Effects of an adrA mutant on Salmonella enterica gene expression during root colonization. Salmonella enterica subsp. enterica serovar Typhimurium str. 14028S

Increasing evidence indicates that despite exposure to harsh environmental stresses, Salmonella enterica successfully persists on plants, utilizing fresh produce as a vector to animal hosts. This study examined the mechanisms of S. enterica plant colonization, including the role of the diguanylate cyclase AdrA. Utilizing microarray analysis, we identified a new function for AdrA in the transcriptional regulation of colanic acid biosynthesis genes. Overall design: Changes in gene expression, comparing wildtype to an adrA mutant, were measured in planktonic bacterial cells after 24-hour incubation with alfalfa seeds. Two independent experiments were performed for each strain (wildtype and the adrA mutant).