ROLE OF MOBILE GENETIC ELEMENTS (PLASMID, CLASS1 INTEGRON AND SXT ELEMENT) IN DISSEMINATION OF MULTIDRUG RESISTANT NON CHOLERA VIBRIOS

The multidrug resistance (MDR) profile and its correlation with plasmid encoded mobile genetic elements were investigated in non cholera Vibrio strains isolated f r om f r e s h w a t e r r i v e r N a rma d a . T h e susceptibility/resistance of 415 Vibrio strains against fourteen antimicrobial agents were tested using disc diffusion method. The isolate showed higher resistance to cotrimoxazole, streptomycin, chloramphenicol, tetracycline, trimethoprim and norfloxacin. Plasmid profiling of 112 multidrug resistant isolates revealed presence of plasmid with varied size viz. 6kb, 8kb, 9kb, 10kb. The antibiotic resistance exhibited by the isolates varied after curing of plasmid except tetracycline. PCR analysis revealed that 12.5% and 10.7% MDR isolates harbored plasmid mediated class1 integrase gene and SXT integrase gene, respectively. Presence of plasmid mediated antibiotic resistant determinants (aad A-B (BGCC#771), Sul 1-B (BGCC#1064, BGCC#1033), inDS (BGCC#1044), Int-Fb5'-CS (BGCC#790), Int-Bb 3'-CS (BGCC#851), and qacE?1-F (BGCC#1062) contained class1 integron. The transferability of plasmid located class1 integrase gene and SXT integrase gene were confirmed by mating experiment. The present study comprehensively established the role of mobile genetic elements (plasmid located class 1 integron and SXT element) in dissemination of antibiotic resistance within the environmental gene pool of non-cholera Vibrio spp.