PGRP-S^-/- mice are more resistant to intravenous than intraperitoneal infection with B subtilisPGRP-S^+/+ (light gray bars) or PGRP-S^-/- (dark gray bars) mice were injected intraperitoneally or intravenously with B subtilis, 4 × 10⁹ (A, n = 16/group), or 2 × 10⁹ (B-C, n = 8/group). Survival at 48 hours (A) was compared using the Chi-square test (no additional deaths occurred after that time). Bacterial loads in tissue fluids and organs at 30 hours (B) or 6 hours (C) after challenge were determined, and the significance of differences was calculated using the Mann-Whitney U test.