FIG. 1.

Western blot analysis of RpoS expression in pathogenic E. coli strains. Wild-type E. coli strains, rpoS::Ap mutant strain 55, and strain 55-1 carrying pPS4.4 (rpoS) were aerobically grown to the stationary phase in LB-MES medium, and equivalent amounts of protein were loaded into each lane and probed with anti-RpoS antibody to detect RpoS (38 kDa). Individual strains used are indicated above each lane.