Discussion

Anthelmintic resistance is a major clinical and economic problem for numerous helminth species of domestic livestock and companion animals and an emerging concern for helminth control in humans. Recent improvements in helminth reference genomes, sequencing technologies and informatic approaches are now enabling genome-wide approaches to identify the genetic loci in helminth genomes that underly anthelmintic resistance. Once such loci are identified, sequencing technologies can also be used for diagnosis and surveillance of anthelmintic resistance and to study its molecular epidemiology in the field. In this presentation, I will focus on the recent progress for benzimidazole and ivermectin resistance in Haemonchus contortus and related nematode species of livestock. The chromosomal scale reference genome assembly of H. contortus has transformed our ability to study the molecular genetics of resistance in this species. I will review some recent data from genetic crosses and genome-wide scans of natural field populations that identify the major benzimidazole and ivermectin resistance loci. I will also discuss the use of amplicon sequencing to detect anthelmintic resistance mutation in field populations and its practical application to improve diagnostics and surveillance.