FIG. 4.

Motility and flagellin expression in E. coli O157:H7 strain ATCC 43895 (wild type), the O-antigen-negative mutant (Δper), and the complemented strain (compl). Bacteria were stabbed into 0.3% motility agar and incubated at 37°C for 18 h (A) or 40 h (B). White areas represent bacterial growth (motility halo). Flagellin expression was examined using cells from the agar plates by immunoblotting (C) after 18 h of growth or 40 h of growth (Δper 40 h). ΔfliC, E. coli O157:H7 strain ATCC 43894 with the flagellin gene deleted.