Characterization of plasmids from multiple antibiotic resistant Vibrios isolated from molluscan and crustacean of Kerala

The present study was aimed to investigate the occurrence of multiple antibiotic resistance, the role of plasmids and their relationship with the multiple antibiotic resistance in 30 Vibrios isolated from selected seafoods of Kerala, India. The isolated Vibrios were screened for plasmid DNA and were tested for transformation and conjugation efficiencies. Antibiotic resistance studies revealed that the levels of Multiple Antibiotic Resistance of Vibrio strains to various antibiotics differed considerably and were found to be varied in the expression of their resistance pattern. All studied Vibrio strains were found to be resistant to antibiotics; amoxycillin, ampicillin and carbeniciliin. 87 % were resistant to rifampicin; 74% to cefuroxime; 67 to streptomycin; 53% to norfloxacin and ciprofloxacin and 47% to furazolidone and nalidixic acid. The nine strains isolated from crustaceans and from molluscans have been found to harbor 1-3 plasmids with size varies from 5.98 kb to 19.36 kb. The average transformation efficiency is about 5x10^–8 and the conjugation efficiency is varied from 2.1x 10^-3 to 10^-9. The study of antibiotic resistance pattern could be useful to test the extent of drug resistance in seafoods and help to devise a nationwide antibiotic policy.