Fig. 2
Administration of EB211 and EB279 led to an increased survival rate and a reduced bacterial burden in the lungs of immunocompromised mice with A. baumannii pneumonia. Immunocompromised mice were inoculated intranasally with XDR A. baumannii A.b.56 at a 50% lethal dose (LD50; 4×107 CFU per mouse). Immunocompromised infected mice were administered intraperitoneally twice daily with EB211 (12 mg/kg), EB279 (12 mg/kg), a cocktail of the two scFvs (CKT; 6 mg/kg of each), an irrelevant scFv (MEH158; an S. aureus-specific scFv) (12 mg/kg), colistimethate sodium (CMS; 30 mg/kg), or normal saline (NS), or once daily with EB211 (12 mg/kg) (Q24H) two hours after inoculation for 72 h. (A) The survival rate of mice (n = 8) monitored daily for up to seven days after infection. The log-rank test was used to compare Kaplan-Meier survival curves. *p < 0.05 for EB211, EB279, CKT, or CMS versus NS. The results represent three independent experiments. (B) Bacterial burden in the lungs of immunocompromised infected mice (n = 6) administered with the scFvs, CMS, or NS after 24, 48, and 72 h of infection. The results represent the mean ± SEM of three independent experiments. *p < 0.05 for EB211 (Q24H) versus NS; **p < 0.01 for EB211, EB211 (Q24H), EB279, CKT, or CMS versus NS.