FIG 7.

ClyJ-3 shows improved protective efficacy in vivo. (a) ClyJ-3 protects mice from lethal S. pneumoniae infection with higher efficacy than ClyJ and Cpl-1. Female BALB/c mice (6 to 8 weeks old) were injected intraperitoneally with 8 × 10⁷ CFU/mouse of S. pneumoniae NS26 and divided randomly into 8 groups. At 1 h postinfection, groups (n = 12) received a single intraperitoneal dose of 50 or 100 μg/mouse of ClyJ, ClyJ-3, or Cpl-1, 100 μg/mouse of penicillin G, or an equal volume of PBS buffer. (b) Establishment of an equivalent dose of ClyJ and ClyJ-3 in vivo. Female BALB/c mice (6 to 8 weeks old) were injected intraperitoneally with 3.8 × 10⁷ CFU/mouse of S. pneumoniae NS26. At 1 h postinfection, groups (n = 12) received a single intraperitoneal dose of 40 μg/mouse of ClyJ, 2 μg/mouse of ClyJ-3, or an equal volume of PBS buffer. The survival rates for all groups were recoded for 10 days. Survival curves were analyzed by log rank (Mantel-Cox) and Gehan-Breslow-Wilcoxon tests. *, P < 0.05; ***, P < 0.01.