FIG. 2.

Secreted and membrane proteins of E. coli O157:H7 strain ATCC 43895 (wild type) and the O-antigen-negative mutant (Δper). Proteins were separated by 10% SDS-PAGE. (A) Secreted proteins from culture supernatants visualized by silver staining. (B) Membrane proteins visualized by Coomassie blue staining. The positions of molecular mass markers (in kilodaltons) are indicated on the left. The proteins in similar gels were transferred to PVDF membranes for immunoblotting and probed with (C) anti-EspA and anti-EspB or (D) anti-intimin, reacted with secondary antibodies conjugated with HRP, and visualized by autoradiography. Δeae, E. coli O157:H7 with the intimin gene deleted.