After transporting Asian seabass Lates
calcarifer from a fish farm to the Burapha University facilities,
they began to die. The affected or moribund fish
exhibited abdominal swelling, yellowish decoloration around
the anus, darkening of the gills and exophthalmic eyes.
The internal signs of the disease included abdominal cavities
filled with a cloudy yellow and gelatinous fluid together
with liver hemorrhage. Isolated bacteria from several
organs were biochemically characterized as Photobacterium
damselae subsp. damselae. It was further confirmed by
PCR. An infectivity experiment by intraperitoneal injection
with an isolate LCA 24907 showed its virulence to Asian
seabass with LD50 of 8.1 ¥ 105 CFU/g fish body weight.
This is the first report of isolating P. damselae subsp.
damselae from Asian seabass.
