title: Biological behaviour in mice of Trypanosoma cruzi isolates from Amazonas and Paraná, Brazil.
abstract: The biological behaviour of 23 Trypanosoma cruzi isolates in Swiss mice was compared. Nineteen isolates were obtained from patients in the acute phase of Chagas disease (13), sylvatic reservoir hosts (Didelphis marsupialis) (3), and triatomine bugs (Rhodnius robustus) (3) from four regions of the State of Amazonas (AM). Four isolates were obtained from chronic chagasic patients in the State of Paraná (PR): three autochthones, and one allochthone from the State of Minas Gerais. Only one isolate was unable to infect the mice. The AM and PR isolates showed the largest number of significant differences from each other. The former had lower mean values in the pre-patent (5.4 days) and patent (4.6 days) periods (PP), with the parasitaemia (Pmax) reaching a peak of 9.9×10(4) blood trypomastigotes (BT)/mL of blood by the 7th day following inoculation. The AM isolates also had higher positivity to fresh-blood examination (FBE) (84.1%) compared to haemoculture (HC) (58.7%) and polymerase chain reaction (PCR) (33.3%), in addition to higher mortality (2.9%). The PR isolates had higher values for PP (18.5 days) and Pmax (99.9×10(4)BT/mL) as well as higher positivity to FBE (87.2%), HC (100%), and PCR (83.3%). The correlations between the biological behaviour of the T. cruzi isolates and the clinical and epidemiological characteristics of Chagas disease are discussed.
authors.affiliation: Post-Graduate Program in Health Sciences at the State University of Maringá (UEM), Av. Colombo 5790, Bloco 126, CEP: 87020-900, Maringá, Paraná, Brazil.
authors.forename: Daniele
authors.initials: D
authors.lastname: Dos Reis
authors.forename: Wuelton Marcelo
authors.initials: WM
authors.lastname: Monteiro
authors.forename: Gleison Daion Piovezana
authors.initials: GD
authors.lastname: Bossolani
authors.forename: Ana Paula Margioto
authors.initials: AP
authors.lastname: Teston
authors.forename: Monica Lucia
authors.initials: ML
authors.lastname: Gomes
authors.forename: Silvana Marques
authors.initials: SM
authors.lastname: de Araújo
authors.forename: Maria das Graças Vale
authors.initials: Md
authors.lastname: Barbosa
authors.forename: Max Jean
authors.initials: MJ
authors.lastname: de Ornelas Toledo
mesh_terms: D000818:Animals; D001938:Brazil; D014355:Chagas Disease / Q000401:mortality / Q000469:parasitology*; D048293:Didelphis; D006801:Humans; D008297:Male; D051379:Mice; D018512:Parasitemia / Q000469:parasitology; D012239:Rhodnius; D014349:Trypanosoma cruzi / Q000472:pathogenicity / Q000502:physiology*; D014774:Virulence