Sera of Chagasic patients react with antigens from the tomato parasite Phytomonas serpens

The genus Phytomonas comprises trypanosomatids that can parasitize a broad range of plant species. These fagellates can cause diseases in some plant families with a wide geographic distribution, which can result in great economic losses. We have demonstrated previously that Phytomonas serpens 15T, a tomato trypanosomatid, shares antigens with Trypanosoma cruzi, the agent of human Chagas disease. Herein, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identify proteins of P. serpens 15T that are recognized by sera from patients with Chagas disease. After 2D-electrophoresis of whole-cell lysates, 31 peptides were selected and analyzed by tandem mass spectrometry. Twenty-eight polypeptides were identifed, resulting in 22 different putative proteins. The identifed proteins were classifed into 8 groups according to biological process, most of which were clustered into a cellular metabolic process category. These results generated a collection of proteins that can provide a starting point to obtain insights into antigenic cross reactivity among trypanosomatids and to explore P. serpens antigens as candidates for vaccine and immunologic diagnosis studies.

Colony polymerase chain reaction of stably transfected Trypanosoma cruzi grown on solid medium

Tools for the genetic manipulation of Trypanosoma cruzi are largely unavailable, although several vectors for transfection of epimastigotes and expression of foreign or recombinant genes have been developed. We have previously constructed several plasmid vectors in which recombinant genes are expressed in T. cruzi using the rRNA promoter. In this report, we demonstrate that one of these vectors can simultaneously mediate expression of neomycin phosphotransferase and green fluorescent protein when used to stably transfect cultured epimastigotes. These stably transfected epimastigotes can be selected and cloned as unique colonies on solid medium. We describe a simple colony PCR approach to the screening of these T. cruzi colonies for relevant genes. Thus, the methodologies outlined herein provide important new tools for the genetic dissection of this important parasite.

Transfusion-transmited virus (TTV) in Brazil: preliminary report

TTV e um virus DNA recentemente descoberto no Japao a partir de um paciente portador de hepatite pos-transfusional de origem desconhecida. Neste estudo, avaliamos a presenca deste virus em pacientes com hepatopatias cronicas dos estados de Sao Paulo e do Para, representando duas regioes geograficamente diferentes. O DNA do TTV foi encontrado em 21/105 (20 por cento) e 9/20 (45 por cento) dos casos de Sao Paulo e do Para, respectivamente. O sequenciamento do DNA amplificado confirmou a presenca dos genotipos 1a e 2a, bem como de outros genotipos ainda nao descritos ate o momento. Em conclusao, TTV esta presente em casos de hepatopatias cronicas do Sudeste e do Norte do Brasil. por outro lado, maiores estudos ainda sao necessarios antes de se estabelecer relacao causal entre o TTV e a hepatite em seres humanos