Authors : Stephen K. Mathew
DOI : 10.18231/2394-5478.2018.0085
Volume : 5
Issue : 3
Year : 0
Page No : 408-414
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.