Genetic characterization of vancomycin-resistant enterococci isolates from wild rabbits.

The presence of van A-containing E. faecium isolates was demonstrated in three of 77 faecal samples (3.9%) of wild rabbits recovered in Portugal. Enterococcal strains with intrinsic vancomycin resistance (van C-1 or van C-2/3 gene) were found in five (6.5%) and three (3.9%) faecal samples, respectively. The mechanisms of resistance for other antibiotics were studied in these vancomycin-resistant isolates. All van A strains showed resistance for tetracycline [with the presence of tet (L) gene, associated or not with tet (M) gene] and for erythromycin [with the presence of the erm (B) gene]. Two isolates were resistant to ciprofloxacin and one to ampicillin. Two van C-1 strains and one van C-2/3 strain were tetracycline resistant [containing the tet (M) gene associated with tet (L) gene] and erythromycin resistant [with erm (B) gene]. Two van C-1 and two van C-2/3 strains were also ciprofloxacin resistant and one van C-1 strain was, additionally, resistant to quinupristin-dalfopristin. The two remaining isolates (van C-1, van C-2/3) did not show resistance for any additional antibiotic. The intestinal tract of wild rabbits could be a reservoir of van A-containing enterococci. Copyright 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.