Polymorphism and selection of rpoS in pathogenic Escherichia coli

BackgroundThough RpoS is important for survival of pathogenic Escherichia coli in natural environments, polymorphism in the rpoS gene is common. However, the causes of this polymorphism and consequential physiological effects on gene expression in pathogenic strains are not fully understood.ResultsIn this study, we found that growth on non-preferred carbon sources can efficiently select for loss of RpoS in seven of ten representative …