Phylogenetics and population genetics of benzimidazole resistance alleles in different Haemonchus species and introgression of such alleles between different species

• Applicant: Dr. Alexander Georg Eberhardt
• Subject Area: Parasitology and Biology of Tropical Infectious Disease Pathogens
• Term: from 2010 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 177906429

The emergence of drug resistance in parasitic nematodes is a major threat both to the livestock industry and to human health. Species of Haemonchus are blood-feeding parasitic nematodes that are among the most economically important parasites of cattle, sheep and goats worldwide and are important models for gastrointestinal parasitism. Anthelmintic resistance of H. contortus, which predominantly infects sheep and goats, is widespread and is making control increasingly difficult and in some cases impossible. H. placei is a closely related species that predominantly infects cattle where resistance is beginning to emerge but yet to be studied in any detail. In particular I am interested in two projects. First, I want to investigate the prevalence, sequence diversity and evolutionary relationships of benzimidazole drug resistance alleles in different species of the genus Haemonchus. This should provide important information about how drug resistance emerges and spreads. Second, I want to investigate the potential of resistance genes passing from one parasite species to another as this would be a particularly serious issue for parasite control in cattle. This is theoretically possible for H. contortus and H. placei since fertile progeny can be produced by experimental crosses of the adult parasites in the laboratory. Furthermore, co-infections with both species commonly occur in both cattle and sheep in nature. I plan to investigate inter-species hybridization and introgression of benzimidazole drug resistance genes using molecular genetic and population genetic analysis on both experimental co-infections with the two species and on natural parasite populations in the field.

• DFG Programme: Research Fellowships
• International Connection: Canada
• Host: Professor Dr. John Gilleard