FIG. 2.

Autoaggregation in LB broth. Overnight cultures were incubated statically for 10 h. The optical density of culture medium withdrawn from 1 to 2 cm from the surface was measured at 600 nm (open squares). For each test strain, a parallel tube (filled triangles) was vortexed before measurements were taken. Autoaggregation ability is proportionate to the distance between the vortexed and static culture plots. (A) EAEC strain 042; (B) E. coli K-12 TOP-10 carrying the pBR322 vector; (C) E. coli K-12 TOP-10 carrying the hra1 gene cloned into pBR322 (pBJ1); (D) E. coli K-12 TOP-10 carrying a pBJ1 derivative with the predicted surface-exposed region of Hra1 deleted (pBJ2).