English

Abstract

BACKGROUND: Enterococci have emerged as the second most common cause of nosocomial infections over the past 2-3 decades and antibiotic resistance is a major obstacle for treatment. Identification of enterococci to species level is helpful and crucial for proper patient treatment, epidemiologic and infection control purposes. The emergence of vancomycin resistant enterococci is of particular concern as it has limited the therapeutic options available for the clinicians. AIM: To speculate and determine the antimicrobial susceptibility of clinical isolates of enterococci with special reference to vancomycin. SETTINGS AND DESIGN: A prospective descriptive study was carried out in Rajarajeswari medical college and hospital, Bangalore. MATERIAL AND METHODS: The study included a total of 90 clinical isolates of enterococcus from urine, pus, blood and endotracheal aspirates over a period of one year from November 2012 to October 2013. The isolates were confirmed to belong to genus Enterococcus and speciation was based on potassium tellurite (0.04 %) reduction, arginine deamination and fermentation of arabinose, mannitol, raffinose, and sorbitol. Antimicrobial susceptibility was determined by Kirby Bauer disk diffusion and MIC of vancomycin was determined by agar dilution method according to CLSI guidelines. STATISTICAL ANALYSIS: p value was calculated by Fisher’s exact test. RESULTS: Amongst the total 90 Enterococcal isolates, 76 isolates (84.5 %) were Enterococcus faecalis, 13 isolates (14.4 %) were Enterococcus faecium and 1 isolate (1.1 %) was Enterococcus raffinosus. Out of the 90 isolates, 65 (72.2 %) were from urine, 15 (16.6 %) from pus, 5 (5.6 %) from blood and 5 (5.6 %) from endotracheal aspirates. High level gentamicin resistance was 22.4 % for E. faecalis and 30.8 % for E. faecium by Kirby Bauer disc diffusion method. Occurrence of vancomycin resistant enterococci (VRE) in our setting is 2.2 %. Isolates had 100 % sensitivity to linezolid. CONCLUSION: Enterococcus faecalis was the most common species. Maximum isolates were from urine samples. Higher level of gentamicin resistance could lead to failure of synergistic therapy. Speciation and regular monitoring for antibiotic resistance with special attention to vancomycin and high level aminoglycosides is warranted.