IN-VITRO CHARACTERIZATION OF LINES OF OESOPHAGOSTOMUM-DENTATUM SELECTED OR NOT SELECTED FOR RESISTANCE TO PYRANTEL, LEVAMISOLE AND IVERMECTIN

Lines of Oesophagostomum dentatum artificially selected or not selecte d for resistance to pyrantel, levamisole and ivermectin were used in t his study. From the 10th generation of selection eggs were collected f rom each line and subjected to an in vitro larval development assay (L DA) and an egg hatch assay (EHPA). Significant differences were observ ed between an unselected line of O. dentatum and the lines selected fo r resistance to levamisole or pyrantel in both assays. The LDA was mor e sensitive than EHPA in detecting anthelmintic resistance in O. denta tum. The results obtained from the LDA confirmed side-resistance betwe en levamisole and morantel/pyrantel. The in vitro tests failed to show significant differences between ivermectin-sensitive and resistant li nes. (C) 1997 Published by Elsevier Science Ltd.