High level resistance to gentamicin and vancomycin in enterococci isolated from poultry in Argentina

Abstract

In chicken husbandry, antimicrobial resistance among enterococci has been observed. Glycopeptides and gentamicin MinimumInhibitory Concentrations in fecal poultry enterococci were determined. Glycopeptide and high-level gentamicin resistance(HLGR) genes were investigated. E. faecalis (n = 105) and E. faecium (n = 70) were the predominant species. In E. faecalis, HLGR(19%) was observed. In high-level gentamicin resistant E. faecalis, presence of aac (6´) -Ie-aph (2´´)-Ia gene was confirmed. VanA E.faecium (7.1%) were found, with HLGR (20%) and high-level streptomycin resistance (40%). vanA genotype was detected inglycopeptide resistant E. faecium (100%). These results highlight the presence of horizontally transferable antimicrobialresistance determinants in E. faecalis and E. faecium recovered from poultry. Existence of enterococcal reservoirs in poultry shouldbe taken into account as a potential source of antimicrobial resistance genes, strengthening their potential spread to humansthrough the food chain of horizontal transferable resistance determinants.