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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #332505

Research Project: The Role of Mucosal Surfaces and Microflora in Immunity and Disease Prevention

Location: Harry K. Dupree Stuttgart National Aquaculture Research Cntr

Title: The carbohydrate L-rhamnose promotes biofilm formation which enhances Flavobacterium columnare virulence

Author
item Lange, Miles
item Farmer, Bradley
item Brown, Jason
item Barnett, Louis - Matt
item Peatman, Eric - Auburn University
item Beck, Benjamin

Submitted to: Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 12/21/2016
Publication Date: 2/21/2017
Citation: Lange, M.D., Farmer, B.D., Brown, J.D., Barnett, L.M., Peatman, E., Beck, B.H. 2017. The carbohydrate L-rhamnose promotes biofilm formation which enhances Flavobacterium columnare virulence [abstract]. Aquaculture America. p. 1.

Interpretive Summary:

Technical Abstract: Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry, continual efforts to better understand basic mechanisms that contribute to disease are urgently needed. The current work sought to evaluate the effect of L-rhamnose on the growth characteristics of F. columnare. While we initially did not observe any key changes between the in vitro growth or in the colonization of gill tissue by F. columnare when rhamnose-treated; it soon became apparent that the difference lies in the ability to form more robust biofilms when under the influence of the carbohydrate, L-rhamnose. In vitro biofilm assays demonstrated enhanced biofilm formation in a dose dependent manner when using either L-rhamnose or D-galactose but not with D-glucose. Quantitative PCR analyses of gliding motility genes early after L-rhamnose stimulation revealed a pattern of upregulation in planktonic cells to facilitate increased movement and attachment to the host; then during biofilm formation their initial downregulation and later upregulation once again to facilitate the different stages of development. The overall mortality observed in the in vivo bacterial challenges indicates that biofilm formation has a direct association to virulence. Our results allow for some conclusions to be made about the formation of F. columnare biofilms and their likely mechanism of pathogenicity.