author(s)
Petchimuthu M, Rosalind George M and Rijijohn K

abstract
Polymerase chain reaction (PCR) technique was used to assay for the detection of virulence gene in the genomes of the Photobacterium damselae subsp. damselae isolated from cage culture and wild source fishes, particularly hlyA gene responsible of hemolysin toxins production in this genus. Sixty one strains of P. damselae subsp. damselae were isolated from cage and wild caught fishes. A pair of primers was designed to detect the hemolysin gene (HlyA) of P. damselae subsp. damselae by PCR method. The expected product size (417bp) was obtained from P. damselae subsp. damselae isolates. Photobacterium damselae subsp. damselae grew on TCBS agar plate producing green colonies whereas P. damselae subsp. piscicida did not grow. The PCR methods used are cost and labour effective when compared with the other molecular methods and commercially available kits.