Antibiotic resistance genes and virulence factors in Enterococcus faecium and Enterococcus faecalis from diseased farm animals: pigs, cattle and poultry

Abstract

AbstractEighty enterococcal isolates (E. faecium, n=38,E. faecalis, n=42) from diseased farm animals (swine, cattle, poultry) in Lithuania have been studied for the prevalence of antibiotic resistance and for resistance and virulence genetic determinants. 86% ofE. faeciumand 71% ofE. faecalisisolates were multidrug resistant (resistant to three or more unrelated antibiotics). Resistance to aminoglycosides, tetracycline and erythromycin was found most frequently in both species (61%, 69%) and was linked toaph(3’)-IIIa,aac(6’)-Ie-aph(2”)-Ia,ant(6)-Ia (aminoglycoside resistance),tetM,tetL(tetracycline resistance),ermA,ermB(erythromycin resistance) gene combinations, which were supplemented with chloramphenicol resistance genescatA7,catA8(E. faecalis) andcatA9(E. faecium). AllE. faecalisisolates harboured genes coding for virulence factorsagg,esp,fsr gelEalone or in combinations with the high prevalence ofespgene in isolates from cattle (63%) and pigs (79%). The origin- dependent incidence ofagggene variantsprgBandasp1was observed. The results indicate the existence of a large pool of potentially virulent and multidrug resistantE. faecalisin diseased farm animals posing risk to humans.