Laboratory maintenance of Flavobacterium psychrophilum and Flavobacterium columnare.

Bacteria in the genus Flavobacterium are highly heterogeneous and are comprised of pathogenic and non-pathogenic species. They are found in a wide variety of environments that include fresh and marine water, soil, and ocean sediments. This unit focuses on laboratory maintenance of two important fish pathogens within this genus. Flavobacterium psychrophilum and F. columnare are fastidious, slow-growing organisms that require specialized medium for optimal growth in the laboratory. Methods are described for the preparation of media, broth and agar culture, cryopreservation, and enumeration of viable cells for these bacteria. In addition, the diseases caused by these pathogens are described along with methods of diagnosis and treatments. This unit serves as a general guide for the cultivation of F. psychrophilum and F. columnare and discusses some of the difficulties that have been encountered for each.