FIG. 5.

Intraperitonal injection of infected cells leads to bacterial dissemination. J774A.1 cells were infected by 2-h incubation with L. monocytogenes, and peritoneal cells were harvested by peritoneal lavage from mice 60 min following i.p. injection with 10⁷ L. monocytogenes organisms. Infected J774A.1 cells (▴; 5.37 log₁₀ CFU) and peritoneal cells (⧫; 5.72 log₁₀ CFU) or broth-grown bacteria (□; 5.11 log₁₀ CFU) were injected i.p. into mice, and CFU of bacteria in liver (A), spleen (B), and brain (C) were quantified 24 and 48 h postinjection. CFU of bacteria in each inoculum (log₁₀ per mouse) are shown with the symbols described above at time zero in panel A. Results shown are the mean log₁₀ CFU of bacteria/organ ± SEM from groups of four mice. Error bars not shown are smaller than the symbol.