Lesions caused by Sarcocystis spp., parasites of opossums (Didelphis aurita), in acute and chronic infections in birds (Melopsittacus undulatus).

Protozoa of the genus Sarcocystis are obligatory heterogenous parasites with both definitive and intermediate hosts. Opossums (Didelphis aurita) can shed multiple species of Sarcocystis with birds as the intermediate host. The pathologies of Sarcocystis species in birds have not been thoroughly elucidated. Therefore, the aim of the present study to determine the main lesions that can occur in acute and chronic infections in intermediate hosts, when they ingest infective sporocysts that are shed in the opossum's feces, using budgerigars as a model. To this end, 12 budgerigars, Melopsittacus undulatus, were divided into two groups that received an inoculum with 60 and 120 sporocysts. Birds that died or were euthanized were necropsied, and the lung, tongue, liver, brain, heart, and skeletal striated muscles were collected and fixed in 10% formalin for histopathological analysis. The infectivity varied according to the sample and infective dose. Acute histopathological lesions were characterized by evidence of slightly degenerated hepatocyte cords that permeated the region of the blood vessel and hepatic sinusoids. Pulmonary tissue lesions were also observed in the parabronchial region with the presence of inflammatory infiltrates associated with areas of edema and atelectasis. In chronic infections, few mature cysts were observed in the chest, and many mature cysts in the thigh and tongue muscles. Thus, it was possible to conclude that lesions are highly characteristic in acute infection and, in chronic infections, cysts were present but without major lesions. In this case, the preferred organs of parasitism were the thigh and the tongue.

Detection of Trypanosoma cruzi DNA in false negative samples of collected triatomines, xenodiagnosis material, and biopsies of experimentally infected animals.

Direct test over the gut material from triatomine vectors and xenodiagnosis over mammalian hosts are classical techniques for Trypanosoma cruzi parasitological diagnosis. Nevertheless, negative results can be a source of uncertainty. Experimental models have allowed evaluating the tissue invasion of different strains of T. cruzi, but conventional techniques for tissue biopsies involve time-consuming and elaborated procedures and have low sensitivity. Gut material of collected triatomines (microscopically negative) (n = 114), material of mammal xenodiagnoses (microscopically negative) (n = 138), and biopsy material (microscopically negative) from experimentally infected animals (n = 34) with isolates from endemic areas of Chagas' disease from Venezuela were used for DNA extraction and PCR for the amplification of kinetoplast DNA (kDNA) and satellite DNA (sDNA) of T. cruzi. Positive PCR was observed in 53.6% of collected triatomine material, 15.8% of parasitological negative xenodiagnosis material, and 70.6% in biopsies, revealing underestimation by the parasitological tests and the valour of this analysis with preserved material. Anzoátegui was the state with the highest percentage of infection, and the triatomine species Rhodnius prolixus and Panstrongylus geniculatus had the highest percentages of infection. Didelphis marsupialis and Canis familiaris were the most infected by T. cruzi revealed by PCR of xenodiagnosis material. In addition, the PCR technique allowed demonstrating the invasion of T. cruzi in all tissues analyzed, constituting a molecular marker of tissue invasion.

Surveillance of phlebotomine fauna and Didelphis marsupialis (Didelphimorphia: Didelphidae) infection in an area highly endemic for visceral leishmaniasis in Colombia / Vigilancia de la fauna flebotomínea e infección de Didelphis marsupialis (Didelphimorphia: Didelphidae) en un área de alta endemia de leishmaniasis visceral en Colombia

Abstract Introduction: The study of the interaction between the parasite, the vector and the mammalian hosts, including man, allows to understand the behavior of the leishmaniases. Objective: To determine the presence of Lutzomyia species and to detect the Leishmania infection in Didelphis marsupialis in an endemic area for visceral leishmaniasis. Materials and methods: Phlebotomine fauna and individuals of D. marsupialis were collected with CDC and Tomahawk™ traps, respectively. The species of Lutzomyia were identified using the Young and Duncan key (1994). Ear and tail biopsies and blood samples from D. marsupialis were taken to identify the Leishmania species by amplifying a fragment of the gene associated with the 70 kD heat shock protein. Results: Seven Lutzomyia species were identified: Lu. evansi, Lu. gomezi, Lu. panamensis, Lu. dubitans, Lu. cayennensis cayennensis, Lu. rangeliana and Lu. trinidadensis. The first three species have epidemiological importance in Colombia because of their implications in the transmission of the Leishmania parasite. Sixty-five tissue samples from 19 D. marsupialis individuals were negative for Leishmania spp. Conclusions: The presence of the Lutzomyia species that have been identified as vectors for Leishmania inside and around houses in the village of El Bledo, in El Carmen de Bolívar represents a risk of infection. Furthermore, the presence of Lu. panamensis is reported for first time in El Carmen de Bolívar in Colombia. Although the lack of detection of Leishmania spp. in D. marsupialis samples may suggest that D. marsupialis does not play an important role in the transmission cycle of Leishmania in this region, it is necessary to carry out further longitudinal studies to confirm this hypothesis.

Resumen Introducción. El estudio de la interacción entre el parásito, el vector y los huéspedes mamíferos, incluido el hombre, permite entender el comportamiento de la leishmaniasis. Objetivo. Determinar la presencia de especies del género Lutzomyia y detectar la infección por Leishmania spp. en Didelphis marsupialis en un área endémica de leishmaniasis visceral. Materiales y métodos. Se recolectaron flebotomíneos y D. marsupialis con trampas CDC y Tomahawk™, respectivamente. Las especies de Lutzomyia se identificaron usando la clave de Young y Duncan, 1994. Se tomaron biopsias de oreja, cola y muestras de sangre de D. marsupialis para diagnosticar Leishmania spp. mediante la amplificación de un fragmento del gen de la proteína de choque térmico de 70 kD. Resultados. Se identificaron siete especies de Lutzomyia: Lu. evansi, Lu. gomezi, Lu. panamensis, Lu. dubitans, Lu. cayennensis cayennensis, Lu. rangeliana y Lu. trinidadensis. Las tres primeras especies son reconocidas como vectores en el país por estar implicadas en la transmisión de Leishmania spp. En total, 65 muestras de tejidos de oreja, cola y de sangre provenientes de 19 D. marsupialis fueron negativas para Leishmania spp. en la PCR-HSP70. Conclusiones. La presencia de flebotomíneos con importancia epidemiológica en la zona evaluada representa un riesgo de transmisión. Asimismo, Lu. panamensis es reportada por primera vez en El Bledo (Carmen de Bolívar). La ausencia de Leishmania spp. en D. marsupialis podría sugerir que esta especie no tiene un papel importante en el ciclo de transmisión de Leishmania en la vereda El Bledo, por lo que es necesario profundizar en estudios longitudinales para corroborar esta hipótesis.

Identification of opossums Didelphis aurita (Wied-Neuweid, 1826) as a definitive host of Sarcocystis falcatula-like sporocysts.

This study was conducted to identify the Sarcocystis species that infect the opossum Didelphis aurita in order to determine which sporocysts they are excreating in to the environment and help determine the role of D. aurita in the epidemiology of Sarcocystis. Sporocysts were obtained from intestinal tracts of 8 of 13 D. aurita trapped in Rio de Janeiro state, Brazil, and were orally inoculated into Melopsittacus undulatus and Balb/c nude Mus musculus. Portions of organs and muscles were processed for histology, immunohistochemistry, transmission electron microscopy (TEM), and PCR using primers JNB 33/54, and ITS. Amplification products were subjected to RFLP using DraI and HinfI. Some birds were euthanized 6, 7, 13, 16, and 24 days after inoculation (DAI). All other birds and all mice were euthanized 60 DAI. Schizonts were observed in the lungs using histology and immunostaining in birds examined prior to 60 DAI. Sarcocysts with a ~ 1.5-µm-thick wall were found in the breast, thigh, and tongue of some birds. Sarcocystis asexual stages were isolated in cell cultures inoculated with sporozoites. Parasite DNA isolated from bird tissues and cell cultures demonstrated that S. falcatula-like parasites were present in all samples derived from positive opossums. Asexual stages molecularly characterized as S. lindsayi-like were isolated in cell culture from one opossum with an apparent multiple infection. This study demonstrated that D. aurita is a definitive host for S. falcatula-like parasites and indicates that S. lindsayi-like parasites can be found in coinfections of this opossum species.

Helmintofauna de Didelphis albiventris (lund, 1841) no município de Palotina, Paraná, Brasil / Didelphis albiventris (lund, 1841) helminths in the city of Palotina, Paraná, Brazil / Helmintofauna de Didelphis albiventris (lund, 1841) en el municipio de Palotina, Parana, Brasil

Entre fevereiro de 2009 a abril de 2011, nove exemplares adultos (sete machos e duas fêmeas) de Didelphis albiventris (Lund, 1841), foram encontrados mortos por atropelamento no município de Palotina, Paraná. Os animais foram encaminhados para necropsia e coleta de material. Os parasitos encontrados foram fixados em formol acético e, posteriormente identificados. Os nove gambás estavam parasitados por helmintos, com predominância para o filo Nemathelminthes (66%), seguido por Acanthocephala (17%) e Platyhelminthes (17%). Foram isolados os seguintes helmintos e respectivas prevalências: Turgida turgida (89%) no estômago; Cruzia tentaculata (44%), Aspidodera sp. (22%) e Trichuris sp. (11%) no intestino grosso; Hamanniella microcephala (78%) e Rhopalias coronatus (11%) no intestino delgado. Em 80% dos D. albiventris ocorreu a associação parasitária entre, no mínimo, duas espécies de helmintos.(AU)

From February 2009 to April 2011, nine adult specimens (seven male and two female) of Didelphis albiventris (Lund, 1841) were found dead by roadkill in Palotina, Paraná. The animals were submitted for necropsy and collection of material. The parasites found were fixed in formalin acetic acid and subsequently identified. The nine opossums were parasitized by helminths, predominantly belonging to the Nemathelminthes (66%) phylum, followed by Acanthocephala (17%) and Platyhelminthes (17%). The following helminths were isolated and their prevalences were as follows: Turgida turgida (89%) in the stomach; Cruzia tentaculata (44%), Aspidodera sp. (22%) and Trichuris sp. (11%) in the large intestine; Hamanniella microcephala (78%) and Rhopalias coronatus (11%) in the small intestine.Parasitic association between at least two helminth species occurred in 80% of D. albiventris samples.(AU)

De febrero de 2009 a abril de 2011, nueve ejemplares adultos (siete machos y dos hembras) de Didelphis albiventris (Lund, 1841), fueron encontrados muertos por arrollamiento en el municipio de Palotina, Paraná. Los animales fueron enviados para necropsia y colecta de material. Los parásitos encontrados fueron fijados en formol acético, y posteriormente identificados. Las nueve zarigüeyas estaban parasitadas por helmintos, especialmente por Nemathelminthes (66%), seguido de Acanthocephala (17%) y Platyhelminthes (17%). Fueron aislados los siguientes helmintos y sus respectivas prevalencias: Turgida turgida (89%) en el estómago; Cruzia tentaculata (44%), Aspidodera sp. (22%) y Trichuris sp. (11%) en el intestino grueso; Hamanniella microcephala (78%) y Rhopalias coronatus (11%) en el intestino delgado. En 80% de los D. albiventris ocurrió la asociación parasitaria entre al menos dos especies de helmintos.(AU)

PULMONARY LESIONS CAUSED BY THE LUNGWORM (DIDELPHOSTRONGYLUS HAYESI) IN THE OPOSSUM (DIDELPHIS VIRGINIANA) IN COLIMA, MEXICO.

Didelphostrongylus hayesi is an important and prevalent pulmonary nematode in the opossum ( Didelphis virginiana ). An in-depth description of the pulmonary lesions caused by this nematode is lacking. The objective of this investigation was to make a detailed account of the gross, subgross, and microscopic changes that occur in the lungs of opossums naturally infected with D. hayesi. Forty-four opossums trapped in the state of Colima, Mexico, were euthanized by an overdose of barbiturates. Following a postmortem examination, the right lung was cut from the main bronchi and placed in a Petri dish containing a saline solution for the detection and identification of live parasites. The left lung was fixed and cut serially for subgross microscopic examination and sections of lung were cut and stained for histopathologic examination. The most remarkable gross change in parasitized lungs was a poorly collapsible pulmonary parenchyma and mild emphysema. The right lung tested positive for lungworms on gross examination in 20/44, and 11/44 (25%) of the left lungs showed tan nodules on the pleural surface. Microscopically, the bronchi of 20/44 animals harbored adult and larval stages of D. hayesi (left lung), the same 20 opossums from which nematodes were grossly evident at necropsy (right lung). Adults and larvae were present in bronchi, bronchioles, and alveoli mixed with desquamated cells and many eosinophils, and to a lesser extent neutrophils, alveolar macrophages, and giant cells. Bronchi and bronchioles exhibited goblet cell hyperplasia and metaplasia respectively, and infiltration of lymphoplasmacytic cells in the interstitium and lamina propria. The tan nodules consisted of focal alveolar endogenous lipidosis, which likely resulted from parasitic airway obstruction. The lungs of 3/20 parasitized opossums also showed alveolar bronchiolization (Lambertosis). The absence of Eucoleus aerophilus or bacterial pneumonia incriminates D. hayesi as the putative cause of pulmonary lesions in these opossums.

A review of Sarcocystis spp. shed by opossums (Didelphis spp.) in Brazil / Revisão sobre Sarcocystis spp. excretados por gambás (Didelphis spp.) no Brasil

South American opossums are the definitive hosts of Sarcocystis neurona, Sarcocystis falcatula, Sarcocystis speeri and Sarcocystis lindsayi. The sporocysts of these species of Sarcocystis are morphologically similar and methods like infectivity and pathogenicity for intermediate hosts (immunodeficient mice and psittacine birds) and molecular tools are used for identification. Opossums are synanthropic wild animals, and widely distributed in Brazilian territory. Previous studies have shown high environmental contamination with S. neurona sporocysts in several Brazilian regions. This paper reviews information on Sarcocystis spp. shed by various opossum species and its occurrence in Brazil.(AU)

Os gambás Sul-americanos são os hospedeiros definitivos de Sarcocystis falcatula, Sarcocystis neurona, Sarcocystis speeri e Sarcocystis lindsayi. Estas espécies de Sarcocystis são morfologicamente similares, mas podem ser distinguidas por sua patogenicidade e infectividade em hospedeiros intermediários (aves e camundongos imunodeficientes) e técnicas moleculares. Os gambás são animais silvestres e sinantrópicos e amplamente distribuídos no território nacional. Estudos anteriores demonstraram uma alta contaminação ambiental com esporocistos de S. neurona em diversas regiões brasileiras. Este artigo revisa informações sobre Sarcocystis spp. excretados por gambás e sua ocorrência no Brasil.(AU)

Domestic, peridomestic and wild hosts in the transmission of Trypanosoma cruzi in the Caatinga area colonised by Triatoma brasiliensis

The role played by different mammal species in the maintenance of Trypanosoma cruzi is not constant and varies in time and place. This study aimed to characterise the importance of domestic, wild and peridomestic hosts in the transmission of T. cruzi in Tauá, state of Ceará, Caatinga area, Brazil, with an emphasis on those environments colonised by Triatoma brasiliensis. Direct parasitological examinations were performed on insects and mammals, serologic tests were performed on household and outdoor mammals and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53), while in pigs it was 6% (2/34). The percentages of the most abundantly infected wild animals were as follows: Thrichomys laurentius 74% (83/112) and Kerodon rupestris 10% (11/112). Of the 749 triatomines collected in the household research, 49.3% (369/749) were positive for T. brasiliensis, while 6.8% were infected with T. cruzi (25/369). In captured animals, T. brasiliensis shares a natural environment with T. laurentius, K. rupestris, Didelphis albiventris, Monodelphis domestica, Galea spixii, Wiedomys pyrrhorhinos, Conepatus semistriatus and Mus musculus. In animals identified via their food source, T. brasiliensis shares a natural environment with G. spixii, K. rupestris, Capra hircus, Gallus gallus, Tropidurus oreadicus and Tupinambis merianae. The high prevalence of T. cruzi in household and peridomiciliar animals reinforces the narrow relationship between the enzootic cycle and humans in environments with T. brasiliensis and characterises it as ubiquitous.

Diversidade de ixodida em roedores e marsupiais capturados no Parque Estadual da Pedra Branca, Rio de Janeiro, Brasil / Diversity of ixodida in small rodents and marsupials in the Pedra Branca state park, state of Rio de Janeiro, Brazil

Durante 24 meses foram capturados, inspecionados e liberados no mesmo espaço do Parque Estadual da Pedra Branca, Rio de Janeiro, 96 marsupiais e 64 roedores. Neles foram recolhidos manualmente 105 carrapatos, de 10 espécies em duas famílias. A espécie de carrapato dominante entre os roedores foi Amblyomma longirostre e entre os marsupiais foi Ixodes loricatus. Houve correlação direta significativa entre a temperatura e a intensidade de parasitismo por carrapatos...

During 24 months 96 marsupials and 64 rodents were captured, inspected and set free in the same space of the Pedra Branca State Park, Rio de Janeiro. From them, 105 ticks from 10 species in two families were manually collected. The dominant tick species on the rodents was Amblyomma longirostre and on the marsupials was Ixodes loricatus. There was a significant correlation of the temperature in relation to intensity of parasitism for ticks, demonstrating that the higher the temperature, greater is the number of ticks...

Didelphis aurita (Marsupialia: Didelphidae): a new host for Sarcocystis lindsayi (Apicomplexa: Sarcocystidae).

Nine opossums, Didelphis aurita , were captured in the city of Seropédica, State of Rio de Janeiro, Brazil and examined for species of Sarcocystis. Sporocysts were observed in the mucosal scrapings of the small intestine from 3 opossums. Five budgerigars, Melopsittacus undulatus , were infected with sporocysts from each of these infected opossums and 5 budgerigars were used as controls. Of the 15 sporocyst-treated budgerigars, 5 birds that received sporocysts from 1 of the infected opossums developed tissue parasites. Meronts in the vascular endothelium of the lung venous capillaries and cysts in the skeletal and cardiac muscle cells were observed in histological sections stained with hematoxylin and eosin. The microscopic cysts, which were predominantly in the tongue and leg muscles, ranged from 65.3 to 118.1 µm in length and 14.0 to 29.4 µm in width and from 0.9 to 1.9 µm in thickness of the cystic wall. Sections examined by transmission electron microscopy revealed that the cyst wall contained numerous slender and jagged-shaped protrusions, each with a finger-like formation at the end. The morphology, especially of the cyst wall, and the morphometry of the tissue cysts indicate that the parasite is Sarcocystis lindsayi and, therefore, the opossum, D. aurita , is now considered a definitive host for this species in Brazil.

Biological, biochemical and molecular features of Trypanosoma cruzi strains isolated from patients infected through oral transmission during a 2005 outbreak in the state of Santa Catarina, Brazil: its correspondence with the new T. cruzi Taxonomy Consensus (2009)

We examined strains of Trypanosoma cruzi isolated from patients with acute Chagas disease that had been acquired by oral transmission in the state of Santa Catarina, Brazil (2005) and two isolates that had been obtained from a marsupial (Didelphis aurita) and a vector (Triatoma tibiamaculata). These strains were characterised through their biological behaviour and isoenzymic profiles and genotyped according to the new Taxonomy Consensus (2009) based on the discrete typing unities, that is, T. cruzi genotypes I-VI. All strains exhibited the biological behaviour of biodeme type II. In six isolates, late peaks of parasitaemia, beyond the 20th day, suggested a double infection with biodemes II + III. Isoenzymes revealed Z2 or mixed Z1 and Z2 profiles. Genotyping was performed using three polymorphic genes (cytochrome oxidase II, spliced leader intergenic region and 24Sα rRNA) and the restriction fragment length polymorphism of the kDNA minicircles. Based on these markers, all but four isolates were characterised as T. cruzi II genotypes. Four mixed populations were identified: SC90, SC93 and SC97 (T. cruzi I + T. cruzi II) and SC95 (T. cruzi I + T. cruzi VI). Comparison of the results obtained by different methods was essential for the correct identification of the mixed populations and major lineages involved indicating that characterisation by different methods can provide new insights into the relationship between phenotypic and genotypic aspects of parasite behaviour.

Uso de método de biologia molecular quantitativo (PCR real-time) na avaliação de reservatórios para leishmaniose visceral / Use of molecular biology method quantitative (real-time PCR) in the evaluation of reservoirs for visceral leishmaniasis

A leishmaniose visceral (LV) é uma zooantroponose sistêmica de importância reconhecida em saúde pública, 90% dos casos no novo mundo são oriundos do Brasil. Os cães domésticos e as raposas são considerados como os principais reservatórios. A persistência da Leishmania em áreas endêmicas e o insucesso das medidas de prevenção, dirigidas exclusivamente ao reservatório canino, sugerem que outros animais podem ter importância na manutenção do ciclo de transmissão da LV. Avaliar potenciais reservatórios para LV numa área endêmica, utilizando método de biologia molecular quantitativo (PCR real-time). MÉTODOS: Foram estudados animais domésticos (bovinos, equídeos, caprinos e ovinos) e animais silvestres (marsupial), no município de Salinas da Margarida, Bahia, de 2007 a 2009. Todos os animais domésticos de produção mantidos e/ou pernoitando nas áreas urbanas do município foram incluídos. Os marsupiais foram capturados com armadilha animal modelo Tomahawk colocadas no peridomicílio das residências onde ocorreram casos de LV humana e/ou canina na localidade de Encarnação. Nos animais domésticos de produção foi coletado apenas amostra de sangue periférico e nos marsupiais, além de sangue, foi obtida uma amostra de pele através de biópsia da orelha. Em todas as amostras foi realizado PCR real-time para investigar a presença de DNA do parasito e estimar a carga parasitária. Os primers e sondas utilizados foram selecionados em gene SSU rRNA, que aparece 160 vezes no genoma de Leishmania spp. e é altamente conservado entre as espécies de Leishmania. No total, foram avaliados 80 animais domésticos (20 bovinos, 33 equídeos, 20 caprinos e 7 ovinos) e 103 marsupiais, todos da espécie Didelphis albiventris. Cinco bovinos foram positivos no teste de PCR real-time com carga parasitária variando de 12,7 a 183,5 parasitos/mL. Apenas um marsupial apresentou amostra de sangue positiva (6,0 parasitos/mL). Todos os demais animais testaram negativo. A técnica de PCR real-time pode ser uma ferramenta útil para avaliar o papel de potenciais reservatórios domésticos e silvestres para LV. A execução do PCR real-time é menos trabalhosa e mais prática do que a realização do teste de xenodiagnóstico, além disso, ela poder ser automatizada, permitindo a análise de grande número de amostras em estudos epidemiológicos. A detecção de carga parasitária de Leishmania em sangue de bovinos, em quantidade comparável à encontrada em cães, sugere que eles podem ser reservatórios para LV. A relativa abundância de bovinos nas áreas endêmicas para LV, assim como as evidências da preferência alimentar do vetor por estes animais, ressaltam a importância do papel que os bovinos podem ter na transmissão da LV. Mais trabalhos são necessários para elucidar estas questões.

Dinâmica do Panstrongylus megistus nos ciclos de transmissão de Trypanosoma cruzi em áreas de cerrado e mata atlântica no estado de Minas Gerais, Brasil / Dynamics of Panstrongylus megistus in Trypanosoma cruzi transmission cycles in areas of savannah and rainforest in the state of Minas Gerais, Brazil

O triatomíneo Panstrongylus megistus pode ser encontrado ao longo do Brasil em um diversificado número de hábitats, tanto silvestres como artificiais. Este trabalho teve como objetivo estudar a dinâmica populacional de P. megistus nos ciclos de transmissão do Trypanosoma cruzi em áreas de Cerrado e Mata Atlântica no Estado de Minas Gerais/ Brasil. Os municípios estudados foram Bambuí (Cerrado) e Piracema (Mata Atlântica). Foram realizadas coletas nos ambientes natural e artificial, com objetivo de identificar a dinâmica populacional, as fontes alimentares(FA) e os ecótopos naturais utilizados por P. megistus, bem como caracterizar a interrelação dos ciclos de transmissão do T. cruzi a partir dos reservatórios e vetores associados. As amostragens de campo foram realizadas em locais de maior presença do barbeiro e proximidade de áreas naturais. A partir dos dados avaliados foi observado o sucesso das atividades de controle vetorial, alcançadas em momentos diferentes em cada município. Através da análise por morfometria geométrica, foi possível identificar uma semelhança entre as populações doméstica e silvestre de P. megistus, sugerindo o ambiente natural como principal foco de infestação triatomínica nos municípios...

As análises de FA revelaram uma grande mobilidade da espécie no ambiente domiciliar, destacando as aves (49%) e os cães(22%) como principais recursos utilizados. A investigação do ambiente natural levou ao encontro do primeiro foco silvestre de P. megistus em Bambuí, após 69 anos de pesquisas, demonstrando a baixa densidade da espécie no meio silvestre. Foram identificados os gambás (Didelphis sp.) e os cães domésticos como principais reservatórios de T. cruzi nos ambientes natural e artificial, respectivamente. Os dados mostram que as infestações domiciliares por P. megistus, embora reduzidas,se mantêm permanentes na última década avaliada, mesmo com poucos focos silvestres, como detectado em Bambuí. Ficou evidenciado também a ocorrência de um progressivo declínio das densidades triatomínico-tripanossômicas nas áreas estudadas, o que se deve provavelmente à fatores relacionados com a permanente vigilância epidemiológica, à redução da população rural, a melhoria das habitações rurais e redução das áreas naturais associada à expansão agropecuária...

Dinâmica do Panstrongylus megistus nos ciclos de transmissão de Trypanosoma cruzi em áreas de cerrado e mata atlântica no estado de Minas Gerais, Brasil

O triatomíneo Panstrongylus megistus pode ser encontrado ao longo do Brasil em um diversificado número de hábitats, tanto silvestres como artificiais. Este trabalho teve como objetivo estudar a dinâmica populacional de P. megistus nos ciclos de transmissão do Trypanosoma cruzi em áreas de Cerrado e Mata Atlântica no Estado de Minas Gerais/ Brasil. Os municípios estudados foram Bambuí (Cerrado) e Piracema (Mata Atlântica). Foram realizadas coletas nos ambientes natural e artificial, com objetivo de identificar a dinâmica populacional, as fontes alimentares(FA) e os ecótopos naturais utilizados por P. megistus, bem como caracterizar a interrelação dos ciclos de transmissão do T. cruzi a partir dos reservatórios e vetores associados. As amostragens de campo foram realizadas em locais de maior presença do barbeiro e proximidade de áreas naturais. A partir dos dados avaliados foi observado o sucesso das atividades de controle vetorial, alcançadas em momentos diferentes em cada município. Através da análise por morfometria geométrica, foi possível identificar uma semelhança entre as populações doméstica e silvestre de P. megistus, sugerindo o ambiente natural como principal foco de infestação triatomínica nos municípios.

As análises de FA revelaram uma grande mobilidade da espécie no ambiente domiciliar, destacando as aves (49%) e os cães(22%) como principais recursos utilizados. A investigação do ambiente natural levou ao encontro do primeiro foco silvestre de P. megistus em Bambuí, após 69 anos de pesquisas, demonstrando a baixa densidade da espécie no meio silvestre. Foram identificados os gambás (Didelphis sp.) e os cães domésticos como principais reservatórios de T. cruzi nos ambientes natural e artificial, respectivamente. Os dados mostram que as infestações domiciliares por P. megistus, embora reduzidas,se mantêm permanentes na última década avaliada, mesmo com poucos focos silvestres, como detectado em Bambuí. Ficou evidenciado também a ocorrência de um progressivo declínio das densidades triatomínico-tripanossômicas nas áreas estudadas, o que se deve provavelmente à fatores relacionados com a permanente vigilância epidemiológica, à redução da população rural, a melhoria das habitações rurais e redução das áreas naturais associada à expansão agropecuária.

Proteomic analysis of two Trypanosoma cruzi zymodeme 3 strains.

Two Trypanosoma cruzi Z3 strains, designated as 3663 and 4167, were previously isolated from insect vectors captured in the Brazilian Amazon region. These strains exhibited different infection patterns in Vero, C6/36, RAW 264.7 and HEp-2 cell lineages, in which 3663 trypomastigote form was much less infective than 4167 ones. A proteomic approach was applied to investigate the differences in the global patterns of protein expression in these two Z3 strains. Two-dimensional (2D) protein maps were generated and certain spots were identified by mass spectrometry (MS). Our analyses revealed a significant difference in the expression profile of different proteins between strains 3663 and 4167. Among them, cruzipain, an important regulator of infectivity. This data was corroborated by flow cytometry analysis using anti-cruzipain antibody. This difference could contribute to the infectivity profiles observed for each strain by in vitro assay using different cell lines.

An investigation of Leishmania spp. in Didelphis spp. from urban and peri-urban areas in Bauru (São Paulo, Brazil).

Blood and bone marrow samples were taken from 112 Didelphis spp., collected between March 2005 and February 2006, from urban and peri-urban areas of Bauru, São Paulo State, Brazil, to evaluate the hypothesis that these animals might constitute a reservoir of Leishmania spp. Anti-Leishmania ssp. antibodies were screened in the serum samples using an enzyme-linked immuno-sorbent assay (ELISA) and the polymerase chain reaction (PCR). PCR was performed on fragments of DNA samples from Leishmania spp. using primers 13A and 13B, and showed a positive outcome in 91.6% of the 112 samples tested. Of the 107 samples analyzed by ELISA, 71% were positive. Evidence of epidemiological risk factors such as a circulating parasite and freely moving vectors suggests that Didelphis spp. may participate in the transmission cycle of Leishmania spp. in Bauru.

A genetically diverse but distinct North American population of Sarcocystis neurona includes an overrepresented clone described by 12 microsatellite alleles.

The population genetics and systematics of most coccidians remain poorly defined despite their impact on human and veterinary health. Non-recombinant parasite clones characterized by distinct transmission and pathogenesis traits persist in the coccidian Toxoplasma gondii despite opportunities for sexual recombination. In order to determine whether this may be generally true for tissue-cyst forming coccidia, and to address evolutionary and taxonomic problems within the genus Sarcocystis, we characterized polymorphic microsatellite markers in Sarcocystis neurona, the major causative agent of equine protozoal myeloencephalitis (EPM). Bayesian statistical modeling, phylogenetic reconstruction based on genotypic chord distances, and analyses of linkage disequilibrium were employed to examine the population structure within S. neurona and closely related Sarcocystis falcatula isolates from North and South America. North American S. neurona were clearly differentiated from those of South America and also from isolates of S. falcatula. Although S. neurona is characterized by substantial allelic and genotypic diversity typical of interbreeding populations, one genotype occurs with significantly excessive frequency; thus, some degree of asexual propagation of S. neurona clones may naturally occur. Finally, S. neurona isolated from disparate North American localities and diverse hosts (opossums, a Southern sea otter, and horses) comprise a single genetic population. Isolates associated with clinical neurological disease bear no obvious distinction as measured by these presumably neutral genetic markers.

Genetic characterization of Trypanosoma cruzi natural clones from the state of Paraíba, Brazil

Eighteen Trypanosoma cruzi stocks from the state of Paraíba, Brazil, isolated from man, wild mammals, and triatomine bugs were studied by multilocus enzyme electrophoresis and random primed amplified polymorphic DNA. Despite the low number of stocks, a notable genetic, genotypic, and phylogenetic diversity was recorded. The presence of the two main phylogenetic subdivisions, T. cruzi I and II, was recorded. The strong linkage disequilibrium observed in the population under survey suggests that T. cruzi undergoes predominant clonal evolution in this area too, although this result should be confirmed by a broader sample. The pattern of clonal variation does not suggests a recent origin by founder effect with a limited number of different genotypes.