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Validation of diagnostic assays to screen broodstock for Flavobacterium psychrophilum infections
journal contribution
posted on 2023-05-17, 15:52 authored by Long, A, Polinski, MP, Call, DR, Cain, KDIt is hypothesized that the frequency of bacterial coldwater disease outbreaks can be reduced through the detection of the aetiologic agent, Flavobacterium psychrophilum, in broodstock followed by culling of eggs from heavily infected broodstock. Before a culling programme can be instituted, however, it is necessary to determine the sensitivity and specificity of existing assays for the detection of F. psychrophilum. In this study, tissue and ovarian fluid samples were collected from 224 fish at five hatcheries and screened using an enzyme-linked immunosorbent assay (ELISA), a membrane-filtration fluorescent antibody test (MF-FAT), bacteriological culture and nested PCR. Latent class analysis was used to estimate sensitivity and specificity of kidney culture, kidney ELISA, nested PCR and MF-FAT. Analytical sensitivity of the ELISA varied but was greatest when bacteria were cultured under iron-limiting conditions. Diagnostic sensitivity estimates ranged from 0.02 (kidney culture) to 0.97 (kidney ELISA). Specificity estimates ranged from 0.02 (MF-FAT) to 0.98 (kidney ELISA). In a separate challenge experiment, the ELISA confirmed the presence of F. psychrophilum in subclinically infected fish. Results from this study demonstrate that the ELISA is an appropriate tool to screen broodstock and provides an indication of infection severity, which is crucial for implementation of a screening/culling programme.
History
Publication title
Journal of Fish DiseasesVolume
35Issue
6Pagination
407-419ISSN
1365-2761Department/School
Institute for Marine and Antarctic StudiesPublisher
Blackwell Publishing LtdPlace of publication
United KingdomRights statement
Copyright 2012 Blackwell Publishing LtdRepository Status
- Restricted