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Selection for virulence in the fish pathogen Aeromonas salmonicida, using coomassie brilliant blue agar

R. C. Cipriano·J.M. Bertolini
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Abstract

Coomassie Brilliant Blue Agar was used to quantify the frequency of the A-layer phenotype in different isolates of Aeromonas salmonicida . Hydrophilic, non-clumping isolates of A. salmonicida consisted predominantly of the A-layer minus phenotype. These bacteria were avirulent by intraperitoneal injection into susceptible brook trout ( Salvelinus fontinalis ) and could not be reisolated from infected fish. By contrast, hydrophobic, clumping isolates were predominantly of the A-layer positive phenotype, highly virulent in brook trout, and easily recovered from dead or moribund fish. A-layer positive and negative clones of A. salmonicida were derived by plating bacteria on Coomassie Blue Agar. The plating showed clearly that Coomassie Blue Agar could be used as a highly selective in vitro screening method to reclaim the virulence of certain isolates of A. salmonicida having a relatively low percentage of A-layer positive phenotypes.

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BibTeXRIS

R. C. Cipriano, J.M. Bertolini. 1988. Selection for virulence in the fish pathogen Aeromonas salmonicida, using coomassie brilliant blue agar. https://doi.org/10.7589/0090-3558-24.4.672

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