Anthelmintic resistant nematodes of sheep pose a very serious threat to sheep production in the EC. To prevent the development of irreversible resistance in the worms, fast and sensitive tests are required . Current tests are time consuming and not reliable if less than 25% of worms are resistant. Further selection for resistance is rapid if changes in drug use are not made. The new fast and sensitive tests to detect resistance will be based upon DNA and Protein technology using dot-blots, PCR and ELISA. Research will focus on tests for resistance against the three main groups of anthelmintics, benzimidazoles, levamisole and ivermectin and three very important nematodes Haemonchus contortus, Ostertagia circumcincta and Nematodirus battus. The DNA test for benzimidazole resistance in H. contortus is nearing completion and will be evaluated in field tests. This serve as a model for tests for levamisole and ivermectin resistance. These latter tests are very important as resistance to these two drugs is only beginning to emerge in Europe. Tests will be evaluated against field isolates in two climatic zones, maritime (UK) and Mediterranean (Greece). Changes in the amino acid sequences of nicotinic acetylcholine receptors associated with the development of resistance to levamisole will be determined together with changes in ivermectin receptors. From this information probes will be constructed to detect levamisole and ivermectin resistant worms and the tests evaluated with field isolates. The inheritance of resistance will be determined for use in computer simulation models to predict the rate of emergence of resistance in Europe. The sensitive tests for resistance for routine use in veterinary laboratories of the EC will be developed into easy and cheap tests by a SME company.
Funding SchemeCSC - Cost-sharing contracts
7303 GC Apeldoorn
3508 TD Utrecht
28871 Alcala De Henares
G61 1QH Glasgow