FIG 3.
IgG, IgM, CRP, and C3 opsonization and survival in serum of PChohigh and PCholow NTHi strains. (A to D) NTHi bacteria were incubated with 10% NHS (C3) or 10% HI-NHS (IgG, IgM, and CRP), and the surface binding of IgG (A), IgM (B), CRP (C), or C3 (D) was determined by flow cytometry (n = 3). (E) Bacteria were incubated with 10% NHS or 10% HI-NHS for 1 h, and survival was determined by dividing the CFU in 10% NHS by the CFU in 10% HI-NHS after 1 h of incubation (n = 3). A one-tailed unpaired t test with Welch’s correction was used for statistical analysis. *, P < 0.05; **, P < 0.01; NS, not significant.