The infectivity of single flagellates of Trypanosoma cruzi

Abstract

Single organisms of Trypanosoma cruzi of the virulent Peru strain were isolated by direct visualisation and were injected peritoneally into CFI mice. Single trypanomastigotes of different morphology and from different sources (mouse blood, in vitro cufture and bug faeces) were used. Single trypanomastigotes from mouse blood caused parasitaemia and fataiity in a high percentage of mice. This was true irrespective of the morphology (broad or narrow form) of the trypano mastigo tec. Single organisms of the culture forms were also capable of causing infection, although these were less infectious than single trypanomastigotes obtained from mouse blood or the reduviid bug. The difficulties attendant on the performance of the cloning technique are discussed and some indication is given of how these problems can be overcome.Organismos únicos de Trypanosoma cruzi virulento, da cepa Peru, foram isoiados por visualização direta e injetados peritonialmente em camundongos CFI. Trypanomastigotas únicos de diferentes morfologia e origem (sangue de camundongos, cultura in vitro e fezes de triatommeo) foram usados. Trypanomastigotas únicos de sangue de camundongos causaram parasitemia e mortalidade em alta percentagem de camundongos. Isto ocorreu independentemente da morfologia (formas largas e delgadas) dos Trypanomastigotas. Organismos únicos de formas de cultura foram também capazes de causar infecção, embora fossem menos infecciosos que um só trypanomastigota obtido de sangue de camundongo ou de triatomfneo. São discutidas as dificuldades presentes na execução da tócnica de "cloning" e é dada orientação de como estes problemas podem ser superados.