Haemonchus contortus: Sequence Heterogeneity of Internucleotide Binding Domains from P-Glycoproteinsand an Association with Avermectin/Milbemycin Resistance

NHR-176 regulates cyp-35d1 to control hydroxylation-dependent metabolism of thiabendazole in Caenorhabditis elegans

“…An increase in PGP expression has been found in ivermectinresistant strains of C. elegans [59] and also H. contortus [60]. A number of mutations in pgp genes have also been observed between ivermectin/TBZ-resistant and -susceptible isolates of H. contortus [61][62][63][64]. Furthermore, exposure to the PGP inhibitor verapamil eliminated all differences between susceptible and resistant isolates of the cattle-parasitic nematodes C. oncophora and O. ostertagi [34].…”

Drug Resistance in Human Helminths: Current Situation and Lessons from Livestock

“…IVM and other macrocyclic lactones affect gastrointestinal nematodes by causing starvation and/or paralysis by opening chloride channels, which are thought to be associated with alfa-subunits of glutamate-gated ion channels located on muscles of the pharynx and possibly the somatic musculature (122 (124) came to the conclusion that P-gp might be involved in resistance to IVM in this helminth species. Other mechanisms of resistance may be present as well, as suggested by Gill et al (64) and Gill and Lacey (65).…”

Effect of multidrug resistance modulators on the activity of ivermectin and moxidectin against selected strains of Haemonchus contortus infective larvae

“…Furthermore, Blackhall et al (1998), found that repeated ivermectin and moxidectin treatment selected for a specific allele of P-gp in H. contortus. Sangster et al (1999) have independently found selection on P-gp genes in ivermectin resistant field strains of H. contortus. P-gp antagonists, termed MDR modulators have been used to augment drug activity against MDR organisms.…”