Phenotypic and Molecular Identification of Bacterial Species in Indian Major Carps and Exotic Carps from South 24 Parganas, West Bengal, India

The present study was done to find rapid and accurate identification of bacterial species which will help in prevention and cure of diseases in various aquatic animals. Phenotypic identification of bacterial isolates was done by conventional tests and commercial methods. Antibiotic sensitivity study revealed only gatifloxacin and chloramphenicol were found to be effective, both inhibited 83.33% sensitivity to the bacterial strains. Prevalence study revealed that aeromoniais were the dominant disease. The identities of selected bacterial strains were further confirmed by molecular characterization through 16S rDNA analysis. In 1.2% agarose gel electrophoresis, approximately 1.5 kbp bands were obtained by PCR amplification. In 2% agarose gel electrophoresis, approximately 675 bp and 1100 bp bands were obtained by PCR amplification for two Flavobacterium columnare specific primers set. Among the 7 isolates, 2 were identified as Commonas aquatica (accession number KT716080) and Aeromonas hydrophila (accession number KX455879) by using universal primers. Three isolates were identified as Flavobacterium columnare using specific primers by culture dependant and culture-independent methods. The sequence results of other bacterial isolates are awaited. The gene sequences of culture independent samples and culture dependent strains Commonas aquatica and Aeromonas hydrophila have been submitted to NCBI with accession numbers KX452118, KX452119, KT716080, KX455879, respectively.