Fig. 4

Azithromycin inhibits the early steps of invasion. Video microscopy of merozoite invasion of erythrocytes was performed in the presence of 75 and 134 μM azithromycin (in ethanol) compared to a no drug control (0 μM). Five schizont ruptures were observed for each treatment. Of the merozoites that contacted erythrocytes, some were observed to deform erythrocytes and then successfully invade their host cells (contact–invade), while others did not progress beyond initial attachment (contact–detach) or progressed to deformation but did not invade (contact–deform). From several rupturing schizonts, the number of merozoites exhibiting each of these steps was counted for each drug treatment and the percentages are shown along with the number of events in the column boxes. A Chi-squared test was performed to indicate significant differences at the following levels (**P ≤0.01, ***P ≤0.001)