Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: 3/7/2005
Publication Date: 6/9/2005
Citation: Bader, J.A., Shoemaker, C.A., Klesius, P.H. 2005. First description of an adhesion defective mutant of Flavobacterium columnare produced by b-lactam selection. In proceedings of American Society for Microbiology.
Technical Abstract: The aim of this study was to develop and evaluate adhesion mutants of Flavobacterium columnare, the causative agent of columnaris disease in fish. Columnaris disease is the second most important bacterial fish pathogen effecting the channel catfish (Ictalurus punctatus) aquaculture industry in the USA.Through the serial passage of F. columnare, ARS-1 on ampicillin (b-lactam) enriched modified Hsu-Shotts medium adhesion defective mutants were derived. Whole-cell proteins were evaluated by SDS-PAGE. Adhesion was evaluated using In Vivo and In Vitro assays. Virulence was evaluated by immersion and injection challeges. Humoral responses were measured by an indirect FAST-ELISA technique. b-lactam selection resulted in a F. columnare mutant that differed from the parent strain in colony morphology, whole cell proteins, adhesion and virulence. The mutant differed from its parent in virulence during immersion challenge, but not during injection challenge or generation of antibodies. Flavobacterium columnare exposure to ampicillin produced mutants that lacked or had reduced adhesion characteristics to adhere to fish tissue. This is the first description of an adhesion-defective mutant of F. columnare and the effects of altered adhesion on columnaris disease. This mutant has considerable potential as a tool to study the role of adhesion in columnaris disease.