Detection and Characterisation of Vancomycin Resistant Enterococcal Isolates of Clinical Samples From a Tertiary Care Hospital

Abstract

The emergence of Vancomycin resistant enterococci (VRE) has posed serious threats to the community because they exhibit multiple drug resistance, thus limiting the therapeutic options for the clinicians. As Vancomycin resistant enterococci (VRE) also have ampicillin resistance and high level aminoglycoside resistance, they are the most difcult to treat. The therapeutic options are limited by elimination of the synergy between aminoglycoside and the beta lactum drugs which is the treatment of choice for enterococcal infections which is of great concern. More antibiotic resistance makes these pathogens excellent survivors in hospital environment and cause nosocomial infections. Atotal of 142 enterococcal isolates from various clinical samples were identied to their species level and subjected to antimicrobial susceptibility testing to various antibiotics. Initial screening for Vancomycin resistance was done using the Vancomycin Screen Agar and the isolates showing resistance were subjected to Vancomycin and Teicoplanin MIC and later these isolates showing resistance were conrmed by genotypic methods for Vancomycin resistant genes.Total VRE isolates as per Vancomycin MIC value were 19 and the prevalence rate was 13.3% (19/142).In PCR assay, a total of 16 isolates including 13 E.faecium and 3 E.faecalis were found to be of Van B genotype and the remaining 3 isolates including 2 E.faecium and 1 E.faecalis were found to be of Van A genotype. In this study, the prevalence of Vancomycin resistance in Enterococcal species is 13.3% as per vancomycin MIC by Micro broth dilution technique. The phenotypic detection of Vancomycin resistance by MIC of Vancomycin and Teicoplanin correlates with the genotypic method of detection of Vancomycin resistant genes (VanA, VanB).