مقاومت آنتي بيوتيكي در ايزوله هاي انتروكوكس جداشده از نمونه هاي باليني

Antibiotic Resistance of Enterococci Isolated from Clinical Specimens

Background and Objectives: Enteroccoci organism producing life threatening infections such as endocarditis, septicemia, meningitides and urinary tract infections create a state of necessity of more research in this area. Hence we studied the antibiotic susceptibility patterns of Enterococci isolated from clinical samples.Materials and Methods: Between 2001-2002 enterococci were isolated from different clinical speciments. Antibiotic susceptibility of isolates were examined with disk diffusion test to vancomycin and other panel of antibiotics. For vancomycin, minimum inhibitory concentrations (MICs) were also determined by macro-dilution broth according to Clinical and Laboratory Standards Institute (CLSI) method. The presence of plasmids in vancomycin resistant and vancomycin susceptible enterococci was also compared.Results: From a total number of 52 enterococci isolates the majority of isolates were E. faecalis (92/3%) while only E. faecium were isolated in (7/7%). Two (3.8%) out of 52 isolates were YRE, with MIC of 8 > jig/ml to vancomycin. Among 52 isolates, we found resistance to oxacillin in (100%); penicillin: 98.1%, co-trimoxazole: 94.2%, doxycycline: 84.6%, gentamicin: 69.2%, nitrofurantoin: 34.6%, ampicillin: 57.7%. Plasmid bands of 4.5, 17.2, 23.5kb were only observed in two vancomycin resistant isolates.Conclusion: The findings of this study show an emerging of vancomycin resistant enterococci among resistant entrococci. Resistance of enterococci isolates against majority of common antibiotics has been increased.