تنوع ژنتيكي سويه هاي انتروكوكوس فكاليس مقاوم به سيپروفلوكسازين جداشده از نمونه هاي باليني به روش پالسد فيلد ژل الكتروفورزيس

Genetic Diversity among Ciprofloxacin Resistant Enterococcus faecalis Isolated from Clinical Specimens with Pulsed-Field Gel Electrophoresis (PFGE) Method

Abstract Background and objective: Resistance to ciprofloxacin among Enterococcus faecalis (E.f) isolates especially in UTI makes difficulties for treatment. In this study, the genetic diversity using PFGE method and detection of resistance genes including parC, gyrA , gyrB and parE among ciprofloxacin resistant E.f isolated from clinical specimens, are determined. Materials and methods: A total of 384 entreococcal isolates were collected from 6 hospitals and 3 private laboratories in Tehran and 50 ciprofloxacin resistant E.f isolates were obtained. Identification of species and resistance genes were done by PCR method. Antimicrobial and minimum inhibitory concentration (MICs) tests were assayed with standard methods and finally genotyping was accomplished using PFGE method. Results: The range of ciprofloxacin MICs was 16 to 512 µg/ml. All of these isolates contained parC, 98 % gyrA , gyrB and 80 % parE genes. PFGE analysis, grouped 50 strains in 11 common types and 7 single types. The P4, P9 and P10 genotypes were shared between hospital and community isolates. Conclusion: According to these results the E.f isolates showed high clonal diversity. Because of the ciprofloxacin high MICs level among common pulsotypes we concluded that they have various distributions which may be due to highly transmission of resistant genes among enterococci. Indeed the colonized patients with these resistant isolates are reservoir for releasing of the resistant genes to community which requires more surveillance programs.