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

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.

Automated summary

Infectious bacterial pathogens are a major concern in aquaculture, leading to significant financial losses. This study reviewed the literature on Flavobacterium psychrophilum, a common salmonid pathogen causing bacterial coldwater disease, and used Bayesian analysis to examine rainbow trout mortality patterns in laboratory challenges. The study found that injection as the exposure method resulted in higher mortality compared to bath immersion, different bacterial isolates had varying effects on mortality, and bacterial dose interacted with fish weight and exposure method.