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Percorrer por autor "Korkeala, Hannu"

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  • Clostridium botulinum type B outbreak causing mild symptoms in Portugal
    Publication . Martins Portinha, Inês; Saraiva, Margarida; Teixeira Lopes, Teresa; Campos Cunha, Isabel; dos Santos Silva, André Filipe; P. Douillard, François; Korkeala, Hannu; Lindström, Miia
    Botulism is a statutory notifiable disease in Portugal since 1999, with 112 cases registered until 2015. The largest number of cases reported per year was 30 cases, from 2 outbreaks in 2000. Most foodborne cases were caused by botulinum neurotoxin type B found in home preserved meat products.The first infant botulism case occurred in 2012. Only one case of type F toxin was ever reported in Portugal.
    2017-10-22Documento de conferência Acesso restrito Ver mais
  • Genomic Epidemiology and Phenotyping Reveal on-Farm Persistence and Cold Adaptation of Raw Milk Outbreak-Associated Yersinia pseudotuberculosis
    Publication . Castro, Hanna; Jaakkonen, Anniina; Hakakorpi, Anna; Hakkinen, Marjaana; Isidro, Joana; Korkeala, Hannu; Lindström, Miia; Hallanvuo, Saija
    Packaged raw milk contaminated with Yersinia pseudotuberculosis mediated a large yersiniosis outbreak in southern Finland in 2014. The outbreak was traced back to a single dairy farm in southern Finland. Here we explore risk factors leading to the outbreak through epidemiologic investigation of the outbreak farm and through genomic and phenotypic characterization of the farm's outbreak and non-outbreak associated Y. pseudotuberculosis strains. We show that the outbreak strain persisted on the farm throughout the 7-month study, whereas the non-outbreak strains occurred sporadically. Phylogenomic analysis illustrated that the outbreak strain was related to previously published genomes of wild animal isolates from Finland, implying that wild animals were a potential source of the outbreak strain to the farm. We observed allelic differences between the farm's outbreak and non-outbreak strains in several genes associated with virulence, stress response and biofilm formation, and found that the outbreak strain formed biofilm in vitro and maintained better growth fitness during cold stress than the non-outbreak strains. Finally, we demonstrate the rapid growth of the outbreak strain in packaged raw milk during refrigerated storage. This study provides insight of the risk factors leading to the Y. pseudotuberculosis outbreak, highlights the importance of pest control to avoid the spread of pathogens from wild to domestic animals, and demonstrates that the cold chain is insufficient as the sole risk management strategy to control Y. pseudotuberculosis risk associated with raw drinking milk.
    2019-05-14Artigo científico Acesso aberto Ver mais