Fig. 2.

Effects of Cry5B on A. ceylanicum adults in vitro. (A) Six micrograms of purified Cry5B (lane 2) was subjected to SDS/PAGE and Coomassie blue staining. (B) Exposure to Cry5B impairs motility of adult hookworms. Groups of 10 adult A. ceylanicum worms were cultured in increasing concentrations of purified Cry5B toxin. Motility was monitored at the times indicated, and the data represent the mean values (±SE) of triplicate wells containing each concentration of toxin. Statistically significant (P < 0.001) differences in motility were observed between control worms (buffer only) and worms cultured in 50 or 200 μg/ml Cry5B toxin throughout the observation period (24–120 h). Statistically significant differences (P < 0.001) between control worms (0 μg/ml) and the 5 μg/ml toxin group were detected from 42–120 h in culture. (C) Cry5B toxin reduces A. ceylanicum egg excretion. Adult female hookworms were maintained for 24 h in the presence of increasing concentrations of purified Cry5B toxin. Experimental groups consisted of four replicate wells (three worms per well) at each concentration of toxin. Values represent the mean number of eggs (±SE) counted in each well. P values represent statistical comparisons between each group and the control worms (no toxin).