Comparison of static-bath and flowing-water Flavobacterium columnare challenge methods with juvenile Chinook Salmon
Published by Oxford University Press on behalf of American Fisheries Society 2025.
| Publié dans: | Journal of aquatic animal health. - 1998. - 37(2025), 3 vom: 22. Sept., Seite 147-153 |
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| Auteur principal: | |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2025
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| Accès à la collection: | Journal of aquatic animal health |
| Sujets: | Journal Article Comparative Study Flavobacterium columnare Chinook Salmon flowing-water challenge thermal refugia |
| Résumé: | Published by Oxford University Press on behalf of American Fisheries Society 2025. OBJECTIVE: Flavobacterium columnare is a common pathogen of Chinook Salmon Oncorhynchus tshawytscha in the Klamath River. Elevated water temperatures invoke congregation behavior within thermal refugia and are associated with columnaris disease. A flowing-water F. columnare challenge system was compared with the standard static-bath challenge as an initial step in simulating a riverine exposure METHODS: Juvenile Chinook Salmon were exposed to 103 CFU/mL F. columnare for 20 h either in an aerated static bath or within a recirculation swim chamber set at one body length per second. Fish were held at a constant 20°C or exposed to short-term temperature fluctuations to a maximum of 24°C prior to the challenge. Mucus and gill samples were collected at the end of the 20-h challenge and from fish held up to 96 h postchallenge. Samples were assayed for detection of F. columnare by quantitative PCR and conventional plate culture method RESULTS: In static-bath challenge groups, F. columnare was detected in asymptomatic (38%) and moribund Chinook Salmon (29%). In contrast, F. columnare was detected in only one asymptomatic (4%) and one moribund (4%) Chinook Salmon in the flowing-water challenge groups. Prechallenge temperature conditions had no effect on infection. Other yellow-pigmented bacteria were isolated from the Chinook Salmon (particularly static-bath challenge) but were not associated with morbidity or amplified in the F. columnare quantitative PCR CONCLUSIONS: Low transmission of F. columnare occurred among juvenile Chinook Salmon under flowing-water conditions simulating a thermal refugia during early summer (20°C, flow of one body length per second, 20-h exposure to 103 CFU/mL). The flowing-water system is sufficient to examine the environmental factors (velocity, temperature, host density, duration, and bacterial concentration of exposure) of riverine exposures on F. columnare transmission to juvenile Chinook Salmon |
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| Description: | Date Completed 22.09.2025 Date Revised 22.09.2025 published: Print Citation Status MEDLINE |
| ISSN: | 1548-8667 |
| DOI: | 10.1093/jahafs/vsaf003 |