title: The sexually linked Mpi locus is presumably involved in imidothiazole resistance in Oesophagostomum dentatum parasites.
abstract: Information about genetic changes during the selection process could indicate mechanisms underlying the spread of resistance to anthelmintic drugs. For clarification of the role of the Mpi locus encoding mannose-phosphate isomerase enzyme in determining resistance, genotyping of Oesophagostomum dentatum strains was performed using an isoelectrofocusing technique. In levamisole- and pyrantel-selected strains the allele associated with resistance has probably been found. Significant values for genetic differentiation between treated and untreated strains of common origin were recorded by F(st) indices (theta = 0.078; P = 0.0008). The specific genomic makeup of a flubendazole-resistant strain, which did not correlate with that of the remaining isolates, might be ascribed to a different action of the anthelmintic or different environmental conditions under which resistance against this drug arose. The absence of heterozygotes in male populations indicated an XX/X0 system of sex determination for the Mpi locus, thus providing a greater potential for the development of resistance. A possible involvement of alleles linked with mannose-phosphate isomerase in alterations of membrane receptors that can be associated with resistance against imidothiazole-based drugs is discussed.
authors.affiliation: Danish Center for Experimental Parasitology, The Royal Veterinary and Agricultural University, Frederiksberg. snabel@saske.sk
authors.forename: V
authors.initials: V
authors.lastname: Snábel
authors.forename: T
authors.initials: T
authors.lastname: DeMeeŵs
authors.forename: M
authors.initials: M
authors.lastname: Várady
authors.forename: P
authors.initials: P
authors.lastname: Nansen
authors.forename: H
authors.initials: H
authors.lastname: Bjørn
authors.forename: J
authors.initials: J
authors.lastname: Corba
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology*; D004351:Drug Resistance / Q000235:genetics; D005260:Female; D008040:Genetic Linkage; D007978:Levamisole / Q000494:pharmacology; D008297:Male; D008463:Mebendazole / Q000031:analogs & derivatives / Q000494:pharmacology; D009815:Oesophagostomum / Q000187:drug effects* / Q000235:genetics*; D011715:Pyrantel / Q000494:pharmacology; D012730:Sex Chromosomes; D013552:Swine; D013844:Thiazoles / Q000494:pharmacology*
chemical_list: D000871:Anthelmintics; D013844:Thiazoles; D007978:Levamisole; D011715:Pyrantel; D008463:Mebendazole; C018945:flubendazole