FIG. 1.

EPEC-induced cell killing by trypan blue uptake. T84 cells were grown in Lab-Tek chamber slides, changed to antibiotic-free adherence medium, treated with inhibitors and/or infected with an E. coli strain for 2 h, and then stained with trypan blue as described in Materials and Methods. Cells were viewed by differential interference contrast microscopy at a magnification of ×200. (A) Uninfected control; (B) cells treated with 100 nM wortmannin alone; (C) cells infected with EPEC strain E851/71; (D) cells infected with E851/71 in the presence of 100 nM wortmannin; (E) cells infected with laboratory strain HB101; (F) cells infected with HB101 in the presence of wortmannin.