Detection of polymyxin B resistance in Enterobacterales by broth disk elution method

Background: Antibiotic resistance being the critical issue faced by medical field, especially by Gram negative bacteria. It is a great threat in the case of both hospitals acquired and community acquired infections. They possess various mechanisms for their survival. The widespread resistance in Gram negative bacteria has necessitated evaluation of the use of older antimicrobials such as polymyxins. Polymyxins are disfavoured owing to their potential clinical toxicity, especially nephrotoxicity. Thus, they got abandoned in the sixties. But now they are re- emerged and used as last resort antibiotics. Methods: 274 isolates of Enterobacterales including Klebsiella pneumoniae, Escherichia coli, Citrobacter spp. Enterobacter spp. was collected from various diagnostic microbiology laboratories in Kerala. The polymyxin resistance among Enterobacterales by broth disk elution method recommended by CLSI. Results: In this study prevalence of multi drug resistant is 37% and extensively drug resistant strains is 25%. And the threatening fact is that the colistin also shows resistance among Enterobacterales (9.2%). Conclusions: Though the resistance to Polymyxin B is to the lesser side in the present study, increase in resistance to the agent is being documented globally elsewhere. So, rational use of Polymyxin B is warrantied as we could cherish polymyxin B as a 搇ife - saving drug� to avoid no drug available. Knowledge of antimicrobial resistance and development of new antimicrobial agents and improved treatments are essential in the current situation.