Transcription profiling of rat colonic mucosa at different time points following Salmonella infection

Salmonella enteritidis is suggested to translocate in the small intestine. Previously we identified that prebiotics, fermented in the colon, increased Salmonella translocation in rats, suggesting involvement of the colon in translocation. Effects of Salmonella on colonic gene expression in vivo are largely unknown. The aim of this study was to characterize time dependent Salmonella induced changes of colonic mucosal gene expression in rats using whole genome microarrays. Rats were orally infected with Salmonella enteritidis to mimic a foodbore infection and colonic gene expression was determined at day 1, 3 and 6 post-infection (n=8 per timepoint). Agilent rat whole genome microarray (G4131A Agilent Technologies) were used. Results indicate that colon is clearly a target tissue for Salmonella considering the abundant changes in mucosal gene expression observed. Keywords: Time point infection study, colon mucosa, Rat In the present study, large-scale gene expression analysis was performed to reveal whether Salmonella induced changes of colonic mucosal gene expression in rats. Wistar rats were infected with Salmonella enteritidis. Non-infected control rats were sham-treated. Rats were sacrificed on day 1, 3 or 6 post infection or sham-treatment (n=8 rats per treatment and per time point). RNA was isolated from colonic mucosal scrapings. mRNA samples of 8 rats per group were pooled. Each pooled group-sample was hybridised in duplicate on Agilent rat whole genome microarrays containing 44290 60-mer spots. From the 12 arrays one duplicate array (Colon mucosa non-infected day6) did not pass quality control and was left out from further analysis.