Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.700
Filtrar
1.
Ann Parasitol ; 66(2): 165-174, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32592455

RESUMO

Neither physiological nor pathological changes following treatments explained why trypanosomes in the same group of experimentally treated animals correlated in virulence. Also, they behaved like each other but not similar to other groups despite the same T. evansi injected strain. The current study aims to discuss whether molecular changes might occur to Trypanosoma evansi isolates followed treatments are responsible for that difference or not. Ten preserved isolates from T. evansi after previous treatments besides the original strain of T. evansi that injected before treatments were used in the present study. These isolates were intraperitoneally inoculated in 11 groups of male Wister Albino rats with equal doses. Parasitological findings and the molecular changes accompanied were discussed along with the experiment based on PCR-TR3/TR4 specific-primers. The study also achieved alignments, gene sequence and phylogenetic analysis for submitted and reference strains belong to T. evansi, T. brucei, T. b. brucei, and T. b. gambiense deposited in GenBank. The present results assessed molecularly the effectiveness and highly antitrypanosomal activity of human plasmas O+ and A+ on T. evansi than others, and how their strains drifted from its original sequence to the nearest form of T. brucei. At the same time, T. evansi in other plant extract groups multiplied progressively like cancer cells and became more virulent and close to reference strains of T. evansi. Our data further indicated that T. evansi after treatment was a paraphyletic group. It also corroborated the antitrypanosomal activityspecificity and the molecular changes occurring were correlated to the type of treatment.


Assuntos
Antiprotozoários , Trypanosoma , Tripanossomíase , Animais , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Humanos , Masculino , Filogenia , Ratos , Ratos Wistar , Trypanosoma/efeitos dos fármacos , Trypanosoma/genética , Trypanosoma/patogenicidade , Tripanossomíase/sangue , Tripanossomíase/tratamento farmacológico
2.
Parasitol Res ; 119(6): 1891-1901, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32382990

RESUMO

Amphibian populations are declining around the world, and the main reasons are the environmental changes and pathogens. However, there are few studies addressing the interaction and impact of the different pathogens that affect amphibians, such as hemoparasites. These parasites had been described as common in some amphibian species, but unfortunately, their description and characterization are unclear and scarcely spread. The objective of the present study was to evaluate the morphological and molecular characterization of hemoparasites present in vaillant's frogs. Seven frogs of Lithobates vaillanti were captured at the biological station La Florida in Tabasco, Mexico. Blood smears were performed, and results show that 100% of the animals have hemoparasites. Three types of hemoparasites were found. Eighty-five percent of the frogs were positive to Hepatozoon sp., 57% to Lankesterella sp., and 28% to Trypanosoma sp. According to the molecular analysis of the obtained sequences of Trypanosoma sp. and Hepatozoon sp., both protozoans were positioned in between the clusters of parasites of different geographical regions. Nevertheless, no species names were assigned to any of these parasites because more sequences and analysis are needed.


Assuntos
Ranidae/parasitologia , Animais , Eucoccidiida/classificação , Eucoccidiida/isolamento & purificação , Florida , México , Parasitos/classificação , Parasitos/isolamento & purificação , Trypanosoma/classificação , Trypanosoma/isolamento & purificação
3.
Exp Parasitol ; 212: 107885, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32234306

RESUMO

A phage-display library was generated using a Bus thalamus scorpion toxin (BTK-2) as a peptide scaffold. BTK-2 belongs to the disulfide-rich family of proteins with pronounced structural stability due to the presence of three disulfide bridges that connects antiparallel beta-sheets and one alpha helix. Using BTK-2 as a phage display scaffold, we introduced mutations in five residues located in the alpha-helix and two residues located in the smaller loop, keeping intact the disulfide bridges to create a peptide phage-displayed library with disulfide-rich family properties. The library was subjected to in vivo and in vitro phage display selections against Trypanosoma evansi, the etiological agent of "Surra", a disease that affects a wide range of mammals. The development of T. evansi specific biomarkers is essential to improve diagnostic methods and epidemiological studies leading to a more accurate clinical decision for the treatment of this disease of economic impact for commercial livestock production. In this study, we identified two disulfide-rich peptides targeting T. evansi parasites. Further specificity studies are necessary to investigate the potential of selected peptides as new biomarkers to aid diagnostic and treatment procedures of T. evansi infections.


Assuntos
Dissulfetos , Peptídeos , Trypanosoma/química , Tripanossomíase/diagnóstico , Tripanossomíase/terapia , Sequência de Aminoácidos , Animais , Biomarcadores , Clonagem Molecular , Dissulfetos/química , Camundongos , Camundongos Endogâmicos BALB C , Mutagênese , Oligonucleotídeos/química , Biblioteca de Peptídeos , Peptídeos/química , Peptídeos/genética , Venenos de Escorpião/química , Venenos de Escorpião/genética
4.
Nat Commun ; 11(1): 1326, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165615

RESUMO

Persistent pathogens have evolved to avoid elimination by the mammalian immune system including mechanisms to evade complement. Infections with African trypanosomes can persist for years and cause human and animal disease throughout sub-Saharan Africa. It is not known how trypanosomes limit the action of the alternative complement pathway. Here we identify an African trypanosome receptor for mammalian factor H, a negative regulator of the alternative pathway. Structural studies show how the receptor binds ligand, leaving inhibitory domains of factor H free to inactivate complement C3b deposited on the trypanosome surface. Receptor expression is highest in developmental stages transmitted to the tsetse fly vector and those exposed to blood meals in the tsetse gut. Receptor gene deletion reduced tsetse infection, identifying this receptor as a virulence factor for transmission. This demonstrates how a pathogen evolved a molecular mechanism to increase transmission to an insect vector by exploitation of a mammalian complement regulator.


Assuntos
Fator H do Complemento/metabolismo , Trypanosoma/fisiologia , Moscas Tsé-Tsé/parasitologia , Animais , Anticorpos Monoclonais/metabolismo , Células CHO , Bovinos , Membrana Celular/metabolismo , Complemento C3b/metabolismo , Fator H do Complemento/química , Cricetinae , Cricetulus , Camundongos Endogâmicos BALB C , Parasitemia/sangue , Ligação Proteica , Domínios Proteicos , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Receptores de Superfície Celular/metabolismo , Regulação para Cima
5.
PLoS Negl Trop Dis ; 14(3): e0008096, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203517

RESUMO

BACKGROUND: Vector-borne diseases are important causes of mortality and morbidity in humans and livestock, particularly for poorer communities and countries in the tropics. Large-scale programs against these diseases, for example malaria, dengue and African trypanosomiasis, include vector control, and assessing the impact of this intervention requires frequent and extensive monitoring of disease vector abundance. Such monitoring can be expensive, especially in the later stages of a successful program where numbers of vectors and cases are low. METHODOLOGY/PRINCIPAL FINDINGS: We developed a system that allows the identification of monitoring sites where pre-intervention densities of vectors are predicted to be high, and travel cost to sites is low, highlighting the most efficient locations for longitudinal monitoring. Using remotely sensed imagery and an image classification algorithm, we mapped landscape resistance associated with on- and off-road travel for every gridded location (3m and 0.5m grid cells) within Koboko district, Uganda. We combine the accessibility surface with pre-existing estimates of tsetse abundance and propose a stratified sampling approach to determine the most efficient locations for longitudinal data collection. Our modelled predictions were validated against empirical measurements of travel-time and existing maps of road networks. We applied this approach in northern Uganda where a large-scale vector control program is being implemented to control human African trypanosomiasis, a neglected tropical disease (NTD) caused by trypanosomes transmitted by tsetse flies. Our accessibility surfaces indicate a high performance when compared to empirical data, with remote sensing identifying a further ~70% of roads than existing networks. CONCLUSIONS/SIGNIFICANCE: By integrating such estimates with predictions of tsetse abundance, we propose a methodology to determine the optimal placement of sentinel monitoring sites for evaluating control programme efficacy, moving from a nuanced, ad-hoc approach incorporating intuition, knowledge of vector ecology and local knowledge of geographic accessibility, to a reproducible, quantifiable one.


Assuntos
Entomologia , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica , Modelos Biológicos , Modelos Estatísticos , Tecnologia de Sensoriamento Remoto , Animais , Custos e Análise de Custo , Humanos , Insetos Vetores , Gado , Controle de Pragas , Trypanosoma , Tripanossomíase Africana , Moscas Tsé-Tsé , Uganda , Doenças Transmitidas por Vetores
6.
Parasitol Res ; 119(3): 805-813, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32006230

RESUMO

Addressing the problems linked to tsetse-transmitted trypanosomiases requires considerable data on tsetse distribution and trypanosome infections. Although efforts to map tsetse and trypanosome infections have been undertaken at continental level, published data are still rare in wildlife reserves of West and Central Africa. To fill this gap, data on tsetse distribution and trypanosome infections were generated in the wildlife reserve of Santchou. For this study, each tsetse caught was identified and its DNA extracted. Different trypanosome species were identified by PCR. Entomological and parasitological data were transported onto a satellite image in order to visualize their distributions. From 195 Glossina palpalis palpalis that were caught, 33.8% (66/195) carried trypanosome infections with 89.4% (59/66) of single infections and 10.6% (7/66) mixed infections. From the 66 flies with trypanosome infections, 54.5% (36/66), 27.3% (18/66) and 18.2% (12/66) were respectively due to Trypanosoma congolense, Trypanosoma brucei s.l. and Trypanosoma vivax. The global infection rates were 18.5% (36/195) for Trypanosoma congolense (forest and savannah), 9.2% (18/195) for Trypanosoma brucei s.l. and 6.1% (12/195) for Trypanosoma vivax. The maps generated show the distribution of tsetse and trypanosome infections. This study showed an active transmission of trypanosomes in the wildlife reserve of Santchou. The maps enabled to identify areas with high transmission risk and where control operations must be implemented in order to eliminate tsetse and the diseases that they transmit.


Assuntos
Animais Selvagens/parasitologia , Insetos Vetores/parasitologia , Trypanosoma/genética , Tripanossomíase Africana/veterinária , Moscas Tsé-Tsé/parasitologia , Animais , Camarões/epidemiologia , DNA de Protozoário/genética , Insetos Vetores/genética , Insetos Vetores/fisiologia , Reação em Cadeia da Polimerase , Trypanosoma/classificação , Trypanosoma/isolamento & purificação , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/parasitologia , Tripanossomíase Africana/transmissão , Moscas Tsé-Tsé/genética , Moscas Tsé-Tsé/fisiologia
7.
PLoS Negl Trop Dis ; 14(2): e0007983, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32106219

RESUMO

The development of chemotherapies against eukaryotic pathogens is especially challenging because of both the evolutionary conservation of drug targets between host and parasite, and the evolution of strain-dependent drug resistance. There is a strong need for new nontoxic drugs with broad-spectrum activity against trypanosome parasites such as Leishmania and Trypanosoma. A relatively untested approach is to target macromolecular interactions in parasites rather than small molecular interactions, under the hypothesis that the features specifying macromolecular interactions diverge more rapidly through coevolution. We computed tRNA Class-Informative Features in humans and independently in eight distinct clades of trypanosomes, identifying parasite-specific informative features, including base pairs and base mis-pairs, that are broadly conserved over approximately 250 million years of trypanosome evolution. Validating these observations, we demonstrated biochemically that tRNA:aminoacyl-tRNA synthetase (aaRS) interactions are a promising target for anti-trypanosomal drug discovery. From a marine natural products extract library, we identified several fractions with inhibitory activity toward Leishmania major alanyl-tRNA synthetase (AlaRS) but no activity against the human homolog. These marine natural products extracts showed cross-reactivity towards Trypanosoma cruzi AlaRS indicating the broad-spectrum potential of our network predictions. We also identified Leishmania major threonyl-tRNA synthetase (ThrRS) inhibitors from the same library. We discuss why chemotherapies targeting multiple aaRSs should be less prone to the evolution of resistance than monotherapeutic or synergistic combination chemotherapies targeting only one aaRS.


Assuntos
Alanina-tRNA Ligase/antagonistas & inibidores , Antiprotozoários/farmacologia , Inibidores Enzimáticos/farmacologia , Leishmania/enzimologia , Proteínas de Protozoários/antagonistas & inibidores , Treonina-tRNA Ligase/antagonistas & inibidores , Trypanosoma/efeitos dos fármacos , Alanina-tRNA Ligase/genética , Alanina-tRNA Ligase/metabolismo , Antiprotozoários/química , Inibidores Enzimáticos/química , Humanos , Leishmania/efeitos dos fármacos , Leishmania/genética , Leishmaniose/parasitologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Treonina-tRNA Ligase/genética , Treonina-tRNA Ligase/metabolismo , Trypanosoma/enzimologia , Trypanosoma/genética , Tripanossomíase/parasitologia
8.
Rev Bras Parasitol Vet ; 29(1): e016319, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049143

RESUMO

Leishmania infantum is a trypanosomatid that causes parasitic dermatopathy in dogs. Trypanosoma caninum is another trypanosomatid, which infects the skin of dogs, although cutaneous abnormalities are absent. This study aimed to investigate the occurrence of T. caninum infection and its associated cutaneous and histological changes and compare it with the occurrence of L. infantum infection in dogs. The study included 150 dogs, of which T. caninum infection was identified in 3 (2%) and L. infantum infection in 15 (10%) of them, with no association (p>0.05) of these infections with the breed, gender, age, or cutaneous abnormalities. The cutaneous abnormalities were based on 1 (4.8%) and 12 (57.1%) dogs infected by T. caninum and L. infantum, respectively. The dermatohistopathological abnormalities in the dogs infected with T. caninum included mild perivascular lymphohistioplasmacytic infiltrates in the clinically asymptomatic ones, while in those with dermatological abnormalities, acanthosis, epidermal orthokeratotic hyperkeratosis, melanomacrophages, and co-infection with Microsporum sp. and Trichophyton sp. were observed. InL. infantum infected, the histopathological findings included chronic granulomatous inflammatory infiltrates and structures compatible with amastigotes. Despite the low frequency of T. caninum infection, our findings suggest that this trypanosomatid, unlike L. infantum, does not cause any macroscopic skin abnormalities.


Assuntos
Doenças do Cão/patologia , Leishmania infantum/genética , Leishmaniose Visceral/veterinária , Trypanosoma/genética , Tripanossomíase/veterinária , Animais , Brasil/epidemiologia , Coinfecção , DNA de Protozoário/genética , Doenças do Cão/epidemiologia , Cães , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/patologia , Reação em Cadeia da Polimerase , Prevalência , Tripanossomíase/epidemiologia , Tripanossomíase/patologia
9.
PLoS Negl Trop Dis ; 14(2): e0008059, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32032359

RESUMO

During a blood meal, female Anopheles mosquitoes are potentially exposed to diverse microbes in addition to the malaria parasite, Plasmodium. Human and animal African trypanosomiases are frequently co-endemic with malaria in Africa. It is not known whether exposure of Anopheles to trypanosomes influences their fitness or ability to transmit Plasmodium. Using cell and molecular biology approaches, we found that Trypanosoma brucei brucei parasites survive for at least 48h after infectious blood meal in the midgut of the major malaria vector, Anopheles coluzzii before being cleared. This transient survival of trypanosomes in the midgut is correlated with a dysbiosis, an alteration in the abundance of the enteric bacterial flora in Anopheles coluzzii. Using a developmental biology approach, we found that the presence of live trypanosomes in mosquito midguts also reduces their reproductive fitness, as it impairs the viability of laid eggs by affecting their hatching. Furthermore, we found that Anopheles exposure to trypanosomes enhances their vector competence for Plasmodium, as it increases their infection prevalence. A transcriptomic analysis revealed that expression of only two Anopheles immune genes are modulated during trypanosome exposure and that the increased susceptibility to Plasmodium was microbiome-dependent, while the reproductive fitness cost was dependent only on the presence of live trypanosomes but was microbiome independent. Taken together, these results demonstrate multiple effects upon Anopheles vector competence for Plasmodium caused by eukaryotic microbes interacting with the host and its microbiome, which may in turn have implications for malaria control strategies in co-endemic areas.


Assuntos
Anopheles/parasitologia , Malária/parasitologia , Plasmodium yoelii/fisiologia , Trypanosoma/fisiologia , Animais , Coinfecção , Interações Hospedeiro-Parasita , Camundongos , Reação em Cadeia da Polimerase , Reprodução
10.
PLoS Negl Trop Dis ; 14(2): e0008044, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069278

RESUMO

BACKGROUND: Animal trypanosomosis caused by Trypanosoma evansi is known as "surra" and is a widespread neglected tropical disease affecting wild and domestic animals mainly in South America, the Middle East, North Africa and Asia. An essential necessity for T. evansi infection control is the availability of reliable and sensitive diagnostic tools. While DNA-based PCR detection techniques meet these criteria, most of them require well-trained and experienced users as well as a laboratory environment allowing correct protocol execution. As an alternative, we developed a recombinase polymerase amplification (RPA) test for Type A T. evansi. The technology uses an isothermal nucleic acid amplification approach that is simple, fast, cost-effective and is suitable for use in minimally equipped laboratories and even field settings. METHODOLOGY/PRINCIPLE FINDINGS: An RPA assay targeting the T. evansi RoTat1.2 VSG gene was designed for the DNA-based detection of T. evansi. Comparing post-amplification visualization by agarose gel electrophoresis and a lateral flow (LF) format reveals that the latter displays a higher sensitivity. The RPA-LF assay is specific for RoTat1.2-expressing strains of T. evansi as it does not detect the genomic DNA of other trypanosomatids. Finally, experimental mouse infection trials demonstrate that the T. evansi specific RPA-LF can be employed as a test-of-cure tool. CONCLUSIONS/SIGNIFICANCE: Compared to other DNA-based parasite detection methods (such as PCR and LAMP), the T. evansi RPA-LF (TevRPA-LF) described in this paper is an interesting alternative because of its simple read-out (user-friendly), short execution time (15 minutes), experimental sensitivity of 100 fg purified genomic T. evansi DNA, and ability to be carried out at a moderate, constant temperature (39°C). Therefore, the TevRPA-LF is an interesting tool for the detection of active T. evansi infections.


Assuntos
Técnicas de Amplificação de Ácido Nucleico/métodos , Recombinases/metabolismo , Trypanosoma/isolamento & purificação , Tripanossomíase/diagnóstico , Animais , DNA de Protozoário/genética , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Trypanosoma/genética
11.
Acta Trop ; 204: 105328, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31904345

RESUMO

Tsetse-transmitted trypanosomosis remains a major animal health problem in Nigeria, in a context where changes in land cover, climate and control interventions are modifying its epidemiological patterns. Evidence-based decision making for the progressive control of the disease requires spatially-explicit information on its occurrence and prevalence, as well as on the distribution and abundance of the tsetse vector. In the framework of the continental Atlas of tsetse and African animal trypanosomosis (AAT), a geo-referenced database was assembled for Nigeria, based on the systematic review of 133 scientific publications (period January 1990 - March 2019). The three main species of trypanosomes responsible for the disease (i.e. Trypanosoma vivax, T. congolense and T. brucei) were found to be widespread, thus posing a national-level problem. Their geographic distribution extends beyond the tsetse-infested belt, owing to the combined effect of animal movement and mechanical transmission by non-tsetse vectors. T. simiae, the major trypanosomal pathogen in pigs, T. godfreyi and the human-infective T. brucei gambiense were also reported. AAT was reported in a number of susceptible host species, including cattle, sheep, goats, pigs, camels, horses, donkeys and dogs, while no study on wildlife was identified. Estimates of prevalence are heavily influenced by the sensitivity of the diagnostic techniques, ranging from an average of 3.5% for blood films to 31.0% for molecular techniques. Two riverine tsetse species (i.e. Glossina palpalis palpalis and G. tachinoides) were found to have the broadest geographical range, as they were detected in all six geopolitical zones of Nigeria. By contrast, the distribution of savannah species (i.e. G. morsitans submorsitans and G. longipalpis) appears to be highly fragmented, and limited to protected areas. Very little information is available for forest species, with one single paper reporting on G. fusca congolensis and G. nigrofusca nigrofusca in the Niger Delta region. The future development of a national Atlas of tsetse and AAT, relying on both published and unpublished information, could improve on the present review and provide further epidemiological evidence for decision making.


Assuntos
Animais Selvagens , Gado , Trypanosoma/classificação , Tripanossomíase Africana/veterinária , Moscas Tsé-Tsé/fisiologia , Animais , Nigéria/epidemiologia , Tripanossomíase Africana/epidemiologia
12.
Proc Biol Sci ; 287(1918): 20191969, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31910787

RESUMO

Supplemental feeding of wildlife populations can locally increase the density of individuals, which may in turn impact disease dynamics. Flower strips are a widely used intervention in intensive agricultural systems to nutritionally support pollinators such as bees. Using a controlled experimental semi-field design, we asked how density impacts transmission of a virus and a trypanosome parasite in bumblebees. We manipulated bumblebee density by using different numbers of colonies within the same area of floral resource. In high-density compartments, slow bee paralysis virus was transmitted more quickly, resulting in higher prevalence and level of infection in bumblebee hosts. By contrast, there was no impact of density on the transmission of the trypanosome Crithidia bombi, which may reflect the ease with which this parasite is transmitted. These results suggest that agri-environment schemes such as flower strips, which are known to enhance the nutrition and survival of bumblebees, may also have negative impacts on pollinators through enhanced disease transmission. Future studies should assess how changing the design of these schemes could minimize disease transmission and thus maximise their health benefits to wild pollinators.


Assuntos
Abelhas/virologia , Crithidia/fisiologia , Interações Hospedeiro-Parasita , Trypanosoma , Agricultura , Animais , Abelhas/fisiologia , Flores , Polinização , Vírus de RNA
13.
Parasit Vectors ; 13(1): 21, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931864

RESUMO

BACKGROUND: Trypanosoma evansi is the causative agent of surra, a disease that occurs in many animal species. The disease is responsible for substantial losses in global production and can be fatal if not diagnosed early. This study aims to determine the prevalence of T. evansi in livestock, equids and dromedary camels in Palestine. METHODS: Blood samples were collected during 2015-2017 from domesticated animals (n = 259 animals; 77% females and 23% males) including camels (n = 87), horses (n = 46), donkeys (n = 28), mules (n = 2), sheep (n = 49) and goats (n = 48) from eight districts: Ariha (Jericho), Nablus, Bethlehem, Deir Al Balah, Jenin, Rafah, Tubas, and Khan Yunis. Parasite prevalence was determined using PCR and blood smear microscopy. PCR-positive samples were further phylogenetically analyzed using DNA sequences of the 18S ribosomal RNA gene. RESULTS: The overall infection prevalence was 18% (46/259). The positivity rates according to PCR and microscopy examination were 17% (45/259) and 2.7% (7/259), respectively. The infection rates were as follows: camels, 26/61 (30%); horses, 8/46 (17%); donkeys, 3/28 (11%); mules, 1/2 (50%); sheep, 2/42 (4%); and goats, 6/42 (13%). Phylogenetic analyses of the 18S rRNA gene showed that 24 positive T. evansi samples from Palestine formed a monophyletic cluster with seven T. evansi sequences from Africa, Asia and South America, and three T. brucei sequences from Africa retrieved from GenBank. The spatial analysis showed three statistically significant foci of T. evansi infection in Jenin, Tubas (P = 0.02) and Ariha (Jericho) (P = 0.04). No statistically significant foci were detected in the Gaza Strip. CONCLUSIONS: To the best of our knowledge, this is the first confirmation of high levels of infection with T. evansi as a causative agent of surra in Palestine. Our study emphasizes the need for a stringent surveillance system and risk assessment studies as prerequisites for control measures. Further investigations focusing on vectors and evaluation of risk factors are needed.


Assuntos
Equidae/parasitologia , Gado/parasitologia , Trypanosoma/isolamento & purificação , Tripanossomíase/epidemiologia , Animais , Sangue/parasitologia , Camelus/parasitologia , DNA de Protozoário/genética , Feminino , Masculino , Oriente Médio/epidemiologia , Filogenia , Prevalência , RNA Ribossômico 18S/genética , Ovinos/parasitologia , Coloração e Rotulagem/métodos , Trypanosoma/genética , Tripanossomíase/veterinária
14.
Parasitol Res ; 119(2): 687-694, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31897793

RESUMO

Wild rodents, as natural reservoir hosts carrying various species of pathogens, play an important role in the evolution and emergence of zoonotic diseases. In this study, protist parasites, namely Babesia sp., Trypanosoma sp. and Hepatozoon sp. were studied in rodent populations in Lithuania. Two hundred forty rodent specimens of seven species were analysed by a combined approach using polymerase chain reaction (PCR)-based techniques and traditional microscopic examination. The total prevalence of blood parasites reached 35% in rodent communities. The prevalence of Hepatozoon sp. reached the highest value (32%), followed by Trypanosoma sp. (5%) and Babesia sp. (3%). Myodes glareolus and Microtus agrestis were the most heavily infected rodent species. Comparison of microscopy and PCR-based methods showed that the two approaches might give different results and thus can lead to an underestimation of the actual prevalence and abundance of parasites. In our study, PCR-based assays were more sensitive and robust than traditional microscopy. However, precise molecular results for the estimation of the prevalence of Babesia sp. and Hepatozoon sp. were achieved only by using several sets of primers. To avoid inaccurate results, the improvement and detailed description of molecular and microscopy protocols are required.


Assuntos
Arvicolinae/parasitologia , Babesia/isolamento & purificação , Eucoccidiida/isolamento & purificação , Trypanosoma/isolamento & purificação , Animais , Lituânia , Microscopia , Reação em Cadeia da Polimerase
15.
Chem Pharm Bull (Tokyo) ; 68(1): 46-57, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31902901

RESUMO

Over the past decade, a number of new 1,4-naphthoquinones have been isolated from natural sources and new 1,4-naphthoquinones with diverse structural features have been synthesized. Cardioprotective, anti-ischemic, hepatoprotective, neuroprotective and some other new properties were found for these compounds; their role in protecting against neurodegenerative diseases has been established. Their anti-inflammatory, antimicrobial and antitumor activities have been studied in more detail; new, previously unknown intracellular molecular targets and mechanisms of action have been discovered. Some compounds of this class are already being used as a medicinal drugs and some substances can be used as biochemical tools and probes for non-invasive detection of pathological areas in cells and tissues in myocardial infarction and neurodegenerative diseases using modern molecular imaging techniques.


Assuntos
Anti-Infecciosos/química , Anti-Inflamatórios/química , Naftoquinonas/química , Substâncias Protetoras/química , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/farmacologia , Bactérias/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Naftoquinonas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Trypanosoma/efeitos dos fármacos
16.
J Infect Public Health ; 13(4): 514-520, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31831393

RESUMO

BACKGROUND AND OBJECTIVES: This study provides a longitudinal scientometric analysis of global trypanosomiasis research between 1988 and 2017 as indexed in Clarivate Analytics' Web of Science (WoS). Contributions by researchers from different countries and continents are outlined based on publication productivity, international collaborations, citation analysis, and keyword analysis. METHODS: Bibliographic records of research publications indexed by WoS were downloaded based on a broad search of related terms. The authors compared the growth of literature by continent using 5-year increments, conducted a citation and co-authorship analysis by country, and a keyword analysis by publication using the scientometric visualization software VOSviewer. RESULTS: The trypanosomiasis research literature has seen more than a fourfold annual increase in production over the study period. Contributions by authors affiliated with European and South American countries proportionately account for the most research literature. The United States and Brazil, however, occupy central roles for citations and as national contributors to the literature. The terms 'trypanosomiasis cruzi' and 'chagas disease' have become more prominent, reflecting the regional growth of research from South America. INTERPRETATION AND CONCLUSION: Relative contributions from regions where the disease is prevalent show mixed developments. Contributions by African authors have declined proportionately to other areas of the world. However, South American contributions have increased during the study period. The contributing countries to the literature do not necessarily represent regions in which the diseases are prevalent. The same is true of the citation relationships, where European and North American contributions are more frequently cited.


Assuntos
Bibliometria , Pesquisa Biomédica/estatística & dados numéricos , Tripanossomíase , Animais , Europa (Continente) , Humanos , Cooperação Internacional , América do Sul , Trypanosoma , Estados Unidos
17.
Biochimie ; 168: 110-123, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31704351

RESUMO

An enriched fraction of an inhibitor of both the catalytic subunit of the cAMP-dependent protein kinase (PKA) from pig heart and a Trypanosoma equiperdum PKA catalytic subunit-like protein (TeqC-like) was obtained from the soluble fraction of T. equiperdum parasites after three consecutive purification steps: sedimentation through a linear 5-20% sucrose gradient, diethylaminoethyl-Sepharose anion-exchange chromatography, and Bio-Sil Sec-400-S size-exclusion high-performance liquid chromatography. The inhibitor was identified as the T. equiperdum PKA regulatory subunit-like protein (TeqR-like) on the basis of Western blot and mass spectrometry analyses, and behaved as an uncompetitive or anti-competitive inhibitor of the parasite TeqC-like protein, with respect to a fluorescently labeled substrate (kemptide, sequence: LRRASLG), showing a Ki of 1.17 µM. The isolated protein possesses a molecular mass of 57.54 kDa, a Stokes radius of 3.64 nm, and a slightly asymmetric shape with a frictional ratio f/fo = 1.43. As revealed during the purification steps and by immunoprecipitation experiments, the TeqR-like and TeqC-like proteins were not associated forming a heterooligomeric complex, differing from traditional PKA subunits. Co-immunoprecipitation results followed by mass spectrometry sequencing identified two isoforms of the parasite heat-shock protein 70, α-tubulin, and ß-tubulin as candidates that interact with the TeqR-like protein in T. equiperdum.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico , Subunidades Proteicas/química , Trypanosoma/enzimologia , Animais , Proteínas Quinases Dependentes de AMP Cíclico/química , Proteínas Quinases Dependentes de AMP Cíclico/isolamento & purificação , Ligantes , Suínos
18.
Acta Trop ; 203: 105302, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31857080

RESUMO

African animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious health problems in livestock. Although tsetse infestations have been observed in Blue Nile State in Sudan, tsetse was eradicated in West Kordofan in 1962, and no further studies have been carried out. Accordingly, in this study, we investigated the prevalence of trypanosomosis in cattle, sheep, and goats in Blue Nile and West Kordofan States, Sudan. This cross-sectional study was conducted using 70 cattle, 62 sheep, and 116 goats, and the microhematocrit centrifugation technique was used as a parasitological test. KIN-multispecies polymerase chain reaction (PCR) was used to detect Trypanozoon sp., Trypanosoma congolense, and T. vivax; RoTat 1.2 variable surface glycoprotein-specific PCR was used to detect T. evansi; and TviCatL PCR was used to specifically detect T. vivax. The seroprevalence of trypanosomosis was assessed using card agglutination tests CATT/ T. evansi. The parasitological prevalence rates were 4% (3/70) in cattle, 2% (1/62) in sheep, and 4% (5/116) in goats. The molecular prevalence rates of T. vivax, the most prevalent parasite, were 99% (69/70) in cattle, 98% (61/62) in sheep, and 84% (98/116) in goats. Trypanozoon (T. evansi or T. brucie) rates were 30% (21/70) in cattle, 32% (20/62) in sheep, and 12% (14/116) in goats. Among Trypanozoon-positive isolates, T. evansi was confirmed in 24% (5/21) of cattle, 70% (14/20) of sheep, and 86% (12/14) of goats. Finally, T. congolense was recorded only in cattle in Blue Nile State, with a prevalence of 14% (10/70). The seroprevalence rates of CATT/T. evansi were 46% (32/70) in cattle, 45% (28/62) in sheep, and 14% (16/116) in goats. Thus, we confirmed molecularly, for the first time, the presence of Trypanozoon, particularly T. evansi and T. vivax, in sheep and goats in Sudan. Our results show that sheep and goats could be an important reservoir for trypanosomes, potentially leading to the spread of the disease to the northern parts of the country following the movement of these animals. These findings provide important insights into the epidemiology of the disease and could affect the establishment of control strategies against trypanosomosis in Sudan.


Assuntos
Gado/parasitologia , Trypanosoma/isolamento & purificação , Animais , Bovinos/parasitologia , Estudos Transversais , Cabras/parasitologia , Estudos Soroepidemiológicos , Ovinos/parasitologia , Sudão/epidemiologia
19.
Molecules ; 24(23)2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31795283

RESUMO

Parasitic infections like leishmaniasis and trypanosomiasis remain as a worldwide concern to public health. Improvement of the currently available drug discovery pipelines for those diseases is therefore mandatory. We have recently reported on the antileishmanial and antitrypanosomal activity of a set of cinnamate esters where we identified several compounds with interesting activity against L. donovani and T. brucei rhodesiense. For a better understanding of such compounds' anti-infective activity, analyses of the underlying structure-activity relationships, especially from a quantitative point of view, would be a prerequisite for rational further development of such compounds. Thus, quantitative structure-activity relationships (QSAR) modeling for the mentioned set of compounds and their antileishmanial and antitrypanosomal activity was performed using a genetic algorithm as main variable selection tool and multiple linear regression as statistical analysis. Changes in the composition of the training/test sets were evaluated (two randomly selected and one by Kennard-Stone algorithm). The effect of the size of the models (number of descriptors) was also investigated. The quality of all resulting models was assessed by a variety of validation parameters. The models were ranked by newly introduced scoring functions accounting for the fulfillment of each of the validation criteria evaluated. The test sets were effectively within the applicability domain of the best models, which demonstrated high robustness. Detailed analysis of the molecular descriptors involved in those models revealed strong dependence of activity on the number and type of polar atoms, which affect the hydrophobic/hydrophilic properties causing a prominent influence on the investigated biological activities.


Assuntos
Antiprotozoários/química , Antiprotozoários/farmacologia , Cinamatos/química , Cinamatos/farmacologia , Relação Quantitativa Estrutura-Atividade , Ésteres , Leishmania/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular , Testes de Sensibilidade Parasitária , Reprodutibilidade dos Testes , Trypanosoma/efeitos dos fármacos
20.
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA