Differential susceptibility of white bass (Morone chrysops), striped bass (Morone saxatilis) and hybrid striped bass (M. chrysops x M. saxatilis) to Flavobacterium columnare and effects of mucus on bacterial growth and bio

Authors: Farmer, Bradley; Fuller, Adam; Beck, Benjamin; Abernathy, Jason; Lange, Miles; Webster, Carl

Submitted to: Journal of Fish Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/13/2020
Publication Date: 10/5/2020
Citation: Farmer, B.D., Fuller, S.A., Beck, B.H., Abernathy, J.W., Lange, M.D., Webster, C.D. 2020. Differential susceptibility of white bass (Morone chrysops), striped bass (Morone saxatilis) and hybrid striped bass (M. chrysops x M. saxatilis) to Flavobacterium columnare and effects of mucus on bacterial growth and biofilm development. Journal of Fish Diseases. 44(2):161-169. https://doi.org/10.1111/jfd.13272.
DOI: https://doi.org/10.1111/jfd.13272

Interpretive Summary: Columnaris disease, caused by the bacterium Flavobacterium columnare, generates substantial economic losses during the production of many freshwater fish species, one of which is the hybrid striped bass, which is a cross between white bass and striped bass. Columnaris can be highly effective in the formation of biofilms on fish skin and gills. Previous research showed that there was a distinct difference between the susceptibility of hybrid striped bass. To better understand these differences and investigate the bacteria’s response to mucus, we assessed total bacterial growth and biofilm formation in the absence or presence of mucus from hybrid striped bass as well as each parental species, white bass and striped bass. Species and mucus concentration differences were detected in the total growth of the bacteria exposed to host mucus. Our data suggests that bass mucus can significantly affect biofilm formation. There was a significant correlation between total bacterial growth and biofilms formation and bass species susceptibility. This study provides new insight into our understanding of the host pathogen interaction in F. columnare and Morone.

Technical Abstract: Columnaris disease generates substantial losses during the production of many freshwater fish species; one of which is the hybrid striped bass. The ubiquitous aquatic bacterium Flavobacterium columnare can be highly effective in the formation of biofilms on fish skin and gills. Previous research showed that there was a distinct difference between columnaris disease susceptibility of hybrid striped bass (Morone saxatilis x M. chrysops) & one of its parental species, white bass (M. chrysops). To better underst& these differential susceptibilities & investigate a possible mucosal relationship, we assessed total bacterial growth & biofilm formation in the absence or presence of mucus derived from each moronid parental species: white bass & striped bass (M. saxatilis). In the present study, differential susceptibility was confirmed through the columnaris susceptibility profiling of the other parent species, the striped bass (M. saxatilis). In addition to intra species investigations, individual hybrid striped bass mucosal affects were also studied for deferential responses to bacterial growth & biofilm formation. Species & concentration dependent differences were detected in the total growth of the bacteria exposed to host mucus. Our data suggests that bass mucus can significantly affect biofilm formation dependent upon the F. columnare isolate tested. There appears to be a correlation between the bacteria’s response of growth & biofilms & bass species susceptibility. This study provides insight into our underst&ing of the host pathogen interaction between F. columnare & moronids.