Genomic diversity of vancomycin-resistant Enterococcusfaecium isolated in France
Abstract number: p1342
Mihaila-Amrouche L., Loubinoux J., Doloy A., Collobert G., Gaitch N., Bouvet A.
Vancomycin-resistant Enterococcusfaecium (VREF) has emerged as a nosocomial pathogen in the USA but remains rare in Europe. An increase of VREF incidence was observed in France (0.4% in 2003 to 2.9% in 2004). Thus, we compared 78 VREF strains isolated from 2004 to 2005 in different regions of France.
Clinical data from the colonised or infected patients were collected. Identification of VREF isolates was first performed with the rapid ID32 STREP commercialized systems (bioMérieux, Marcy l'Etoile, France) and then confirmed by species-specific PCR amplification of the D alanine-D alanine ligase genes. Antimicrobial susceptibility to 11 antibiotics was determined by the agar diffusion method according to the guidelines of the 'Comité de l'Antibiogramme de la Société Française de Microbiologie' (http://www.sfm.asso.fr). For beta-lactams and glycopeptides, the minimal inhibitory concentrations (MICs) were also determined. The genes vanA, vanB, vanC1 and vanC2/3 responsible for resistance to glycopeptides were identified by multiplex PCR. Clonality of isolates was studied by pulsed-field gel electrophoresis (PFGE) after digestion of DNA with SmaI.
VREF isolates were more often responsible for colonisation than infection. Most of the isolates (74/78) were resistant to penicillin G, amoxicillin, and piperacillin (MICs>256 mg/L). Intermediate susceptibility to amoxicillin was observed for 4 strains. Most of the strains (76/78) were resistant to macrolides. Resistance to aminoglycosides and tetracycline was variable. All strains were resistant to vancomycin (MICs 24256 mg/L), and intermediate or resistant to teicoplanine (MICs 6256 mg/L). All strains but one had the gene vanA. PFGE identified fourteen different clones.
Resistance to glycopeptides in VREF isolates was mainly due to the presence of the gene vanA. More than 10 different clones were identified by PFGE. These results demonstrate the genomic diversity of VREF isolated in France. A single clone was present in some hospitals. Thus, the transmission of VREF isolates between patients must be taken into account for the prevention of these nosocomial infections.
|Session name:||XXIst ISTH Congress|
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