A1 Journal article (refereed)
Higher resource level promotes virulence in an environmentally transmitted bacterial fish pathogen (2017)

Kinnula, H., Mappes, J., Valkonen, J., Pulkkinen, K., & Sundberg, L.-R. (2017). Higher resource level promotes virulence in an environmentally transmitted bacterial fish pathogen. Evolutionary Applications, 10(5), 462-470. https://doi.org/10.1111/eva.12466

JYU authors or editors

Publication details

All authors or editorsKinnula, Hanna; Mappes, Johanna; Valkonen, Janne; Pulkkinen, Katja; Sundberg, Lotta-Riina

Journal or seriesEvolutionary Applications



Publication year2017


Issue number5

Pages range462-470


Publication countryUnited Kingdom

Publication languageEnglish


Research data linkhttps://doi.org/10.5061/dryad.57917

Publication open accessOpenly available

Publication channel open accessOpen Access channel

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/54257


Diseases have become a primary constraint to sustainable aquaculture, but remarkably little attention has been paid to a broad class of pathogens: the opportunists. Opportunists often persist in the environment outside the host, and their pathogenic features are influenced by changes in the environment. To test how environmental nutrient levels influence virulence, we used strains of Flavobacterium columnare, an environmentally transmitted fish pathogen, to infect rainbow trout and zebra fish in two different nutrient concentrations. To separate the effects of dose and nutrients, we used three infective doses and studied the growth of bacteria in vitro. High nutrient concentration promoted both the virulence and the outside‐host growth of the pathogen, most notably in a low‐virulence strain. The increase in virulence could not be exhaustively explained by the increased dose under higher nutrient supply, suggesting virulence factor activation. In aquaculture settings, accumulation of organic material in rearing units can locally increase water nutrient concentration and therefore increase disease risk as a response to elevated bacterial density and virulence factor activation. Our results highlight the role of increased nutrients in outside‐host environment as a selective agent for higher virulence and faster evolutionary rate in opportunistic pathogens.


Free keywordsinfection, nutrient

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Ministry reportingYes

Reporting Year2017

JUFO rating1

Last updated on 2024-11-05 at 18:45