FIG 4.

Protective efficacy of selected humanized MAbs in a murine lethal bacteremia model. Passive immunization was performed by intraperitoneal injections of MAbs 24 h prior to lethal intravenous challenge with strain 3O grown in LB broth (A), strain 81009 grown in LB broth (B), or strain 81009 grown in depleted human serum (C). Doses of 100 μg/mouse were used routinely, and survival curves for 14 days are depicted in panels A and C. Dose response curves with three selected MAbs within the range of 1 to 150 μg were performed, and survival rates over control at day 14 postinjection are plotted in panel B. Combined results of 2 (A) or 3 (C) independent experiments are shown. P values were calculated using the log rank test (***, P < 0.001).