A study on virulence determinants and antimicrobial resistance among Enterococci isolates

Introduction and Aim: Presence of virulence factors may cause increased persistence of Enterococci in the healthcare environment, increase ability to colonise inpatients and thereby result in the transmission of infection. The present study was performed to detect the presence of virulence traits among the clinical strains of Enterococci and to determine its association between virulence factors   and susceptibility to various antibiotics.   Materials and Methods: Clinical isolates of Enterococci were identified to species level by conventional method and Vitek 2 automated method and subjected to antibiotic susceptibility testing using disk diffusion and Minimum Inhibitory Concentration (MIC) method. Presence of hemolysin, gelatinase and biofilm was detected by phenotypic method.   Results: Out of 708 isolates from urine 39 (5.51%) Enterococcus faecalis, and 3 isolates each of Enterococcus faecium (0.42 %) and Enterococcus durans (0.42 %) were biofilm producers. Beta hemolysin production was detected in 342 (48.30%) E. faecalis obtained from urine and 9/48 (18.75 %) from pus. Out of the isolates studied, 9/774 (1.16 %) isolates were found to be positive for beta-hemolysin production, gelatinase and biofilm production. All the 9 (100.00 %) isolates were resistant to penicillin, high level gentamicin, ciprofloxacin and levofloxacin.   Conclusion: Virulence factors described in Enterococci enable these organisms to colonise patient tissue, increase resistance to antimicrobial agents and aggravate infection outcome.