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

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Tripomastigota muito largo como padrão morfológico de cepas do Trypanosoma cruzi do extremo Sul do Brasil? Very stout trypomastigotes as morphological pattern of strains of Trypanosoma cruzi of the southern region of Brazil

Foi estudado, em camundongos, o padrão morfológico-evolutivo de tripomastigotas sanguíneos de cinco cepas silvestres de Trypanosoma cruzi de Santa Catarina. Os resultados mostraram predomínio da forma muito larga ( > 70%) ao longo de toda a fase aguda de infecção em quatro cepas de média virulência. Com uma cepa de elevada virulência, a forma delgada foi prevalente no período inicial de infecção seguido de maior ocorrência da muito larga. Tendo em vista que a maioria das cepas de T. cruzi que possuem predomínio da forma muito larga foram isoladas no sul do Brasil (Rio Grande do Sul e Santa Catarina) e que existem evidências de diferentes comportamentos biológicos entre estes parasitas sangüíneos, os autores sugerem a investigação de possíveis correlações dos padrões morfológicos com os aspectos epidemiológicos e clínicos da doença de Chagas.<br>The morphological patterns of boold trupomastigotes from live sylvatic trypanosoma cruzi strains from Santa Catarina, South Brazil, were studied during thse course of infection in experimentally infected mice. A predominance of stout trypomastigotes (> 70%) was observed during all over the acute phase in four strains of medium virulence. With the remaining strain, of high virulence, the slender forms predominating at the early infection stage were soon also replaced by stout forms. Since almost all T. cruzistrains displaying predominance of this peculiar morphological pattern have been isolated in South Brazil (Rio Grande do Sul, Santa Catarina) and since there are evidences pointing out to the existence of biological differences among these distinct boold parasites, the authors suggest further investigations of possibel correlations between the morphological markers and clinical-epidemiological aspects of Chagas' disease

Trypanosoma cruzi Infection in Didelphis marsupialis in Santa Catarina and Arvoredo Islands, Southern Brazil

Between 1984 and 1993 the prevalence of the Trypanosoma cruzi infection in opossums (Didelphis marsupialis) was studied in Santa Catarina and Arvoredo Islands, State of Santa Catarina, Brazil. The association of the triatomine bug Panstrongylus megistus with opossums nests and the infection rate of these triatomines by T. cruzi was also studied. Thirteen different locations were studied in Santa Catarina Island (SCI), in which 137 D. marsupialis were collected. Sixty two opossums were collected at the Arvoredo Island (AI), located 12 miles north from SCI. All captured animals were submitted to parasitological examinations that revealed the presence of T. cruzi in 21.9% of the opossums captured in SCI and 45.2% among opossums captured in the AI. The presence of P. megistus was detected in most of the D. marsupialis nests collected in the SCI, however, in the non-inhabited AI only eight triatomines were collected during the whole study. The presence of T. cruzi-infected D. marsupialis associated with P. megistus in human dwellings in the SCI, and the high infection rate of D. marsupilais by T. cruzi in the absence of a high vector density are discussed

Trypanocidal and Leishmanicidal Properties of Substitution-Containing Chalcones

Ten chalcones were synthesized and tested as potential leishmanicidal and trypanocidal agents. All tested compounds caused concentration-dependent inhibition of the in vitro growth of Leishmania braziliensis and Trypanosoma cruzi with no significant toxic effect towards host macrophages. Our results show that the positions of the substituents seem to be critical for their antiprotozoal activities

Patent application in biotechnology at subclass C12N in Brazil at the period of 2001 to 2005

An analysis of Instituto Nacional de Propriedade Industrial (INPI) patent database from 2001 to 2005 showed that less than 5% of the total patent deposited in the subclass C12N, which referred to "Microorganisms or Enzymes, Compositions thereof, Propagating, Preserving or Maintaining Microorganisms, Mutation or Genetic Engineering, Culture Media", were from national depositors. In contrast, more than 34% of all these deposits came from the United States of America during the same period. Among the national depositors, public universities and government research institutions contributed with 83% over all the deposits, demonstrating that research and development in the field of Biotechnology in Brazil has been concentrated within Brazilian public institutions during this period