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1.
Mem Inst Oswaldo Cruz ; 115: e200504, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32578684

RESUMO

BACKGROUND: Biodiversity screens and phylogenetic studies are dependent on reliable DNA sequences in public databases. Biological collections possess vouchered specimens with a traceable history. Therefore, DNA sequencing of samples available at institutional collections can greatly contribute to taxonomy, and studies on evolution and biodiversity. METHODS: We sequenced part of the glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) and the SSU rRNA (V7/V8) genes from 102 trypanosomatid cultures, which are available on request at www.colprot.fiocruz.br. OBJECTIVE: The main objective of this work was to use phylogenetic inferences, using the obtained DNA sequences and those from representatives of all Trypanosomatidae genera, to generate phylogenetic trees that can simplify new isolates screenings. FINDINGS: A DNA sequence is provided for the first time for several isolates, the phylogenetic analysis allowed the classification or reclassification of several specimens, identification of candidates for new genera and species, as well as the taxonomic validation of several deposits. MAIN CONCLUSIONS: This survey aimed at presenting a list of validated species and their associated DNA sequences combined with a short historical overview of each isolate, which can support taxonomic and biodiversity research and promote culture collections.


Assuntos
Biodiversidade , Código de Barras de DNA Taxonômico , Trypanosomatina/classificação , Trypanosomatina/genética , Filogenia
2.
Folia Parasitol (Praha) ; 672020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32350156

RESUMO

Here we describe the new trypanosomatid, Phytomonas borealis sp. n., from the midgut of the spiked shieldbugs, Picromerus bidens (Linnaeus), collected in two locations, Novgorod and Pskov Oblasts of Russia. The phylogenetic analyses, based on the 18S rRNA gene, demonstrated that this flagellate is a sister species to the secondary monoxenous Phytomonas nordicus Frolov et Malysheva, 1993, which was concurrently documented in the same host species in Pskov Oblast. Unlike P. nordicus, which can complete its development (including exit to haemolymph and penetration into salivary glands) in Picromerus bidens, the new species did not form any extraintestinal stages in the host. It also did not produce endomastigotes, indispensable for transmission in other Phytomonas spp. These observations, along with the fact that P. bidens overwinters at the egg stage, led us to the conclusion that the examined infections with P. borealis were non-specific. Strikingly, the flagellates from the Novgorod population contained prokaryotic endosymbionts, whereas the parasites from the second locality were endosymbiont-free. This is a first case documenting presence of intracellular symbiotic bacteria in Phytomonas spp. We suggest that this novel endosymbiotic association arose very recently and did not become obligate yet. Further investigation of P. borealis and its intracellular bacteria may shed light on the origin and early evolution of endosymbiosis in trypanosomatids.


Assuntos
Fenômenos Fisiológicos Bacterianos , Heterópteros/parasitologia , Simbiose , Trypanosomatina/classificação , Animais , Heterópteros/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia , Filogenia , RNA de Protozoário/análise , RNA Ribossômico 18S/análise , Federação Russa , Trypanosomatina/microbiologia
3.
Int J Parasitol ; 49(13-14): 1075-1086, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31734337

RESUMO

The extreme biological diversity of Oceanian archipelagos has long stimulated research in ecology and evolution. However, parasitic protists in this geographic area remained neglected and no molecular analyses have been carried out to understand the evolutionary patterns and relationships with their hosts. Papua New Guinea (PNG) is a biodiversity hotspot containing over 5% of the world's biodiversity in less than 0.5% of the total land area. In the current work, we examined insect heteropteran hosts collected in PNG for the presence of trypanosomatid parasites. The diversity of insect flagellates was analysed, to our knowledge for the first time, east of Wallace's Line, one of the most distinct biogeographic boundaries of the world. Out of 907 investigated specimens from 138 species and 23 families of the true bugs collected in eight localities, 135 (15%) were infected by at least one trypanosomatid species. High species diversity of captured hosts correlated with high diversity of detected trypanosomatids. Of 46 trypanosomatid Typing Units documented in PNG, only eight were known from other geographic locations, while 38 TUs (~83%) have not been previously encountered. The widespread trypanosomatid TUs were found in both widely distributed and endemic/sub-endemic insects. Approximately one-third of the endemic trypanosomatid TUs were found in widely distributed hosts, while the remaining species were confined to endemic and sub-endemic insects. The TUs from PNG form clades with conspicuous host-parasite coevolutionary patterns, as well as those with a remarkable lack of this trait. In addition, our analysis revealed new members of the subfamilies Leishmaniinae and Strigomonadinae, potentially representing new genera of trypanosomatids.


Assuntos
Biodiversidade , Insetos/parasitologia , Trypanosomatina/classificação , Trypanosomatina/isolamento & purificação , Animais , Evolução Biológica , Interações Hospedeiro-Parasita , Papua Nova Guiné , Filogenia , Trypanosomatina/genética
4.
Emerg Infect Dis ; 25(11): 2088-2092, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31625841

RESUMO

Through whole-genome sequencing analysis, we identified non-Leishmania parasites isolated from a man with a fatal visceral leishmaniasis-like illness in Brazil. The parasites infected mice and reproduced the patient's clinical manifestations. Molecular epidemiologic studies are needed to ascertain whether a new infectious disease is emerging that can be confused with leishmaniasis.


Assuntos
Infecções por Euglenozoa/epidemiologia , Infecções por Euglenozoa/parasitologia , Trypanosomatina/genética , Idoso , Animais , Brasil/epidemiologia , DNA Espaçador Ribossômico , Genes de Helmintos , Humanos , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Masculino , Camundongos , Filogenia , Trypanosomatina/classificação
5.
Mol Biochem Parasitol ; 232: 111199, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31276694

RESUMO

Here we report that trypanosomatid flagellates of the genus Blastocrithidia possess catalase. This enzyme is not phylogenetically related to the previously characterized catalases in other monoxenous trypanosomatids, suggesting that their genes have been acquired independently. Surprisingly, Blastocrithidia catalase is less enzymatically active, compared to its counterpart from Leptomonas pyrrhocoris, posing an intriguing biological question why this gene has been retained in the evolution of trypanosomatids.


Assuntos
Catalase/metabolismo , Proteínas de Protozoários/metabolismo , Trypanosomatina/enzimologia , Sequência de Aminoácidos , Catalase/química , Catalase/genética , Evolução Molecular , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Filogenia , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Alinhamento de Sequência , Trypanosomatina/classificação , Trypanosomatina/genética , Trypanosomatina/metabolismo
6.
Biol Rev Camb Philos Soc ; 94(5): 1701-1721, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31095885

RESUMO

Parasitic trypanosomatids and phototrophic euglenids are among the most extensively studied euglenozoans. The phototrophic euglenid lineage arose relatively recently through secondary endosymbiosis between a phagotrophic euglenid and a prasinophyte green alga that evolved into the euglenid secondary chloroplast. The parasitic trypanosomatids (i.e. Trypanosoma spp. and Leishmania spp.) and the freshwater phototrophic euglenids (i.e. Euglena gracilis) are the most evolutionary distant lineages in the Euglenozoa phylogenetic tree. The molecular and cell biological traits they share can thus be considered as ancestral traits originating in the common euglenozoan ancestor. These euglenozoan ancestral traits include common mitochondrial presequence motifs, respiratory chain complexes containing various unique subunits, a unique ATP synthase structure, the absence of mitochondria-encoded transfer RNAs (tRNAs), a nucleus with a centrally positioned nucleolus, closed mitosis without dissolution of the nuclear membrane and nucleoli, a nuclear genome containing the unusual 'J' base (ß-D-glucosyl-hydroxymethyluracil), processing of nucleus-encoded precursor messenger RNAs (pre-mRNAs) via spliced-leader RNA (SL-RNA) trans-splicing, post-transcriptional gene silencing by the RNA interference (RNAi) pathway and the absence of transcriptional regulation of nuclear gene expression. Mitochondrial uridine insertion/deletion RNA editing directed by guide RNAs (gRNAs) evolved in the ancestor of the kinetoplastid lineage. The evolutionary origin of other molecular features known to be present only in either kinetoplastids (i.e. polycistronic transcripts, compaction of nuclear genomes) or euglenids (i.e. monocistronic transcripts, huge genomes, many nuclear cis-spliced introns, polyproteins) is unclear.


Assuntos
Evolução Biológica , Euglenozoários/classificação , Biologia Molecular , Trypanosomatina/genética , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Euglênidos/classificação , Euglênidos/genética , Euglenozoários/genética , Genoma/fisiologia , Íntrons/fisiologia , Mitocôndrias/genética , Processos Fototróficos , Filogenia , Interferência de RNA , RNA Ribossômico 28S/genética , Trypanosomatina/classificação , Trypanosomatina/enzimologia
7.
PLoS One ; 14(4): e0214484, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30943229

RESUMO

Here we described a new trypanosomatid species, Phytomonas lipae, parasitizing the dock bug Coreus marginatus based on axenic culture and in vivo material. Using light and electron microscopy we characterized the development of this flagellate in the intestine, hemolymph and salivary glands of its insect host. The intestinal promastigotes of Phytomonas lipae do not divide and occur only in the anterior part of the midgut. From there they pass into hemolymph, increasing in size, and then to salivary glands, where they actively proliferate without attachment to the host's epithelium and form infective endomastigotes. We conducted molecular phylogenetic analyses based on 18s rRNA, gGAPDH and HSP83 gene sequences, of which the third marker performed the best in terms of resolving phylogenetic relationships within the genus Phytomonas. Our inference demonstrated rather early origin of the lineage comprising the new species, right after that of P. oxycareni, which represents the earliest known branch within the Phytomonas clade. This allowed us to compare the development of P. lipae and three other Phytomonas spp. in their insect hosts and reconstruct the vectorial part of the life cycle of their common ancestor.


Assuntos
Heterópteros/parasitologia , Estágios do Ciclo de Vida , Glândulas Salivares/parasitologia , Trypanosomatina/genética , Animais , Proteínas de Choque Térmico/genética , Intestinos/parasitologia , Kinetoplastida , Funções Verossimilhança , Filogenia , Proteínas de Protozoários/genética , RNA Ribossômico 18S/genética , Trypanosomatina/classificação , Trypanosomatina/fisiologia
8.
J Eukaryot Microbiol ; 66(4): 600-607, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30480347

RESUMO

We describe the monoxenous trypanosomatids parasitizing true bugs and flies on the island of Curaçao. Out of 248 examined true bugs belonging to 17 species, 93 individuals were found to be infected (overall 38% prevalence) by at least one trypanosomatid species (referred to as typing units; TUs). Out of 80 flies, six were infected. All detected trypanosomatids were compared based on their 18S rRNA sequences with TUs parasitizing bugs and flies described from mainland South America, allowing us to assess their diversity and distribution. Besides Leptomonas pyrrhocoris and Leptomonas seymouri, two known species of the subfamily Leishmaniinae, our analysis revealed six new TUs falling into the groups 'jaculum', Blastocrithidia and Herpetomonas. Moreover, two new members of the genus Phytomonas and three new TUs belonging to the monophyletic group designated as 'new clade II' sensu Mol. Phylogenet. Evol, 69, 255 (2013) were isolated. The detected trypanosomatids were characterized by moderate diversity (13 TUs) species richness. Out of nine and four TUs from the heteropteran and dipteran hosts, respectively, 11 TUs have not been encountered before. Although a sampling bias may partially affect the comparison between trypanosomatid communities on Curaçao and the mainland, the high proportion of unique TUs from the former location suggests that the prominent role of islands in increasing the global diversity of macroscopic organisms may also extend to their protistan parasites.


Assuntos
Dípteros/parasitologia , Heterópteros/parasitologia , Trypanosomatina/isolamento & purificação , Animais , Curaçao , Filogenia , RNA de Protozoário/análise , RNA Ribossômico 18S/análise , Trypanosomatina/classificação , Trypanosomatina/genética
9.
Parasitology ; 146(1): 1-27, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29898792

RESUMO

Unicellular flagellates of the family Trypanosomatidae are obligatory parasites of invertebrates, vertebrates and plants. Dixenous species are aetiological agents of a number of diseases in humans, domestic animals and plants. Their monoxenous relatives are restricted to insects. Because of the high biological diversity, adaptability to dramatically different environmental conditions, and omnipresence, these protists have major impact on all biotic communities that still needs to be fully elucidated. In addition, as these organisms represent a highly divergent evolutionary lineage, they are strikingly different from the common 'model system' eukaryotes, such as some mammals, plants or fungi. A number of excellent reviews, published over the past decade, were dedicated to specialized topics from the areas of trypanosomatid molecular and cell biology, biochemistry, host-parasite relationships or other aspects of these fascinating organisms. However, there is a need for a more comprehensive review that summarizing recent advances in the studies of trypanosomatids in the last 30 years, a task, which we tried to accomplish with the current paper.


Assuntos
Evolução Biológica , Regulação da Expressão Gênica , Genoma de Protozoário , Filogenia , Trypanosomatina , Animais , Regulação da Expressão Gênica/genética , Humanos , Trypanosomatina/classificação , Trypanosomatina/genética , Trypanosomatina/metabolismo
10.
Curr Opin Cell Biol ; 53: 70-76, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29929066

RESUMO

From unicellular protists to the largest megafauna and flora, all eukaryotes depend upon the organelles and processes of the intracellular membrane trafficking system. Well-defined machinery selectively packages and delivers material between endomembrane organelles and imports and exports material from the cell surface. This process underlies intracellular compartmentalization and facilitates myriad processes that define eukaryotic biology. Membrane trafficking is a landmark in the origins of the eukaryotic cell and recent work has begun to unravel how the revolution in cellular structure occurred.


Assuntos
Membrana Celular/metabolismo , Células Eucarióticas/metabolismo , Evolução Molecular , Animais , Transporte Biológico , Eucariotos/metabolismo , Membranas Intracelulares/metabolismo , Organelas/metabolismo , Trypanosomatina/classificação , Trypanosomatina/citologia
11.
Trends Parasitol ; 34(6): 466-480, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29605546

RESUMO

Trypanosomes and leishmanias are widely known parasites of humans. However, they are just two out of several phylogenetic lineages that constitute the family Trypanosomatidae. Although dixeny - the ability to infect two hosts - is a derived trait of vertebrate-infecting parasites, the majority of trypanosomatids are monoxenous. Like their common ancestor, the monoxenous Trypanosomatidae are mostly parasites or commensals of insects. This review covers recent advances in the study of insect trypanosomatids, highlighting their diversity as well as genetic, morphological and biochemical complexity, which, until recently, was underappreciated. The investigation of insect trypanosomatids is providing an important foundation for understanding the origin and evolution of parasitism, including colonization of vertebrates and the appearance of human pathogens.


Assuntos
Evolução Biológica , Insetos/parasitologia , Trypanosomatina/classificação , Animais , Biodiversidade , Interações Hospedeiro-Parasita , Humanos , Trypanosomatina/genética , Trypanosomatina/fisiologia
12.
BMC Evol Biol ; 18(1): 31, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29540192

RESUMO

BACKGROUND: Trypanosomatid parasites such as Trypanosoma spp. and Leishmania spp. are a major source of infectious disease in humans and domestic animals worldwide. Fundamental to the host-parasite interactions of these potent pathogens are their cell surfaces, which are highly decorated with glycosylated proteins and other macromolecules. Trypanosomatid genomes contain large multi-copy gene families encoding UDP-dependent glycosyltransferases (UGTs), the primary role of which is cell-surface decoration. Here we report a phylogenetic analysis of UGTs from diverse trypanosomatid genomes, the aim of which was to understand the origin and evolution of their diversity. RESULTS: By combining phylogenetics with analyses of recombination, and selection, we compared UGT repertoire, genomic context and sequence evolution across 19 trypanosomatids. We identified a UGT lineage present in stercorarian trypanosomes and a free-living kinetoplastid Bodo saltans that likely represents the ancestral state of this gene family. The phylogeny of parasite-specific genes shows that UGTs repertoire in Leishmaniinae and salivarian trypanosomes has expanded independently and with distinct evolutionary dynamics. In the former, the ancestral UGT repertoire was organised in a tandem array from which sporadic transpositions to telomeric regions occurred, allowing expansion most likely through telomeric exchange. In the latter, the ancestral UGT repertoire was comprised of seven subtelomeric lineages, two of which have greatly expanded potentially by gene transposition between these dynamic regions of the genome. CONCLUSIONS: The phylogeny of UGTs confirms that they represent a substantial parasite-specific innovation, which has diversified independently in the distinct trypanosomatid lineages. Nonetheless, developmental regulation has been a strong driver of UGTs diversification in both African trypanosomes and Leishmania.


Assuntos
Glicosiltransferases/genética , Trypanosomatina/genética , Adaptação Biológica , Animais , Infecções por Euglenozoa/parasitologia , Genoma , Interações Hospedeiro-Parasita , Humanos , Isoenzimas/genética , Filogenia , Trypanosomatina/classificação , Trypanosomatina/fisiologia
13.
Parasitology ; 145(4): 430-442, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-27976601

RESUMO

We propose a taxonomic revision of the dixenous trypanosomatids currently classified as Endotrypanum and Leishmania, including parasites that do not fall within the subgenera L. (Leishmania) and L. (Viannia) related to human leishmaniasis or L. (Sauroleishmania) formed by leishmanias of lizards: L. colombiensis, L. equatorensis, L. herreri, L. hertigi, L. deanei, L. enriettii and L. martiniquensis. The comparison of these species with newly characterized isolates from sloths, porcupines and phlebotomines from central and South America unveiled new genera and subgenera supported by past (RNA PolII gene) and present (V7V8 SSU rRNA, Hsp70 and gGAPDH) phylogenetic analyses of the organisms. The genus Endotrypanum is restricted to Central and South America, comprising isolates from sloths and transmitted by phlebotomines that sporadically infect humans. This genus is the closest to the new genus Porcisia proposed to accommodate the Neotropical porcupine parasites originally described as L. hertigi and L. deanei. A new subgenus Leishmania (Mundinia) is created for the L. enriettii complex that includes L. martiniquensis. The new genus Zelonia harbours trypanosomatids from Neotropical hemipterans placed at the edge of the Leishmania-Endotrypanum-Porcisia clade. Finally, attention is drawn to the status of L. siamensis and L. australiensis as nomem nudums.


Assuntos
Leishmania/genética , Filogenia , Trypanosomatina/classificação , Animais , América Central/epidemiologia , Genes de Protozoários , Humanos , Leishmaniose/epidemiologia , Leishmaniose/parasitologia , Leishmaniose/transmissão , Lagartos/parasitologia , Tipagem Molecular , Porcos-Espinhos/parasitologia , Psychodidae/parasitologia , RNA Ribossômico/genética , Bichos-Preguiça/parasitologia , América do Sul/epidemiologia , Trypanosomatina/genética
14.
Mem Inst Oswaldo Cruz ; 113(1): 45-55, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29211107

RESUMO

BACKGROUND: Didelphis spp. are a South American marsupial species that are among the most ancient hosts for the Trypanosoma spp. OBJECTIVES: We characterise a new species (Trypanosoma janseni n. sp.) isolated from the spleen and liver tissues of Didelphis aurita in the Atlantic Rainforest of Rio de Janeiro, Brazil. METHODS: The parasites were isolated and a growth curve was performed in NNN and Schneider's media containing 10% foetal bovine serum. Parasite morphology was evaluated via light microscopy on Giemsa-stained culture smears, as well as scanning and transmission electron microscopy. Molecular taxonomy was based on a partial region (737-bp) of the small subunit (18S) ribosomal RNA gene and 708 bp of the nuclear marker, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) genes. Maximum likelihood and Bayesian inference methods were used to perform a species coalescent analysis and to generate individual and concatenated gene trees. Divergence times among species that belong to the T. cruzi clade were also inferred. FINDINGS: In vitro growth curves demonstrated a very short log phase, achieving a maximum growth rate at day 3 followed by a sharp decline. Only epimastigote forms were observed under light and scanning microscopy. Transmission electron microscopy analysis showed structures typical to Trypanosoma spp., except one structure that presented as single-membraned, usually grouped in stacks of three or four. Phylogeography analyses confirmed the distinct species status of T. janseni n. sp. within the T. cruzi clade. Trypanosoma janseni n. sp. clusters with T. wauwau in a well-supported clade, which is exclusive and monophyletic. The separation of the South American T. wauwau + T. janseni coincides with the separation of the Southern Super Continent. CONCLUSIONS: This clade is a sister group of the trypanosomes found in Australian marsupials and its discovery sheds light on the initial diversification process based on what we currently know about the T. cruzi clade.


Assuntos
DNA de Protozoário/genética , Didelphis/parasitologia , RNA Ribossômico 18S/genética , Trypanosomatina/genética , Animais , Brasil , Filogeografia , Reação em Cadeia da Polimerase , Floresta Úmida , Trypanosoma cruzi , Trypanosomatina/classificação , Trypanosomatina/isolamento & purificação
15.
Parasitol Res ; 117(2): 623-628, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29282526

RESUMO

Currently, light microscopic examination of cell morphology cannot discriminate Crithidia mellificae and Lotmaria passim with 100% certainty. Here, a minor groove-binding (MGB) probe-based multiplex real-time PCR assay was developed for the simultaneous and quantitative detection of C. mellificae and L. passim in honey bees. A conserved Hymenoptera 18S rRNA gene was built in as an internal control that allows accurate detection of PCR inhibition and failure of DNA extraction. The newly developed assay was also applied to field samples. Of 21 honey bee colonies (446 bees) sampled from six counties in both central and eastern Massachusetts, 3 colonies (14.29%) and 8 bees (1.79%) were infected with L. passim, and 1 colony (4.76%) and 1 bee (0.22%) with C. mellificae. Our data showed a low rate of trypanosomatid infection, and L. passim was more prevalent than C. mellificae in honey bee samples in Massachusetts.


Assuntos
Abelhas/parasitologia , Crithidia/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Trypanosomatina/isolamento & purificação , Animais , Crithidia/classificação , Crithidia/genética , Massachusetts , Trypanosomatina/classificação , Trypanosomatina/genética
16.
São Paulo; s.n; s.n; 2018. 95 p. ilus, graf.
Tese em Português | LILACS | ID: biblio-915566

RESUMO

Doenças causadas por agentes infecciosos e parasitários são chamadas negligenciadas por não despertarem interesse das indústrias farmacêuticas para o desenvolvimento de novas alternativas terapêuticas. Essas doenças são responsáveis por levar milhões de pessoas à morte todos os anos e afetam principalmente os países pobres e em desenvolvimento. Dentre estas, a doença de Chagas e as leishmanioses, parasitoses causadas por parasitas flagelados pertencentes à família Trypanosomatidae, T. cruzi e Leishmaina sp., respectivamente, se apresentam como um sério problema de saúde pública mundial. Endêmicas em vários países e causando milhões de mortes anualmente, ainda hoje não existem fármacos eficientes e seguros para o tratamento dessas doenças. Este panorama torna eminente a necessidade de pesquisa e desenvolvimento de novos fármacos para essas parasitoses. A busca por agentes quimioterápicos envolve a seleção de vias metabólicas essenciais à sobrevivência dos parasitas. Dentre estas, destacamse cisteíno-proteases presentes nesses tripanossomatídeos, deste modo a cruzaína no T. cruzi, e a CPB2.8 na Leishmania mexicana, se mostram como alvos bioquímicos promissores. A disponibilidade de estruturas cristalográficas da cruzaína e do sequenciamento genômico da CPB2.8, nos permite utilizar estratégias de planejamento de fármacos baseado no receptor (SBDD) na identificação de candidatos a fármacos para essas doenças. Entre as técnicas modernas de SBDD utilizadas, a triagem virtual possibilita identificar promissores candidatos a novos fármacos. Assim neste trabalho, obteve-se por meio da técnica de modelagem comparativa o modelo da enzima CPB2.8 de L. mexicana, visto a indisponibilidade da estrutura cristalográfica no Protein Data Bank (PDB). De modo a refinar o modelo construído realizou-se a simulação por dinâmica molecular de 100ns, apresentando estabilização a partir de 80ns. A simulação por dinâmica molecular foi validada por meio do gráfico de Ramachandran, gráfico de raio de giro, RMSD, gráfico de superfície hidrofóbica. Foram calculados os mapas de interação molecular no programa GRID das seguintes proteínas: cruzaína, CPB2.8, catepsina B e catepsina L, e, posteriormente, foi construído um modelo farmacofórico baseado no sítio ativo das enzimas cruzaína e CPB2.8. O modelo farmacofórico da cruzaína foi validado por curva ROC apresentando valor de AUC 61%. A triagem virtual foi realizada para ambas as proteínas e foram obtidos 369 compostos para a cuzaína e 225 compostos para a CPB2.8. Foi realizado o ancoramento molecular desses compostos obtidos pela triagem virtual a fim de diminuir a quantidade de compostos a serem avaliados experimentalmente


Neglected diseases are caused by parasites and infectious agents and affect mainly people in poor areas being prevalent in 149 countries and causing 534,000 deaths per year. Among neglected diseases we can highlight Chagas Disease and Leishmaniasis, both have a high rate of morbidity and mortality and both are addressed in this project in the search of new drugs against a NTD. Nowadays, the search for new drugs involves the selection of biological pathways essential for parasite survival, in this class of parasites we can suggest the cysteine proteases, a proteases family present in Trypanosoma cruzi and and Leishmania ssp. In order to obtain a new agent against Neglected Disease in this work was obtained the model of the enzyme CPB2.8 of L. mexicana using the comparative modeling technique, due to the unavailability of the crystallographic structure in the Protein Data Bank (PDB). In order to refine the constructed model was performed the molecular dynamics simulation of 100ns, stabilization was achieved from 80ns. Molecular dynamics simulation was validated using the Ramachandran graph, radius of rotation graph, RMSD, hydrophobic surface area graph. The molecular interaction fields were calculated in the GRID program to cruzain, CPB2.8, cathepsin B and cathepsin L. Based on molecular interaction fields generated pharmacophoric models were constructed using information about the active site of the enzymes cruzain and CPB2.8. The pharmacophoric model of cruzain was validated by ROC curve presenting AUC value of 61%. Virtual screening was performed for both proteins and 369 compounds were obtained for cuzain and 225 compounds for CPB2.8. Docking studies of these compounds was performed in order to decrease the amount of compounds to be evaluated experimentally


Assuntos
Cisteína Proteases/análise , Doenças Negligenciadas/prevenção & controle , Triagem/estatística & dados numéricos , Trypanosoma cruzi/classificação , Descoberta de Drogas , Leishmania/classificação , Preparações Farmacêuticas , Trypanosomatina/classificação
17.
Am J Trop Med Hyg ; 97(5): 1482-1485, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29140234

RESUMO

To better understand the ecology of Trypanosoma cruzi in the northeastern Peruvian Amazon, we evaluated the prevalence of T. cruzi and other trypanosomatids in four orders of wild mammals hunted and consumed by inhabitants of three remote indigenous communities in the Peruvian Amazon. Of 300 wild mammals sampled, 115 (38.3%) were infected with trypanosomatids and 15 (5.0%) with T. cruzi. The prevalence of T. cruzi within each species was as follows: large rodents (Cuniculus paca, 5.5%; Dasyprocta spp., 2.6%), edentates (Dasypus novemcinctus, 4.2%), and carnivores with higher prevalence (Nasua nasua, 18.8%). The high prevalence of T. cruzi and other trypanosomatids in frequently hunted wild mammals suggests a sizeable T. cruzi sylvatic reservoir in remote Amazonian locations.


Assuntos
Animais Selvagens/parasitologia , Doença de Chagas/veterinária , Mamíferos/parasitologia , Trypanosoma cruzi/isolamento & purificação , Trypanosomatina/isolamento & purificação , Animais , Tatus/parasitologia , Doença de Chagas/epidemiologia , Peru/epidemiologia , Prevalência , Procyonidae/parasitologia , Roedores/parasitologia , Trypanosoma cruzi/classificação , Trypanosomatina/classificação
18.
Parasit Vectors ; 10(1): 287, 2017 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-28595622

RESUMO

Trypanosomatids are protozoan parasites of the class Kinetoplastida predominately restricted to invertebrate hosts (i.e. possess a monoxenous life-cycle). However, several genera are pathogenic to humans, animals and plants, and have an invertebrate vector that facilitates their transmission (i.e. possess a dixenous life-cycle). Phytomonas is one dixenous genus that includes several plant pathogens transmitted by phytophagous insects. Trypanosoma and Leishmania are dixenous genera that infect vertebrates, including humans, and are transmitted by hematophagous invertebrates. Traditionally, monoxenous trypanosomatids such as Leptomonas were distinguished from morphologically similar dixenous species based on their restriction to an invertebrate host. Nonetheless, this criterion is somewhat flawed as exemplified by Leptomonas seymouri which reportedly infects vertebrates opportunistically. Similarly, Novymonas and Zelonia are presumably monoxenous genera yet sit comfortably in the dixenous clade occupied by Leishmania. The isolation of Leishmania macropodum from a biting midge (Forcipomyia spp.) rather than a phlebotomine sand fly calls into question the exclusivity of the Leishmania-sand fly relationship, and its suitability for defining the Leishmania genus. It is now accepted that classic genus-defining characteristics based on parasite morphology and host range are insufficient to form the sole basis of trypanosomatid taxonomy as this has led to several instances of paraphyly. While improvements have been made, resolution of evolutionary relationships within the Trypanosomatidae is confounded by our incomplete knowledge of its true diversity. The known trypanosomatids probably represent a fraction of those that exist and isolation of new species will help resolve relationships in this group with greater accuracy. This review incites a dialogue on how our understanding of the relationships between certain trypanosomatids has shifted, and discusses new knowledge that informs the present taxonomy of these important parasites.


Assuntos
Filogenia , Trypanosomatina/classificação , Animais , Plantas , Trypanosomatina/isolamento & purificação
19.
Protist ; 168(1): 71-79, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28043008

RESUMO

Phytomonas spp. (phytomonads) are a diverse and globally distributed group of unicellular eukaryotes that parasitize a wide range of plants and are transmitted by insect hosts. Here we report the discovery and characterisation of a new species of Phytomonas, named Phytomonas oxycareni n. sp., which was obtained from the salivary glands of the invasive species of true bug Oxycarenus lavaterae (Heteroptera). The new Phytomonas species exhibits a long slender promastigote morphology and can be found both within the lumen of the insect host's salivary glands as well as within the cells of the salivary gland itself. Sampling multiple individuals from the same population post-winter hibernation on two consecutive years revealed that infection was persistent over time. Finally, phylogenetic analyses of small subunit ribosomal RNA genes revealed that this species is sister to other species within the genus Phytomonas, providing new insight into the evolutionary history of the clade.


Assuntos
Heterópteros/parasitologia , Trypanosomatina/classificação , Animais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Filogenia , RNA de Protozoário/genética , RNA Ribossômico 18S/genética , Glândulas Salivares/parasitologia , Trypanosomatina/genética , Trypanosomatina/ultraestrutura
20.
Eur J Protistol ; 57: 85-98, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28073072

RESUMO

Blastocrithidia papi sp. n. is a cyst-forming trypanosomatid parasitizing firebugs (Pyrrhocoris apterus). It is a member of the Blastocrithidia clade and a very close relative of B. largi, to which it is almost identical through its SSU rRNA gene sequence. However, considering the SL RNA gene these two species represent quite distinct, not even related typing units. Morphological analysis of the new species revealed peculiar or even unique features, which may be useful for future taxonomic revision of the genus Blastocrithidia. These include a breach in the microtubular corset of rostrum at the site of contact with the flagellum, absence of desmosomes between flagellum and rostrum, large transparent vacuole near the flagellar pocket, and multiple vacuoles with fibrous content in the posterior portion of the cell. The study of the flagellates' behavior in the host intestine revealed that they may attach both to microvilli of enterocytes using swollen flagellar tip and to extracellular membranes layers using hemidesmosomes of flagellum. Laboratory experiments on B. papi transmission in P. apterus demonstrated that the parasite may be transmitted vertically (via contaminated surface of eggs) and horizontally (via contaminated substrate and/or necrophagy). We argue that the parasite exploits transmission mechanisms intended for obligate bacterial symbionts of P. apterus.


Assuntos
Heterópteros/parasitologia , Estágios do Ciclo de Vida , Trypanosomatina/citologia , Trypanosomatina/fisiologia , Animais , Heterópteros/microbiologia , Intestinos/parasitologia , Trypanosomatina/classificação
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