A PCR-based assay for the identification of the fish pathogen Renibacterium salmoninarum

By means of a one-step one-tube extraction from less than 1 mg of tissue it is possible to identify, via the polymerase chain reaction, Renibacterium salmoninarum in salmon with bacterial kidney disease. A 149-bp DNA sequence unique to R. salmoninarum was specifically amplified and its nature confirmed by Southern hybridization using a non-isotopically labelled probe. The sensitivity of the approach allowed the detection of 22 R. salmoninarum cells. The procedure was successfully applied in the identification of the causative agent of bacterial kidney disease in kidney tissue from infected fishes.