The history and current status of Renibacterium salmoninarum, the causative agent of bacterial kidney disease in Pacific salmon

Abstract

Bacterial kidney disease (BKD) is a long standing problem among salmonid fish in the Pacific Northwest, USA. The disease, caused by Renibacterium salmoninarum, a Gram-positiive, slow-growing, fastidious, obligate pathhogen of salmonids, was described firast in Scotland in 1930,a nd in the eastern USA in 1934. By the end of the next decade it had been identified in Pacific salmon in California, Washington and Oregon. In time, it was found in all hatcheries in theregion and in all species of Pacific salmon cultured there. The bacterium was probably inroduced into the hatcheries with eggs from infected wild stocks, but early hatchery, e.g. feeding raw salmon viscera, greatly enhanced its spread. Routine pastruerization of fish products in the diests has reduced, but not eliminated, BKD in these stocks of fish. This unieque and highly succesful pathogen has been the subject of extensive research aimed at prevention and control of BKD through chemotherapy, diet modification, vacccnation, genetic manipulation, broodstock selection, and treatment of gegs and spawning adult fish. Important advances allow rapid and sensitive detection of R. salmoninarum using a variety of methods,. However, in spite of this, BKD ciontinues to be serius problem for both wikld and cultured salmonids.