title: Molecular characterization of susceptible and naturally resistant strains of Trypanosoma cruzi to benznidazole and nifurtimox.
abstract: Twenty-seven Trypanosoma cruzi strains, susceptible or naturally resistant to the nitroderivatives benznidazole and nifurtimox, were analyzed using the following molecular markers: (i) isoenzyme patterns of six enzymes; (ii) genetic variability assayed by randomly amplified polymorphic DNA (RAPD) with two different primers; and (iii) gene probes for P-glycoprotein (TcPGP), hypoxanthine-guanine phosphoribosyltransferase (HGPRT), the ribosomal RNA gene (rDNA) and the mini-exon gene (MEX), RAPD and isoenzyme profiles divided the T. cruzi strains into three groups, whereas the gene probes divided the T. cruzi strains in two groups. Strains classified as group I or II by RAPD or zymodemes Z1 or Z2 by isoenzyme analysis were either susceptible or naturally resistant to the nitroderivatives. In contrast, strains classified as group III by RAPD and zymodeme ZB by isoenzyme analysis were only drug susceptible and showed polymorphisms for HGPRT and TcPGP. No correlation was observed between drug susceptibility and polymorphisms of rDNA and MEX. Eighteen T. cruzi strains isolated from different geographic regions were included in this study. Thus, from a total of 45 T. cruzi strains analyzed, all 19 of zymodeme B were susceptible to the experimental treatment independent of their geographic origin.
authors.affiliation: Laboratório de Parasitologia Celular e Molecular, Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, MG, Brazil.
authors.forename: S M
authors.initials: SM
authors.lastname: Murta
authors.forename: R T
authors.initials: RT
authors.lastname: Gazzinelli
authors.forename: Z
authors.initials: Z
authors.lastname: Brener
authors.forename: A J
authors.initials: AJ
authors.lastname: Romanha
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics; D000818:Animals; D001938:Brazil; D014355:Chagas Disease / Q000469:parasitology; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004351:Drug Resistance; D005091:Exons / Q000235:genetics; D017125:Genes, Protozoan; D014644:Genetic Variation; D005956:Glucose-6-Phosphate Isomerase / Q000032:analysis; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D007527:Isoenzymes / Q000032:analysis; D009547:Nifurtimox / Q000494:pharmacology*; D009593:Nitroimidazoles / Q000494:pharmacology*; D011110:Polymorphism, Genetic; D019105:Random Amplified Polymorphic DNA Technique; D014344:Trypanocidal Agents / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D016054:DNA, Protozoan; D004275:DNA, Ribosomal; D007527:Isoenzymes; D009593:Nitroimidazoles; D014344:Trypanocidal Agents; D007041:Hypoxanthine Phosphoribosyltransferase; D005956:Glucose-6-Phosphate Isomerase; D009547:Nifurtimox; C009999:benzonidazole