title: Instability of benzimidazole resistance in nematode eggs.
abstract: The resistance of the eggs of benzimidazole resistant Haemonchus contortus and Trichostrongylus colubriformis is not stable and will decrease in the absence of drug challenge. Dosing animals harbouring resistant H contortus with either thiabendazole or mebendazole selects for nematodes producing thiabendazole resistant eggs. The eggs of a thiabendazole selected strain of H contortus were more resistant to thiabendazole, parbendazole and oxibendazole but less resistant to cambendazole and mebendazole.
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology*; D004351:Drug Resistance; D005260:Female; D006189:Haemonchus / Q000187:drug effects; D009348:Nematoda / Q000187:drug effects*; D010063:Ovum / Q000187:drug effects; D014251:Trichostrongyloidea / Q000187:drug effects
chemical_list: D001562:Benzimidazoles