Noohi N, Talebi M, Ebrahimipour G, Pourshafie M. The study of high level gentamicin resistanance in Enterococcus species isolated from healthy human in Tehran, 2007-8. Iran J Med Microbiol 2009; 2 (3 and 4) :47-52
URL:
http://ijmm.ir/article-1-128-en.html
1- Department of Microbiology, Faculty of Science, Shahid Beheshti University, Tehran, Iran , nasrinnoohi@gmail.com
2- Division of Bacteriology, Pasteur Institute of Iran
3- Department of Microbiology, Faculty of Science, Shahid Beheshti University, Tehran, Iran
Abstract: (16143 Views)
Background and Objective: Enterococci are natural inhabitants of the gastrointestinal tract of humans and
animals. Over the past decade, enterococci have become one of the leading causes of nosocomial infections,
because they have acquired resistance to many antimicrobial agents such as vancomycin and gentamicin.
Development of high-level gentamicin resistance amongenterococci represents a serious therapeutic problem as
it precludes synergy between aminoglycosides and cell-wall active agents. High-level gentamicin resistance
(MIC ≥500 mg/ml) in enterococci is predominantly mediated byaac (6')-Ie-aph (2'')-Ia gene..The aim of
present study was determination of high level gentamicin resistance in Enterococcus species isolated from
healthy human in Tehran.
Material and methods: After enrichment of the fecal samples collected from healthy volunteers in BHI broth
containing gentamicin, the isolates were subcultured on m-Enterococcus agar containing gentamicin. The
isolates were identified to the genus and species levels and MIC was determined. Antibiotic susceptibility of the
isolates was tested by agar diffusion method for 8 various antibiotics. Theaac(6')-Ie-aph(2'')-Ia gene was
identified by PCR technique.
Results: gentamicin resistant enterococci(GRE) were isolated from 76(15.2%) of 500 fecal samples. The
isolated species were: E. faecalis 45(59.2%) ,E. faecium 29(38.1%) and E. gallinarum 2(2.63%). GRE isolates
were highly resistant to gentamicin (MIC ≥500 µg/ml). Eleven different antimicrobial resistance patterns were
observed in this study. All of isolates carried the aac(6')-Ie-aph(2'')-Iaresistance gene.
Conclusion: These results represent a rather high prevalence of gentamicin resistance enterococci as a normal
flora in the community. The aac(6')-Ie-aph(2'')-Iagene was the most common gene among the gentamicinresistant isolates evaluated in this stud.
Type of Study:
Original Research Article |
Subject:
Antibiotic Resistance Received: 2013/11/16 | Accepted: 2013/11/16 | ePublished: 2013/11/16