FIG 7.

Transcomplementation of ΔclsAB-, ΔclsBC-, or ΔclsABC-mutant S. Typhimurium with plasmid-borne clsA or clsB does not restore the intracellular survival or IL-1β secretion phenotypes in macrophages. (A) Macrophages were infected and lysed at 6 hpi, and the surviving intracellular bacteria were enumerated. Triplicate wells were infected for each genotype. The graph depicts the individual mean number of CFU per well ± SEM for two or three independent experiments, depending on the genotype. Statistical significance was calculated using a one-way ANOVA followed by Dunnett’s posttest. No significant (ns) difference was observed between the complementation strains and pEmpty for each genotype. (B) The supernatants of the infected cells depicted in panel A were collected at 6 hpi, and the levels of secreted IL-1β secretion were freshly quantified using a sandwich ELISA. Three wells were infected per bacterial genotype, and the data are shown as the average pg/mL ± SD of secreted IL-1β. This graph represents one of two or three independent experiments depending on the genotype. Statistical significance was calculated using a one-way ANOVA followed by Dunnett’s posttest. No significant (ns) difference was observed between the complementation strains and pEmpty for each genotype.