Detecção de Leishmania sp. em pequenos mamíferos silvestres e sinantrópicos no município de Belo Horizonte,MG

Submitted by Nuzia Santos ([email protected]) on 2017-08-23T17:13:43Z No. of bitstreams: 1 Lutiana Amaral de Melo.pdf: 23055499 bytes, checksum: 9653be05ad766a0d0b5fffbc4753136f (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2017-08-23T17:18:28Z (GMT) No. of bitstreams: 1 Lutiana Amaral de Melo.pdf: 23055499 bytes, checksum: 9653be05ad766a0d0b5fffbc4753136f (MD5)Made available in DSpace on 2017-08-23T17:18:28Z (GMT). No. of bitstreams: 1 Lutiana Amaral de Melo.pdf: 23055499 bytes, checksum: 9653be05ad766a0d0b5fffbc4753136f (MD5) Previous issue date: 2008CPqRRPAPES – IV FIOCRUZComunidade EuropéiaPIBIC-CNPqFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil.As Leishmanioses do Novo Mundo são classicamente caracterizadas com o zoonoses de ecótopos silvestres. No entanto, os parasitos do gênero Leishmania têm demonstrado ao longo dos anos uma notável plasticidade, exemplificada pela diversidade de espécies deste gênero encontrada nas Américas, bem como sua adaptação a diferentes vetor es e hospedeiros. Foi esta capacidade de adaptação que, lhes permitiu persistir, ao long o dos anos, frente às mudanças ecológicas impostas pelo comportamento humano. As profundas modi ficações ambientais, em razão do desmatamento e da urbanização descontrola da podem resultar na extinção de espécies vetoras e hospedeiras e na subseqüente adaptaçã o e interação dos parasitos com novas espécies. A interação parasito-vetor-hospedeiro no contexto das leishmanioses é complexa e dinâmica. Um processo de “sinantropizaç ão” do ciclo de transmissão envolvendo hospedeiros como o cão doméstico, vem sendo observado para a Leishmaniose Visceral e de forma mais lenta e menos evidente, também para a Leishmaniose Tegumentar. Belo Horizonte, nos últimos 20 anos, caracterizou-se com o região endêmica para leishmanioses. Estudos epidemiológicos para busca ativa de reserva tórios silvestres destas doenças são escassos no país e em Belo Horizonte não há qualquer estudo prévio. Com o objetivo de detectar a presença de Leishmania sp. em pequenos mamíferos, silvestres e sinantrópicos, capturados na Regional Nordeste em Belo Horizonte, MG , foram colocadas armadilhas no peridomicílio e em fragmentos de mata da área de estudo. Os animais capturados foram sacrificados e amostras biológicas (baço, fígado, pele, sangue, medula óssea) foram coletadas para a detecção da infecção através de métodos parasitológicos (cultura) e moleculares. Durante o período de coletas (junho ⁄ 2006 a junho ⁄ 2007) foram capturados (1) Akodon sp., (4) Bolomys lasiurus , (22) Mus musculus , (5) Oryzomys grupo subflavus , (9) Rattus novergicus , (19) Rattus rattus entre roedores e (33) Didelphis albiventris e (1) D. aurita, marsupiais, além de (2) Galictis sp., carnívoro. Dentre os animais capturados, dois espécimes de gambás apresentaram formas flageladas na c ultura de medula. Detectou-se infecção mista, por T. cruzi e T. rangeli, através da PCR em um dos isolados, tendo sido confirmada a infecção por T. cruzi através de isoenzimas. O outro isolado foi identificado como Leishmania (Leishmania ) através de testes moleculares e isoenzimas. Além disso, 28 animais (29%), das diferentes ordens, apresentaram-se positivos na PCR convencional para o gênero Leishmania . Destaca-se, pela primeira vez, o achado de Leishmania (Viannia) em D. aurita, Galictis sp., Mus musculus e Rattus novergicus . Nas amostras de tecido identificou-se, através da PCR-RFLP e da hibridização com sondas subgênero especí ficas, Leishmania ( Viannia) como agente etiológico. Provavelmente, trata-se de L. (V.) braziliensis, pois esta tem sido a única espécie deste subgênero isolada na área. Esta espécie circula entre os mamíferos sinantrópicos, roedores e gambás, capturados tanto na área verde quanto peridomiciliar, urbana e densamente habitada. Inquéritos entomológicos , na mesma área, têm encontrado Lutzomyia whitmani como a espécie mais freqüentemente capturada. Diante disso, observa-se que, todos os elos da cadeia epidemiológica de transmissão de LTA, agente etiológico, vetor, animais infectados apresentando parasitismo cutâne o e o homem, coexistem neste ambiente. Sendo assim, é possível que estes animais possam, em determinadas circunstâncias, participar do ciclo de transmissão. No entanto, a sua real contribuição deve ser objeto de investigações complementares que envolvam, por exemplo, xenodiag nóstico e quantificação da carga parasitária.In the New World, the leishmaniasis are classically chara cterized as zoonoses of sylvatic ecotopes. Nevertheless, Leishmania parasites have demonstrated a remarkable plasticity, e.g. a diversity of species of this genus found in the Americas, as w ell as their adaptation to different vectors and hosts. This adaptation capacity has allowe d them to subsist along the years in the presence of ecological changes imposed by the human behavior. The profound environmental changes due to deforestation and the uncontrolled urbanization can cause the extinction of some vector and host species, and the subsequent adaptation a nd interaction of the parasites with new species. The interaction parasite-vec tor-host in the context of leishmaniasis is complex and dynamic. A incorporation process of o thers hosts to the transmission cycle, such as the domestic dog, is being observed i n studies of visceral and cutaneous leishmaniasis, although in the last case in a slower and less evident manner. In the last 20 years, Belo Horizonte has been characterized as an endemic region for leishmaniasis. Epidemiological studies for searching sylvatic reservoirs of thes e diseases are scant in our country, and in Belo Horizonte there are no previous studies. With t he purpose to detect the presence of Leishmania sp. in small mammals in northeastern Belo Horizonte, MG, vari ous traps were placed in the household surroundings and remains of the woods in the research area. The captured animals were sacrificed, and biological samples (spleen, liver, skin, blood, bone marrow) were gathered for detection of the infection by means of parasitological (culture) and molecular methods. Throughout the collecting period (June/2006 t o June/2007), the following animals were captured: (1) Akodon sp., (4) Bolomys lasiurus , (22) Mus musculus , (5) Oryzomys group subflavus , (9) Rattus norvegicus , (19) Rattus rattus among the rodents, and (3) Didelphis albiventris and (1) D. aurita , opossums, besides (2) Galictis sp., carnivore. Among these captured animals, two specimens of opossums s howed flagellated forms in the culture. A mixed infection T. cruzi / T. rangeli was detected in one of the isolates by means of PCR. The T. cruzi infection was confirmed by isoenzymes. Another isolate was identified as Leishmania ( Leishmania ) via molecular tests and isoenzymes. It was further observed that 28 animals (29%), from different orders, were PCR positive for Leishmania and the tissues more frequently positive were skin and kidney. It wa s possible to identify the causative agent as Leishmania (Viannia) when PCR-RFLP and hybridization with specific subgenus probes were used. Probably, it is concerned with L. (V.) braziliensis , since this is the only species of this subgenus isolated in the studied area . This species could be found among synanthropic mammals, rodents and opossums, captured either i n the green area or in the household surroundings, urban and crowded inhabited area. Entomol ogical surveys in the same area have shown Lutzomyia whitmani as the species most frequently captured. These findings show that all links of the epidemiological cycle of ATL, etiological agent, vector, infected animals presenting cutaneous parasitism and humans coexist in the same environment. Thus, it is possible that these animals can participat e in the transmission cycle under specific circumstances. Nevertheless, their real contr ibution must be the target of further investigation

Endogenous phospholipase A2 inhibitors in snakes: a brief overview

Abstract The blood plasma of numerous snake species naturally comprises endogenous phospholipase A2 inhibitors, which primarily neutralize toxic phospholipases A2 that may eventually reach their circulation. This inhibitor type is generally known as snake blood phospholipase A2 inhibitors (sbPLIs). Most, if not all sbPLIs are oligomeric glycosylated proteins, although the carbohydrate moiety may not be essential for PLA2 inhibition in every case. The presently known sbPLIs belong to one of three structural classes – namely sbαPLI, sbβPLI or sbγPLI – depending on the presence of characteristic C-type lectin-like domains, leucine-rich repeats or three-finger motifs, respectively. Currently, the most numerous inhibitors described in the literature are sbαPLIs and sbγPLIs, whereas sbβPLIs are rare. When the target PLA2 is a Lys49 homolog or an Asp49 myotoxin, the sbPLI is denominated a myotoxin inhibitor protein (MIP). In this brief overview, the most relevant data on sbPLIs will be presented. Representative examples of sbαPLIs and sbγPLIs from two Old World – Gloydius brevicaudus and Malayopython reticulatus – and two New World – Bothrops alternatus and Crotalus durissus terrificus – snake species will be emphasized

Relationship of Leishmania-specific IgG levels and IgG avidity with parasite density and clinical signs in canine leishmaniasis.

The clinical status and tissue parasite burden of the skin and spleen of 40 dogs naturally infected with Leishmania chagasi (syn. Leishmania infantum), together with 5 uninfected control dogs, were assessed. On the basis of the clinical evaluation, infected dogs were classified as asymptomatic (AD) or symptomatic (SD). Infected animals were also grouped according to their parasite load as exhibiting low (LP), medium (MP) and high (HP) parasitism. The results indicated a high parasite load in the skin samples of SD animals in relation to the AD group. The serum immunoglobin isotype profiles of the studied animals revealed increased levels of IgG 1 in the AD and LP dogs, whereas high levels of IgG 2 were correlated with SD and HP dogs. The avidity index (AI) of IgG total in the SD group was high in comparison of that of the AD group. Moreover, animals with a larger parasite burden either in the spleen or skin showed higher AI values than animals with lower parasitism. Based on these findings, it is suggested that CVL commences with an asymptomatic clinical form with low parasitism, high production of IgG 1 and low affinity of IgG total molecules, and evolves into a symptomatic clinical form with higher parasitism intensity, higher IgG 2 levels, and high affinity of IgG tota

Mixed infection of Leishmania infantum and Leishmania braziliensis in rodents from endemic urban area of the New World

Submitted by Nuzia Santos ([email protected]) on 2016-02-25T17:02:23Z No. of bitstreams: 1 Mixed infection of Leishmania infantum and Leishmania braziliensis in rodents from endemic urban area of the New World.pdf: 5842580 bytes, checksum: 3e0c063f3713e67c7c8fe7ef0cd646b3 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-02-25T17:10:22Z (GMT) No. of bitstreams: 1 Mixed infection of Leishmania infantum and Leishmania braziliensis in rodents from endemic urban area of the New World.pdf: 5842580 bytes, checksum: 3e0c063f3713e67c7c8fe7ef0cd646b3 (MD5)Made available in DSpace on 2016-02-25T17:10:22Z (GMT). No. of bitstreams: 1 Mixed infection of Leishmania infantum and Leishmania braziliensis in rodents from endemic urban area of the New World.pdf: 5842580 bytes, checksum: 3e0c063f3713e67c7c8fe7ef0cd646b3 (MD5) Previous issue date: 2015Fundação Oswaldo Cruz. Fundação Oswaldo Cruz Mato Grosso do Sul. Campo Grande, MS, Brasil.WHO Collaborating Center for Leishmaniasis. Servicio de Parasitología. Centro Nacional de Microbiología. Instituto de Salud Carlos III, Madri, Espanha.WHO Collaborating Center for Leishmaniasis. Servicio de Parasitología. Centro Nacional de Microbiología. Instituto de Salud Carlos III, Madri, Espanha.Fundação Ezequiel Dias. Diretoria de Pesquisa e Desenvolvimento. Serviço de Biologia Molecular e Bioinformática. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Grupo de Estudos em Leishmanioses. Belo Horizonte, MG, Brasil.Sete Soluções e Tecnologias Ambientais. Belo Horizonte, MG, Brasil.Prefeitura de Belo Horizonte. Secretaria de Saúde de Belo Horizonte, Belo Horizonte, MG, Brasil.Sete Soluções e Tecnologias Ambientais. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Biologia Geral. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Grupo de Estudos em Leishmanioses. Belo Horizonte, MG, Brasil.BACKGROUND: In Brazil Leishmania braziliensis and L. infantum are the principal species responsible for cutaneous and visceral leishmaniases, respectively. Domestic dogs are the main reservoirs of visceral leishmaniasis, while rodents and marsupials are the main reservoirs for cutaneous leishmaniasis. It has also been suggested that dogs could play a role in transmission of cutaneous leishmaniasis. The identification of the species of Leishmania, the reservoirs, and the vectors involved in each particular transmission cycle is critical for the establishment of control activities. Belo Horizonte has emerged as an endemic region for leishmaniases, however, epidemiological studies assessing the contribution of wild reservoirs to transmission are scarce in the area. The aim of this study was to investigate Leishmania spp. infection in possible reservoirs of an urbanized area. RESULTS: A high rate of infection was found in small mammals (64.9%) and dogs (DG1 30.4% and DG2 48.6%). The presence of L. infantum and L. braziliensis was detected in small mammals and dogs, and mixed infections by both species were detected in rodents which, to the best of our knowledge, is the first description of this phenomenon in an urban area. Additionally, L. amazonensis was detected in the canine samples. CONCLUSION: The possible role of these animals as a source of infection of the vector of each species of Leishmania identified should not be overlooked and should be taken into account in future control activities. The results of mixed infection by L. braziliensis and L. infantum in cosmopolitan rodents as M. musculus and R. rattus, may have important implications in the context of the control of leishmaniasis in urban areas, especially when considering that these rodents live in close relationship with human dwellings, especially those in more precarious condition

Relationship of Leishmania-specific IgG levels and IgG avidity with parasite density and clinical signs in canine leishmaniasis.

The clinical status and tissue parasite burden of the skin and spleen of 40 dogs naturally infected with Leishmania chagasi (syn. Leishmania infantum), together with 5 uninfected control dogs, were assessed. On the basis of the clinical evaluation, infected dogs were classified as asymptomatic (AD) or symptomatic (SD). Infected animals were also grouped according to their parasite load as exhibiting low (LP), medium (MP) and high (HP) parasitism. The results indicated a high parasite load in the skin samples of SD animals in relation to the AD group. The serum immunoglobin isotype profiles of the studied animals revealed increased levels of IgG 1 in the AD and LP dogs, whereas high levels of IgG 2 were correlated with SD and HP dogs. The avidity index (AI) of IgG total in the SD group was high in comparison of that of the AD group. Moreover, animals with a larger parasite burden either in the spleen or skin showed higher AI values than animals with lower parasitism. Based on these findings, it is suggested that CVL commences with an asymptomatic clinical form with low parasitism, high production of IgG 1 and low affinity of IgG total molecules, and evolves into a symptomatic clinical form with higher parasitism intensity, higher IgG 2 levels, and high affinity of IgG tota

Insights on the structure of native CNF, an endogenous phospholipase A(2) inhibitor from Crotalus durissus terrificus, the South American rattlesnake

Several snake species possess endogenous phospholipase A(2) inhibitors (sbPLIs) in their blood plasma, the primary role of which is protection against an eventual presence of toxic phospholipase A(2) (PLA(2)) from their venom glands in the circulation. These inhibitors have an oligomeric structure of, at least, three subunits and have been categorized into three classes (alpha, beta and gamma) based on their structural features. sb gamma PLIs have been further subdivided into two subclasses according to their hetero or homomeric nature, respectively. Despite the considerable number of sb gamma PLIs described, their structures and mechanisms of action are still not fully understood. In the present study, we focused on the native structure of CNF, a homomeric sb gamma PLI from Crotalus durissus terrificus, the South American rattlesnake. Based on the results of different biochemical and biophysical experiments, we concluded that, while the native inhibitor occurs as a mixture of oligomers, tetrameric arrangement appears to be the predominant quaternary structure. The inhibitory activity of CNF is most likely associated with this oligomeric conformation. In addition, we suggest that the CNF tetramer has a spherical shape and that tyrosinyl residues could play an important role in the oligomerization. The carbohydrate moiety, which is present in most sb gamma PLIs, is not essential for the inhibitory activity, oligomerization or complex formation of the CNF with the target PLA(2). A minor component, comprising no more than 16% of the sample, was identified in the CNF preparations. The amino-terminal sequence of that component is similar to the B subunits of the heteromeric sb gamma PLIs; however, the role played by such molecule in the functionality of the CNF, if any, remains to be determined. (C) 2014 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES