Table 1.
Establishment of persistent infections among survivors after challenge with S. typhimurium
| Strain | Proportion persistently infected* | Splenic bacterial load mean (SD) |
|---|---|---|
| MC1 | 0/44 (0%) | — |
| MC2 | 43/144 (30%) | 2.0 × 104 (3.4 × 104) |
| MC71 | 29/79 (37%) | 1.3 × 104 (1.3 × 104) |
BALB/c mice (female, 6–8 weeks of age) were challenged orally (14) with a dose corresponding to LD30. Mice surviving the acute phase of the infection (7–20 days postinfection) were killed 28–30 days postinfection, and their spleens were removed for enumeration of bacteria.
*
Persistent infection was defined by the presence of splenic bacteria and splenomegaly (mean spleen weight 0.97 ± 0.34 g, as compared to 0.16 ± 0.05 g for sterile spleens recovered from the survivors).