FIG 3.

Cytotoxic effects of Aeromonas cell-free supernatants on human epithelial cells. HeLa cells were incubated with cell-free bacterial supernatants for 4 h and fixed to identify cytotoxic phenotypes. (A) Control HeLa cells. The inset shows an intact membrane. (B) HeLa cells following 4 h of incubation with Aeromonas supernatant, showing evident blebbing of the plasma membrane. The inset shows that the bleb is contiguous with the cell membrane. (C) HeLa cells following 4 h of incubation with another Aeromonas isolate supernatant, showing an irregular shape. The inset demonstrates pores in the plasma membrane (marked by arrowheads). Bars, 7.5 μm (main panels) and 1.5 μm (insets).