FIG. 4.

S. pneumoniae 19F Taiwan-14 strain expresses two independent pili. (A) Western blotting performed with polyclonal anti-PitB and anti-RrgB antibodies on mutanolysin extracts of 19F Taiwan-14 wild-type and knockout isogenic mutants lacking PI-1 and/or PI-2 (19F Tw14ΔPI1, Tw14ΔPI2, and Tw14ΔPI1ΔPI2). (B and E) Double immunogold labeling performed with mouse anti-PitB (gold particle size, 20 nm) and guinea pig anti-RrgB (gold particle size, 5 nm) on 19F Taiwan-14 wild type (wt) and 19F Tw14ΔPI1ΔPI2. (C) Deletion mutant 19F Tw14ΔPI1 labeled with mouse anti-PitB (gold particle size, 5 nm). (D) 19F Tw14ΔPI2 labeled with mouse anti-RrgB (gold particle size, 5 nm). Scale bar, 0.2 μm. α, anti.