FIG 7.

ORF261 binding to the K1 capsule. (A) Antibody blocking assay. The antibody anti-ORF249 was used as a control. The number of plaques formed was counted. (B) Recombinant protein ORF261 competition in the phage adsorption assay. LB medium and BSA were used as controls, and the adsorption rate was set at 100%. All assays were performed in triplicate, and significance was determined by a Student t test for comparison between the control group and the treated group. *, P < 0.05; **, P < 0.01. (C) Binding of protein ORF261 to WT, ΔneuC mutant, and complementary C-ΔneuC strains. ORF261 with GFP bound easily to WT and complementary strains, but not as well to the ΔneuC strain. Proteins containing only GFP could not bind to the strains. (D) HPGPC was used to detect the molecular weight after protein ORF261 was incubated with PSA.PSA-0 or PSA-1 was product of PSA treated with PBS or ORF 261. Other peaks are impurities or solvents.