@article{troxell_petri_daron_pereira_mendoza_hassan_koci_2015, title={Poultry Body Temperature Contributes to Invasion Control through Reduced Expression of Salmonella Pathogenicity Island 1 Genes in Salmonella enterica Serovars Typhimurium and Enteritidis}, volume={81}, ISSN={0099-2240 1098-5336}, url={http://dx.doi.org/10.1128/AEM.02622-15}, DOI={10.1128/aem.02622-15}, abstractNote={ABSTRACT
          
            Salmonella enterica
            serovars Typhimurium (
            S
            . Typhimurium) and Enteritidis (
            S
            . Enteritidis) are foodborne pathogens, and outbreaks are often associated with poultry products. Chickens are typically asymptomatic when colonized by these serovars; however, the factors contributing to this observation are uncharacterized. Whereas symptomatic mammals have a body temperature between 37°C and 39°C, chickens have a body temperature of 41°C to 42°C. Here,
            in vivo
            experiments using chicks demonstrated that numbers of viable
            S
            . Typhimurium or
            S
            . Enteritidis bacteria within the liver and spleen organ sites were ≥4 orders of magnitude lower than those within the ceca. When similar doses of
            S
            . Typhimurium or
            S
            . Enteritidis were given to C3H/HeN mice, the ratio of the intestinal concentration to the liver/spleen concentration was 1:1. In the avian host, this suggested poor survival within these tissues or a reduced capacity to traverse the host epithelial layer and reach liver/spleen sites or both.
            Salmonella
            pathogenicity island 1 (SPI-1) promotes localization to liver/spleen tissues through invasion of the epithelial cell layer. Following
            in vitro
            growth at 42°C, SPI-1 genes
            sipC
            ,
            invF
            , and
            hilA
            and the SPI-1
            rtsA
            activator were downregulated compared to expression at 37°C. Overexpression of the
            hilA
            activators
            fur
            ,
            fliZ
            , and
            hilD
            was capable of inducing
            hilA-lacZ
            at 37°C but not at 42°C despite the presence of similar levels of protein at the two temperatures. In contrast, overexpression of either
            hilC
            or
            rtsA
            was capable of inducing
            hilA
            and
            sipC
            at 42°C. These data indicate that physiological parameters of the poultry host, such as body temperature, have a role in modulating expression of virulence.
          }, number={23}, journal={Applied and Environmental Microbiology}, publisher={American Society for Microbiology}, author={Troxell, Bryan and Petri, Nicholas and Daron, Caitlyn and Pereira, Rafaela and Mendoza, Mary and Hassan, Hosni M. and Koci, Matthew D.}, editor={Elkins, C. A.Editor}, year={2015}, month={Sep}, pages={8192–8201} }