Vancomycin-resistance Enterococcal Colonization in Hospitalized Patients in Relation to Antibiotic Usage in a Tertiary Care Hospital of North India

BACKGROUND: Alarming rise of vancomycin-resistant enterococci (VRE) is a global cause of concern. Several factors have been held responsible for such rise, of which antibiotic usage is a prominent one. OBJECTIVE: This study was undertaken to determine the intestinal VRE colonization rate amongst hospitalized patients in relation to use of various antibiotics in the Intensive Care Unit (ICU) of a tertiary care university hospital, India. MATERIALS AND METHODS: Stool samples were collected weekly from all the patients in the adult ICU for a period of 6 months and processed for isolation and phenotypic and genotypic characterization of VRE isolates. Patient and treatment details were noted and cases (those with VRE in stool) and controls (those without VRE in stool) were compared statistically. Further, a multivariate analysis was done to identify those antibiotics as independent risk factors for VRE colonization. RESULTS: VRE colonization was found in 34.56% (28/81) of the patients studied, with the majority 75% (21/28) carrying the vanA gene. The cases had significantly more (P < 0.05) duration of hospital stay and antibiotic exposure. Intake of metronidazole, vancomycin, and piperacillin-tazobactam were identified as significant risk factors both in univariate and multivariate analysis. CONCLUSION: A potential reservoir of VRE was thus revealed even in low VRE prevalence setting. Based on this high colonization status, restriction of empirical antibiotic use, reviewing of the ongoing antibiotic policy, and active VRE surveillance as an integral part of infection control strategy were suggested.