Presence of vancomycin, aminoglycosides, and erythromycin resistance genes in enterococci isolated from clinical samples in Turkey.

Background: Emergence of high-level aminoglycoside and glycopeptide resistance causes more severe prognosis, higher mortality, and recurrence in enterococcal infections. The present study was conducted to investigate the antimicrobial resistance patterns, prevalence of AMEs, erm and van genes of enterococci isolated from various clinical samples at Istanbul University, Cerrahpasa Medical School hospital.
Methods: During the period of 2012-2013, a total of 128 enterococcal isolates collected from various clinical samples were typed with the API 20 strep test, and antibiotic sensibilities were analysed with the disc diffusion and E-test methods. The detection of resistant genes was determined by a multiplex PCR method.
Results: Forty-nine percent E. faecalis, 46% E. faecium, 4 E. avium and 2 E. durans were detected. E. faecium resistance rates were significantly higher than E. faecalis (p < 0.001). The resistant genes were analysed in 50 enterococcus strains. The vanA gene was found in 29 of the 30 VRE strains. The most prevalent AMEs genes were aac (6')-Ie-aph (2")-Ia gene (72%), followed by aph (3')-IIIa gene (30%). The ermB gene was found in 49 of a total of 50 strains.
Conclusions: This study shows that aac (6')-Ie-aph (2")-Ia, ermB, and vanA genes are common among enterococci isolates in our hospital and spread of VRE along with acquisition of resistance to most of the antibiotics used in therapy.