Detection of Photobacterium damselae Subsp piscicida in Seawaters by Fluorescent Antibody

A fluorescent antibody (FA) technique specific for Photobacterium damselae subsp. piscicida was tested via challenge experiments performed in microcosms. In the challenge tank, the pathogen concentration trended from 1.71x10(6) to 0 cell/100 ml, respectively, on the first and last days of the experiment. In the control tank, the pathogen was never detected. Results showed that the FA protocol could be used as a rapid and specific method allowing the early detection of Photobacterium damselae subsp. piscicida in fish farm waters. FA enables early detection of photobacteriosis in the environment, as bacteria can be detected even in absence of clinical sign of disease.