593 resultados para neotropical Leishmania


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Here we present the first in a series of articles about the ecology of immature stages of anophelines in the Brazilian Yanomami area. We propose a new larval habitat classification and a new larval sampling methodology. We also report some preliminary results illustrating the applicability of the methodology based on data collected in the Brazilian Amazon rainforest in a longitudinal study of two remote Yanomami communities, Parafuri and Toototobi. In these areas, we mapped and classified 112 natural breeding habitats located in low-order river systems based on their association with river flood pulses, seasonality and exposure to sun. Our classification rendered seven types of larval habitats: lakes associated with the river, which are subdivided into oxbow lakes and nonoxbow lakes, flooded areas associated with the river, flooded areas not associated with the river, rainfall pools, small forest streams, medium forest streams and rivers. The methodology for larval sampling was based on the accurate quantification of the effective breeding area, taking into account the area of the perimeter and subtypes of microenvironments present per larval habitat type using a laser range finder and a small portable inflatable boat. The new classification and new sampling methodology proposed herein may be useful in vector control programs.

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In the Brazilian Amazon, American tegumentary leishmaniasis (ATL) is endemic and presents a wide spectrum of clinical manifestations due, in part, to the circulation of at least seven Leishmaniaspecies. Few reports of Leishmania (Viannia) naiffiinfection suggest that its occurrence is uncommon and the reported cases present a benign clinical course and a good response to treatment. This study aimed to strengthen the clinical and epidemiological importance of L. (V.) naiffiin the Amazon Region (Manaus, state of Amazonas) and to report therapeutic failure in patients infected with this species. Thirty Leishmania spp samples isolated from cutaneous lesions were characterised by multilocus enzyme electrophoresis. As expected, the most common species was Leishmania (V.) guyanensis (20 cases). However, a relevant number ofL. (V.) naiffi patients (8 cases) was observed, thus demonstrating that this species is not uncommon in the region. No patient infected withL. (V.) naiffievolved to spontaneous cure until the start of treatment, which indicated that this species may not have a self-limiting nature. In addition, two of the patients experienced a poor response to antimonial or pentamidine therapy. Thus, either ATL cases due to L. (V.) naifficannot be as uncommon as previously thought or this species is currently expanding in this region.

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Leishmania donovani is the known causative agent of both cutaneous (CL) and visceral leishmaniasis in Sri Lanka. CL is considered to be under-reported partly due to relatively poor sensitivity and specificity of microscopic diagnosis. We compared robustness of three previously described polymerase chain reaction (PCR) based methods to detectLeishmania DNA in 38 punch biopsy samples from patients presented with suspected lesions in 2010. Both, Leishmaniagenus-specific JW11/JW12 KDNA and LITSR/L5.8S internal transcribed spacer (ITS)1 PCR assays detected 92% (35/38) of the samples whereas a KDNA assay specific forL. donovani (LdF/LdR) detected only 71% (27/38) of samples. All positive samples showed a L. donovani banding pattern upon HaeIII ITS1 PCR-restriction fragment length polymorphism analysis. PCR assay specificity was evaluated in samples containing Mycobacterium tuberculosis, Mycobacterium leprae, and human DNA, and there was no cross-amplification in JW11/JW12 and LITSR/L5.8S PCR assays. The LdF/LdR PCR assay did not amplify M. leprae or human DNA although 500 bp and 700 bp bands were observed in M. tuberculosis samples. In conclusion, it was successfully shown in this study that it is possible to diagnose Sri Lankan CL with high accuracy, to genus and species identification, using Leishmania DNA PCR assays.

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Studies on natural infection by Leishmania spp of sandflies collected in endemic and nonendemic areas can provide important information on the distribution and intensity of the transmission of these parasites. This study sought to investigate the natural infection by Leishmaniain wild female sandflies. The specimens were caught in the city of Corumbá, state of Mato Grosso do Sul (Brazil) between October 2012-March 2014, and dissected to investigate flagellates and/or submitted to molecular analysis to detect Leishmania DNA. A total of 1,164 females (77.56% of which were Lutzomyia cruzi) representing 11 species were investigated using molecular analysis; 126 specimens of Lu. cruziwere dissected and also submitted to molecular analysis. The infection rate based on the presence of Leishmania DNA considering all the sandfly species analysed was 0.69%; only Leishmania (Leishmania) amazonensis was identified in Lu. cruzi by the molecular analysis. The dissections were negative for flagellates. This is the first record of the presence of L. (L.) amazonensis DNA in Lu. cruzi, and the first record of this parasite in this area. These findings point to the need for further investigation into the possible role of this sandfly as vector of this parasite.

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In Brazil, human and canine visceral leishmaniasis (CVL) caused byLeishmania infantum has undergone urbanisation since 1980, constituting a public health problem, and serological tests are tools of choice for identifying infected dogs. Until recently, the Brazilian zoonoses control program recommended enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescence assays (IFA) as the screening and confirmatory methods, respectively, for the detection of canine infection. The purpose of this study was to estimate the accuracy of ELISA and IFA in parallel or serial combinations. The reference standard comprised the results of direct visualisation of parasites in histological sections, immunohistochemical test, or isolation of the parasite in culture. Samples from 98 cases and 1,327 noncases were included. Individually, both tests presented sensitivity of 91.8% and 90.8%, and specificity of 83.4 and 53.4%, for the ELISA and IFA, respectively. When tests were used in parallel combination, sensitivity attained 99.2%, while specificity dropped to 44.8%. When used in serial combination (ELISA followed by IFA), decreased sensitivity (83.3%) and increased specificity (92.5%) were observed. Serial testing approach improved specificity with moderate loss in sensitivity. This strategy could partially fulfill the needs of public health and dog owners for a more accurate diagnosis of CVL.

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During its life cycle Leishmania spp. face several stress conditions that can cause DNA damages. Base Excision Repair plays an important role in DNA maintenance and it is one of the most conserved mechanisms in all living organisms. DNA repair in trypanosomatids has been reported only for Old World Leishmania species. Here the AP endonuclease from Leishmania (L.) amazonensis was cloned, expressed in Escherichia coli mutants defective on the DNA repair machinery, that were submitted to different stress conditions, showing ability to survive in comparison to the triple null mutant parental strain BW535. Phylogenetic and multiple sequence analyses also confirmed that LAMAP belongs to the AP endonuclease class of proteins.

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Constrictotermes cyphergaster (Silvester, 1901) builds arboreal nests in Brazilian Cerrado stricto sensu, which are frequently cohabited by inquilines termites and by termitophiles. In a study made at the Parque Estadual da Serra de Caldas Novas, Goiás, Brazil, there were four nests with multiple reproductives, and secondary reproductives were found in 26 nests. Nymphs of Inquilinitermes were more abundant (9,47%) than nymphs of C. cyphergaster (0,78%).

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The Neotropical genus Xanthandrus Verral, 1901 is revised. Six species are redescribed: X. bucephalus (Wiedemann, 1830), X. cubanus Fluke, 1936, X. mellinoides (Macquart, 1846), X. mexicanus Curran, 1930, X. nitidulus Fluke, 1937, and X. plaumanni Fluke, 1937. Three species are included based on original descriptions: X. flavomaculatus Shannon, 1927, X. palliatus (Fluke, 1945), and X. simplex (Loew, 1861). New synonyms proposed: Argentinomyia longicornis (Walker, 1837) = Xanthandrus biguttatus Hull, 1945 syn. nov., and Xanthandrus bucephalus (Wiedemann, 1830) = Melanostoma quadrinotata Bigot, 1884 syn. nov. Description of terminalia, a key for Neotropical species, and illustrations are also presented.

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Unanthribus gen. nov. is proposed to include Unanthribus maximus sp. nov. (type species) described from Brazil (Pará), and U. grandis (Jordan, 1911) comb. nov., which is redescribed. The species are illustrated and keyed.

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Mallodon vermiculatus sp. nov. (from Panama) and Nothopleurus santacruzensis sp. nov. (from Bolivia) are described and illustrated. Mallodon dasystomus dasystomus (Say, 1824) = M. mandibularis Lackerbeck, 1998 syn. nov.

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Novos táxons descritos em Apomecynini: Eyiaba gen. nov., com duas espécies novas, E. picta sp. nov. (Brasil: São Paulo) e E. itapetinga sp. nov. (Brasil: Bahia); Adetus jacareacanga sp. nov. (Brasil: Pará) e Parmenonta dominicana sp. nov. (República Dominicana). Chave para identificação das espécies de Eyiaba é fornecida.

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In order to investigate the affinities of the hitherto considered Neotropical Cleomenini genera, a detailed morphological comparative study was carried out based on representatives of their type species and other congeneric species. The results, when compared with representatives of Cleomenes Thomson and other non Neotropical Cleomenini genera together with representatives of Rhopalophorini Blanchard and Rhinotragini Thomson, show that: 1) Listroptera Audinet-Serville, 1834, Dihammaphora Chevrolat, 1859, Haenkea Tippmann, 1953, Aguassay Napp & Mermudes, 2001 and Timabiara Napp & Mermudes, 2001 form a very homogeneous group, not related to other Cleomenini, but sharing several synapomorphies with the Rhopalophorini; therefore they are herein transferred to this tribe; 2) the affinities of Dihammaphoroides Zajciw, 1967, were not clearly defined, needing further investigations; nevertheless, the genus is tentatively included in Rhopalophorini due to its morphological similarity with Dihammaphora and allied genera; 3) Pandrosos Bates, 1867 is brought back to Rhinotragini, in which it was originally placed. Therefore, the tribe Cleomenini Lacordaire is no longer represented in the New World.

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O gênero Kroeberia e a espécie K. fuliginosa Lindner, 1930, são redescritos. Uma espécie nova, K. minor, é descrita do Brasil (Pará e Amazonas). As duas espécies são ilustradas e uma chave de identificação é fornecida.

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The following new taxa of South American Cercopidae are described: Ferorhinella gen. nov., with type species Sphenorhina brevis Walker, 1851; Deois (Deois) knighti sp. nov. (Brazil), Deois (Deois) sexpunctata sp. nov. (Brazil), Deois (Pandysia) constricta sp. nov. (Brazil), Mahanarva (Ipiranga) bahiaensis sp. nov. (Brazil), Maxantonia bifurcata sp. nov. (Brazil), Neosphenorhina curvipenis sp. nov. (Brazil), Sphenorhina brevispina sp. nov. (Ecuador), Sphenorhina nigricephala sp. nov. (Ecuador), Sphenorhina minuta sp. nov. (Brazil), Tropidorhinella onorei sp. nov. (Colombia), Zuata luteofascia sp. nov. (Colombia). Ferorhinella brevis (Walker, 1851) comb. nov. In addition, descriptions are given for a new colour form of Mahanarva (M.) phantastica (Breddin, 1904) and a newly found variation in the male genitalia of Deoisella fasciata Costa & Sakakibara, 2002.

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The following new species of South American Cercopidae, are described: Ischnorhina quadrimelasma sp. nov. (Bolivia), Laccogrypota quadrilineata sp. nov. (Bolivia), (Neolaccogrypota youngi sp. nov. (Peru), and Neosphenorhina schombergi sp. nov. (Brazil).