Indian Journal of Microbiology Research


A profile of vancomycin-resistant enterococcal infections and a comparison of resistance detection methods


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Author Details: Stephen K. Mathew*

Volume : 5

Issue : 3

Online ISSN : 2394-5478

Print ISSN : 2394-546X

Article First Page : 408

Article End Page : 414


Abstract

Scope: Vancomycin-resistant enterococci (VRE) are being increasingly reported from hospitals across the world. This study provides a profile of enterococcal infections and compares various methods of detecting vancomycin resistance.
Materials and Methods: All clinically significant isolates of enterococci over a 2-year period were included. Antibiotic susceptibility was carried out as per CLSI guidelines. Vancomycin resistance was detected by 3 methods: disk diffusion, agar screen, E-test. The 3 methods were compared.
Results: 156 clinical samples yielded Enterococcus spp. over the study period. Maximum resistance was noted to penicillin, erythromycin, and ciprofloxacin. E. faecium strains showed a higher percentage of resistance to the antibiotics tested. 15 (9.6%) enterococcal strains were resistant to vancomycin; 10 (6.4%) strains were intermediate. Compared to E-test, disk diffusion and agar screen had sensitivities of 100%. Disk diffusion had 97.2% specificity and agar screen demonstrated 92.9% specificity.
Conclusion: Prevalence of VRE in Indian hospitals is increasing. Though disk diffusion had a higher specificity than the agar screen at identifying resistant isolates, intermediate strains were identified as sensitive. BHI agar containing 6 µg/ml of vancomycin can be used to screen for VRE, and E-test can be used to confirm resistance.

Keywords: Bacterial infections, Enterococcus, Drug resistance, Vancomycin, Vancomycin resistance.

Doi No:-10.18231/2394-5478.2018.0085