Study of prevalence of multidrug resistant (MDR) Enterococci at a tertiary care hospital of Rajasthan

Background: Enterococci, though commensals in adult faeces are important nosocomial pathogens. Their emergence in past two decades is in many respects attributable to their resistance to many commonly used antimicrobial agents (aminoglycosides, cephalosporins, aztreonam, semisynthetic penicillin, trimethoprim-sulphamethoxazole). Objectives: To study the prevalence of Multidrug resistant (MDR) Enterococci plus Vancomycin resistance and High Level Gentamicin Resistance (HLGR) in different enterococcal isolates. Materials and methods: Total 125 enterococcal isolates were studied. Identification was done by conventional biochemical methods. Antibiotic susceptibility testing was done by Kirby-Bauer disc diffusion method on Mueller?Hinton agar and results were interpreted as per CLSI guidelines. Enterococci resistant to more than three drugs plus high level Gentamicin (120 ?g) resistance were labelled as multidrug resistant (MDR). HLGR was determined by disc diffusion method using high level Gentamicin disc (120 ?g). Minimum inhibitory concentration (MIC) determination for detecting Vancomycin resistance was done by HiComb MIC Test strips and microbroth dilution method. Results: Total 125 entetococcal isolates were studied. In this study the multiple drug resistance was verified in 44 (35.20%) isolates of Enterococcus species and only 2 isolates (1.72%) were found to be VRE but HLGR was detected in 53.6% of the isolates. Conclusion: During past two decades, enterococci resistant to multiple antimicrobial agents have been recognized, including strains resistant to vancomycin, β-lactams and aminoglycosides, making it a formidable nosocomial pathogen. Such strains pose therapeutic dilemmas for clinicians. Thus, it is crucial for laboratories to provide accurate antimicrobial resistance patterns for enterococci so that effective therapy and infection control measures can be initiated.