Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

Characterization of two isolates of Trypanosoma cruzi obtained from the patient Berenice, the first human case of Chagas’ disease described by Carlos Chagas in 1909

Submitted by sandra infurna ([email protected]) on 2016-06-29T16:46:02Z No. of bitstreams: 1 carlos22_morel_etal_IOC_1996.pdf: 246408 bytes, checksum: 8cfbf156c135a4c79323e614791b9036 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-06-29T16:55:46Z (GMT) No. of bitstreams: 1 carlos22_morel_etal_IOC_1996.pdf: 246408 bytes, checksum: 8cfbf156c135a4c79323e614791b9036 (MD5)Made available in DSpace on 2016-06-29T16:55:46Z (GMT). No. of bitstreams: 1 carlos22_morel_etal_IOC_1996.pdf: 246408 bytes, checksum: 8cfbf156c135a4c79323e614791b9036 (MD5) Previous issue date: 1996Submitted by Angelo Silva ([email protected]) on 2016-07-07T11:16:54Z No. of bitstreams: 3 carlos22_morel_etal_IOC_1996.pdf.txt: 17230 bytes, checksum: 8f5b2bfe8f41a8edc21225d08ba10da6 (MD5) carlos22_morel_etal_IOC_1996.pdf: 246408 bytes, checksum: 8cfbf156c135a4c79323e614791b9036 (MD5) license.txt: 2991 bytes, checksum: 5a560609d32a3863062d77ff32785d58 (MD5)Approved for entry into archive by sandra infurna ([email protected]) on 2016-07-07T12:16:21Z (GMT) No. of bitstreams: 3 license.txt: 2991 bytes, checksum: 5a560609d32a3863062d77ff32785d58 (MD5) carlos22_morel_etal_IOC_1996.pdf: 246408 bytes, checksum: 8cfbf156c135a4c79323e614791b9036 (MD5) carlos22_morel_etal_IOC_1996.pdf.txt: 17230 bytes, checksum: 8f5b2bfe8f41a8edc21225d08ba10da6 (MD5)Made available in DSpace on 2016-07-07T12:16:21Z (GMT). No. of bitstreams: 3 license.txt: 2991 bytes, checksum: 5a560609d32a3863062d77ff32785d58 (MD5) carlos22_morel_etal_IOC_1996.pdf: 246408 bytes, checksum: 8cfbf156c135a4c79323e614791b9036 (MD5) carlos22_morel_etal_IOC_1996.pdf.txt: 17230 bytes, checksum: 8f5b2bfe8f41a8edc21225d08ba10da6 (MD5) Previous issue date: 1996Universidade Federal de Ouro Preto. Escola de Farmácia. Departamento de Análises Clínicas. Ouro Preto, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Bioquímica e Biologia Molecular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Bioquímica e Biologia Molecular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Laboratório de Parasitologia Celular e Molecular. Belo Horizonte, MG, Brasil.Two isolates of Trypanosoma cruzi were obtained from the patient Berenice, the first human case of Chagas’ disease (Chagas 1909), when she was 55 and 71 years old, respectively. The isolates were characterized on the basis of their epimastigote-trypomastigote differentiation in liquid media and of the electrophoretic pattern of EcoR1 digestion products of kinetoplast DNA (kDNA) minicircles (schizodeme) and isoenzyme patterns (zymodeme). Clear differences were found between the isolates, suggesting the occurrence of a heterogeneous population of T. cruzi in the infection of this patient

New evidence of spontaneous cure in human Chagas' disease Novas evidências da cura espontânea da doença de Chagas humana

A new case of spontaneous cure of human Chagas' disease is described in Uruguay. An 87-year-old man who had a typical acute phase of Trypanosoma cruzi infection in 1947 and never received specific treatment against the disease, when examined in 1998 revealed several completely negative parasitological and serological tests, including traditional serology, PCR and flow cytometry. As a whole, such findings fulfill the current criteria to define the cure of Chagas' disease. Clinical data suggest the possibility of a benign evolution of Chagas' disease in this case, but the basic findings (slight cardiac and esophageal impairment) could also be due to the advanced age of the patient.<br>Um novo caso de cura espontânea da doença de Chagas humana é descrito no Uruguai. Um homem de 87 anos de idade que teve um quadro típico de doença de Chagas aguda em 1947 e nunca recebeu tratamento específico, revelou-se em 1998 completamente negativo para exames sorológicos e parasitológicos, inclusive por PCR e citometria de fluxo. Estes achados, no conjunto, preenchem os critérios correntes para a definição de cura da doença de Chagas. O quadro clínico atual sugere a possiblidade de uma evolução benigna da doença de Chagas, mas os achados principais (comprometimento leve do coração e do esôfago) poderiam também dever-se à avançada idade do paciente