PGRP-S^-/- mice have lower survival following intraperitoneal infection with B subtilis but not S aureus and E coli. Mice were injected intraperitoneally with 4 × 10⁹B subtilis (n = 58/group; left panel), 1 × 10⁹S aureus (n = 32/group; middle panel), or 3 × 10⁸E coli (n = 28/group; right panel), and their survival was monitored for 10 days. The significance of differences in the survival of PGRP-S^+/+ and PGRP-S^-/- mice was calculated at 48 hours (B subtilis) or 96 hours (S aureus and E coli) after challenge using Chi-square test (no additional deaths occurred after that time). The results from 2 to 4 separate experiments were combined.