title: Selection and characterization of Toxoplasma gondii mutants resistant to artemisinin.
abstract: Toxoplasma gondii infection, like malaria, is sensitive to inhibition by artemisinin (ART). Mechanisms of action for ART in malaria treatment have been proposed, but little is known about its effects in T. gondii infection. To better understand its inhibitory effects on T. gondii, mutants resistant to ART were selected by progressive culture in permissive levels of the drug. Five clonal isolates were established and characterized. The isolates were approximately 65-fold less sensitive to ART than is the parental RH and showed cross-resistance to the ART derivatives dihydroartemisinin and artemether. In addition to ART resistance, 1 clone (C9) formed morphologically unusual parasitophorous vacuoles and another (A2) was avirulent for mice and protected mice from challenge with the wild type. These clonal T. gondii mutant isolates will be useful for the study of not only the mechanism of action of ART but also parasite vacuole biology and virulence factors.
authors.affiliation: Division of Infectious Diseases, University of Colorado Health Sciences Center, Denver 80262, USA. berens_r@defiance.uchsc.edu
authors.forename: R L
authors.initials: RL
authors.lastname: Berens
authors.forename: E C
authors.initials: EC
authors.lastname: Krug
authors.forename: P B
authors.initials: PB
authors.lastname: Nash
authors.forename: T J
authors.initials: TJ
authors.lastname: Curiel
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D000077549:Artemether; D037621:Artemisinins; D004351:Drug Resistance / Q000235:genetics; D005020:Ethyl Methanesulfonate; D005260:Female; D006801:Humans; D008769:Methylnitronitrosoguanidine; D051379:Mice; D008813:Mice, Inbred ICR; D016296:Mutagenesis; D012717:Sesquiterpenes / Q000627:therapeutic use*; D014122:Toxoplasma / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development; D014124:Toxoplasmosis, Animal / Q000188:drug therapy* / Q000235:genetics
chemical_list: D000962:Antimalarials; D000981:Antiprotozoal Agents; D037621:Artemisinins; D012717:Sesquiterpenes; D008769:Methylnitronitrosoguanidine; C039060:artenimol; D005020:Ethyl Methanesulfonate; C031327:artemisinin; D000077549:Artemether