|Pereira Junior, D|
Submitted to: Journal of Fish Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2005
Publication Date: 4/1/2005
Citation: Figueiredo, H.C., Klesius, P.H., Arias, C., Evans, J.J., Shoemaker, C.A., Pereira Junior, D.J., Peixoto, M.T. 2005. Isolation and characterization of strains of flavobacterium columnare from brazil. Journal of Fish Diseases. 28(4):199-204. Interpretive Summary: The disease caused by Flavobacterium columnare accounts for significant economic losses in the aquaculture industry, leading to mortality and reduced growth in catfish and other cultured fish. This bacterium affects a wide range of cultured fish species and losses may exceed $100 million annually, worldwide. Tilapia is one of the most cultured species and it has wide popularity throughout the world as a food fish. We found that tilapia from a recirculating water system in Brazil were infected with F. columnare. Four isolates were identified as F. columnare using phenotypic and genomic techniques. The techniques employed to identify these isolates included biochemical reactions, enzyme production, fatty acid profile and analysis of the 16S-23S rDNA intergenic spacer region. The pathogenesis of these isolates was demonstrated in both tilapia and channel catfish by experimental challenge. This is the first characterization of F. columnare in cultured tilapia from Brazil.
Technical Abstract: Flavobacterium columnare is an important pathogen of freshwater fish, implicated in skin and gill disease, often causing high mortality. An outbreak of skin disease in fingerlings and adult Nile tilapia (Oreochromis niloticus, Linneus), cultivated in a recirculation system, was investigated. Four strains were isolated and characterized by biochemical reactions, enzyme production, fatty acid profile, and analysis of the 16S-23S rDNA intergenic spacer region (ISR). All strains were identified as F. columnare. Experimental infection assays with one of these strains (BZ-5-02) were conducted and pathogenicity (by intramuscular route) was demonstrated, in Nile tilapia and channel catfish (Ictalurus punctatus, Rafinesque). This is the first report of characterization of Brazilian strains of F. columnare.