Characterization of Vibrio alginolyticus and Vibrio parahaemolyticus isolated from Penaeus monodon: Antimicrobial resistance, plasmid profiles and random amplification of polymorphic DNA analysis

Vibrio alginolyticus and Vibrio parahaemolyticus are important pathogens which cause serious episode to shrimp. We characterize the suitability of randomly amplified polymorphic DNA (RAPD), and plasmid profiling for rapid molecular characterization of pathogenic bacteria for epidemiological and antibiogram study to find out the relationship between plasmids and bacterial sensitivity to antibiotics. Nine primers, belonging to OPA and OPY series were selected for the RAPD study. Primer OPA3 and OPY2 amplified 3 to 7 bands ranging from 0.306 to 3.94 Kb in V. alginolyticus. In V. parahaemolyticus, primer OPA 3 and OPY 2 amplified 3 to 7 bands of molecular wt 0.306 to 4.11 Kb. V. alginolyticus possess only one plasmid each with molecular weight 10. 23 Kb. V. parahaemolyticus strains contained 1 to 3 plasmids with molecular weight 7.12 to 10.23 Kb. The strains were mostly resistant to Ampicillin and Cefuroxime. Among the strains 90 and 70% were resistant Bacitracin and Co-trimazole, respectively. All strains of V. alginolyticus and V. parahaemolyticus were sensitive to Amoxycillin, Chlorotetracycline and Ciprofloxacin. Unique distinct amplicons generated by RAPD polymerase chain reaction (PCR) and plasmid profiling will be used for several diagnostic markers for identification of these pathogenic microorganisms and in epidemiological study.