Ultrastructural evalution of mebendazole action in Pseudodactylogyrus bini (Monogenea), gill parasites from Luopean eel Anguilla Anguilla

Abstract

The broad-spectrum anthelmintic mebendazole (MBZ) has demonstrated its efficacy against a range of fish-parasitizing monogeneans. The action of this drug in the gill parasitic monogenean Pseudodactylogyrus bini has been elucidated by the use of transmission electron microscopy (TEM). Parasites were exposed in vitro to MBZ (1 and 10 mg/l) for up to 42 h whereafter they were fixed and prepared for TEM studies. It was demonstrated that the tegument and subtegumental layers in parasites exposed to 10 mg MBZ/l for 36 h were disorganized and partly destroyed, and that the drug interfered with the organization of the flame-cell microtubule system. This is in accordance with the suggestion that tubulin and thereby the cytoskeleton is the main MBZ target, although other drug action mechanisms cannot be excluded