Tubulin and benzimidazole-resistance in Trichostrongylus colubriformis (Nematoda).

Benzimidazole treatment produced greater effects on microtubule-dependent acetylcholinesterase secretion, the presence of microtubules in intestinal cells, and colchicine binding in susceptible compared with benzimidazole-resistant Trichostrongylus colubriformis. In addition, the binding of benzimidazoles was markedly reduced in preparations from the latter strain, indicating that the mechanism of resistance to benzimidazoles in this nematode involves a reduced affinity of tubulin for benzimidazoles.