Speciation of Enterococcal Isolates in a Tertiary Care Hospital and Molecular Characterisation of Vancomycin Resistant Enterococci (VRE)

Abstract

Background: Enterococci are gram positive cocci which reside as commensal microbial flora in gastrointestinal tract, vagina, biliary tract and male urethra. E.faecalis is the predominant species followed by E.faecium. Resistance against glycopeptides and aminoglycosides are being increasingly demonstrated and that is conferred upon largely by van A gene. Aims: To isolate and speciate Enterococci from various clinical samples, antibiogram pattern determination, followed by genotyping of vancomycin resistant Enterococci. Settings and Design: Prospective study. Materials and Methods: 200 Enterococcal isolates were collected and processed for speciation based on battery of phenotypic characteristics. Antibiotic sensitivity testing was performed as per CLSI guidelines 2014 for glycopeptide and aminoglycoside antibiotics. Enterococci which were resistant to vancomycin were subjected to polymerase chain reaction for van A gene detection. Statistical analysis used: Nil. Results: Of the 200 isolates 5 were resistant to vancomycin and teicoplanin (2.5%), 30 were resistant to high level gentamicin (15%). van A gene was detected in 3 of the 5 vancomycin resistant isolates. E.faecium was observed to be more resistant to the antimicrobials. Conclusions: If the vancomycin resistance in Enterococci gets dispersed throughout the world, it may pose a challenge in the treatment of Gram positive infections and may lead to treatment failure. Further treatment options may not be available. Hence these infections have to be prevented and the sequence of development of resistance to higher drugs has to be controlled by active surveillance and prevention. Key-words: E.faecalis, E.faecium, High-level Gentamicin resistance, Vancomycin-resistance, Van A gene Key Messages: Implementation of vigorous surveillance and provision of timely data