[Glycopeptide-resistant Enterococcus faecium. Analysis of the resistance genotype, virulence and genetic lines]

The objective of this study was to analyse the genotypic characteristics of all Enterococcus isolates with acquired vancomycin resistance (VRE) recovered in the Hospital Clinic (Barcelona, Spain) in a period of three years and two months.

All VRE isolated in the referred Hospital in the period January 2004-March 2007 were included in the study. The vancomycin resistance mechanism was investigated, as well as other antibiotic resistance mechanisms. Isolates were also typed by pulsed-field-gel-electrophoresis (PFGE) and multi-locus-sequence-typing (MLST).

Thirty-nine VRE were recovered, all being identified as E. faecium, representing 2% of total enterococci obtained in that period. Thirty-eight of them carried the vanA gene, and one isolate the vanB2 gene. The 39 VRE were classified into 13 different pulsotypes (A-M), with one main pulsotype, A, which included 13 isolates. The sequence type was identified by MLST in 24 VRE (with unrelated or closely-related PFGE patterns), and they were ascribed to the clonal complex CC17, but two classified as CC9. All VRE showed a multiresistance phenotype, including, in most cases ampicillin, ciprofloxacin, erythromycin, streptomycin, gentamicin, kanamycin and chloramphenicol, harbouring multiple antibiotic resistance genes. The presence of esp and/or hyl genes was identified in 37 VRE.

All VRE, but one, showed the vanA genotype and they were mostly ascribed to the high-risk clonal complex CC17.