بررسی میزان پراکندگی و الگوی مقاومت آنتی بیوتیکی سویه های انتروکوک جدا شده از نمونه های بالینی بیمارستان های آموزشی شهر همدان

Background and purpose: Multi-resistant enterococci are important nosocomial pathogens that are shown to have high prevalence in recent years. Knowledge of antimicrobial resistance pattern is essential to formulate treatment guidelines for infections caused by enterococci. The aim of this study was to investigate the antimicrobial resistance among enterococci isolated from Hamedan hospitals. Material and methods: The study was carried out during 2012-2014 in 242 Enterococcus faecalis and Enterococcus faecium Strains isolated from clinical specimens of teaching inpatients and outpatients hospitals in Hamedan. Identified species by biochemical methods were confirmed by PCR. Antibiotic resistance was performed by disk diffusion. MIC (Minimum Inhibitory Concentration) of vancomycin and Teicoplanin were determined by Microdilution Broth method. Results: A total of 280 enterococcal isolates were studied of which, 175 (62.5%) were identified as Enterococcus faecalis, 67(24%) as Enterococcus faecium, and 38(13.5%) as Enterococcus spp. No resistance to Linezolid and Nitrofurantoin was detected among E.faecalis isolates. All isolates of E. faecium were susceptible to Linezolid. Resistance rates to ampicillin, Vancomycin, Teicoplanin, ciprofloxacin, erythromycin, Norfloxacin, gentamicin and Nitrofurantoin were found higher in E.faecium isolates than those of the E.faecalis group. Conclusion: Due to the high prevalence of Vancomycin-resistant enterococci and also increasing resistance of enterococcus to most common antibiotics, there is a need for preventive and control measurements. Therefore, antibiotic susceptibility testing is recommended for all patients before prescription of appropriate antibiotics.