal carriage (species and resistance determinants). Strains isolated between 1999 and 2005 during systematic screening for multiresistant bacteria in patients hospitalized in 3 intensive care units (ICU) of the University Hospital of Montpellier were studied. Methods: The systematic screening was weekly performed. Rectal swabs were cultured on D-Coccosel agar medium containing 4 mg/l vancomycin and MICs for vancomycin and teicoplanin were determined by E-test. Strains were subjected to both phenotypic and genotypic identification and vanA, vanB and vanC genes were detected by PCR. Results: We analyzed 13003 samples for 5113 patients. Among them, 401 (7.84%) patients were GRE carriers with 280 Enterococcus gallinarum (vanC1 ), 102 Enterococcus casseliflavus–flavescens (vanC2-C3 ), 5 Enterococcus faecalis (3 vanA, 2 vanB), and 14 Enterococcus faecium (10 vanA, 4 vanB). A unique case of cross contamination between two patients was observed. During the same time, only one strain of GRE was isolated during an infectious process in another unit. Carriage rate of E. faecium and E. faecalis vanA or vanB was 0.37%: 68.4, 21 and 10.6% in the gastrointestinal, in the polyvalent and the respiratory ICU, respectively. Conclusion: Our results were in agreement with national data showing a relatively low GRE fecal carriage rate in ICUs, E. faecium vanA being the mainly encountered GRE. Since 2004, GRE detection is increasingly reported in France and an emerging E. faecium vanA clone has been identified during outbreaks. In contrast, only one E. faecium vanB strain has been isolated in our institution since this date and a unique strain of E. faecalis vanA was isolated during an infectious process since 1999. These data underlined the efficacy of transmission prevention measures established when GRE are identified. [Copyright &y& Elsevier]