Figure 7: Virulence assays of transfected trophozoites. (a) Cytopathic activity. The destruction of MDCK cells monolayers by clone A trophozoites, pNEO, pEhVps4, or pEhVps4-E211Q transfected cells was determined as described [32, 33]. (b) Erythrophagocytosis. Rate of phagocytosis of clone A trophozoites, pEhVps4, pEhVps4-E211Q or pNEO transfected cells was evaluated at 5, 10, and 15 minutes . Histograms show the mean count SD of three independent experiments by duplicate. (c) Hepatic damage in hamsters infected with transfected trophozoites. Three groups of six hamsters were infected with pNEO, pEhVps4, or pEhVps4-E211Q transfected trophozoites. After 7 days, animals were sacrificed and liver damage was recorded. Pictures were taken from the liver side where the abscesses appeared to be larger and are representative for each group. Upper panels, livers from hamsters infected with pNEO transfected trophozoites (control); middle panels, livers from hamsters infected with pEhVps4 transfected trophozoites; lower panels, livers from hamsters infected with pEhVps4-E211Q transfected trophozoites. 6/6, 6/6 and 0/6 denote number of infected animals/number of inoculated animals.