We studied 138 glycopeptide-resistant enterococci (GRE) strains, consisting of 131 glycopeptide-resistant Enterococcus faecium (GREfm) and 7 glycopeptide-resistant Enterococcus faecalis (GREfs). The GREfm strains were resistant to penicillin, ampicillin, vancomycin, and teicoplanin, while the GREfs strains were only resistant to vancomycin and teicoplanin. The van A gene was the only glycopeptide determinant present in all GRE isolates investigated. Genes coding for Hyl and Hyl+ Esp were detected in 39 (29.8%) and 92 (70.2%) of the 131 GREfm isolates, respectively. Three of the 7 GREfs were positive for gelE+asa 1 genes, 3 for gel E gene, and 1 for asa 1 gene. The genetic relationship between the 138 GRE was analyzed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). GREfm isolates were clustered in a single genogroup (pulsotype A), and GREfs were clustered in six genogroups (pulsotypes B-G). Among the isolates investigated by MLST, only 18 PCR products were sequenced (12 E. faecium and 6 E. faecalis), and 9 sequence types (STs) were identified. 1. Introduction Enterococci form part of the normal flora of both the human and animal gastrointestinal tract but are also found in other anatomical sites including the vagina and oral cavity. Of the 20 enterococcal species known, Enterococcus faecalis and Enterococcus faecium are among the leading causes of several human infections, including bacteremia, septicemia, endocarditis, urinary tract infections, wound infections, neonatal sepsis, and meningitidis. Glycopeptide-resistant enterococci (GRE) are a mutant of Enterococcus that originally developed in individuals exposed to antibiotics. They have increasingly emerged as a major cause of nosocomial infections worldwide [1]. This emergence has been associated with gradual replacement of Enterococcus faecalis by Enterococcus faecium and an epidemic rise of vancomycin-resistant E. faecium [2]. Vancomycin is the antibiotic of choice for infections caused by penicillin-resistant strains, alone or in combination with aminoglycosides. Acquired vancomycin resistance to this organism greatly reduces the number of treatment options and, therefore, constitutes a major therapeutic concern. This problem is further compounded by the fact that resistance genes can potentially be transferred to other pathogenic organisms such as Staphylococcus aureus. GRE strains were reported for the first time in France and the United Kingdom in 1988 [3], and then in the USA [4]. In France, the incidence of glycopeptide resistance in E. faecium bacteremia is
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