Enterococcal Infections and Antimicrobial Resistance in a Tertiary Care Hospital, Eastern India

Sahu, Llalli S; Dash, Muktikesh; Paty, Bimoch P; Purohit, Gopal K; Chayan, Nirupama

doi:10.21608/aeji.2015.17846

Enterococcal Infections and Antimicrobial Resistance in a Tertiary Care Hospital, Eastern India

Document Type : Original Article

Authors

¹ Microbiology Department, S.C.B Medical College and Hospital, Utkal University, Cuttack, Odisha, India.

² Biotechnology School, KIIT University, Bhubaneswar, Odisha, India.

10.21608/aeji.2015.17846

Abstract

Background and study aim: During last two decades, there has been a world-wide trend in increasing occurrence of entero-coccal infections in the hospitals. The aim of present study was to determine the spectrum of enterococcal infections, speciesprevalence, antimicrobial resistance and characteristics of vancomycin resistant enterococci (VRE) in a tertiary care hospital, Eastern India.

Patients and Methods: Between January 2013 and July 2014, 152 Enterococcus species were obtained from clinical samples. Enterococci were identified using standard biochemical tests. Antimicrobial susceptibility was tested by Kirby-Bauer disk diffusion according to Clinical & Laboratory Standards Institute (CLSI) guidelines.VRE agar base was used to screen VRE isolates. Minimum inhibitory concentration (MIC) values of VRE isolates were determined using Epsilometer-test. VRE isolates were also examined by PCR to detect vanA gene.
Results: From 1602 clinical samples, 961 (60%) were culture positive and 152(15.8%) enterococcal isolates were obtained. Most common species isolated was E. faecalis (63.8%) followed by E. faecium (35.5%). Majority of enterococcal infections were detected from ICUs and surgical wards and clinically presented as UTIs. Disk diffusion method showed 67.1% were resistant to penicillin, 61.2% ampicillin, 58.5% ciprofloxacin, 46.7% high-level gentamicin, 42. 8% high-level streptomycin, 7.9% teicoplanin and none to linezolid. Twenty (13.2%) enterococcal isolates were vancomycin resistant in VRE screen and disk diffusion method. Epsilometer-test of VRE isolates showed 8 (40%) isolates were resistant and 9 (45%) were intermediately resistant. From 20 VRE isolates, six showed VanA and two VanB phenotypes and all six VanA phenotypes had vanA gene cluster.
Conclusion: More accurate and reliable MIC determination tests should be performedin all suspected VRE isolates. Confirmatory PCR is required for identifying resistant gene cluster.

Keywords