Figure 1.

S. Typhi CU fimbrial operons organization. S. Typhi possesses 12 putative fimbrial gene clusters divided in 5 clades (γ₁, γ₃, γ₄, α, and π) depending of the usher homologies. Stg, Sth, Bcf, and Fim are γ₁ fimbriae, while Saf and Sef are in clade γ₃ and Sta, Stb, and Stc are in clade γ₄. Tcf is the only representative of α clade. Std and Ste are π fimbriae. Ushers are represented by black arrow and chaperones by white arrow. No distinction is made for major/minor subunits, adhesins, or other proteins (gray arrows). Pseudogenes are marked by asterisk.