FIG. 5.

InvB is required for SopE translocation into host cells. Intestinal Henle-407 cells were infected for 30 min with a serovar Typhimurium strain lacking sopB and sopE2 or with its isogenic derivative lacking invB, and the numbers of bacteria that resisted the treatment with gentamicin due to bacterial internalization were enumerated as previously described (14). Notice that in the absence of sopB and sopE2, Salmonella internalization is exclusively the result of the activity of translocated SopE (34). Values represent the means and standard deviations of three determinations of the percentage of the initial inoculum that survived the gentamicin treatment; values have been normalized to that of the ΔsopB ΔsopE2 mutant, which was considered to be 100% (actual value, 12% ± 2%).