Fig. 2

Polymicrobial infection causes lethal sepsis in old but not young mice. C57BL/6 mice ranging in age from 8–19 weeks (n = 13) were subjected to polymicrobial infection by intraperitoneal injection of different doses of a slurry of the cecal contents obtained from healthy adult mice. Survival was monitored for 48 h, and signs of sepsis were scored on a scale from 0–20 after 16 h (A). Young (10 weeks; n = 12) and old (64 weeks; n = 6) mice were subjected to equal doses of cecal slurry (0.3 mg/g body weight; BW), and clinical parameters and mortality were monitored at least every 2 h after injection for up to 24 h. The mortality of old versus young mice was compared with the log-rank Mantel–Cox test, p = 0.0014 (B)