Comparison and evaluation of Renibacterium salmoninarum quantitative PCR diagnostic assays using field samples of Chinook and coho salmon

  • Sandell T
  • Jacobson K
  • 1

    Readers

    Mendeley users who have this article in their library.
  • N/A

    Citations

    Citations of this article.

Abstract

Renibacterium salmoninarum is a Gram-positive bacterium causing bacterial kidney disease (BKD) in susceptible salmonid fishes. Several quantitative PCR (qPCR) assays to measure R. salmoninarum infection intensity have been reported, but comparison and evaluation of these assays has been limited. Here, we compared 3 qPCR primer/probe sets for detection of R. salmoninarum in field samples of naturally exposed Chinook and coho salmon first identified as positive by nested PCR (nPCR). Additional samples from a hatchery population of Chinook salmon with BKD were included to serve as strong positive controls. The 3 qPCR assays targeted either the multiple copy major soluble antigen (msa) genes or the single copy abc gene. The msa/non-fluorescent quencher (NFQ) assay amplified R. salmoninarum DNA in 53.2% of the nPCR positive samples, whereas the abc/NFQ assay amplified 21.8% of the samples and the abc/TAMRA assay 18.2%. The enzyme-linked immunosorbent assay (ELISA) successfully quantified only 16.4% of the nPCR positive samples. Although the msa/NFQ assay amplified a greater proportion of nPCR positive samples, the abc/NFQ assay better amplified those samples with medium and high ELISA values. A comparison of the geometric mean quantity ratios highlighted limitations of the assays, and the abc/NFQ assay strongly amplified some samples that were negative in other tests, in contrast to its performance among the sample group as a whole. These data demonstrate that both the msa/NFQ and abc/NFQ qPCR assays are specific and effective at higher infection levels and outperform the ELISA. However, most pathogen studies will continue to require multiple assays to both detect and quantify R. salmoninarum infection.

Author-supplied keywords

  • *Micrococcaceae
  • *Salmon
  • Actinomycetales Infections/microbiology/*veterinar
  • Animals
  • Enzyme-Linked Immunosorbent Assay/veterinary
  • Fish Diseases/diagnosis/*microbiology
  • Polymerase Chain Reaction/methods/*veterinary
  • Reproducibility of Results
  • Sensitivity and Specificity

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Authors

  • T A Sandell

  • K C Jacobson

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free