FIG. 4.

Bacterial counts in blood from 6-week-old female transgenic BALB/c mice challenged intraperitoneally with standardized inocula of 5 × 10⁶ CFU of Rif^s (susceptible) isolates and two isogenic Rif^r (resistant) transformants harboring the rpoB19 (S557F) or rpoB23 (S548F) allele. Results obtained after 6 h of infection are shown. The results shown are means for groups of at least five mice. P values were determined by two-tailed Student's t test. The levels of cytokines (TNF-α and IL-6) and of the chemokine KC are also displayed.