Antimicrobial Resistance of Enterococci from Wild Animals in Slovakia

The spread of antibiotic resistant strains is not limited to the clinical environment, but the emergence of resistant bacteria and antibiotic resistance genes in the environment has now become one of the environmental pollution factors. As a model organism for the study of the spread of antibiotic resistance genes, which are a part of digestive tract, we decided to use the genus of Enterococcus isolated from wild living animals in Slovakia to perform screening for the presence of antibiotic resistance. In our work, two hundred and eighty-three isolates were analysed. Among isolates the Enterococcus faecalis (67.1%) followed by E. hirae (15.9%), E. faecium (6.4%), E. casseliflavus (4.2%), E. durans (3.5%) and E. mundtii (2.8%) species dominated. The most frequently resistance to tetracycline (29.3%) and erythromycin (15.9%) was detected. In birds and mammals a similar frequency of resistant enterococci was observed. The differences in antimicrobial resistance to ampicillin and vancomycin were observed. Higher prevalence of ampicillin resistant isolates was detected in birds. On the other hand, vancomycin resistant enterococci were detected in mammals but not in birds. The presence of selected antimicrobial resistance genes was studied by PCR with tet(M) and erm(B) genes being to be the most frequently encountered. Vancomycin resistant enterococci harboured only van(C1) gene. The occurrence of antimicrobial resistance in enterococci from the digestive tract of wild living animals suggests the genetic pollution of environment which could pose a risk for human and animal health.