Random Amplified Polymorphic DNA (RAPD) Typing of Multidrug Resistant Enterococcus faecium Urinary Isolates from a Tertiary Care Centre, Northern India

Background: Enterococci, though they are a part of commensal flora, are becoming increasingly important as nosocomial pathogens, due to their inherited and acquired resistances to several antimicrobial agents. In this context, Enterococcus faecium (E.faecium) requires a special mention due to its characteristic of Multidrug Resistance (MDR) and its ability to disseminate. Aim: This study was undertaken to phenotypically characterize and determine clonal relatedness amongst the indoor isolates of Enterococcus faecium (E. faecium) which were isolated from patients with urinary tract infections (UTIs). Settings and design: This study was carried out prospectively in a tertiary care university hospital and in Department of Microbiology, Varanasi, India. Material and Methods: Urine samples were collected from patients who were admitted in different departments of the hospital with a clinical diagnosis of UTIs and they were processed for a period of one year. Enterococcal species were identified by doing extensive biochemical tests. Anti-microbial susceptibility testing was done by disc diffusion and agar dilution methods. Molecular typing of the isolates was done by Random Amplified Polymorphic DNA (RAPD) typing method. Results: A total of 48 Enterococcal urinary isolates were identified in indoor patients, among which a majority (46, 95.83%) were E.faecium isolates. These isolates exhibited high resistance to fluoroquinolones (91.3%) and to ampicillin (60.86%) in particular. Two isolates were found to be resistant to vancomycin on screen agar. RAPD typing showed two major clusters, one of which had ten strains of 100% similarity, all of which were isolated from a common source. Conclusion: This study showed dissemination of multidrug resistant E. faecium isolates within the hospital. Being a quick and cost effective method, RAPD typing can be used to show clonal relatedness and to trace possible sources of organisms for epidemiological purposes.