Fig 5. Combination treatment can potentially increase efficacy of anti-PspA mAbs and standard-of-care antibiotics.

(A-B) 24 h after i.p. infection with ~2.1–3.2x10⁴ CFU of exponential phase PJ-1324 (~21- to 32-fold LD₁₀₀), CD-1 mice were treated i.p. with 200 μL PBS alone (vehicle), or 200 μL PBS containing 100 μg isotype IgG2a mAb or 140csH1 ± 1 mg ceftriaxone (~50 mg/kg). Survival was followed for 15 days after infection. Combined results of three independent experiments are shown. *, p<0.05, Mantel-Cox test. (C) 30 min after i.p. infection with 3.2–6.5x10⁷ CFU exponential phase BAA-658 (ERM resistant), groups of 4–5 female CD-1 mice were treated i.p. with 200 μl of PBS containing 300 μg of mouse isotype IgG2a antibody or 140csH1. Mice were immediately treated intragastrically with 200 μL PBS, 1.5% ethanol (vehicle) or 200 μL PBS, 1.5% ethanol, 1.5 mg/mL ERM (Dose: 15 mg/kg). Survival was monitored for 8 days. Combined results of three independent experiments are shown. *, p<0.05 vehicle + isotype vs. vehicle +140csH1; ^#, p<0.04 vehicle + 140csH1 vs. ERM + 140csH1; ^$, p<0.0001 ERM + isotype vs. ERM + 140csH1, Mantel-Cox test.