Indian J Med Microbiol. 2021 Jan;39(1):19-23. doi: 10.1016/j.ijmmb.2020.10.013. Epub 2020 Nov 11.
INTRODUCTION: Bacteroides fragilis group, the most encountered anaerobic bacterium is emerging with resistance to antibiotics. This study explores the antibiogram and occurrence of resistance genes in isolates of B fragilis group from clinical samples.
METHOD: In this study the antimicrobial susceptibility test was done using commercially available E strip test and the results were recorded according to CLSI guidelines. Genotypic investigations were performed by conventional PCR to detect the target resistant genes.
RESULTS: Ceftriaxone, cefoxitin, clindamycin and imipenem were found to be the most resistant antimicrobials in E test method. Metronidazole has shown resistance in 7 strains in vitro while resistance nim genes were detected in 12 strains from 62 randomly selected isolates. Other resistance genes (cfiA, ermF and cepA) were expressed at 58%, 62.9% and 48.3% respectively, among these strains.
CONCLUSION: B fragilis group harbouring the resistant genes may not be fully expressed phenotypically. Hence, detection of these genes by PCR might be necessary for a pertinent conclusion.