IN-VITRO CHARACTERIZATION OF ANTHELMINTIC SUSCEPTIBILITY OF FIELD ISOLATES OF THE PIG NODULAR WORM OESOPHAGOSTOMUM SPP, SUSCEPTIBLE OR RESISTANT TO VARIOUS ANTHELMINTICS

Varady M., Bjorn H. & Nansen P. 1996. In vitro characterization of ant helmintic susceptibility of field isolates of the pig nodular worm Oes ophagostomum spp., susceptible or resistant to various anthelmintics. International Journal for Parasitology 26: 733-740. A larval developme nt assay (LDA) and an egg latch paralysis assay (EHPA) were used to me asure the sensitivity to anthelmintics of eggs and larvae of nodular w orms (Oesophagostomum spp.) in pigs. The tests were carried out using in vivo defined resistant and susceptible isolates of Oesophagostomum dentatum, O. quadrispinulatum and Oesophagostomum spp. For measurement of pyrantel/morantel and levamisole sensitivity the LDA was found abl e to distinguish between susceptible or resistant isolates of Oesophag ostomum . The EHPA was able to detect levamisole resistance, but the t est failed to show differences in response to pyrantel between pyrante l susceptible and resistant lines. The possible routine application of LDA and EHPA in the diagnosis of anthelmintic resistance in Oesophago stomum spp. is discussed. Copyright (C) 1996 Australian Society for Pa rasitology.