Fig. 3.

Effect of prior infection with strain K279a on the susceptibility of A/J mice to S. maltophilia challenge. One group of mice (n = 20) that had been infected with a sublethal dose of K279a 21 days earlier (□) and another group of mice (n = 19) that had previously been inoculated with PBS only (▪) were infected with K279a, and then the numbers of c.f.u. in the lungs were determined at 0, 4, 8 and 12 h post-inoculation. The values presented at each time point are the mean±sd obtained from five infected animals, with the exception of the 0 h point for the PBS control (four animals). Mice that had previous exposure to K279a exhibited a significantly reduced bacterial load compared with the PBS control group at 8 h post-inoculation (Student's t test, P<0.01).