Enterococcus faecium resistente a glucopéptidos. Análisis del genotipo de resistencia,virulencia y líneas genéticas

Objective

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.

Methods

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).

Results

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.

Conclusion

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