title: PCR-based assay to survey for knockdown resistance to pyrethroid acaricides in human scabies mites (Sarcoptes scabiei var hominis).
abstract: Permethrin, in the form of a topical cream, is being increasingly used for community-based programs to control endemic scabies. The development of resistance has reduced the use of pyrethroids for the control of many arthropods of economic and health importance. The best recognized form of pyrethroid resistance, known as knockdown resistance or kdr, has been linked to specific mutations in the target of these agents, the para-homologous voltage-sensitive sodium channel gene (Vssc). To develop tools to study resistance to pyrethroid acaricides, we cloned 3711 and 6151 bp, respectively, of cDNA and genomic fragments of the Vssc gene from scabies mite, Sarcoptes scabiei. The sequence encompasses the major polymorphic amino acid residues associated with pyrethroid resistance. A polymerase chain reaction-based strategy has been developed that enables genotyping individual scabies mites. This will facilitate early detection and monitoring of pyrethroid resistance in scabies mite populations under drug selection pressure.
authors.affiliation: Queensland Institute of Medical Research and Australian Centre for International and Tropical Health and Nutrition, University of Queensland, Brisbane, Queensland, Australia. cielop@qimr.edu.au
authors.forename: Cielo
authors.initials: C
authors.lastname: Pasay
authors.forename: Shelley
authors.initials: S
authors.lastname: Walton
authors.forename: Katja
authors.initials: K
authors.lastname: Fischer
authors.forename: Deborah
authors.initials: D
authors.lastname: Holt
authors.forename: James
authors.initials: J
authors.lastname: McCarthy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017931:DNA Primers; D018076:DNA, Complementary / Q000032:analysis; D006801:Humans; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D026023:Permethrin / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012520:Sarcoptes scabiei / Q000187:drug effects / Q000235:genetics*; D012532:Scabies / Q000517:prevention & control*; D015222:Sodium Channels / Q000235:genetics
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D007306:Insecticides; D015222:Sodium Channels; D026023:Permethrin