Prevalence and distribution of Renibacterium salmoninarum in non-salmonid fishes from Laurentian Great Lakes and inland habitats

Abstract Renibacterium salmoninarum (RS), the causative agent of bacterial kidney disease, has been a serious threat to salmonid health in the Laurentian Great Lakes. Despite its wide spread presence in the Great Lakes basin, little is known about RS ecology and the potential role of non-salmonid species as one of the pathogen’s reservoirs. This information is of paramount importance to fishery managers in order to better understand RS distribution in the different biotic components of the Great Lakes watershed. In this study, non-salmonid species from lakes Michigan and Huron, and from 13 inland waters of the Great Lakes watershed were collected from 1999 to 2008. Out of 380 fish sampled from lakes Michigan and Huron, 42 (11.05%) tested positive for RS as determined by the nested polymerase chain reaction. Prevalence was lower in Lake Huron (5.71%) compared to Michigan (20.74%), but the difference was not statistically significant. Prevalence of RS was not found to be significantly different between species or sites; however, when species were grouped into demersal vs. pelagic categories, significant differences (P