BRUNDABAN SAHU, A.K. NAYAK, S.D. SINGH, B.K. BEHERA AND GADADHAR DASH
Abstract
Antibiotic resistant E. coli strains isolated during processing of fish were characterised to establish their level of resistance to different antibiotics and to know whether the genetic resistance mechanism is mobile in nature. About 80% of the strains were resistant against 4 to 6 antibiotics, while three strains exhibited resistance against more than ten antibiotics taken for the study. Risk assessment study of the E. coli strains by Multiple Antibiotic Resistance (MAR) Indexing suggest that the strains have been originated from high-risk source of contamination. MIC of Vancomycin for the strains was above 100 mg/ml and that of Ampicillin for above 70% of the strains was above 80 mg/ml. Besides, MIC of 6 antibiotics namely, Tetracycline, Chloramphenicol, Ampicillin, Vancomycin, Kanamycin and Streptomycin for one particular strain varied from above 60 μg/ml to above 160 μg/ml. At the same time, MIC level of 4 antibiotics namely, Tetracycline, Ampicillin, Vancomycin and Streptomycin varied at the similar extent for two other strains. One of the three strains exhibiting resistance against more than ten antibiotics was found to have lost its antibiotic resistance property during plasmid curing experiments. This suggests the resistance mechanism may be plasmid mediated that is mobile in nature and there is every possibility of its transformation to dreaded pathogen in the environment and create serious menace.