Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Acta Trop ; 207: 105495, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32305295

RESUMO

The applicability of molecular biology/PCR for canine visceral leishmaniasis diagnosis presents challenges, mainly due to the diversity of targets described. The objectives of this study were to compare the sensitivities and reliability of five targets (kDNA/120, kDNA/145, ITS1, hsp70/234 and hsp70/1300) in four different tissue samples (bone marrow, popliteal lymph node, skin and conjunctival swab). Sixty-five dogs (32 males and 33 females) naturally infected with Leishmania infantum and ten dogs without infection were examined. Dogs were characterized by serological and parasitological methods. The parasitological test was considered the gold standard for analysis. All tests presented high specificity 100% (95% CI 0.72-1), and variable sensitivity. The targets kDNA/145, ITS1, kDNA/120, hsp70/234 and hsp70/1300 detected 100% (65/65), 93.4% (61/65), 92.3% (60/65), 84.61% (55/65) and 72.3% (77/65) of positive animals respectively. The performance of PCR methods was analyzed in two different scenarios. The highest sensitivity value identified in all scenarios studied was kDNA/145. Our results suggest that popliteal lymph node and conjunctival swab samples, besides being less invasive collections, represent a good substratum for PCR-based diagnosis, and the target kDNA/145 is the best choice for detecting L. infantum DNA in naturally infected dogs.

2.
Vet Parasitol ; 274: 108920, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31493694

RESUMO

Visceral leishmaniasis (VL) is a zoonosis caused by the parasite Leishmania infantum and the dog is its main reservoir in rural and urban areas. The diagnosis of infection is mainly based on the presence of anti-Leishmania IgG antibodies in the serum of infected dogs. In this study, the sensitivity and specificity of qualitative rapid tests (RTs) dual path platform (DPP) Bio-Manguinhos, rapid enzyme-linked immunosorbent assay (ELISA) IDEXX, Kalazar Detect and ALERE, as well as quantitative ELISA Bio-Manguinhos and in-house indirect immunofluorescence assay (IFA) tests were analyzed in sera from infected and uninfected dogs. Serial dilutions of the in-house IFA were compared with RTs and ELISA Bio-Manguinhos. The results showed that none of the tests reached 100% sensitivity and specificity. There was no statistical difference between the analyzed RTs. The most sensitive test was the DPP Bio-Manguinhos (97.9%), while the rapid ELISA IDEXX showed higher specificity (100%). In the treatment setting of infected and/or diseased animals, quantitative tests for monitoring the evolution of antibody titers are required, which indicates the maintenance of in-house IFA in animal handling. Furthermore, we demonstrate that the RTs present higher sensitivity in serum samples with superior antibody titers obtained in the in-house IFA. However, the RTs exhibited false negatives in samples with low titers of antibodies. Among the RTs, only the DPP Bio-Manguinhos presented better performance in this situation. Therefore, the use of RTs for the diagnosis of VL in dogs with low titers of antibodies, such as asymptomatic, should be carefully evaluated.


Assuntos
Doenças do Cão/sangue , Leishmania infantum , Leishmaniose Visceral/veterinária , Testes Sorológicos/veterinária , Animais , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Cães , Leishmaniose Visceral/sangue , Leishmaniose Visceral/diagnóstico , Sensibilidade e Especificidade
3.
Mem Inst Oswaldo Cruz ; 114: e190111, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31433006

RESUMO

BACKGROUND: In addition to the limited therapeutic arsenal and the side effects of antileishmanial agents, drug resistance hinders disease control. In Brazil, Leishmania braziliensis causes atypical (AT) tegumentary leishmaniasis lesions, frequently refractory to treatment. OBJECTIVES: The main goal of this study was to characterise antimony (Sb)-resistant (SbR) L. braziliensis strains obtained from patients living in Xakriabá indigenous community, Minas Gerais, Brazil. METHODS: The aquaglyceroporin 1-encoding gene (AQP1) from L. braziliensis clinical isolates was sequenced, and its function was evaluated by hypo-osmotic shock. mRNA levels of genes associated with Sb resistance were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Atomic absorption was used to measure Sb uptake. FINDINGS: Although clinical isolates presented delayed recovery time in hypo-osmotic shock, AQP1 function was maintained. Isolate 340 accumulated less Sb than all other isolates, supporting the 65-fold downregulation of AQP1 mRNA levels. Both 330 and 340 isolates upregulated antimony resistance marker (ARM) 56/ARM58 and multidrug resistant protein A (MRPA); however, only ARM58 upregulation was an exclusive feature of SbR field isolates. CA7AE seemed to increase drug uptake in L. braziliensis and represented a tool to study the role of glycoconjugates in Sb transport. MAIN CONCLUSIONS: There is a clear correlation between ARM56/58 upregulation and Sb resistance in AT-harbouring patients, suggesting the use of these markers as potential indicators to help the treatment choice and outcome, preventing therapeutic failure.


Assuntos
Antimônio/farmacologia , Resistência a Medicamentos/genética , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Proteínas de Protozoários/genética , Tripanossomicidas/farmacologia , Aquagliceroporinas/metabolismo , Resistência a Medicamentos/efeitos dos fármacos , Humanos , Leishmania braziliensis/genética , Testes de Sensibilidade Parasitária , Proteínas de Protozoários/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
4.
Artigo em Inglês | MEDLINE | ID: mdl-31355149

RESUMO

Lipophosphoglycan (LPG) is the major Leishmania surface glycoconjugate having importance during the host-parasite interface. Leishmania (Viannia) braziliensis displays a spectrum of clinical forms including: typical cutaneous leishmaniasis (TL), mucocutaneous (ML), and atypical lesions (AL). Those variations in the immunopathology may be a result of intraspecies polymorphisms in the parasite's virulence factors. In this context, we evaluated the role of LPG of strains originated from patients with different clinical manifestations and the sandfly vector. Six isolates of L. braziliensis were used: M2903, RR051 and RR418 (TL), RR410 (AL), M15991 (ML), and M8401 (vector). LPGs were extracted and purified by hydrophobic interaction. Peritoneal macrophages from C57BL/6 and respective knock-outs (TLR2-/- and TLR-4-/-) were primed with IFN-γ and exposed to different LPGs for nitric oxide (NO) and cytokine production (IL-1ß, IL-6, IL-12, and TNF-α). LPGs differentially activated the production of NO and cytokines via TLR4. In order to ascertain if such functional variations were related to intraspecies polymorphisms in the LPG, the purified glycoconjugates were subjected to western blot with specific LPG antibodies (CA7AE and LT22). Based on antibody reactivity preliminary variations in the repeat units were detected. To confirm these findings, LPGs were depolymerized for purification of repeat units. After thin layer chromatography, intraspecies polymorphisms were confirmed especially in the type and/size of sugars branching-off the repeat units motif. In conclusion, different isolates of L. braziliensis from different clinical forms and hosts possess polymorphisms in their LPGs that functionally affected macrophage responses.


Assuntos
Glicoesfingolipídeos/química , Glicoesfingolipídeos/imunologia , Leishmania braziliensis/genética , Leishmania braziliensis/metabolismo , Leishmaniose Cutânea/imunologia , Ativação de Macrófagos , Receptor 4 Toll-Like/metabolismo , Animais , Citocinas/metabolismo , Técnicas de Inativação de Genes , Glicoesfingolipídeos/isolamento & purificação , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Macrófagos/imunologia , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico , Psychodidae/parasitologia , Receptor 4 Toll-Like/genética , Fatores de Virulência
5.
Mol Immunol ; 106: 36-45, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30576950

RESUMO

Cutaneous leishmaniasis (CL) mainly caused by Leishmania braziliensis is a chronic inflammatory disease widely spread in Brazil. Genetic variant strains of this parasite have been associated with atypical clinical manifestations of CL in an endemic area in Brazil. Furthermore, these strains have presented distinct biological behaviors in golden hamster, suggesting differential activation of the immune response. In the present study we proposed to evaluate the localized immune response in golden hamsters infected with known molecular variant strains of L. braziliensis, in distinct time points post-infection (PI). Detailed analyses of the mRNA expression of cytokines and chemokines in hamster-skin lesions were performed. Heat map matrix and hierarchical cluster analysis were carried out to segregate the strains due to mRNA expression. Distinct patterns of immune response were found in both time points, more evident in the recent-phase disease (30 days-PI). At this time point, the genetic variant strains expressed high levels of tnfα, il12 and tgfß whilst the non-variant strain expressed ifnγ, il6, il4, il10, il13 and ccl17. The hierarchical clustering highlights this distinct pattern in which all genetic variant strain was grouped in the cluster I and the non-variant strain grouped into the cluster II. At late-phase disease (60 days-PI) all isolates expressed high levels of il4 and il10. The non-variant strain shown a significant reduced expression of ifnγ, il6, ccl17, and ccl22 whilst distinct patterns were observed for the genetic variant strains. For the first time, a large panel of cytokines and chemokines mRNA-expression was analyzed in experimental trials using golden hamsters as animal model and genetic variant strains of L. braziliensis. Our findings suggest that genetic variant strains of L. braziliensis are able to trigger differential gene expression of cytokines and chemokines in the skin lesion from infected hamsters. The parasite intrinsic ability to activate distinct pathways in the host-parasite interaction may be associated to the large spectrum of clinical manifestation observed in CL-patients.


Assuntos
Quimiocinas/imunologia , Regulação da Expressão Gênica/imunologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Pele/imunologia , Animais , Cricetinae , Modelos Animais de Doenças , Leishmania braziliensis/genética , Leishmaniose Cutânea/genética , Leishmaniose Cutânea/patologia , Mesocricetus , Pele/parasitologia , Pele/patologia
6.
Mem. Inst. Oswaldo Cruz ; 114: e190111, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1020081

RESUMO

BACKGROUND In addition to the limited therapeutic arsenal and the side effects of antileishmanial agents, drug resistance hinders disease control. In Brazil, Leishmania braziliensis causes atypical (AT) tegumentary leishmaniasis lesions, frequently refractory to treatment. OBJECTIVES The main goal of this study was to characterise antimony (Sb)-resistant (SbR) L. braziliensis strains obtained from patients living in Xakriabá indigenous community, Minas Gerais, Brazil. METHODS The aquaglyceroporin 1-encoding gene (AQP1) from L. braziliensis clinical isolates was sequenced, and its function was evaluated by hypo-osmotic shock. mRNA levels of genes associated with Sb resistance were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Atomic absorption was used to measure Sb uptake. FINDINGS Although clinical isolates presented delayed recovery time in hypo-osmotic shock, AQP1 function was maintained. Isolate 340 accumulated less Sb than all other isolates, supporting the 65-fold downregulation of AQP1 mRNA levels. Both 330 and 340 isolates upregulated antimony resistance marker (ARM) 56/ARM58 and multidrug resistant protein A (MRPA); however, only ARM58 upregulation was an exclusive feature of SbR field isolates. CA7AE seemed to increase drug uptake in L. braziliensis and represented a tool to study the role of glycoconjugates in Sb transport. MAIN CONCLUSIONS There is a clear correlation between ARM56/58 upregulation and Sb resistance in AT-harbouring patients, suggesting the use of these markers as potential indicators to help the treatment choice and outcome, preventing therapeutic failure.


Assuntos
Humanos , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/genética , Resistência a Medicamentos/efeitos dos fármacos , Leishmaniose Cutânea/parasitologia , Aquagliceroporinas/metabolismo , Antimônio/farmacologia , Resistência a Medicamentos/genética , Reação em Cadeia da Polimerase em Tempo Real
7.
Rev. bras. parasitol. vet ; 27(4): 570-574, Oct.-Dec. 2018.
Artigo em Inglês | LILACS-Express | ID: biblio-1042488

RESUMO

Abstract The role of cats in the epidemiological cycle of leishmaniasis remains unclear. To better understand the occurrence of leishmaniasis in cats, we studied the frequency of Leishmania in serum samples of 100 cats living in an endemic region for canine and human leishmaniasis by serological, parasitological, and molecular methods. Of the 100 cats, 54 were seropositive for Leishmania antibodies by immunofluorescence antibody test. None of the bone marrow aspirates collected from these cats tested positive for the parasite in culture or upon polymerase chain reaction (PCR) analysis. Biopsy samples of the ears also tested negative for Leishmania upon PCR analysis. These findings may indicate that the region is endemic for canine leishmaniasis and cats are infected by Leishmania; or that cross-reaction with antibodies against other parasites increases the frequency of seropositivity; or that cats respond to Leishmania infection by producing antibodies when few or no parasites are present in bone marrow and tissue samples. Overall, our results suggest that cats can be infected by Leishmania ; however, we failed to demonstrate feline parasitosis. These findings highlight the need to study leishmaniasis in cats, since sandflies feed on cats, these animals may act as a reservoir for the parasite.


Resumo O papel dos gatos no ciclo epidemiológico da leishmaniose ainda não está claro. Para entender melhor a ocorrência de leishmaniose em gatos, estudou-se a frequência de Leishmania em amostras de soro de 100 gatos, os quais vivem em uma região endêmica para leishmaniose canina e humana, por métodos sorológicos, parasitológicos e moleculares. Dos 100 gatos, 54 foram soropositivos para anticorpos de Leishmania por teste de anticorpos de imunofluorescência. Nenhum dos aspirados de medula óssea coletados desses gatos mostrou-se positivo para o parasita em cultura, ou após a realização da reação em cadeia da polimerase (PCR). Amostras de biópsia das orelhas também foram negativas para Leishmania submetidas a PCR. Esses achados indicam que na região estudada endêmica para leishmaniose canina, os gatos podem se infectar por Leishmania; ou que a reação cruzada com anticorpos contra outros parasitas aumenta a frequência de soropositividade; ou que os gatos respondem à infecção por Leishmania produzindo anticorpos quando poucos ou nenhum parasita estão presentes na medula óssea e em amostras de tecido. Em geral, os resultados sugerem que os gatos podem ser estar infectados por Leishmania spp. No entanto, não foi possível demonstrar parasitismo felino. Essas descobertas evidenciam a necessidade de estudar a leishmaniose em gatos, uma vez que, como os flebotomíneos se alimentam em gatos, e esses animais podem atuar como um reservatório para o parasita.

8.
Rev Bras Parasitol Vet ; 27(4): 570-574, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30183999

RESUMO

The role of cats in the epidemiological cycle of leishmaniasis remains unclear. To better understand the occurrence of leishmaniasis in cats, we studied the frequency of Leishmania in serum samples of 100 cats living in an endemic region for canine and human leishmaniasis by serological, parasitological, and molecular methods. Of the 100 cats, 54 were seropositive for Leishmania antibodies by immunofluorescence antibody test. None of the bone marrow aspirates collected from these cats tested positive for the parasite in culture or upon polymerase chain reaction (PCR) analysis. Biopsy samples of the ears also tested negative for Leishmania upon PCR analysis. These findings may indicate that the region is endemic for canine leishmaniasis and cats are infected by Leishmania; or that cross-reaction with antibodies against other parasites increases the frequency of seropositivity; or that cats respond to Leishmania infection by producing antibodies when few or no parasites are present in bone marrow and tissue samples. Overall, our results suggest that cats can be infected by Leishmania ; however, we failed to demonstrate feline parasitosis. These findings highlight the need to study leishmaniasis in cats, since sandflies feed on cats, these animals may act as a reservoir for the parasite.


Assuntos
Doenças do Gato/parasitologia , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Animais , Brasil/epidemiologia , Doenças do Gato/diagnóstico , Doenças do Gato/epidemiologia , Gatos , Doenças Endêmicas , Imunofluorescência , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia
9.
Parasitol Res ; 117(10): 3157-3168, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30022292

RESUMO

A variety of clinical forms of American cutaneous leishmaniasis (ACL) caused by Leishmania braziliensis, as well as differing immune responses of patients, have been reported for an ACL focus in the state of Minas Gerais, Brazil. In addition, two genetic profiles of L. braziliensis have been described, of which one variant profile (hsp70-variant) has been associated with atypical lesions. We investigated the biological behavior of genetic variant strains of L. braziliensis isolated from patients with different clinical manifestations of ACL. Experimental infections were performed with golden hamsters for five L. braziliensis strains in standardized doses of 1 × 106 parasites per inocula. The characteristics of skin lesions, histopathological features, and parasite burden were independently analyzed at 30 and 60 days post-infection. The data revealed distinct patterns in the onset time of visible skin lesions as well as in lesion size and parasite burden among the strains. The extent and density of the inflammatory infiltrate differed among strains, although cellular composition of granulomas appeared similar. Multivariate analysis indicated the occurrence of two clusters: one comprising native strains (cluster 1) and one comprising the reference strain (cluster 2). Within cluster 1, the genetic variants of L. braziliensis did not group with the non-variant strain suggesting that the distinct patterns of biological behavior of these strains could be associated with the known genetic diversity previously described for them.


Assuntos
Variação Genética/genética , Leishmania braziliensis/genética , Leishmaniose Cutânea/patologia , Pele/patologia , Adulto , Animais , Brasil/epidemiologia , Cricetinae , Proteínas de Choque Térmico HSP70/genética , Humanos , Leishmania braziliensis/classificação , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Masculino , Mesocricetus/parasitologia , Pele/parasitologia
10.
Parasitol Res ; 117(6): 1839-1845, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29675681

RESUMO

Leishmaniasis represents a complex of diseases with a broad clinical spectrum and epidemiological diversity. Involving a variety of agents, reservoirs, and vectors, cutaneous leishmaniasis (CL) presents different transmission patterns, which makes its control especially difficult. Epidemiological characterization with identification of existing Leishmania species in a particular region is essential for understanding this parasitosis epidemiology. Because similar results may be observed in places with overlapping transmission of visceral and cutaneous leishmaniasis, contributing to knowledge about the epidemiological cycle of cutaneous leishmaniasis is of global interest. This study proposes to identify the different species of Leishmania present in human CL cases in the state of Mato Grosso do Sul, Brazil. Slides of imprint tissue were selected from patients diagnosed with CL from 2009 to 2013 at the Laboratório de Parasitologia Clínica, Universidade Federal de Mato Grosso do Sul. The slides were scraped and extracted genetic material was amplified with PCR addressing the Leishmania spp. kDNA region. The reaction product was subjected to RFLP for the specific identification of Leishmania. Forty-three samples (82.7%) amplified with PCR were considered positive. Of these, it was possible to determine the species in 40 samples (76.9%) through analysis of electrophoresis profiles. Leishmania (Viannia) braziliensis, Leishmania (Leishmania) amazonensis, and Leishmania (Leishmania) infantum were identified as the etiologic agents of CL in Mato Grosso do Sul. The results of this study permit a more detailed understanding of CL epidemiology and the geographical distribution of its agents.


Assuntos
DNA de Cinetoplasto/genética , Leishmania braziliensis/isolamento & purificação , Leishmania infantum/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Leishmaniose Visceral/epidemiologia , Adulto , Animais , Brasil/epidemiologia , Eletroforese , Feminino , Humanos , Leishmania braziliensis/genética , Leishmania infantum/genética , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/transmissão , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
11.
Parasitology ; 145(9): 1161-1169, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29526166

RESUMO

American tegumentary leishmaniasis (ATL) samples obtained from the lesions of patients with typical (n = 25, 29%), atypical (n = 60, 69%) or both (n = 2%) clinical manifestations were analysed by multilocus enzyme electrophoresis, hsp70 restriction-fragment length polymorphism (PCR-RFLP), hsp70 sequencing and phylogenetics methods. The hsp70 PCR-RFLP analysis revealed two different profiles whose the most samples differed from those expected for Leishmania braziliensis and the other Leishmania species tested: of 39 samples evaluated, two (5%) had a restriction profile corresponding to L. braziliensis, and 37 (95%) had a restriction profile corresponding to a variant pattern. A 1300-bp hsp70 gene fragment was sequenced to aid in parasite identification and a phylogenetic analysis was performed including 26 consensus sequences from the ATL patient's samples and comparing to other Leishmania and trypanosomatids species. The dendrogram allowed to observe a potential population structure of L. braziliensis complex in the studied region, emphasizing that the majority of clinical samples presented a variant genetic profile. Of interest, the L. braziliensis diversity was associated with different clinical manifestations whose parasites with hsp70 variant profile were associated with atypical lesions. The results may be helpful to improve the diagnosis, treatment and control measures of the ATL in endemic areas.


Assuntos
Variação Genética , Leishmania braziliensis/genética , Leishmaniose Cutânea/epidemiologia , Pele/parasitologia , Brasil/epidemiologia , DNA de Protozoário/genética , Doenças Endêmicas , Proteínas de Choque Térmico HSP70/genética , Humanos , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Pele/patologia
12.
J Immunol Methods ; 455: 34-40, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29395166

RESUMO

A relevant issue in Chagas disease serological diagnosis regards the requirement of using several confirmatory methods to elucidate the status of non-negative results from blood bank screening. The development of a single reliable method may potentially contribute to distinguish true and false positive results. Our aim was to evaluate the performance of the multiplexed flow-cytometry anti-T. cruzi/Leishmania IgG1 serology/(FC-TRIPLEX Chagas/Leish IgG1) with three conventional confirmatory criteria (ELISA-EIA, Immunofluorescence assay-IIF and EIA/IIF consensus criterion) to define the final status of samples with actual/previous non-negative results during anti-T. cruzi ELISA-screening in blood banks. Apart from inconclusive results, the FC-TRIPLEX presented a weak agreement index with EIA, while a strong agreement was observed when either IIF or EIA/IIF consensus criteria were applied. Discriminant analysis and Spearman's correlation further corroborates the agreement scores. ROC curve analysis showed that FC-TRIPLEX performance indexes were higher when IIF and EIA/IIF consensus were used as a confirmatory criterion. Logistic regression analysis further demonstrated that the probability of FC-TRIPLEX to yield positive results was higher for inconclusive results from IIF and EIA/IIF consensus. Machine learning tools illustrated the high level of categorical agreement between FC-TRIPLEX versus IIF or EIA/IIF consensus. Together, these findings demonstrated the usefulness of FC-TRIPLEX as a tool to elucidate the status of non-negative results in blood bank screening of Chagas disease.


Assuntos
Anticorpos Antiprotozoários/análise , Doença de Chagas/diagnóstico , Imunoglobulina G/análise , Leishmania/imunologia , Leishmaniose/diagnóstico , Testes Sorológicos/métodos , Trypanosoma cruzi/imunologia , Bancos de Sangue , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Humanos , Modelos Logísticos , Aprendizado de Máquina , Programas de Rastreamento
13.
Histol Histopathol ; 33(7): 705-716, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29345298

RESUMO

Leishmania amazonensis is a major etiological agent of human cutaneous leishmaniasis in the Americas; nevertheless there are some reports of this species causing visceral disease in dogs and men. In the present work we have studied a Leishmania strain isolated from a human case of visceral leishmaniasis. We have infected different mouse strains and analyzed the development of the disease, studying the parasite's ability to visceralize and whether this ability is influenced by host genetics. Female BALB/c, C57BL/6, C57BL/10, CBA, DBA/2, and C3H/He mice were subcutaneously infected with 104 L. amazonensis amastigotes. BALB/c, C57BL/6 and C57BL/10 mice were found to be very susceptible to infection, showing lesions that developed to necrosis and ulceration. CBA mice developed a late but severe lesion. DBA/2 mice developed only discrete lesions, while C3H/He mice did not develop any lesions. All mouse strains except C3H/He showed some degree of visceralization, presenting parasites in the spleen, while BALB/c, C57BL/6 and CBA presented parasites also in the liver. Moreover, most of the strains presented high parasite load at the infection site, whereas DBA and C3H/He mice showed low or no parasite load 90 days after infection, respectively. Histopathology corroborates the results, showing that susceptible mice presented an inflammatory reaction with parasites in the skin, lymph nodes and spleen, while strains that are more resistant presented low parasitism and discrete inflammatory reaction. Results indicate that this isolate is extremely virulent, can easily visceralize and that the pathogenesis of leishmaniasis is, at least in part, related to the genetic background of the host.


Assuntos
Leishmania/parasitologia , Leishmaniose Visceral/patologia , Leishmaniose Visceral/parasitologia , Animais , Suscetibilidade a Doenças , Feminino , Humanos , Camundongos
14.
PLoS One ; 12(12): e0190315, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29284049

RESUMO

Leishmaniases are parasitic diseases transmitted to mammalian hosts by sand fly vectors (Diptera: Psychodidae). Despite the increasing occurrence of visceral and cutaneous leishmaniasis cases in urban centers, their transmission still occur primarily in wild environments and may be associated with professional activities and recreation, such as ecotourism. The Reserva Particular do Patrimônio Natural Santuário do Caraça (RPPNSC) is one of the largest ecotourism attractions in the State of Minas Gerais, Brazil, and comprises an area of environmental preservation with 11,233 hectares presenting a transitional vegetation between Cerrado and Atlantic Forest. The present study describes the abundance of small mammals in RPPNSC, the isolation and identification of Leishmania in five wild animals. Small mammals were bimonthly trapped along 6 trails within the RPPNSC with 10 Tomahawk traps each. Two trails were located in peridomiciliary areas near tourist lodging facilities, and four trails were located at sites visited by tourists in forest areas. The most prevalent species were Akodon cursor, Cerradomys subflavus and Oligoryzomys nigripes. Six isolates of Leishmania were obtained from these animals and identified as Leishmania braziliensis through HSP70-PCR RFLP method. Leishmania spp. DNA was detected by kDNA-PCR method and isolated by biphasic culture. Studies point to some of the captured species as potential wild reservoirs of Leishmania, suggesting they may be involved in the transmission cycle in these wild environments.


Assuntos
Leishmania braziliensis/isolamento & purificação , Mamíferos/parasitologia , Animais , Brasil/epidemiologia
15.
PLoS One ; 12(11): e0187704, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29176902

RESUMO

Knowledge of potential reservoirs of Leishmania spp. in an anthropic environment is important so that surveillance and control measures can be implemented. The aim of this study was to investigate the infection by Leishmania in small mammals in an area located in Minas Gerais, Brazil, that undergoes changes in its natural environment and presents autochthonous human cases of cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). For the capture of the animals, Sherman and Tomahawk traps were used and distributed in the peridomicile of houses with reports of autochthonous cases of CL or VL. Six catches were carried out on two consecutive nights with intervals of two months during one year and samples of spleen, liver, tail skin, ear skin and bone marrow of the animals were obtained. Parasitological and molecular methods were used to detect the infection. Identification of the Leishmania species was performed by PCR RFLPhsp70. Twenty five animals of four species were captured: ten Rattus rattus, nine Didelphis albiventris, five Cerradomys subflavus and one Marmosops incanus. In the PCR-hsp70, five animals were positive (20%). The Leishmania species identified in PCR-RFLPhsp70 were: Leishmania braziliensis in D. albiventris (2), C. subflavus (1) and R. rattus (1) and Leishmania infantum in R. rattus (1). The highest positivity rate for L. braziliensis was obtained in the liver samples. The spleen was the only tissue positive for L. infantum. It was isolated in culture medium L. braziliensis from two samples (liver and spleen) of R. rattus. This is the first record of isolation of L. braziliensis from R. rattus in the southeastern region of Brazil. These results are relevant to the knowledge of the epidemiology of leishmaniasis in the region, mainly in the investigation of the presence of hosts and possible reservoirs of the parasite.


Assuntos
Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Mamíferos/parasitologia , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/parasitologia , Animais , Brasil/epidemiologia , Proteínas de Choque Térmico HSP70/metabolismo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ratos
16.
Acta Trop ; 172: 217-222, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28502644

RESUMO

In the New World genus Leishmania parasites are etiological agents of neglected zoonoses known as leishmaniasis. Its epidemiology is very complex due to the participation of several species of sand fly vectors and mammalian hosts, and man is an accidental host. Control is very difficult because of the different epidemiological patterns of transmission observed. Studies about Leishmania spp. infection in bats are so scarce, which represents a large gap in knowledge about the role of these animals in the transmission cycle of these pathogens, especially when considering that Chiroptera is one of the most abundant and diverse orders among mammals. Leishmaniasis in Mato Grosso do Sul, Brazil are remarkably frequent, probably due to the abundance of its regional mastofauna. The recent record of L. braziliensis in bats from this state indicates the need to clarify the role of these mammals in the transmission cycle. In this study we evaluated the presence of Leishmania parasites in the skin of different species of bats, using PCR directed to Leishmania spp. kDNA for screening followed by PCR/RFLP analysis of the hsp70 gene for the identification of parasite species. Leishmania species identification was confirmed by PCR directed to the G6PD gene of L. braziliensis, followed by sequencing of the PCR product. Samples from 47 bats were processed, of which in three specimens (6.38%) was detected the presence of Leishmania sp. kDNA. PCR/RFLP and sequencing identified the species involved in the infection as L. braziliensis in all of them. This is the first report of Leishmania braziliensis in bats from Pantanal ecosystem and the first record of this species in Platyrrhinus lineatus and Artibeus planirostris, bats with a wide distribution in South America. These results reinforce the need to deepen the knowledge about the possibility of bats act as reservoirs of Leishmania spp. especially considering their ability of dispersion and occupation of anthropic environments.


Assuntos
Quirópteros/parasitologia , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/veterinária , Animais , Brasil/epidemiologia , DNA de Cinetoplasto/genética , Humanos , Leishmania braziliensis/genética , Leishmaniose Cutânea/parasitologia , Áreas Alagadas , Zoonoses
17.
Mem. Inst. Oswaldo Cruz ; 112(4): 309-318, Apr. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-841787

RESUMO

BACKGROUND Leishmaniases are a serious health problem in southeast Brazil, including the city of Belo Horizonte (BH), Minas Gerais state (MG), where there are high rates of incidence and mortality due to visceral leishmaniases. BH is divided into nine sanitary districts (SD) of which one, the Venda Nova SD, was selected for this study because it has high rates of positivity for canine leishmaniasis and high incidence of human leishmaniasis. OBJECTIVES This study aimed to survey the sand fly fauna in Venda Nova SD from August 2011 to July 2013 and perform a descriptive analysis of the vector population. METHODS The sampling was carried out using automatic HP light traps at all covered areas of the Venda Nova SD, in a total of eighteen light traps. Sampled specimens were identified following Galati (2003), and females were submitted to molecular techniques for the detection and identification of Leishmania DNA. A simple environmental description was done for it area and Kernel estimation was used to infer vector density for each study site. FINDINGS A total of 2,427 sand fly specimens belonging to eight species and five genera were collected of which 95.3% were Lutzomyia longipalpis. The seasonal variation curve was delineated by this species. Lu. longipalpis was the most abundant at all collection points and in all months of the study, and exhibited a natural infection rate of 1.01% for Leishmania infantum and 1.77% for Leishmania braziliensis. MAIN CONCLUSIONS The results show the presence and adaptation of Lu. longipalpis to the anthropic environment of BH and reinforces its role as the main vector of L. infantum in the region.


Assuntos
Humanos , Animais , Masculino , Feminino , Cães , Psychodidae/classificação , Psychodidae/parasitologia , Leishmaniose/transmissão , DNA de Protozoário/análise , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Leishmania/classificação , Leishmania/genética , Estações do Ano , Brasil , Densidade Demográfica
18.
Mem Inst Oswaldo Cruz ; 112(4): 309-318, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28327794

RESUMO

BACKGROUND: Leishmaniases are a serious health problem in southeast Brazil, including the city of Belo Horizonte (BH), Minas Gerais state (MG), where there are high rates of incidence and mortality due to visceral leishmaniases. BH is divided into nine sanitary districts (SD) of which one, the Venda Nova SD, was selected for this study because it has high rates of positivity for canine leishmaniasis and high incidence of human leishmaniasis. OBJECTIVES: This study aimed to survey the sand fly fauna in Venda Nova SD from August 2011 to July 2013 and perform a descriptive analysis of the vector population. METHODS: The sampling was carried out using automatic HP light traps at all covered areas of the Venda Nova SD, in a total of eighteen light traps. Sampled specimens were identified following Galati (2003), and females were submitted to molecular techniques for the detection and identification of Leishmania DNA. A simple environmental description was done for it area and Kernel estimation was used to infer vector density for each study site. FINDINGS: A total of 2,427 sand fly specimens belonging to eight species and five genera were collected of which 95.3% were Lutzomyia longipalpis. The seasonal variation curve was delineated by this species. Lu. longipalpis was the most abundant at all collection points and in all months of the study, and exhibited a natural infection rate of 1.01% for Leishmania infantum and 1.77% for Leishmania braziliensis. MAIN CONCLUSIONS: The results show the presence and adaptation of Lu. longipalpis to the anthropic environment of BH and reinforces its role as the main vector of L. infantum in the region.


Assuntos
DNA de Protozoário/análise , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Psychodidae/parasitologia , Animais , Brasil , Cães , Feminino , Humanos , Insetos Vetores/classificação , Leishmania/classificação , Leishmania/genética , Leishmaniose/transmissão , Masculino , Densidade Demográfica , Psychodidae/classificação , Estações do Ano
19.
Artigo em Inglês | MEDLINE | ID: mdl-27007566

RESUMO

Cutaneous leishmaniasis is caused by different species of the Leishmania genus. Leishmania(Leishmania) infantum, causing cutaneous leishmaniasis, has been described in patients living in areas where visceral leishmaniasis is endemic. In this study, it was possible to characterize this species in seven slides from cutaneous tissue imprints from patients with cutaneous leishmaniasis in the State of Mato Grosso do Sul, Brazil.


Assuntos
DNA de Protozoário/análise , Leishmania infantum/genética , Leishmaniose Cutânea/parasitologia , Brasil/epidemiologia , Humanos , Leishmania infantum/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
20.
J Med Entomol ; 53(3): 533-540, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26839335

RESUMO

The adult female of the sand fly species Martinsmyia minasensis (Mangabeira, 1942) is described, and the characters of the genus Martinsmyia Galati, 1995 are defined. We performed morphometric analyses on the spermatheca and wings, and present data on the geographical distribution of M. minasensis, as well as an identification key to females of this genus. The specimens were measured, drawn, photographed, and compared with the similar species M. oliveirai. It was possible to distinguish between M. minasensis and M. oliveirai based on differences found in the common and individual ducts of the spermatheca, as well as wing shape and size.


Assuntos
Phlebotomus/anatomia & histologia , Phlebotomus/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Feminino , Masculino , Tamanho do Órgão , Phlebotomus/genética , Phlebotomus/crescimento & desenvolvimento , Filogenia , Asas de Animais/anatomia & histologia , Asas de Animais/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA