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Zhang K, Jiang N, Chen H, Zhang N, Sang X, Feng Y, Chen R, Chen Q. TatD DNases of African trypanosomes confer resistance to host neutrophil extracellular traps. Sci China Life Sci 2021; 64:621-632. [PMID: 33420923 DOI: 10.1007/s11427-020-1854-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/19/2020] [Indexed: 01/07/2023]
Abstract
African trypanosomatid parasites escape host acquired immune responses through periodic antigenic variation of their surface coat. In this study, we describe a mechanism by which the parasites counteract innate immune responses. Two TatD DNases were identified in each of Trypanosoma evansi and Trypanosoma brucei. These DNases are bivalent metal-dependent endonucleases localized in the cytoplasm and flagella of the parasites that can also be secreted by the parasites. These enzymes possess conserved functional domains and have efficient DNA hydrolysis activity. Host neutrophil extracellular traps (NETs) induced by the parasites could be hydrolyzed by native and recombinant TatD DNases. NET disruption was prevented, and the survival rate of parasites was decreased, in the presence of the DNase inhibitor aurintricarboxylic acid. These data suggest that trypanosomes can counteract host innate immune responses by active secretion of TatD DNases to degrade NETs.
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Affiliation(s)
- Kai Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Hongyu Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Naiwen Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Xiaoyu Sang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Ying Feng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Ran Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China
| | - Qijun Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, 110866, China.
- The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, 110866, China.
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Martínez-Calvillo S, Florencio-Martínez LE, Nepomuceno-Mejía T. Nucleolar Structure and Function in Trypanosomatid Protozoa. Cells 2019; 8:cells8050421. [PMID: 31071985 PMCID: PMC6562600 DOI: 10.3390/cells8050421] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/12/2022] Open
Abstract
The nucleolus is the conspicuous nuclear body where ribosomal RNA genes are transcribed by RNA polymerase I, pre-ribosomal RNA is processed, and ribosomal subunits are assembled. Other important functions have been attributed to the nucleolus over the years. Here we review the current knowledge about the structure and function of the nucleolus in the trypanosomatid parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania ssp., which represent one of the earliest branching lineages among the eukaryotes. These protozoan parasites present a single nucleolus that is preserved throughout the closed nuclear division, and that seems to lack fibrillar centers. Trypanosomatids possess a relatively low number of rRNA genes, which encode rRNA molecules that contain large expansion segments, including several that are trypanosomatid-specific. Notably, the large subunit rRNA (28S-type) is fragmented into two large and four small rRNA species. Hence, compared to other organisms, the rRNA primary transcript requires additional processing steps in trypanosomatids. Accordingly, this group of parasites contains the highest number ever reported of snoRNAs that participate in rRNA processing. The number of modified rRNA nucleotides in trypanosomatids is also higher than in other organisms. Regarding the structure and biogenesis of the ribosomes, recent cryo-electron microscopy analyses have revealed several trypanosomatid-specific features that are discussed here. Additional functions of the nucleolus in trypanosomatids are also reviewed.
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Affiliation(s)
- Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
| | - Luis E Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
| | - Tomás Nepomuceno-Mejía
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla CP 54090, Estado de México, Mexico.
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Cooper C, Thompson RCA, Botero A, Kristancic A, Peacock C, Kirilak Y, Clode PL. A comparative molecular and 3-dimensional structural investigation into cross-continental and novel avian Trypanosoma spp. in Australia. Parasit Vectors 2017; 10:234. [PMID: 28499405 PMCID: PMC5427604 DOI: 10.1186/s13071-017-2173-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 05/03/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Molecular and structural information on avian Trypanosoma spp. throughout Australia is limited despite their intrinsic value in understanding trypanosomatid evolution, diversity, and structural biology. In Western Australia tissue samples (n = 429) extracted from 93 birds in 25 bird species were screened using generic PCR primers to investigate the diversity of Trypanosoma spp. To investigate avian trypanosome structural biology the first 3-dimensional ultrastructural models of a Trypanosoma spp. (Trypanosoma sp. AAT) isolated from a bird (currawong, Strepera spp.) were generated using focussed ion beam milling combined with scanning electron microscopy (FIB-SEM). RESULTS Here, we confirm four intercontinental species of avian trypanosomes in native Australian birds, and identify a new avian Trypanosoma. Trypanosome infection was identified in 18 birds from 13 different bird species (19%). A single new genotype was isolated and found to be closely related to T. culicavium (Trypanosoma sp. CC2016 B002). Other Trypanosoma spp. identified include T. avium, T. culicavium, T. thomasbancrofti, Trypanosoma sp. TL.AQ.22, Trypanosoma sp. AAT, and an uncharacterised Trypanosoma sp. (group C-III sensu Zidková et al. (Infect Genet Evol 12:102-112, 2012)), all previously identified in Australia or other continents. Serially-sectioning Trypanosoma sp. AAT epimastigotes using FIB-SEM revealed the disc-shaped kinetoplast pocket attached perpendicular to the branching mitochondrion. Additionally, the universal minicircle sequence within the kinetoplast DNA and the associated binding protein were determined in Trypanosoma sp. AAT. CONCLUSIONS These results indicate that bird trypanosomes are relatively conserved across continents, while being locally diverse, which supports the hypothesis that bird trypanosomes exist as fewer species than described in the literature. Evidence exists that avian Trypanosoma spp. are infecting mammals and could be transmitted by haemadipsid leeches. Trypanosoma sp. AAT is most likely a separate species currently found only in Australia and the first 3-dimentional ultrastructural analysis of an avian trypanosome provides interesting information on their morphology and organelle arrangement.
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Affiliation(s)
- Crystal Cooper
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Crawley, WA 6009 Australia
| | - R. C. Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150 Australia
| | - Adriana Botero
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150 Australia
| | - Amanda Kristancic
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150 Australia
| | - Christopher Peacock
- Marshall Centre, School of Pathology and Laboratory and Medical Sciences, University of Western Australia, Crawley, WA 6009 Australia
- Telethon Kids Institute, 100 Roberts Rd, Subiaco, WA 6008 Australia
| | - Yaowanuj Kirilak
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Crawley, WA 6009 Australia
| | - Peta L. Clode
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Crawley, WA 6009 Australia
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Affiliation(s)
- Michael P. Rout
- The Rockefeller University, New York, New York, United States of America
| | - Samson O. Obado
- The Rockefeller University, New York, New York, United States of America
| | | | - Mark C. Field
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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Squarre D, Kabongo I, Munyeme M, Mumba C, Mwasinga W, Hachaambwa L, Sugimoto C, Namangala B. Human African Trypanosomiasis in the Kafue National Park, Zambia. PLoS Negl Trop Dis 2016; 10:e0004567. [PMID: 27196336 PMCID: PMC4873190 DOI: 10.1371/journal.pntd.0004567] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- David Squarre
- Zambia Wildlife Authority (ZAWA), Chilanga, Zambia
- * E-mail:
| | - Ilunga Kabongo
- Care for Business (CFB) Medical Center and Hospital, Lusaka, Zambia
| | - Musso Munyeme
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Chisoni Mumba
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Wizaso Mwasinga
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | | | - Chihiro Sugimoto
- Research Centre for Zoonosis Control, Hokkaido University, Kita-Ku, Sapporo, Japan
| | - Boniface Namangala
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
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Barros JHS, Fonseca TS, Macedo-Silva RM, Côrte-Real S, Toma HK, Madeira MDF. Aflagellar epimastigote forms are found in axenic culture of Trypanosoma caninum. Acta Trop 2014; 137:147-51. [PMID: 24879930 DOI: 10.1016/j.actatropica.2014.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/11/2014] [Accepted: 05/20/2014] [Indexed: 11/28/2022]
Abstract
Representatives of the genus Trypanosoma have been traditionally found in epimastigote, espheromastigote and trypomastigote flagellated forms in axenic cultures. Trypanosoma caninum is a trypanosomatid that has recently been reported infecting dogs in endemic areas of canine leishmaniasis in Brazil. It presents specific biological characteristics and it is found exclusively on healthy skin. Here, we describe the evolutive forms of this parasite showing not only the forms commonly found in culture, but also epimastigote forms with no free flagellum. The study was conducted using scanning and transmission electron microscopy and, we demonstrate that typical flagellated epimastigotes originate from forms without flagellum, although the latter may remain without differentiation in the culture. Two hypotheses are considered and discussed in this paper: (i) the aflagellated epimastigotes are a typical developmental forms of T. caninum and (ii) the emergence of these aflagellated forms could be resultant from a disturbed process during cell division caused by interfering specific proteins, which leads to inability to form and regulate the flagellum length. In any case, considering that T. caninum is a parasite that is still little studied, the information brought by our study adds data which may be useful to clarify aspects on the cell cycle of this intriguing parasite that has been found in different regions of Brazil.
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Affiliation(s)
- Juliana H S Barros
- Programa de Pós-Graduação em Pesquisa Clínica em Doenças Infecciosas, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, 21040-900 Rio de Janeiro, Brazil
| | - Tatiana S Fonseca
- Laboratório de Vigilância em Leishmanioses, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, 21040-900 Rio de Janeiro, Brazil
| | - Roger M Macedo-Silva
- Plataforma Multiusuários Rudolf Barth, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, 21040-360 Rio de Janeiro, Brazil
| | - Suzana Côrte-Real
- Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, 21040-360 Rio de Janeiro, Brazil
| | - Helena K Toma
- Laboratório de Diagnóstico Molecular e Hematologia, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, 21491-599 Rio de Janeiro, Brazil
| | - Maria de Fatima Madeira
- Laboratório de Vigilância em Leishmanioses, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, 21040-900 Rio de Janeiro, Brazil.
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Malysheva MN. [Early stages of development of Trypanosoma rotatorium (Mayer, 1843) from peripheral blood and internal organs of Anurans Bufo bufo (Linnaeus) and Rana sp. (Anura)]. Parazitologiia 2014; 48:373-381. [PMID: 25929108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The data on the fauna of trypanosomes of Anura of the Leningrad Province are given. The initial development stages of Trypanosoma rotatorium in peripheral blood and internal organs of the frog are described for the first time.
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Abstract
Leishmania and Trypanosoma belong to the Trypanosomatidae family and cause important human infections such as leishmaniasis, Chagas disease, and sleeping sickness. Leishmaniasis, caused by protozoa belonging to Leishmania, affects about 12 million people worldwide and can present different clinical manifestations, i.e., visceral leishmaniasis (VL), cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), diffuse cutaneous leishmaniasis (DCL), and post-kala-azar dermal leishmaniasis (PKDL). Chagas disease, also known as American trypanosomiasis, is caused by Trypanosoma cruzi and is mainly prevalent in Latin America but is increasingly occurring in the United States, Canada, and Europe. Sleeping sickness or human African trypanosomiasis (HAT), caused by two sub-species of Trypanosoma brucei (i.e., T. b. rhodesiense and T. b. gambiense), occurs only in sub-Saharan Africa countries. These pathogenic trypanosomatids alternate between invertebrate and vertebrate hosts throughout their lifecycles, and different developmental stages can live inside the host cells and circulate in the bloodstream or in the insect gut. Trypanosomatids have a classical eukaryotic ultrastructural organization with some of the same main organelles found in mammalian host cells, while also containing special structures and organelles that are absent in other eukaryotic organisms. For example, the mitochondrion is ramified and contains a region known as the kinetoplast, which houses the mitochondrial DNA. Also, the glycosomes are specialized peroxisomes containing glycolytic pathway enzymes. Moreover, a layer of subpellicular microtubules confers mechanic rigidity to the cell. Some of these structures have been investigated to determine their function and identify potential enzymes and metabolic pathways that may constitute targets for new chemotherapeutic drugs.
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Affiliation(s)
- Juliany Cola Fernandes Rodrigues
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil,
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Oliveira MPDC, Ramos TCP, Pinheiro AMVN, Bertini S, Takahashi HK, Straus AH, Haapalainen EF. Tridimensional ultrastructure and glycolipid pattern studies of Trypanosoma dionisii. Acta Trop 2013; 128:548-56. [PMID: 23933185 DOI: 10.1016/j.actatropica.2013.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/17/2013] [Accepted: 08/01/2013] [Indexed: 11/30/2022]
Abstract
Trypanosoma (Schizotrypanum) dionisii is a non-pathogenic bat trypanosome closely related to Trypanosoma cruzi, the etiological agent of Chaga's disease. Both kinetoplastids present similar morphological stages and are able to infect mammalian cells in culture. In the present study we examined 3D ultrastructure aspects of the two species by serial sectioning epimastigote and trypomastigote forms, and identified common carbohydrate epitopes expressed in T. dionisii, T. cruzi and Leishmania major. A major difference in 3D morphology was that T. dionisii epimastigote forms present larger multivesicular structures, restricted to the parasite posterior region. These structures could be related to T. cruzi reservosomes and are also rich in cruzipain, the major cysteine-proteinase of T. cruzi. We analyzed the reactivity of two monoclonal antibodies: MEST-1 directed to galactofuranose residues of glycolipids purified from Paracoccidioides brasiliensis, and BST-1 directed to glycolipids purified from T. cruzi epimastigotes. Both antibodies were reactive with T. dionisii epimastigotes by indirect immunofluorescense, but we noted differences in the location and intensity of the epitopes, when compared to T. cruzi. In summary, despite similar features in cellular structure and life cycle of T. dionisii and T. cruzi, we observed a unique morphological characteristic in T. dionisii that deserves to be explored.
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Affiliation(s)
- Miriam Pires de Castro Oliveira
- Departamento de Biologia Estrutural e Funcional, Universidade Federal de São Paulo, Rua Botucatu, 740, São Paulo, SP, 04023-900, Brazil.
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Hatama S, Shibahara T, Suzuki M, Kadota K, Uchida I, Kanno T. Isolation of a Megatrypanum trypanosome from sika deer (Cervus nippon yesoensis) in Japan. Vet Parasitol 2007; 149:56-64. [PMID: 17714873 DOI: 10.1016/j.vetpar.2007.07.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 07/05/2007] [Accepted: 07/12/2007] [Indexed: 11/19/2022]
Abstract
A trypanosome was isolated from a sika deer (Cervus nippon yesoensis) in Hokkaido, Japan, during the primary culture of sika deer renal cells. This is the first report of isolation of a Megatrypanum trypanosome from Japanese Cervidae. The trypanosome, designated TSD1, was propagated and maintained in Eagle's modified essential medium containing 20% fetal bovine serum with sika deer renal cells as feeder. The TSD1 trypanosome was morphometrically similar to Trypanosoma cervi, which is commonly isolated from American and European deer. PCR analysis with primers for 18S ribosomal DNA and nucleotide sequencing showed that TSD1 is a member of genus Trypanosoma, subgenus Megatrypanum. Phylogenetically TSD1 is closely related to T. theileri, a common trypanosome of cattle, but is distinguishable from T. theileri by some morphometrical and biological features.
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Affiliation(s)
- Shinichi Hatama
- Hokkaido Research Station, National Institute of Animal Health, 4 Hitsujigaoka, Toyohira, Sapporo, Hokkaido, Japan.
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Gu Z, Wang J, Li M, Zhang J, Ke X, Gong X. Morphological and genetic differences of Trypanosoma in some Chinese freshwater fishes: difficulties of species identification. Parasitol Res 2007; 101:723-30. [PMID: 17558522 DOI: 10.1007/s00436-007-0536-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 04/11/2007] [Indexed: 11/24/2022]
Abstract
Blood smears and purified trypanosome from freshwater fishes yellow catfish (Pseudobagras fulvidraco) and common carp (Cyprinus carpio) captured from Niushan Lake, Hubei Province were examined to determine whether all of their trypanosomes were Trypanosoma pseudobagri, a species of supposed host specificity and widespread existence across China. Trypanosomes occurred in 16/16 blood smears, and morphometric character analysis of trypanosomes from these smears showed that there were three morphospecies, Trypanosoma sp Carpio, T. sp Pseudobagri, and T. sp. 18S rDNA sequences of trypanosomes from 16 samples revealed three genetic groups among these fish trypanosomes. Group 1 was from C. carpio containing T. sp Carpio; groups 2 and 3 were from P. fulvidraco containing T. sp Pseudobagri and T. sp, respectively. The high similarity of morphometric characters and 18S rDNA sequences showed that T. sp Carpio and T. siniperca probably were the same species. T. sp Pseudobagri was the first occurrence in China. Sequence comparison showed that T. sp Pseudobagri sequence was most similar to that of clone Marv, whereas T. sp sequence differ from those of T. sp Carpio and T. sp Pseudobagri by 5.4 and 5.8%, respectively, and tentatively identified as T. pseudobagri. It was concluded that three species of trypanosomes, at least three genotypes occur in Niushan Lake fishes, and P. fulvidraco in this region appear to contain both types, although the identification of T. pseudobagri remains a problem.
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Affiliation(s)
- Zemao Gu
- Laboratory of Healthy Aquaculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
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Abstract
Fine-structural alterations in Trypanosoma rhodesiense trypomastigotes exposed to WR 163577, a prophylactic agent against animal African trypanosomiasis, were determined from cells grown in vitro. Exposure of trypomastigotes to a low concentration of drug resulted only in condensation of kinetoplast DNA fibrils. Exposure to higher drug concentrations caused clumping of nuclear chromatin and of cytoplasmic contents. Although alteration of kinetoplast DNA is the first detectable drug-induced change, the function of the kinetoplast in mammalian forms of African trypanosomes is unclear, and the secondary changes in the nucleus and cytoplasm may constitute the functionally significant alterations caused by WR 163577.
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13
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Sehgal RNM, Valkiunas G, Iezhova TA, Smith TB. Blood parasites of chickens in Uganda and Cameroon with molecular descriptions of Leucocytozoon schoutedeni and Trypanosoma gallinarum. J Parasitol 2007; 92:1336-43. [PMID: 17304817 DOI: 10.1645/ge-927r.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Using microscopy and PCR, we determined the prevalence of blood parasites in village chickens in Uganda and Cameroon. Of 148 individuals tested, 18.3% were infected with Leucocytozoon schoutedeni (Haemosporida, Leucocytozoidae) and 4.1% were infected with Trypanosoma gallinarum (Kinetoplastida, Trypanosomatidae). No other blood parasites were detected. Subsequent phylogenetic analysis of the cytochrome b gene of L. schoutedeni identified 2 distinct lineages that were found at all 3 sampling locations in Uganda. The sequence divergence between these 2 lineages is 1.5%. One of these lineages was also found in chickens in Cameroon, nearly 2,000 km distant. There are no morphological differences between blood stages of the parasites represented by the 2 different lineages, suggesting that cytochrome b gene sequence divergence can be as high as 1.5% within a single well-defined morphospecies of Leucocytozoon. We sequenced a portion of the small subunit ribosomal RNA gene (SSU rRNA) of T. gallinarum, and redescribe T. gallinarum for the first time since its discovery in 1911. These are the first assignments of DNA sequence data to these morphospecies of Leucocytozoon and Trypanosoma and may represent an example of intraspecific sequence divergence.
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MESH Headings
- Animals
- Base Sequence
- Cameroon/epidemiology
- Chickens/parasitology
- Cytochromes b/genetics
- DNA, Kinetoplast/chemistry
- DNA, Kinetoplast/isolation & purification
- DNA, Protozoan/chemistry
- DNA, Protozoan/isolation & purification
- Genetic Variation
- Haemosporida/classification
- Haemosporida/genetics
- Haemosporida/ultrastructure
- Molecular Sequence Data
- Parasitemia/parasitology
- Parasitemia/veterinary
- Phylogeny
- Poultry Diseases/epidemiology
- Poultry Diseases/parasitology
- Prevalence
- Protozoan Infections, Animal/epidemiology
- Protozoan Infections, Animal/parasitology
- RNA, Protozoan/genetics
- RNA, Ribosomal, 18S/genetics
- Trypanosoma/classification
- Trypanosoma/genetics
- Trypanosoma/ultrastructure
- Trypanosomiasis, African/epidemiology
- Trypanosomiasis, African/parasitology
- Trypanosomiasis, African/veterinary
- Uganda/epidemiology
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Affiliation(s)
- Ravinder N M Sehgal
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California 94132, USA.
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Uboldi AD, Lueder FB, Walsh P, Spurck T, McFadden GI, Curtis J, Likic VA, Perugini MA, Barson M, Lithgow T, Handman E. A mitochondrial protein affects cell morphology, mitochondrial segregation and virulence in Leishmania. Int J Parasitol 2006; 36:1499-514. [PMID: 17011565 DOI: 10.1016/j.ijpara.2006.08.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 08/21/2006] [Accepted: 08/22/2006] [Indexed: 11/24/2022]
Abstract
The single mitochondrion of kinetoplastids divides in synchrony with the nucleus and plays a crucial role in cell division. However, despite its importance and potential as a drug target, the mechanism of mitochondrial division and segregation and the molecules involved are only partly understood. In our quest to identify novel mitochondrial proteins in Leishmania, we constructed a hidden Markov model from the targeting motifs of known mitochondrial proteins as a tool to search the Leishmania major genome. We show here that one of the 17 proteins of unknown function that we identified, designated mitochondrial protein X (MIX), is an oligomeric protein probably located in the inner membrane and expressed throughout the Leishmania life cycle. The MIX gene appears to be essential. Moreover, even deletion of one allele from L. major led to abnormalities in cell morphology, mitochondrial segregation and, importantly, to loss of virulence. MIX is unique to kinetoplastids but its heterologous expression in Saccharomyces cerevisiae produced defects in mitochondrial morphology. Our data show that a number of mitochondrial proteins are unique to kinetoplastids and some, like MIX, play a central role in mitochondrial segregation and cell division, as well as virulence.
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15
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Sandberg K, Brega M. Segmentation of thin structures in electron micrographs using orientation fields. J Struct Biol 2006; 157:403-15. [PMID: 17116405 DOI: 10.1016/j.jsb.2006.09.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 09/21/2006] [Accepted: 09/25/2006] [Indexed: 11/23/2022]
Abstract
In this paper, we introduce a new approach for segmenting thin structures in electron micrographs. We introduce two new transforms, the Line Filter Transform (LFT) and the Orientation Filter Transform (OFT). The LFT can be viewed as an alternative to anisotropic diffusion algorithms that is particularly useful for thin structures. The OFT utilizes geometrical information about the structure by measuring correlations of local orientations in the image. By combining these methods with a contour extraction and labeling method we construct a segmentation method for thin structures in 2D images. We discuss how the method can be applied slice-by-slice to electron tomograms and illustrate the process by constructing two models of membrane structures from cellular tomograms. The suggested method has the advantage of being relatively insensitive to non-uniform contrast and high-contrast features such as ribosomes.
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Affiliation(s)
- Kristian Sandberg
- Boulder Laboratory for 3-D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado at Boulder, USA.
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16
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Karlsbakk E, Nylund A. Trypanosomes infecting cod Gadus morhua L. in the North Atlantic: a resurrection of Trypanosoma pleuronectidium Robertson, 1906 and delimitation of T. murmanense Nikitin, 1927 (emend.), with a review of other trypanosomes from North Atlantic and Mediterranean teleosts. Syst Parasitol 2006; 65:175-203. [PMID: 16955339 DOI: 10.1007/s11230-006-9049-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Accepted: 01/03/2006] [Indexed: 11/24/2022]
Abstract
Trypanosomes were isolated from Atlantic cod Gadus morhua L. collected from several fjords in western Norway. Morphological studies showed that the 12 infections studied represented a single species, identified as Trypanosoma pleuronectidium Robertson, 1906 which is resurrected and redescribed. This species is characterised by its body length (57.9 +/- 5.4 microm), nearly central nucleus (NI = 1.05 +/- 0.12) and relatively short post-kinetoplastic (PK) region (3.2 +/- 0.8 microm). T. pleuronectidium is transmitted by the leech Calliobdella nodulifera (Malm). T. murmanense Nikitin, 1927 (emend.) is delimited to a species transmitted by the leech Johanssonia arctica (Johansson). This species is separated from T. pleuronectidium by its attained body length, more anterior nucleus, presence of cytoplasmic refractive granules, adnuclear vacuoles and by a longer PK region. Partial SSU rDNA sequences of T. pleuronectidium and T. murmanense from Norway (1980 nt) diverged by 1.9%. The nominal North Atlantic and Mediterranean trypanosome species are reviewed, and T. flesi Lebailly, 1904, T. bothi Lebailly, 1905 and T. limandae Brumpt & Lebailly, 1904 are considered synonyms of T. platessae Lebailly, 1904. T. triglae senegalensis Ranque, 1973 is not considered conspecific with T. triglae Neumann, 1909, and consequently raised to species status as T. senegalense Ranque, 1973. Some other likely synonymies are discussed. In addition to T. pleuronectidium and T. murmanense, the following marine teleost trypanosomes are provisionally listed as valid species pending further study: T. callionymi Brumpt & Lebailly, 1904; T. cotti Brumpt & Lebailly, 1904; T. delagei Brumpt & Lebailly, 1904; T. dorhni Yakimov, 1911; T. gobii Brumpt & Lebailly, 1904; T. laternae Lebailly, 1904; T. myoxocephali Fantham, Porter & Richardson, 1942; T. platessae Lebailly, 1904; T. scorpaenae Neumann, 1909; T. soleae Laveran & Mesnil, 1901; T. triglae Neumann, 1909; and T. yakimovi Yakimov, 1911.
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Affiliation(s)
- Egil Karlsbakk
- Department of Biology, University of Bergen, Post box 7800, N-5020, Bergen, Norway.
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17
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Abstract
Motility in trypanosomes is achieved through the undulating behaviour of a single "9 + 2" flagellum; normally the flagellar waves begin at the flagellar tip and propagate towards the base. For flagella in general, however, propagation is from base-to-tip and it is believed that bend formation, and sustained regular oscillation, depend upon a localised resistance to inter-doublet sliding - which is normally conferred by structures at the flagellar base, typically the basal body. We therefore predicted that in trypanosomes there must be a resistive structure at the flagellar tip. Electron micrographs of Crithidia deanei, Herpetomonas megaseliae, Trypanosoma brucei and Leishmania major have confirmed that such attachments are present. Thus, it can be assumed that in trypanosomes microtubule sliding at the flagellar tip is resisted sufficiently to permit bend formation.
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Affiliation(s)
- David Woolley
- Department of Physiology, School of Medical Sciences, University of Bristol, Bristol, United Kingdom.
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18
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Meirelles RMS, Henriques-Pons A, Soares MJ, Steindel M. Penetration of the salivary glands of Rhodnius domesticus Neiva & Pinto, 1923 (Hemiptera: Reduviidae) by Trypanosoma rangeli Tejera, 1920 (Protozoa: Kinetoplastida). Parasitol Res 2005; 97:259-69. [PMID: 15997404 DOI: 10.1007/s00436-005-1433-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Accepted: 06/09/2005] [Indexed: 10/25/2022]
Abstract
Penetration of the heteroxenous protozoan Trypanosoma rangeli into the salivary glands of its invertebrate host Rhodnius domesticus has been investigated here using different approaches. Electron microscopy showed that epimastigotes coming from the insect hemocoel cross the basal lamina that surrounds the salivary glands and penetrate through the gland cells cytoplasm. After reaching the gland lumen, epimastigote forms remain adhered to the gland cell microvilli by their flagella, while metacyclic trypomastigotes are found swimming free in the saliva. Analysis by flow cytometry, western blotting and hemolytic activity allowed to demonstrate the presence in T. rangeli of a hemolytic molecule with antigenic cross-reactivity with murine perforin, which could be used by the parasites to reach the salivary gland lumen. This molecule, which we named as rangelysin, has 120 kDa molecular weight, is able to induce hemolysis only in acidic pH, and is produced by both trypomastigote and epimastigote forms.
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Affiliation(s)
- Rosane M S Meirelles
- Laboratório de Biologia Celular de Microrganismos, Departamento de Ultra-estrutura e Biologia Celular, Instituto Oswaldo Cruz/FIOCRUZ, Avenida Brasil 4365, Manguinhos, 21040-900 Rio de Janeiro, RJ, Brazil
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19
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Laakkonen J, Smith A, Hildebrandt K, Niemimaa J, Henttonen H. Significant morphological but little molecular differences between Trypanosoma of rodents from Alaska. J Parasitol 2005; 91:201-3. [PMID: 15856904 DOI: 10.1645/ge-3385rn] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
We examined blood smears of 173 rodents and 33 shrews captured at 4 sites in the Gates of the Arctic National Park, northern Alaska, in summer 2002. Trypanosoma spp. were detected in the plasma of 5 Microtus oeconomus, 4 Microtus miurus, and 1 Lemmus trimucronatus. The trypomastigote morphology from different individuals of M. oeconomus caught at the same site and of M. miurus from different sites varied significantly. The 4 DNA sequences obtained from the blood smear positive samples contained 2 different haplotypes very similar to each other and to that of Trypanosoma microti. Of possible vectors of blood parasites, the flea Amalaraeus dissimilis was collected from M. miurus.
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Affiliation(s)
- Juha Laakkonen
- Finnish Forest Research Institute, PO Box 18, FIN-01301, Vantaa, Finland.
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20
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Abstract
During 2001 and 2002, blood smears from 37 of 120 fishes belonging to 10 species captured in the Okavango Delta region of Botswana, were found to harbour trypanosomes. These trypanosomes displayed differing staining properties, were morphometrically variable, and ranged in total length from 29.5 to 80.8 microm. Mixed populations of the smaller and larger trypanosomes were found in most fish examined. Despite variations in size and appearance, these specimens are tentatively identified as Trypanosoma mukasai Hoare, 1932, likely adding another 9 new hosts to those known for this parasite. It is possible that Trypanosoma clariense Pienaar, 1962, described from Clarias gariepinus in South Africa, is also a junior synonym of T. mukasai.
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Affiliation(s)
- Nico J Smit
- School of Life Sciences, Faculty of Science, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, UK
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21
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Moyersoen J, Choe J, Fan E, Hol WGJ, Michels PAM. Biogenesis of peroxisomes and glycosomes: trypanosomatid glycosome assembly is a promising new drug target. FEMS Microbiol Rev 2005; 28:603-43. [PMID: 15539076 DOI: 10.1016/j.femsre.2004.06.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Revised: 06/14/2004] [Accepted: 06/15/2004] [Indexed: 10/26/2022] Open
Abstract
In trypanosomatids (Trypanosoma and Leishmania), protozoa responsible for serious diseases of mankind in tropical and subtropical countries, core carbohydrate metabolism including glycolysis is compartmentalized in peculiar peroxisomes called glycosomes. Proper biogenesis of these organelles and the correct sequestering of glycolytic enzymes are essential to these parasites. Biogenesis of glycosomes in trypanosomatids and that of peroxisomes in other eukaryotes, including the human host, occur via homologous processes involving proteins called peroxins, which exert their function through multiple, transient interactions with each other. Decreased expression of peroxins leads to death of trypanosomes. Peroxins show only a low level of sequence conservation. Therefore, it seems feasible to design compounds that will prevent interactions of proteins involved in biogenesis of trypanosomatid glycosomes without interfering with peroxisome formation in the human host cells. Such compounds would be suitable as lead drugs against trypanosomatid-borne diseases.
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Affiliation(s)
- Juliette Moyersoen
- Research Unit for Tropical Diseases, Christian de Duve Institute of Cellular Pathology and Laboratory of Biochemistry, Université Catholique de Louvain, ICP-TROP 74.39, Avenue Hippocrate 74, B-1200 Brussels, Belgium
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22
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Abstract
Eukaryotic cilia and flagella are cytoskeletal organelles that are remarkably conserved from protists to mammals. Their basic unit is the axoneme, a well-defined cylindrical structure composed of microtubules and up to 250 associated proteins. These complex organelles are assembled by a dynamic process called intraflagellar transport. Flagella and cilia perform diverse motility and sensitivity functions in many different organisms. Trypanosomes are flagellated protozoa, responsible for various tropical diseases such as sleeping sickness and Chagas disease. In this review, we first describe general knowledge on the flagellum: its occurrence in the living world, its molecular composition, and its mode of assembly, with special emphasis on the exciting developments that followed the discovery of intraflagellar transport. We then present recent progress regarding the characteristics of the trypanosome flagellum, highlighting the original contributions brought by this organism. The most striking phenomenon is the involvement of the flagellum in several aspects of the trypanosome cell cycle, including cell morphogenesis, basal body migration, and cytokinesis.
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Affiliation(s)
- Linda Kohl
- INSERM U565, CNRS UMR5153, and MNHN USM 0503, Muséum National d'Histoire Naturelle, 75231 Paris, France
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23
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Tejero F, Finol HJ. Trypanosoma rangeli: ultrastructure and activity of the mitochondrion. J Submicrosc Cytol Pathol 2004; 36:313-7. [PMID: 15906607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Axenic cultures of pure Trypanosoma rangeli were used to investigate the relation between ultrastructure and activity in the mitochondrion. Every other day, ultrathin sections were obtained from cultivated flagellates and, subsequently, observed in order to register changes in the cytoarchitecture of the organelle. Culture samples were incubated in tetrazolium salts to determine the mitochondrion's metabolic state. The results show a high correspondence between mitochondrion ultrastructural shape and function of the same organelle in populations of T. rangeli maintained under in vitro conditions.
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Affiliation(s)
- F Tejero
- Section of Parasitology, Institute of Tropical Zoology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela.
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24
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Abstract
The hemocytes of Rhodnius prolixus were analyzed during the course of infection with the protozoan Trypanosoma rangeli. The following cell types were identified: prohemocyte, plasmatocyte, adipocyte, granular cell and oenocytoid. The number of these cells changes during the infection course thus indicating a cell response to infection of R. prolixus by T. rangeli. Transmission electron microscopy showed that plasmatocytes were able to ingest epimastigote forms of the parasite, which were then found within a parasitophorous vacuole. Amorphous material was seen within the vacuole suggesting that fusion of host cell lysosomes with the vacuole took place. Intravacuolar parasites in process of digestion were observed. In addition, reaction product indicative of the presence of acid phosphatase was observed in parasite-containing vacuoles. No dividing parasites were seen within the vacuole in contrast to what was observed outside the host cells.
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Affiliation(s)
- M A de Oliveira
- Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Av Alberto Lamego, 2000, Campos dos Goytacazes, RJ 28013-600, Brazil
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25
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Rodrigues AC, Campaner M, Takata CSA, Dell' Porto A, Milder RV, Takeda GF, Teixeira MMG. Brazilian isolates of Trypanosoma (Megatrypanum) theileri: diagnosis and differentiation of isolates from cattle and water buffalo based on biological characteristics and randomly amplified DNA sequences. Vet Parasitol 2004; 116:185-207. [PMID: 14559162 DOI: 10.1016/s0304-4017(03)00236-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We detected and cultivated isolates of Trypanosoma (Megatrypanum) theileri from cattle and water buffaloes in São Paulo state, southeastern Brazil, which were characterized by comparing morphological, growth and molecular features. Although isolates from cattle and water buffalo were morphologically indistinguishable, they differed in their growth characteristics. A dendrogram based on randomly amplified polymorphic DNA (RAPD) patterns indicated close-genetic relationships among all isolates from both species, which were all tightly clustered together and distant from Megatrypanum species from wild mammals. In addition, isolates within the T. theileri-cluster were clearly segregated into two host-associated groups. The sequence of a synapomorphic RAPD-derived DNA fragment (Tth625), which was shared by all T. theileri trypanosomes from cattle and buffalo but not detected in any of 13 other trypanosome species, was used as target for a conventional T. theileri-specific PCR assay. We also defined RAPD fragments (Tthc606 and Tthb606) that distinguished cattle from buffalo isolates. Thus, distinct growth features and genetic variability distinguished between isolates from cattle and water buffaloes of the same geographic origin, suggesting an association of these isolates with their host species. The trypanosomes from water buffalo reported here are the first T. theileri-like isolates from the Asiatic buffalo (Bubalus bubalis) to be continuously cultured and compared with cattle isolates using biological and molecular methods.
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Affiliation(s)
- A C Rodrigues
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av Prof Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil
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26
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Affiliation(s)
- T Sherwin
- Department of Biochemistry and Molecular Biology, University of Manchester, UK
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27
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Magaraci F, Jimenez CJ, Rodrigues C, Rodrigues JCF, Braga MV, Yardley V, de Luca-Fradley K, Croft SL, de Souza W, Ruiz-Perez LM, Urbina J, Gonzalez Pacanowska D, Gilbert IH. Azasterols as Inhibitors of Sterol 24-Methyltransferase in Leishmania Species and Trypanosoma cruzi. J Med Chem 2003; 46:4714-27. [PMID: 14561091 DOI: 10.1021/jm021114j] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper describes the synthesis of some novel azasterols based on (20R,22xi)-5alpha-pregnan-20-(piperidin-2-yl)-3beta,20-diol. These compounds are potential inhibitors of the enzyme sterol 24-methyltransferase (24-SMT), which is a vital enzyme in the biosynthesis of ergosterol and related 24-alkyl sterols. Structure-activity studies were undertaken to understand the important features for activity against the enzyme, with the aim of increasing activity and selectivity. The compounds were evaluated for inhibition of recombinant Leishmania major 24-SMT and the effect of compounds on sterol composition and parasite proliferation. Essentially, compounds which showed good activity against the recombinant enzyme had a significant effect on the sterol composition and growth of parasites. The activity of compounds was found to be related to the basicity and stereochemical location of the nitrogen. Also, presence of an unprotected 3beta-OH seemed to be important for activity. However, some azasterols which were not good inhibitors of 24-SMT also showed antiproliferative activity, suggesting that there may be other modes of actions of these compounds.
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Affiliation(s)
- Filippo Magaraci
- Welsh School of Pharmacy, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3XF, UK
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28
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Shuaibu MN, Kanbara H, Yanagi T, Ichinose A, Ameh DA, Bonire JJ, Nok AJ. In vitro trypanocidal activity of dibutyltin dichloride and its fatty acid derivatives. Parasitol Res 2003; 91:5-11. [PMID: 12851812 DOI: 10.1007/s00436-003-0861-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2003] [Accepted: 02/28/2003] [Indexed: 10/26/2022]
Abstract
Searching for new compounds against pathogenic trypanosomes has been substantially accelerated by the development of in vitro screening assays. In an attempt to explore the chemotherapeutic potential of organotin compounds and to broaden the search for newer trypanocides, fatty acid derivatives of dibutyltin dichloride were synthesized and their in vitro trypanocidal profiles studied on Trypanosoma brucei brucei, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. A 24-h time course experiment was conducted with various concentrations of the compounds using a 24-well microtiter plate technique. The compounds tested were trypanocidal in a dose-dependent fashion: inhibiting survival and growth, resulting in irreversible morphological deformation and the eventual death of the parasites. The minimum inhibitory concentrations of the tested diorganotins are at low micromolar ranges: from 0.15-0.75 microM for T. b. brucei, T. b. gambiense and T. b. rhodesiense. These observations suggest that organotin has chemotherapeutic potential.
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Affiliation(s)
- M N Shuaibu
- Protozoology Department, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki-shi 852-8523, Japan
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29
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Affiliation(s)
- Sue Vaughan
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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30
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Mendoza M, Mijares A, Rojas H, Rodríguez JP, Urbina JA, DiPolo R. Physiological and morphological evidences for the presence acidocalcisomes in Trypanosoma evansi: single cell fluorescence and 31P NMR studies. Mol Biochem Parasitol 2002; 125:23-33. [PMID: 12467971 DOI: 10.1016/s0166-6851(02)00166-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new Ca(2+) intracellular store, the acidocalcisome, has been reported in trypanosomatids. It has been characterized physiologically as a Ca(2+) store sensitive to nigericin. The Ca(2+)/H(+)-ATPase is the system responsible for Ca(2+) accumulation, which depends on a pH gradient formed by ATP- and PPi-dependent proton pumps. In this work we present physiological and morphological evidences for the presence of acidocalcisomes in Trypanosoma evansi. The parasites were purified and loaded with the fluorescent dye Fura 2-AM in order to detect the intracellular changes of Ca(2+) levels in individual cells. The simultaneous incubation of T. evansi cells with ionomycin and nigericin led to large release of Ca(2+) (ca. 200 nM) from intracellular stores, which was not observed with either agent alone. On the other hand, no enhancement of the nigericin-induced Ca(2+) release was observed in the presence of oligomycin. Additionally, the pretreatment with bafilomycin decreases the nigericin-induced Ca(2+) release. These results confirm the presence of an intracellular non-mitochondrial acidic Ca(2+) storage compartment. These results suggest that H(+)-ATPase is involved in the process of Ca(2+) accumulation into the acidocalcisomes. Furthermore, the cells loaded with acridine orange exhibited abundant fluorescent vacuoles, which were sensitive to nigericin or bafilomycin A(1). Electronic transmission microscopy observations demonstrated the presence of electron dense particles in the parasites. High levels of inorganic pyrophosphate and triphosphate were detected in perchloric acid extracts of T. evansi by high resolution 31P NMR. Taken together, these results present the first evidence for the presence of acidocalcisomes in T. evansi.
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Affiliation(s)
- M Mendoza
- Laboratorio de Permeabilidad Iónica, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Apartado Postal 21827, Caracas 1020 A, Venezuela
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31
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Ashraf M, Nesbitt RA, Humphrey PA, Siewe M, Lee CM. Comparative positions of kinetoplasts in Trypanosoma musculi and Trypanosoma lewisi during development in vitro. Cell Prolif 2002; 35:269-73. [PMID: 12269904 PMCID: PMC6496277 DOI: 10.1046/j.1365-2184.2002.00242.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The development of Trypanosoma musculi and Trypanosoma lewisi were studied in vitro in the presence of adherent splenic cells. Both parasites developed only when attached by their flagellar tips to adherent splenic cells. During the proliferation of T. musculi, the kinetoplast migrated towards the nucleus, and once in the vicinity of the nucleus, the nuclear division was triggered. The kinetoplast of T. lewisi did not migrate towards the nucleus, but remained at its original location. The nucleus and kinetoplast divided at the same time in both parasites, and parasites started dividing from their flagellar ends and T. musculi and T. lewisi daughter cells were formed within 48 h. The unavailability of the adherent splenic cells in vitro led the parasites to transform into round/oval nonviable forms.
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Affiliation(s)
- M Ashraf
- Department of Biology, Howard University, Washington, DC 20059, USA.
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32
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Abstract
Avian trypanosomes are widespread parasites of birds, the transmission of which remains mostly unclear, with various blood-sucking insects mentioned as possible vectors. A search for vectors of trypanosomes of sparrowhawk (Accipiter nisus), buzzard (Buteo buteo), lesser-spotted eagle (Aquila pomarina) and kestrel (Falco tinnunculus) was performed in Czech and Slovak Republics. Black flies (Eusimulium spp.), hippoboscid flies (Ornithomyia avicularia), mosquitoes (Culex pipiens pipiens) and biting midges (Culicoides spp.), trapped while attempting to feed on raptor nestlings, were found to contain trypanosomatids in their intestine. Trypanosomes from the raptors and blood-sucking insects were isolated, and their 18S rRNA sequences were used for species identification and for the inference of intra- and interspecific relationships. Together with the trypanosome isolated from a black fly, the bird trypanosomes formed a well-supported Trypanosoma avium clade. The isolates derived from hippoboscid flies and mosquitoes are most likely also avian trypanosomes infecting birds other than the studied raptors. Analysis of the kinetoplast, that has features characteristic for the avian trypanosomes (minicircle size; dimensions of the kinetoplast disc), provided further evidence for the identification of vectors. It is suggested that all trypanosomes isolated from raptors included in this study belong to the T. avium complex and are transmitted by the ornithophilic simuliids such as Eusimulium securiforme.
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Affiliation(s)
- J Votýpka
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic.
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33
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Affiliation(s)
- Julius Lukes
- Institute of Parasitology, Czech Academy of Sciences, Ceské Budejovice.
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34
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Abstract
Peroxisomes of higher eukaryotes, glycosomes of kinetoplastids, and glyoxysomes of plants are related microbody organelles that perform differing metabolic functions tailored to their cellular environments. The close evolutionary relationship of these organelles is most clearly evidenced by the conservation of proteins involved in matrix protein import and biogenesis. The glycosome can be viewed as an offshoot of the peroxisomal lineage with additional metabolic functions, specifically glycolysis and purine salvage. Within the parasitic protozoa, only kinetoplastids have been conclusively demonstrated to possess glycosomes or indeed any peroxisome-like organelle. The importance of glycosomal pathways and their compartmentation emphasizes the potential of the glycosome and glycosomal proteins as drug targets.
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Affiliation(s)
- M Parsons
- Seattle Biomedical Research Institute, 4 Nickerson St., 98177, Seattle, WA, USA.
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35
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Abstract
The flagellum and flagellar pocket are distinctive organelles present among all of the trypanosomatid protozoa. Currently, recognized functions for these organelles include generation of motility for the flagellum and dedicated secretory and endocytic activities for the flagellar pocket. The flagellar and flagellar pocket membranes have long been recognized as morphologically separate domains that are component parts of the plasma membrane that surrounds the entire cell. The structural and functional specialization of these two membranes has now been underscored by the identification of multiple proteins that are targeted selectively to each of these domains, and non-membrane proteins have also been identified that are targeted to the internal lumina of these organelles. Investigations on the functions of these organelle-specific proteins should continue to shed light on the unique biological activities of the flagellum and flagellar pocket. In addition, work has begun on identifying signals or modifications of these proteins that direct their targeting to the correct subcellular location. Future endeavors should further refine our knowledge of targeting signals and begin to dissect the molecular machinery involved in transporting and retaining each polypeptide at its designated cellular address.
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Affiliation(s)
- S M Landfear
- Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, 97201, Portland, OR, USA.
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36
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Abstract
Although only one genus name has been proposed as yet for all plant trypanosomes, 'Phytomonas', it is clear that they can differ from one another in terms of both their biological properties and their effects. Recent serological and molecular studies have confirmed the substantial heterogeneity of these trypanosomatids, which the use of a single genus name does not even hint at. We set out to show in this paper that there is at least one homogeneous group of plant trypanosomes that can be defined explicitly by a single genus and species name and that differs substantially from all the other clusters that may be identified by one technique or another: the phloem-restricted trypanosomatids found in Latin America.
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Affiliation(s)
- M Dollet
- CIRAD, Campus International de Baillarguet, TA30/G, 34398 Cedex 5, Montpellier, France.
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37
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Affiliation(s)
- R A Bloodgood
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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38
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Finol HJ, Boada-Sucre A, Rossi M, Tejero F. Skeletal muscle ultrastructural pathology in mice infected with Trypanosoma evansi. J Submicrosc Cytol Pathol 2001; 33:65-71. [PMID: 11686410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
An ultrastructural study of skeletal muscle alterations wascarried out in mice experimentally infected with Trypanosoma evansi. Manifested anomalies were found, in both muscle fibre and microvasculature. Muscle fibre changes included atrophy, autophagic vacuoles formation, mitochondrial degeneration, nuclei pyknosis and segmental necrosis. In another direction, the cytoplasm of capillary endothelial cells showed rough endoplasmic reticulum and mitochondrial swelling, as well as luminal infoldings; parasites were found in the endothelial cell cytoplasm. A mononuclear infiltrate, formed by macrophages and neutrophils, was also observed. This work shows that skeletal muscle is an important target tissue for Trypanosoma evansi.
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Affiliation(s)
- H J Finol
- Center for Electron Microscopy, Faculty of Sciences, Central University of Venezuela, Caracas.
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39
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Abstract
The process of interaction of the Choachi strain of Trypanosoma rangeli with intestinal epithelial cells of Rhodnius prolixus was analyzed in experiments carried out in vitro and in vivo. For the in vitro experiments small fragments of the anterior region of the posterior midgut were incubated in the presence of the parasites, fixed, and processed for observation with the scanning electron microscope. Parasites attached to the surface of some epithelial cells, especially to the extracellular membrane layers (perimicrovillar membranes), were observed. For the in vivo experiments insects were infected with cultures of T. rangeli, sacrificed at different time intervals, and then processed for scanning and transmission electron microscopy. An intimate contact between the parasites and the membrane layers was observed. The parasites penetrated into cells that showed an electronlucent cytoplasm and a damaged surface, moved within the cytoplasm of the epithelial cell, reached the basal region, crossed the basal lamina, and entered the hemocoel.
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Affiliation(s)
- M A de Oliveira
- Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Av. Alberto Lamego, 2000, Campos dos Goytacazes, RJ, 28015-6210, Brazil
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40
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Ventura RM, Takata CS, Silva RA, Nunes VL, Takeda GF, Teixeira MM. Molecular and morphological studies of Brazilian Trypanosoma evansi stocks: the total absence of kDNA in trypanosomes from both laboratory stocks and naturally infected domestic and wild mammals. J Parasitol 2000; 86:1289-98. [PMID: 11191906 DOI: 10.1645/0022-3395(2000)086[1289:mamsob]2.0.co;2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The kinetoplast DNA (kDNA) minicircle molecules of 14 Brazilian stocks of Trypanosoma evansi were studied by morphological approaches (Giemsa and 4'-6'-diamidino-2-phenylindole staining and transmission electron microscopy) and molecular approaches (probing with an oligonucleotide complementary to the minicircle origin of replication and polymerase chain reaction amplification of a minicircle sequence). All methods indicated the absence of both a typical kinetoplast and kDNA minicircles, even in a very small number of parasites of a single stock or in small numbers of copies of molecules per cell. We did not detect any altered kDNA molecules. There were no kDNA molecules in either old or new stocks of T. evansi maintained by successive passages in mice. Similarly, no kDNA minicircles were detected in trypanosomes in blood smears from naturally infected domestic and wild animals. Thus, the total absence of kDNA in Brazilian stocks of T. evansi from both domestic and wild mammals is probably the natural state of Brazilian T. evansi.
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Affiliation(s)
- R M Ventura
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, Brazil
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41
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Abstract
Amongst the earliest eukaryotes, trypanosomes have developed conventional organelles but sometimes with extreme features rarely seen in other organisms. This is the case of the flagellum, containing conventional and unique structures whose role in infectivity is still enigmatic.
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Affiliation(s)
- P Bastin
- Department of Biochemistry, School of Biological Sciences, University of Manchester, 2.205 Stopford Building, Oxford Road, M13 9PT, Manchester, UK.
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42
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Affiliation(s)
- J Lukes
- Institute of Parasitology, Czech Academy of Sciences, Branisovská 31, 37005 Ceské Budejovice, Czech Republic.
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43
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Abstract
Trypanosoma granulosum, a flagellate protozoon commonly found in the blood of the European eel Anguilla anguilla, was injected experimentally into uninfected eels purchased from a local farm. In order to investigate the infectivity of different stages in the life cycle, trypanosomes from various sources were used for inoculation. Infectivity was greatly reduced in in vitro culture stages inoculated at 20 C. Isolated bloodstream stages injected into groups of animals held at 12 and 20 C could be detected for over 70 days but did not appear to multiply. Naturally infected Hemiclepsis marginata, a piscivorous leech known to serve as vector, produced detectable, single-peak infections in eels held at 20 C. Infections were characterized by a prepatent stage and a phase of rising parasitemia. Peak infection intensities ranged between 1 and 7 x 10(4) trypanosomes/ml. Trypanosomes in the bloodstream of eels experimentally infected with leeches, divided at a very low rate during the early stages of infection. Small morphs present during the early phase of rising parasitemia were gradually replaced by larger trypanosomes. The overall length frequency distribution of trypanosomes was unimodal.
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Affiliation(s)
- A Zintl
- Department of Zoology, Trinity College, Dublin, Republic of Ireland
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44
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Abstract
Species of the trypanosomatid parasite genera Trypanosoma and Leishmania exhibit a particular range of cell shapes that are defined by their internal cytoskeletons. The cytoskeleton is characterized by a subpellicular corset of microtubules that are cross-linked to each other and to the plasma membrane. Trypanosomatid cells possess an extremely precise organization of microtubules and filaments, with some of their organelles, such as the mitochondria, kinetoplasts, basal bodies, and flagella, present as single copies in each cell. The duplication of these structures and changes in their position during life cycle differentiations provide markers and insight into events involved in determining cell form and division. We have a rapidly increasing catalog of these structures, their molecular cytology, and their ontogeny. The current sophistication of available molecular genetic techniques for use in these organisms has allowed a new functional analysis of the cytoskeleton, including functions that are intrinsic to the proliferation and pathogenicity of these parasites.
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Affiliation(s)
- K Gull
- School of Biological Sciences, University of Manchester, United Kingdom.
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45
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Rossi M, Boada-Sucre A, Finol HJ, Tejero F, Bello B, Aso PM, Hernandez G. Ultrastructural alterations in the adrenal gland cortex of mice experimentally infected with a Venezuelan isolate of Trypanosoma evansi. J Submicrosc Cytol Pathol 1999; 31:509-13. [PMID: 10685391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The ultrastructural study of adrenal gland from mice experimentally infected with Trypanosoma evansi, in addition to intravascular and intracellular trypanosomes, showed different degrees of cortical cell alterations and capillary wall modifications. Beside its biological scope, these results suggest a role for the adrenal cortex to partake in Surra's etiopathogenesis and describe for the very first time a T. evansi intracellular stage.
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Affiliation(s)
- M Rossi
- Postgraduate Program on Zoology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela
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46
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47
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Tanoura K, Yanagi T, De Garcia VM, Kanbara H. Trypanosoma rangeli--in vitro metacyclogenesis and fate of metacyclic trypomastigotes after infection to mice and fibroblast cultures. J Eukaryot Microbiol 1999; 46:43-8. [PMID: 10188259 DOI: 10.1111/j.1550-7408.1999.tb04582.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
High metacyclogenesis was induced when freshly-isolated Trypanosoma rangeli from humans were grown in a modified liver-infusion-tryptose medium and transferred into the medium overlaid on mouse fibroblasts at 27 degrees C in a 5% CO2 atmosphere. Such in vitro-generated metacyclic trypomastigotes could induce a significantly high and constant parasitemia in both ICR and SCID mice for a period of about a week but thereafter the parasitemia gradually decreased. Histological examination could not detect any tissue-forms of T. rangeli in various organs of SCID mice. On the other hand, two long-maintained stocks of T. rangeli produced lower metacyclogenesis and only latent parasitemia in both strains of mice. When these populations were incubated in fibroblast cultures at 37 degrees C in a 5% CO2 atmosphere, only trypomastigotes survived for two to three weeks without proliferation, while other forms, mainly epimastigotes, soon began to swell and degenerate. Electron microscopy showed that most surviving trypomastigotes had the basket-like conformation of the kinetoplasts. This is characteristic of the non-dividing trypomastigote stage of T. cruzi, and suggests that T. rangeli trypomastigotes may survive long periods in the blood without proliferation.
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Affiliation(s)
- K Tanoura
- Department of Protozoology, Nagasaki University, Japan
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48
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Monroy FP, Dusanic DG, Minning TA. Trypanosoma musculi survival in the kidneys of chronically infected mice: kidney form ultrastructure, surface characteristics, and serological interactions. J Parasitol 1998; 84:914-9. [PMID: 9794630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
After elimination of Trypanosoma musculi from the general circulation by the immune responses of infected mice, the animals are resistant to reinfection. Yet, parasites survive in the vasa recta of the kidneys for the life of these mice. These kidney forms (KF) actively reproduce in an environment that provides the necessary nutrients and appears to prevent their elimination from these capillaries by the hosts' immune responses. Comparative studies conducted with KF and the bloodstream forms (BSF) indicate that, although both forms appear to be similar morphologically at the ultrastructural level, they differ in their surface reactivities with lectins and tolerance to various pH and solute concentrations. Although antibodies are not detected on the surfaces of KF, urea levels approximating those in the vasa recta dissociate antibody from the surfaces of BSF. The data suggest that parasites found in the vasa recta of these chronically infected mice differ from the BSF and are protected from the humoral and cell-mediated immune responses of the murine hosts by the concentrated solutes present in these capillaries. The KF may be killed by these same immune effector mechanisms upon leaving the capillaries of the kidneys and, therefore, not be found in the general circulation of these chronically infected immune hosts.
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Affiliation(s)
- F P Monroy
- Department of Life Sciences, Indiana State University, Terre Haute 47809, USA
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49
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Abstract
Trypanosoma evansi and T. equiperdum were compared regarding their ultrastructure, their mammalian hosts, way of transmission, pathogenicity, diagnosis and treatment, and biochemical and molecular characteristics. Electron microscopic investigation revealed no ultrastructural differences between the two species except that there were more coated vesicles in the flagellar pocket of T. equiperdum. Biological, biochemical and molecular studies were reviewed and exhibited many similarities between T. evansi and T. equiperdum. The most prominent differences between the two species are the presence of maxicircles in T. equiperdum, which are missing in T. evansi, and the route of transmission. While T. evansi is transmitted by biting flies, T. equiperdum is transmitted from one equine host to another during copulation when mucous membranes come into contact. Otherwise the two species are remarkably similar. The phylogenetic relationship between the two species and T. b. brucei is being discussed, and the hypothesis is proposed that T. evansi arose from a clone of T. equiperdum which lost its maxicircles.
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Affiliation(s)
- R Brun
- Swiss Tropical Institute, Basel.
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50
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Bettiol SS, Jakes K, Le DD, Goldsmid JM, Hocking G. First record of trypanosomes in Tasmanian bandicoots. J Parasitol 1998; 84:538-41. [PMID: 9645853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Trypanosomes were observed in 38% of blood smears from southern brown bandicoots (Isoodon obesulus) and in 10% of blood smears from eastern barred bandicoots (Perameles gunnii). This is the first record of such hemoparasites in Tasmanian marsupials. There appeared to be a statistically significant size difference between trypanosomes found in the 2 bandicoot species, suggesting the possibility of 2 distinct species of parasite. There appears to be a distinction between the trypanosomes found in our temperate Isoodon species and the tropical bandicoot. Isoodon macrurus. The use of the microhematocrit method provided an effective means for concentrating trypanosomes, whereas image analysis was a more effective method than the ocular micrometer for obtaining accurate measurements.
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Affiliation(s)
- S S Bettiol
- Division of Pathology, University of Tasmania, Hobart, Australia
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