Detection and quantification of Renibacterium salmoninarum DNA in salmonid tissues by real-time quantitative polymerase chain reaction analysis.
Renibacterium salmoninarum is an important salmonid pathogen that is difficult to culture. We developed and assessed a real-time, quantitative, polymerase chain reaction (qPCR) assay for the detection and enumeration of R. salmoninarum. The qPCR is based on TaqMan technology and amplifies a 69-base pair (bp) region of the gene encoding the major soluble antigen (MSA) of R. salmoninarum. The qPCR assay consistently detected as few as 5 R. salmoninarum cells per reaction in kidney tissue. The specificity of the qPCR was confirmed by testing the DNA extracts from a panel of microorganisms that were either common fish pathogens or reported to cause false-positive reactions in the enzyme-linked immunosorbent assay (ELISA). Kidney samples from 38 juvenile Chinook salmon (Oncorhynchus tshawytscha) in a naturally infected population were examined by real-time qPCR, a nested PCR, and ELISA, and prevalences of R. salmoninarum detected were 71, 66, and 71%, respectively. The qPCR should be a valuable tool for evaluating the R. salmoninarum infection status of salmonids.
Chase
Dorothy M
DM
US Geological Survey, Biological Resources Discipline, Western Fisheries Research Center, 6505 N.E. 65th Street, Seattle, WA 98115, USA.
Elliott
Diane G
DG
Pascho
Ronald J
RJ
D039903:Actinobacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D000818:Animals; D004269:DNA, Bacterial / Q000032:analysis* / Q000235:genetics; D016680:Genome, Bacterial; D007668:Kidney / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary*; D012474:Salmon / Q000382:microbiology*
D004269:DNA, Bacterial