title: Polymorphisms of blood forms and in vitro metacyclogenesis of Trypanosoma cruzi I, II, and IV.
abstract: Trypanosoma cruzi is the etiologic agent of American trypanosomiasis has broad biological and genetic diversity. Remaining to be studied are polymorphisms of the blood forms and metacyclogenesis of different T. cruzi discrete typing units (DTUs). Our goal was to evaluate the relationship between T. cruzi DTUs, the morphology of blood trypomastigotes, and in vitro metacyclogenesis. T. cruzi strains that pertained to DTUs TcI, TcII, and TcIV from different Brazilian states were used. Parameters that were related to the morphology of eight strains were assessed in thin blood smears that were obtained from mice that were inoculated with blood or culture forms, depending on strain. The metacyclogenesis of 12 strains was measured using smears with Liver Infusion Tryptose culture medium and M16 culture medium (which is poor in nutrients and has a low pH) at the exponential phase of growth, both stained with Giemsa. The morphological pattern of TcII strains was consistent with broad forms of the parasite. In TcIV strains, slender forms predominated. The Y strain (TcII) was morphologically more similar to TcIV. Significant differences in polymorphisms were observed between DTUs. Metacyclogenesis parameters, although displaying large standard deviations, differed between the DTUs, with the following descending rank order: TcII > TcI > TcIV. The mean numbers of metacyclic trypomastigotes for TcII were significantly higher than the other DTUs. Although the DTUs presented overlapping characteristics, the general pattern was that different DTUs exhibited significantly different morphologies and metacyclogenesis, suggesting that the genetic diversity of T. cruzi could be related to parameters that are associated with the evolution of infection in mammalian hosts and its ability to disperse in nature.
authors.affiliation: Post-Graduation Program in Health Sciences at the State University of Maringá (Universidade Estadual de Maringá-UEM), Maringá, PR, Brazil.
authors.forename: Camila Piva
authors.initials: CP
authors.lastname: Abegg
authors.affiliation: Department of Basic Health Sciences, Health Sciences Center at the UEM, Maringá, PR, Brazil.
authors.forename: Ana Paula de
authors.initials: AP
authors.lastname: Abreu
authors.affiliation: Department of Basic Health Sciences, Health Sciences Center at the UEM, Maringá, PR, Brazil.
authors.forename: Juliane Lopes da
authors.initials: JL
authors.lastname: Silva
authors.affiliation: Post-Graduation Program in Health Sciences at the State University of Maringá (Universidade Estadual de Maringá-UEM), Maringá, PR, Brazil; Department of Basic Health Sciences, Health Sciences Center at the UEM, Maringá, PR, Brazil.
authors.forename: Silvana Marques de
authors.initials: SM
authors.lastname: Araújo
authors.affiliation: Post-Graduation Program in Health Sciences at the State University of Maringá (Universidade Estadual de Maringá-UEM), Maringá, PR, Brazil; Department of Basic Health Sciences, Health Sciences Center at the UEM, Maringá, PR, Brazil.
authors.forename: Mônica Lúcia
authors.initials: ML
authors.lastname: Gomes
authors.affiliation: Department of Statistics, Exact Sciences Center at the UEM, Maringá, PR, Brazil.
authors.forename: Érika Cristina
authors.initials: ÉC
authors.lastname: Ferreira
authors.affiliation: Post-Graduation Program in Health Sciences at the State University of Maringá (Universidade Estadual de Maringá-UEM), Maringá, PR, Brazil; Department of Basic Health Sciences, Health Sciences Center at the UEM, Maringá, PR, Brazil. Electronic address: mjotoledo@uem.br.
authors.forename: Max Jean de Ornelas
authors.initials: MJ
authors.lastname: Toledo
mesh_terms: D000818:Animals; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000097:blood / Q000453:epidemiology / Q000469:parasitology*; D006801:Humans; D051379:Mice; D009893:Opossums; D018512:Parasitemia / Q000097:blood / Q000453:epidemiology / Q000469:parasitology*; D011110:Polymorphism, Genetic; D012239:Rhodnius; D014349:Trypanosoma cruzi / Q000145:classification / Q000235:genetics* / Q000254:growth & development
keywords: DTUs; In vitro metacyclogenesis; Morphology; Trypanosoma cruzi