Evaluation of the effect of RpoS on the synthesis of Vi polysaccharide in serotype Typhi. (A) Standards of Vi antigen. (B) Negative control, χ9197 serotype Typhi Ty2 RpoS− ΔtviAEBCD10. (C) Negative control, χ9198 serotype Typhi ISP1820 RpoS+ ΔtviAEBCD10. (D) χ3744 serotype Typhi ISP1820 RpoS+. (E) χ3769 serotype Typhi Ty2 RpoS−. (F) χ8438 serotype Typhi Ty2 RpoS+. (G) χ9060 serotype Typhi Ty2 rpoSΩAp. (H) χ9061 serotype Typhi ISP1820 rpoSΩAp. (I) Noninduced χ9066 serotype Typhi ΔPrpoS183::TTaraCPBADrpoS RpoS. (J) χ9067 serotype Typhi Ty2 RpoS− ΔPrpoS183::TTaraCPBADrpoS RpoS induced by 0.2% arabinose. The strains were grown in LB media with 0, 0.15, 0.3, and 0.4 mM of NaCl. (K) Relation between Vi antigen concentration (μg) and length of rocket (cm).