Näytä suppeat kuvailutiedot

dc.contributor.authorKinnula, Hanna
dc.date.accessioned2016-11-07T14:03:28Z
dc.date.available2016-11-07T14:03:28Z
dc.date.issued2016
dc.identifier.isbn978-951-39-6818-2
dc.identifier.otheroai:jykdok.linneanet.fi:1611469
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/51839
dc.description.abstractEcological factors are known to affect disease dynamics and even lead to disease emergence. Especially in opportunistic, environmentally transmitted pathogens, the environment may significantly contribute to pathogen virulence. Intensive farming, including aquaculture, has been suggested to create conditions favouring development of highly virulent pathogens. At Finnish fish farms, epidemics caused by opportunistic Flavobacterium columnare have been constantly increasing in their prevalence and severity since the 1980’s. Yet, factors behind the increased virulence of the pathogen and their mechanisms of action have largely remained unsolved. In this thesis, I explore the effects of infection dose, outside-host nutrients and coinfection with conspecific strains on virulence and disease dynamics of F. columnare. Virulence of bacterial strains isolated from fish farms was tested in experimental fish infections, where bacterial dose, water nutrient concentration and number of infecting strains were manipulated. Two fish species, zebra fish (Danio rerio) and rainbow trout (Oncorhynchus mykiss), were used as hosts to confirm the suitability of zebra fish for further infection experiments. Finally, strains isolated during 2003-2010 were studied for temporal and local changes in their virulence, growth and competitive ability. Increase in infection dose was found to increase bacterial virulence in both hosts. High nutrient level increased virulence via enhanced bacterial growth and virulence factor activation. I also found that coinfection can increase F. columnare virulence, but the disease outcome depends on the strain characteristics. Finally, it is shown that the aquaculture environment may select for strains with high virulence and enhanced competitiveness. Taken together, the results indicate that all the studied factors can contribute to opportunistic disease outbreaks in aquaculture.
dc.format.extent1 verkkoaineisto (54 sivua, 10 sivua, 4 numeroimatonta sivua)
dc.language.isoeng
dc.publisherUniversity of Jyväskylä
dc.relation.ispartofseriesJyväskylä studies in biological and environmental science
dc.relation.isversionofJulkaistu myös painettuna.
dc.subject.othercolumnaris-tauti
dc.subject.otherinfektioannos
dc.subject.otheryhteisinfektiot
dc.subject.othercolumnaris disease
dc.subject.otherdisease emergence
dc.subject.otherfish farming
dc.subject.otherFlavobacterium columnare
dc.subject.otheropportunistic pathogen
dc.subject.othervirulence
dc.subject.othervirulence evolution
dc.titleThe influence of infective dose, nutrient availability and coinfection on virulence of Flavobacterium columnare : implications of intensive aquaculture on opportunistic infections
dc.typeDiss.fi
dc.identifier.urnURN:ISBN:978-951-39-6818-2
dc.type.dcmitypeTexten
dc.type.ontasotVäitöskirjafi
dc.type.ontasotDoctoral dissertationen
dc.contributor.tiedekuntaMatemaattis-luonnontieteellinen tiedekuntafi
dc.contributor.tiedekuntaFaculty of Mathematics and Scienceen
dc.contributor.yliopistoUniversity of Jyväskyläen
dc.contributor.yliopistoJyväskylän yliopistofi
dc.contributor.oppiaineEkologia ja evoluutiobiologiafi
dc.relation.issn1456-9701
dc.relation.numberinseries321
dc.rights.accesslevelopenAccessfi
dc.subject.ysokalataudit
dc.subject.ysobakteeritaudit
dc.subject.ysoinfektiotaudit
dc.subject.ysoinfektiot
dc.subject.ysotaudinaiheuttajat
dc.subject.ysobakteerit
dc.subject.ysovirulenssi
dc.subject.ysoravinnepitoisuus
dc.subject.ysokalanviljely
dc.subject.ysokalanviljelylaitokset
dc.subject.ysokirjolohi
dc.subject.ysoseeprakala


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