FIG. 6.
Phenotypic characterization of Y. pseudotuberculosis yopM mutants by secretion assay and mouse virulence assay. (A) The following strains were grown under T3SS-inducing conditions as described in Materials and Methods: 32777 (lanes 1 and 7), 32777ΔyopM (lanes 2 and 8), 32777ΔyopM + pyopMYP (lanes 3 and 9), 32777ΔyopM + pyopMΔ6-15 (lanes 4 and 10), 32777ΔyopM + pyopMΔ12-C (lanes 5 and 11), and 32777ΔyopM + pyopMYPTB (lanes 6 and 12). Secreted proteins were analyzed by SDS-PAGE, followed by GelCode Blue staining (left), or a duplicate gel was blotted onto nitrocellulose and probed with mouse antiserum raised against GST-YopM (right). The values to the left are molecular sizes in kilodaltons. (B) Time-to-death analysis of orogastric Y. pseudotuberculosis infections. Groups of three to five mice were infected by oral gavage with 5 × 109 CFU of Y. pseudotuberculosis, and time to death was monitored for 14 days. Results are pooled from two to four independent experiments (32777, n = 13; 32777ΔyopM, n = 12; 32777ΔyopM + pyopMWT, n = 13; 32777ΔyopM + pyopMΔ6-15, n = 11; 32777ΔyopM + pyopMΔ12-C, n = 12; 32777ΔyopM + pyopMYPTB, n = 11).