Trypanosomatids in dogs belonging to individuals with chronic chagas'disease living in Botucatu town and surrounding region, São Paulo State, Brazil

Among domestic animals, dogs are considered to be the major reservoirs of trypanosomatids and, due to their proximity to man, the presence of these parasites in dogs is an alert to actions aiming at triatomine control. Fifty dogs (26 males and 24 females), aged from 2 months to 15 years, belonging to 30 chronic Chagas’ disease individuals from 15 different municipalities in the western region of São Paulo State, Brazil, were subjected to blood collection for the following tests: artificial xenodiagnosis, blood culture, and Polymerase Chain Reaction (PCR). Forty-three (86%) out of 50 dogs were positive to at least one of the tests performed; 34 (68%) were positive to xenodiagnosis, 30 (60%) to blood culture, and 25 (50%) to PCR for T. cruzi and/or T. rangeli. Although triatomines were not detected during the intra and peridomiciliary inspections in the dog owners’ residences, the results obtained demonstrate that there is a transmission cycle whereby triatomine vector may be participating in the infection epidemiological chain

Parasite genotypically related to a monoxenous trypanosomatid of dog's flea causing opportunistic infection in an HIV positive patient

An HIV positive patient presenting a clinical picture of visceral leishmaniasis co-infection was submitted to a bone marrow aspiration after admission to hospital. Amastigotes forms were seen in the bone marrow aspirate and the parasite grew in culture as promastigotes. Molecular analyses showed that the flagellates isolated did not belong to the genera Leishmania, Trypanosoma or Sauroleishmania. It was not possible to establish infection in laboratory animals. In vitro culture of mouse peritoneal macrophages revealed the invasion of the host cells by the flagellates and their killing 48 hr after infection. Opportunistic infection with an insect trypanosomatid was suspected. Further hybridization analyses against a pannel of different monoxenous and heteroxenous trypanosomatids showed kDNA cross-homology with Leptomonas pulexsimulants a trypanosomatid found in the dog's flea.

Morphological evidence by scanning electron microscopy of excretion of metacyclic forms of Trypanosoma cruzi in vector's urine

Observando-se, em microscopia eletrônica de varedura, formas flageladas do Trypanosoma cruzi presas a cutícula da glândula retal de ninfas infectadas de Dipetalogaster maxima verificaram-se nítidas diferenças antes e depois da alimentaçäo. Antes, viam-se numerosos tripomastigotas metacíclicos entre os abundantes epimastigotas que formavam o tapete de flagelados, ao passo que nos insetos que urinavam dentro das 24 horas após o repasto os metacíclicos eram raros, indicando que haviam sido desprendidos pelo fluxo urinário. Foi notado, as vezes, um tipo assimétrico de divisäo celular, originando um epi e um tripomastigota. Nos flagelados dos epimastigotas a presença de dilataçöes a diferentes níveis sugere que lugares secundários de aderência podem ser comuns