DAO 55:101-107 (2003)  -  doi:10.3354/dao055101

Adhesion of high and low virulence Flavobacterium psychrophilum strains to isolated gill arches of rainbow trout Oncorhynchus mykiss

Amin Nematollahi*, Annemie Decostere, Frank Pasmans, Richard Ducatelle, Freddy Haesebrouck

Laboratory of Veterinary Bacteriology and Mycology and Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium

ABSTRACT: The ability of Flavobacterium psychrophilum to adhere to the gill tissue of rainbow trout Oncorhynchus mykiss was evaluated. A gill perfusion model was adopted, offering a number of advantages compared to other in vitro as well as in vivo models. A comparison between the adhesion capacity of a high and low virulence F. psychrophilum strain was made. Experiments were additionally carried out to assess the influence of water quality (organic material, nitrite) and temperature on the adhesion process of the bacterial cells. The high virulence strain attached more readily to the gill tissue than did the low virulence strain. Moreover, the adherence of the high virulence strain of F. psychrophilum was influenced by a number of factors. These were immersion of the gill arches in water to which organic material or nitrite were added, and elevated temperature. The former 2 increased the adhesion ability, while the latter had a negative influence on the adherence process.


KEY WORDS: Flavobacterium psychrophilum · Rainbow trout · Adhesion · Gill tissue


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