Antibiotic Resistance Patterns and Resistance Genes in Enterococci Isolated from Sheep Gastrointestinal Tract in Slovakia

Three hundred Enterococcus isolates from the rumen and faeces of three sheep were analysed for antibiotic resistance. Resistance to tetracycline, kanamycin, and streptomycin was predominant, followed by erythromycin resistance. About 7% of the isolates were resistant to ampicillin and vancomycin only. All tested isolates were susceptible to chloramphenicol. The presence of selected antibiotic resistance determinants was tested by PCR. No tested β-lactamase resistance determinant was detected in ampicillin resistant lactamase positive isolates. Both tet(M) and tet(L) tetracycline resistance determinants were detected. While tet(M) was predominant in both rumen and faecal isolates, clearly a higher frequency of tet(L) determinant was observed in rumen isolates. Among erythromycin resistant isolates, the erm(B) gene was detected only. From this data, it may be concluded that genotypically different enterococcal populations dwell in the upper and lower parts of sheep gastrointestinal tract.