Proteome-wide analysis of Trypanosoma cruzi exponential and stationary growth phases reveals a subcellular compartment-specific regulation

Trypanosoma cruzi, the etiologic agent of Chagas disease, cycles through different life stages characterized by defined molecular traits associated with the proliferative or differentiation state. In particular, T. cruzi epimastigotes are the replicative forms that colonize the intestine of the Triatomine insect vector before entering the stationary phase that is crucial for differentiation into metacyclic trypomastigotes, which are the infective forms of mammalian hosts. The transition from proliferative exponential phase to quiescent stationary phase represents an important step that recapitulates the early molecular events of metacyclogenesis, opening new possibilities for understanding this process. In this study, we report a quantitative shotgun proteomic analysis of the T. cruzi epimastigote in the exponential and stationary growth phases. More than 3000 proteins were detected and quantified, highlighting the regulation of proteins involved in different subcellular compartments. Ribosomal proteins were upregulated in the exponential phase, supporting the higher replication rate of this growth phase. Autophagy-related proteins were upregulated in the stationary growth phase, indicating the onset of the metacyclogenesis process. Moreover, this study reports the regulation of N-terminally acetylated proteins during growth phase transitioning, adding a new layer of regulation to this process. Taken together, this study reports a proteome-wide rewiring during T. cruzi transit from the replicative exponential phase to the stationary growth phase, which is the preparatory phase for differentiation

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 105 tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34th and 35th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.The authors would like to acknowledge the Federal Rural University of the Semiarid (UFERSA), University of São Paulo (USP) and Federal University of Minas Gerais (UFMG) contribution to the provision of laboratories and the availability of the structure

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different\ud stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental\ud transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes\ud infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of\ud pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period,\ud respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 105 tripomastigotes. Clinical examination,\ud determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed\ud cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid,\ud blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented\ud severe infection and died in the 34th and 35th days post-infection (dpi), respectively; but both fetuses were\ud recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130th day (30 dpi) of pregnancy; and Ewe 6\ud aborted one fetus in the 140th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five\ud days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV,\ud body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were\ud observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues\ud from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and\ud placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes

Identificação de antígenos de superfície de tripomastigotas metaciclicos de Trypanosoma cruzi por anticorpos monoclonais

BV UNIFESP: Teses e dissertaçõe

Phytomonas: definição de parâmetros taxonômicos com a utilização de anticorpos monoclonais e sequencias do gene ribossômico

BV UNIFESP: Teses e dissertaçõe

Revisiting the Acanthamoeba species that form star-shaped cysts (genotypes T7, T8, T9, and T17): characterization of seven new Brazilian environmental isolates and phylogenetic inferences

Free-living amoebae of the genus Acanthamoeba are the agents of both opportunistic and non-opportunistic infections and are frequently isolated from the environment. Of the 17 genotypes (T1-T17) identified thus far, 4 (T7, T8, T9, and T17) accommodate the rarely investigated species of morphological group I, those that form large, star-shaped cysts. We report the isolation and characterization of 7 new Brazilian environmental Acanthamoeba isolates, all assigned to group I. Phylogenetic analyses based on partial (similar to 1200 bp) SSU rRNA gene sequences placed the new isolates in the robustly supported clade composed of the species of morphological group I. One of the Brazilian isolates is closely related to A. comandoni (genotype T9), while the other 6, together with 2 isolates recently assigned to genotype T17, form a homogeneous, well-supported group (2-0% sequence divergence) that likely represents a new Acanthamoeba species. Thermotolerance, osmotolerance, and cytophatic effects, features often associated with pathogenic potential, were also examined. The results indicated that all 7 Brazilian isolates grow at temperatures up to 40 degrees C, and resist under hvperosmotic conditions. Additionally, media conditioned by each of the new Acanthamoeba isolates induced the disruption of SIRC and HeLa cell monolayers.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazil) [2009/53574-9]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), BrazilCNPq (Brazil)CNPq (Brazil

Resistência de camundongos imunizados com tripomastigotas de cultura mortos contra infecção por tripomastigotas de Trypanosoma cruzi provenientes do inseto

Mice immunized with heat or merthiolate-killed culture trypomastigotes of the non-virulent G strain were resistant to the challenge by insect-derived trypomastigotes of the CL strain of Trypanosoma cruzi. No parasitemia was detected, by direct microscopic examination of blood samples, in 90% of immunized mice while all control animals developed a high parasitemia. Trypsinization before heat-inactivation, or fixation with paraformaldehyde, apparently reduced the immunogenicity of the G strain trypomastigotes. Mice immunized with trypomastigotes treated by either of these procedures were not protected against infection by virulent T. cruzi. Analysis of the 13I-labeled surface proteins of G strain trypomastigotes inactivated by the various methods suggests that these components are involved in eliciting protective immunity against T. cruzi infection.Camundongos imunizados com tripomastigotas de cultura da cepa G, mortos pelo calor ou mertiolato, mostraram-se resistentes à infecção por tripomastigotas da cepa CL de T. cruzi provenientes do inseto vetor. Em 90% dos camundongos imunizados não foi detectado parasitemia patente ao exame microscópico enquanto todos os animais controle desen volveram alta parasitemia. Tripsinizaçao seguida de aquecimento, ou fixação com para formal deido, aparentemente reduziram a imunogenicidade de tripomastigotas da cepa G, visto que camundongos imunizados com tripomastigotas tratados por qualquer destes métodos não foram protegidos contra infecção por T. cruzi. A análise de proteínas de superficie de tripomastigotas da cepa G. inativados por diferentos métodos, marcados com 131,I, sugere que esses componentes de superfície estão envolvidos na indução da imunidade protetora contra T. cruzi. Camundongos imunizados com tripomastigotas de cultura da cepa G. mortos pelo calor ou mertiolato. mostraram se resistentes à in fecção por tripomastigotas da cepa CL de T. cruzi provenientes do inseto vetor. Em 90% dos camundongos imunizados não foi detectada parasitemia patente ao exame microscópico enquanto todos os animais controle desen volveram alta parasitemia. Tripsinizaçao seguida de aquecimento, ou fixação com para formal deido, aparentemente reduziram a imunogenicidade de tripomastigotas da cepa G, visto que camundongos imunizados com tripomastigotas tratados por qualquer destes métodos não foram protegidos contra infecção por T. cruzi. A análise de proteínas de superficie de tripomastigotas da cepa G. inativados por diferentos métodos, marcados com 131,I, sugere que esses componentes de superfície estão envolvidos na indução da imunidade protetora contra T. cruzi.Escola Paulista de Medicina Imunologia e Parasitologia Departamento de MicrobiologiaUNIFESP, EPM, Imunologia e Parasitologia Depto. de MicrobiologiaSciEL

Parasites reveal movement of bats between the New and Old Worlds

The global distribution of bat taxa indicates that the Atlantic and Pacific Oceans are effective barriers to movement between the Old and New Worlds. For instance, one of the major suborders, Yinpterochiroptera, has an exclusively Old World distribution, and within the other, Yangochiroptera, no species and only five genera are common to both. However, as bats are sometimes blown out to sea, and have colonised isolated islands, occasional natural movement between the New and Old Worlds does appear to be possible. Here we identify new genotypes of a blood parasite, Trypanosoma dionisii, in Old World bats that are closely related to South American strains. Using highly conservative calibration points, divergence of Old and New World strains is estimated to have occurred 3.2-5.0 million years ago (MYA), depending on the method used (upper 95% CL for maximum time 11.4 MYA). The true date of divergence is likely to be considerably more recent. These results demonstrate that taxon-specific parasites can indicate historical movements of their hosts, even where their hosts may have left no lasting phylogenetic footprint. (C) 2012 Elsevier Inc. All rights reserved

Parasites reveal movement of bats between the New and Old Worlds

The global distribution of bat taxa indicates that the Atlantic and Pacific Oceans are effective barriers to movement between the Old and New Worlds. For instance, one of the major suborders, Yinpterochiroptera, has an exclusively Old World distribution, and within the other, Yangochiroptera, no species and only five genera are common to both. However, as bats are sometimes blown out to sea, and have colonised isolated islands, occasional natural movement between the New and Old Worlds does appear to be possible. Here we identify new genotypes of a blood parasite, Trypanosoma dionisii, in Old World bats that are closely related to South American strains. Using highly conservative calibration points, divergence of Old and New World strains is estimated to have occurred 3.2-5.0 million years ago (MYA), depending on the method used (upper 95% CL for maximum time 11.4 MYA). The true date of divergence is likely to be considerably more recent. These results demonstrate that taxon-specific parasites can indicate historical movements of their hosts, even where their hosts may have left no lasting phylogenetic footprint. (C) 2012 Elsevier Inc. All rights reserved