High prevalence of vancomycin and high-level gentamicin resistance in isolates.

Multiple drug-resistant enterococci are major cause of healthcare-associated infections due to their antibiotic resistance traits. Among them, is an important opportunistic pathogen causing various hospital-acquired infections. A total of 53 isolates were obtained from various infections. They were identified by phenotypic and genotypic methods. Determination of antimicrobial resistance patterns was done according to CLSI guidelines. The isolates that were non-susceptible to at least one agent in ≥3 antimicrobial categories were defined as multidrug-resistant (MDR). Detection of antimicrobial resistance genes was performed using standard procedures. According to MDR definition, all of the isolates were MDR (100%). High-level gentamicin resistance was observed among 50.9% of them (MIC ≥ 500 μg/ml). The distributions of and genes were 47.2% and 69.8%, respectively. The , and genes were not detected. Vancomycin resistance was found in 45.3% of strains. The gene was detected in 37.7% of isolates, whereas and genes were not observed in any strain. Erythromycin resistance rate was 79.2% and the frequencies of and genes were 88.6% and 69.8%, respectively. The and genes were not present in any of the isolates. Our data indicate a high rate of MDR strains. All of high-level gentamicin-resistant isolates carried at least one of or genes. Distribution of was notable among the isolates. In addition, and were accountable for resistance to erythromycin.