Factors Affecting Post-Challenge Survival of Flavobacterium psychrophilum in Susceptible Rainbow Trout from the Literature

Abstract

Infectious bacterial pathogens are a concern for aquaculture as estimates suggest that billions of US dollars are lost annually in aquaculture due to disease. One of the most prevalent salmonid pathogens is the bacterium Flavobacterium psychrophilum that causes bacterial coldwater disease. We reviewed the published F. psychrophilum literature and conducted a Bayesian analysis to examine large-scale patterns in rainbow trout (Oncorhynchus mykiss) mortality associated with laboratory challenge. We incorporated factors that were common across a majority of the laboratory exposure studies and these included bacterial dose, culture time, exposure method, bacterial isolate, experimental duration, and fish weight. The comparison showed that injection as the exposure method produced higher mortality than bath immersion, bacterial isolates differed in their effect on mortality, and bacterial dose has an interactive effect with fish weight and exposure method. Our comparison allows for inference on factors affecting rainbow trout mortality due to exposure to F. psychrophilum and suggests avenues to further optimize research protocols to better reach study goals.

Host-specific Infectivity of <i>Flavobacterium psychrophilum</i> Strains Isolated from Ayu and Rainbow Trout

“…The smaller the fish, the less developed the immune system, which may explain why the pathogen was reisolated from the kidneys in this study. Bacterial dose and fish weight interact with each other to influence rainbow trout mortality (Avila et al, 2022). In this study, the dose and fish size were appropriate for establishing disease.…”

Synergistic infection of Edwardsiella ictaluri and Flavobacterium oreochromis in cage cultured tilapia (Oreochromis sp.)

“…In the present study, fish were challenged with E. ictaluri by i.p injection, which is an efficient method that shortens the time to develop signs of disease and is preferred due to the reduction in time and cost (Meza et al, 2019). More importantly, this method produces more reproducible results than other exposure methods (Avila et al, 2022) as every fish is exposed to the pathogen at the same concentrations.…”