FIG. 1.

Cytopathic activity of axenically (ax) grown E. histolytica HK-9 (2 × 10⁵) in the absence or presence of added bacteria. Trophozoites were added to the monolayer together with E. coli (Ec) O55 or 346 at a ratio of 1,000:1 (bacteria-amebae) and incubated for 60 min at 37°C. The monolayer destruction was determined as described in Materials and Methods. The data represent the means and standard deviations of three independent experiments.