Location: Cool and Cold Water Aquaculture ResearchTitle: Growth of flavobacterium columnare in TYE with or without supplemented cations
Submitted to: Current Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2021
Publication Date: 5/15/2021
Citation: Evenhuis, J., Lipscomb, R.S., Birkett, C. 2021. Growth of flavobacterium columnare in TYE with or without supplemented cations. Current Microbiology. 78: 2474–2480. https://doi.org/10.1007/s00284-021-02507-8.
Interpretive Summary: Columnaris disease, caused by the bacterium Flavobacterium columnare, is an emerging problem in rainbow trout aquaculture. Strains of this bacteria are categorized and placed into common groups, called genomovars, based on a genetic typing scheme. To characterize growth differences of strains within and among genomovars, our laboratory grew several strains of F. columnare in different types of growth media. Important differences in growth kinetics and morphology were detected among genomovars depending on the type of growth media used. This research helps to inform appropriate selection of growth media for scientists that culture diverse strains of this bacterial pathogen.
Technical Abstract: Flavobacterium columnare is a problematic pathogen for the aquaculture industry where isolates are classified by genomovars. Suspended growth in a low nutrient media, like tryptone yeast extract salts, is a common method used for laboratory study. The presence of calcium and magnesium are factors contributing to growth, virulence and biofilm formation for F. columnare. Exponential growth occurs within 24hrs for F. columnare when grown in complete tryptone yeast extract salts media at 30ºC. Withholding CaCl2 and MgSO4 components from a complete TYES formulation reduced or completely inhibited growth of genomovar I isolates but not the growth of genomovar II, IIB or III isolates. Only 3 genomovar I isolates, MS-FC-4, FC-CSF-53 and 023-08-3, could achieve O.D. 540 readings = 0.3 but only after 48hrs incubation. Independently adding CaCl2 or MgSO4 to tryptone and yeast extracts did not result in a genomovar specific growth variation, but the suspended growth morphology demonstrated increased clumping. Clumping formed filamentous strings that were suspended at the top of the culture tube when isolates were grown in TYE+MgSO4. Several of the F. columnare isolates from all the genomovars exhibited delayed growth when a single cation source was provided. This study demonstrates phenotypic differences between and within genomovars of a single bacterial species when grown under different TYES media conditions.