Infectious Diseases

Biography

Biography: Firdoos Ahmad Gogry

Abstract

Antibiotic resistance is a significant global health concern. Apart from fundamental applications in clinical settings, antibiotics are extensively used in agriculture, food industry and aquaculture. Presence of antibiotics in the ecosystem, serves a potent  stimulus to elicit a bacterial adaptation response to develop antibiotic resistance. Increased use of colistin, a last resort drug due to failure of Carbapenems has possibly contributed in development and spread of resistance to colistin among Enterobacteriaceae. The colistin belongs to the family of Polymyxins, cationic lipopeptides, with broad-spectrum activity against Gram negative bacteria. In this study we obtained 370 non-duplicate bacterial isolates from sewage water and river Yamuna in Delhi and phenotypically screened for colistin resistance. Of the 59 positive isolates colistin resistance gene mcr-1 was detected among 10 isolates. Chromosomal based genes phoPQ, pmrAB and mgrB were amplified from 5 resistant isolates of Klebsiella pneumoniae; sequencing confirmed 4 isolates with wild type genotype but 1 isolate revealed missense mutation in mgrB and phoQ in phoPQ two component system. Moreover, carbapenem resistant genes blaNDM-5, blaVIM, OXA were also detected in mcr-1 postive bacterial isolates. ESBL determinants blaCTX-M, blaSHV and blaTEM were present in colistin resistant bacteria. Furthermore, group specific analysis of CTX-M reveals  presence of CTX-M-1  and CTX-M-25 among them. Antibiotic susceptibility test of all isolates against 9 different classes of drugs revealed multidrug resistant phenotype with high MIC values. In vitro transconjugation studies showed successful transfer of mcr-1 and other ESBL resistant determinants. Results of our conjugation studies further highlight the risk for dissemination of mcr-1 gene and other resistant determinates to other bacteria including clinically important pathogens.