Project description:Columnaris disease is a prevalent disease in freshwater environments worldwide caused by the ubiquitous aquatic bacterium Flavobacterium species. Adhesion to the external mucosal surfaces of fishes is the initial stage of infection, and the gills specifically have been identified as both a primary target and release site for this pathogen. Previous research has indicated that a predominant US aquaculture product, the hybrid striped bass (Morone chrysops x M. saxatilis), is more susceptible to infection with Flavobacterium columnare (covae) than the maternal white bass (M. chrysops) parental species. Therefore, to further elucidate the differences between these fish we conducted a transcriptomic profiling study examining the differences of gene expression in gill mucosal tissue over time after exposure to F. covae isolate LSU-066-04. Combined with previous work, these data provide a greater understanding of host immune response to a common pathogen in moronids.
Project description:Catfish farming remains number one among U.S. aquaculture production. Flavobacterium columnare, the causative agent of columnaris disease, produces substantial mortality during the production of freshwater farmed finfish species. F. columnare is ubiquitous in the aquatic environment, and outbreaks of disease are often triggered during the spring and summer months of the catfish production cycle. As food fish production continues to increase, the frequency of columnaris disease will only continue to rise within the aquaculture industry and thus new preventative measures will be required. Vaccination against different fish pathogens has proven to be an effective disease management practice within the aquaculture industry. To evaluate the immunological effect of bath immunization on catfish with a recombinant F. columnare DNAk protein vaccine, we performed RNA sequencing on skin samples from control and rDNAK immunized catfish at different time intervals. We evaluated the different gene expression patterns between the groups with a focus on identifying differences in innate and adaptive immune function.
Project description: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. F. columnare naturally occurs in a planktonic, free living state where it can survive for long periods of time, even in the absence of nutrients. In contrast, F. columnare also possesses the ability to form biofilms, broadly defined as surface bound microbial communities inhabiting an organic matrix composed of autogenously derived extracellular polymeric substances. The advantages of adopting this life stage are not completely clear for F. columnare, but biofilm formation could increase virulence by offering protection from desiccation, augment resistance to antimicrobials, improve nutrient acquisition, and protection against other bacteria. To examine gene expression between F. columnare planktonic cells and biofilms, we conducted a study where both phases were grown with and without stimulation and then sampled for RNA sequencing.
