FIG 7.

Effect of allelic exchange of PorB3 on human FH-dependent susceptibility of FHbp and NspA double knockout mutants to killing by 60% infant rat serum. (A) Double-KO mutants of isolate R1 with its endogenous PorB3 replaced by PorB3 R1 or PorB3 S1. (B) Double-KO mutants of isolate S1 with its endogenous PorB replaced by PorB3 R1 or PorB3 S1. The data points represent median values from triplicate measurements. Error bars represent ranges. The results were replicated in an independent experiment. (C and D) Effect of PorB3 on binding of recombinant human FH domains by flow cytometry. Solid black lines, PorB3 R1; black dashed lines, PorB3 S1; gray-filled histogram, bacteria without added recombinant fragment. Panel C, double-KO isolate R1 with allelic replacement of PorB3 R1 or S1; panel D, double-KO isolate S1 with allelic replacement of PorB3 R1 or S1. The results were replicated in two independent experiments.