English

Abstract

BACKGROUND: Identification of enterococci to species level in order to determine the species prevalent in this geographic region and also to determine the species-specific antimicrobial susceptibility pattern. OBJECTIVE: To detect and determine glycopeptide resistance by screening for vancomycin resistant enterococci (VRE) in both colonized and infected patients. METHODS: A total of 123 isolates of enterococcus species were recovered from various clinical and faecal samples of hospitalized patients, from September 2010 to June 2011. Various species of enterococci were identified by standard methods. Vancomycin susceptibility in enterococci was detected by disc diffusion method (DDM), vancomycin screen agar method (VSAM) and agar dilution method to determine minimum inhibitory concentration (MIC). RESULTS: E. faecalis was the predominant isolate from the clinical and faecal samples. Multidrug resistance was more in E. faecium than E. faecalis. MIC method could detect 7 VRE and 27 strains with reduced susceptibility to vancomycin. Disk diffusion test and vancomycin screen agar failed to detect 50 % and 29.4% of resistant strains respectively. CONCLUSION: Vancomycin resistance was also detected in less virulent strains of enterococcus like E. gallinarum and E. dispar. In laboratories where performance of MIC studies is not feasible, VSAM method should be preferred over the DDM for detection of vancomycin resistance in enterococci.