<it>Salmonella </it>induces prominent gene expression in the rat colon

• Main Authors: Roosing Susanne, Kramer Evelien, Keijer Jaap, Rodenburg Wendy, Vink Carolien, Katan Martijn B, van der Meer Roelof, Bovee-Oudenhoven Ingeborg MJ
• Format: Article
• Language: English
• Published: BMC 2007-09-01
• Series: BMC Microbiology
• Online Access: http://www.biomedcentral.com/1471-2180/7/84

<p>Abstract</p> <p>Background</p> <p><it>Salmonella enteritidis </it>is suggested to translocate in the small intestine. <it>In vivo </it>it induces gene expression changes in the ileal mucosa and Peyer's patches. Stimulation of <it>Salmonella </it>translocation by dietary prebiotics fermented in colon suggests involvement of the colon as well. However, effects of <it>Salmonella </it>on colonic gene expression <it>in vivo </it>are largely unknown. We aimed to characterize time dependent <it>Salmonella</it>-induced changes of colonic mucosal gene expression in rats using whole genome microarrays. For this, rats were orally infected with <it>Salmonella enteritidis </it>to mimic a foodborne infection and colonic gene expression was determined at days 1, 3 and 6 post-infection (n = 8 rats per time-point). As fructo-oligosaccharides (FOS) affect colonic physiology, we analyzed colonic mucosal gene expression of FOS-fed versus cellulose-fed rats infected with <it>Salmonella </it>in a separate experiment. Colonic mucosal samples were isolated at day 2 post-infection.</p> <p>Results</p> <p><it>Salmonella </it>affected transport (e.g. Chloride channel calcium activated 6, H⁺/K⁺transporting Atp-ase), antimicrobial defense (e.g. Lipopolysaccharide binding protein, Defensin 5 and phospholipase A2), inflammation (e.g. calprotectin), oxidative stress related genes (e.g. Dual oxidase 2 and Glutathione peroxidase 2) and Proteolysis (e.g. Ubiquitin D and Proteosome subunit beta type 9). Furthermore, <it>Salmonella </it>translocation increased serum IFNγ and many interferon-related genes in colonic mucosa. The gene most strongly induced by <it>Salmonella </it>infection was Pancreatitis Associated Protein (<it>Pap</it>), showing >100-fold induction at day 6 after oral infection. Results were confirmed by Q-PCR in individual rats. Stimulation of <it>Salmonella </it>translocation by dietary FOS was accompanied by enhancement of the <it>Salmonella</it>-induced mucosal processes, not by induction of other processes.</p> <p>Conclusion</p> <p>We conclude that the colon is a target tissue for <it>Salmonella</it>, considering the abundant changes in mucosal gene expression.</p>