FIG 1.

MyD88 contributes to growth of wild-type Y. pestis in the lungs. Groups of 5 to 10 C57BL/6 (filled circles or bars) or Myd88^−/− (open circles or bars) mice were challenged by intranasal infection with 2,000 CFU of Y. pestis CO92. (A) Survival was monitored over 14 days, data were collected in 3 independent trials, and the total number analyzed for each group is shown in parentheses; data were combined and analyzed by the Mantel-Cox log rank test. **, P < 0.01. (B and C) On day 2 postinfection, mice were euthanized, tissues and blood were collected, and bacterial titers in the lungs, liver, spleen, and blood were determined (B) and are shown as percent colonization (C). Data were collected in 2 independent trials; n = 10 WT mice, n = 11 Myd88^−/− mice. Bars in panel B represent the median; bars in panel C represent the standard error. Combined data were analyzed by Mann-Whitney (B) and chi-square (C) tests, with each tissue analyzed independently. *, P < 0.05; NS, not significant.