Effect of BCG on a 4-week id and in BCG challenge.
BALB/c mice were immunized id with 2.5×103 CFU BCG. Naïve and antibiotic-treated (I+R) mice received no immunization. Four weeks later all mice were challenged either id or in with 4×103 CFU BCG, except the BCG control group who received no challenge. Immediately post-challenge the I+R group was treated for 4 weeks with isoniazid and rifampicin. Ears (a), LNs (b) and lungs (c) were harvested 4 weeks after challenge (spleen cfu data not shown). (d) shows the effect of in BCG on in challenge in a separate experiment. Here, BALB/c mice were immunized in with 1×103 CFU BCG. Naïve mice received no immunization. 4 weeks later in-immunized and naïve mice were challenged with 4×104 CFU BCG in. The “BCG in control” group received no challenge. Lungs were harvested 4 weeks after BCG challenge in all groups. CFU from plating of fresh tissues are shown. Log10 BCG CFU individual data points for each mouse are shown. Bars represent the median per group. (a) Ears (**P<0.01, n = 10); (b) LNs (**P<0.01, n = 10); (c) Lungs (**P<0.01, n = 10); (d) Lungs P<0.01, n = 8 naïve; n = 6 BCG in; n = 8 BCG in control).
