Diagnóstico molecular e relações filogenéticas entre nove espécies de Triatominae (Hemiptera, Reduviidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise das possíveis regiões organizadoras nucleolares e da atividade nucleolar em Triatoma melanocephalae T. lenti, importantes vetores da doença de Chagas

Triatoma melanocephalae T. lentisão espécies crípticas de triatomíneos pertencentes ao subcomplexo Brasiliensis. Esses organismos foram agrupados no subcomplexo apenas por caracteres morfológicos e pela disposição geográfica. Sendo assim, estudos citogenéticos são considerados como importantes ferramentas na classificação dos triatomíneos e, com isso, podem auxiliar na criação de um plano de profilaxia da doença. Por meio da técnica citogenética de impregnação por íons prata, foi possível visualizar a atividade nucleolar e as Regiões Organizadoras Nucleolares (RONs) desses insetos. T. melanocephalaapresentou três RONs ativas nos autossomos durante a prófase I. T. lenti apresentou duas RONs ativas nos autossomos durante a prófase I e a metáfase I. Ambas as espécies apresentaram o fenômeno de persistência do material nucleolar encontrado em triatomíneos. Sendo assim, por meio da análise das RONs, foi possível observar que T. lenti, quando comparado com os outros organismos do subcomplexo, apresentou marcações semelhantes à T. tibiamaculata e que T. melanocephalanão apresenta nenhuma relação direta com o subcomplexo. Palavras-chave: Citogenética. Taxonomia. Triatominae. Subcomplexo Brasiliensis. ABSTRACT Analysis of nucleolus organizer regions and nucleolar activity in important vectors of Chagas disease (Triatoma melanocephala and T. lenti) Triatoma melanocephalaand T. lentiare important vectors of Chagas disease. These cryptic species of triatomines are grouped in the subcomplexbrasiliensisdue only to morphological characters and geographical distribution. Cytogenetic studies are important to the classification of insects and can assist in creating a disease prevention plan. The aim of the present study was to determine nucleolar activity and nucleolus organizer regions (NORs) in these insects using the cytogenetic method of silver ion impregnation. T. melanocephalaexhibited three active NORs in autosomes during prophase I. T. lentiexhibited two active NORs in autosomes during prophase I and metaphase I. Both species exhibit the persistent nucleolar material found in triatomines. The analysis of NORs in the present study revealed that T. lenti exhibited labeling similar to that found in T. tibiamaculata, which belongs to the subcomplex, whereas T. melanocephalashows no direct relationship with the subcomplex. Keywords: Cytogenetics. Taxonomy. Triatominae. Brasiliensissubcomplex.

Coloration of the testicular peritoneal sheath as a synapomorphy of triatomines (Hemiptera, Reduviidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Atualidades sobre a doença de Chagas, com ênfase nas possíveis causas da cardiomiopatia crônica

A Organização Mundial de Saúde estima que existem cerca de 10 milhões de infectados pelo Trypanosoma cruzi, 30% dos infectados cronicamente desenvolvem alterações cardíacas, e 10% digestivas e neurológicas. O T. cruzi é um protozoário cinetoplástida flagelado agente etiológico da tripanossomíase americana, popularmente conhecida como a Doença de Chagas, uma antropozoonose conhecida na América Latina. Pelo menos 40 espécies de triatomíneos – conhecido por barbeiros – carregam o protozoário. O gênero Triatoma representa o principal vetor da Doença de Chagas e são adaptados a climas secos de ambientes rurais da América do Sul e Central. Outras formas de infecção podem ocorrer por transfusão de sangue, transplantes, via oral, e transmissão vertical. Há duas fases que caracterizam a infecção pelo T. cruzi: a fase aguda, apresentando um período de incubação de uma semana a um mês, que geralmente é assintomática. Já a fase crônica é mais polêmica e divide a opinião dos pesquisadores, mas basicamente mostra-se como uma cardiomiopatia chagásica, ou uma dilatação no trato digestivo e ainda pode causar lesões no sistema nervoso parassimpático e simpático. Entre essas duas fases ocorre um período indeterminado em que não há nenhuma manifestação clínica da doença. Existem teorias que explicam a patogenicidade das lesões da doença: uma postula que as lesões características da Chagas são referentes à ruptura das células parasitadas e subsequente inflamação. Outra é a teoria da autoimunidade, em que o próprio sistema imune do indivíduo rejeita as células livres de parasitas causando as lesões características da doença. Há evidências substanciais que comprovem a participação das respostas imunes nas lesões miocárdicas, mas como o parasito consegue desencadear estas respostas imunes, ainda não está esclarecido... (Resumo completo, clicar acesso eletrônico abaixo)

Caracterização do padrão eletroforético de glândulas salivares de Triatoma lecticularia e Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae) em diferentes tempos pós repasto sanguíneo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytochemical study of Rhodnius neglectus and Rhodnius prolixus salivary gland cells (Hemiptera, Triatominae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study on Chagas disease occurrence in the municipality of Monte Negro, State of Rondônia, Brazilian Amazon

Introduction: Studies on Chagas disease deal with the perspective of its occurrence in the Amazon region, which is directly correlated to the population growth and the spread of the bug biotope. The state of Rondônia has an immense source of vectors (Triatomine) and reservoirs of Trypanosoma cruzi. Environmental changes brought forth by the deforestation in the region may cause vector behavior changes and bring these vectors to a closer contact with humans, increasing the probability of vector infection. Methods: This study was carried out to check the occurrence of Chagas disease in the municipality of Monte Negro, Rondônia, Brazil, based on a random sampling of the farms and people wherein blood collection from the population and capturing triatomines were done. The blood samples were submitted to serologic tests to detect antibodies of the IgG class against T. cruzi. The triatomines that were collected had their digestive tract checked for the presence of trypanosomatidae with morphology resembling that of the T. cruzi. Results: The population examined was mostly from other states. From the 322 bugs examined on the microscope, 50% showed parasites with morphology compatible with T. cruzi. From the serology of 344 random samples of human blood, 1.2% was found positive, 6% showed inconclusive results, and 92.8% were negative. Conclusions: Monte Negro shows low prevalence of human infection by T. cruzi and none active vector transmission; however, preventive and surveying measures, which are not performed until now, shall be taken due to the abundance of vectors infected by trypanosomatidae.

Using captive sentinels to collect wild triatomines in the region of Marília-SP, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Descrição de uma nova espécie de Rhodnius (Hemiptera, Reduviidae, Triatominae) da Amazônia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo de hidroximetilnitrofural (NFOH) na fase crônica da Doença de Chagas em modelo animal

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise molecular do subcomplexo Brasiliensis (Hemiptera, Triatominae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de transcriptomas por RNAseq em tecidos de cabeça e glândula salivar de Rhodnius montenegrensis e Rhodnius robustus (Hemiptera, Reduviidade, Triatominae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Natural infection of triatomines (Hemiptera: Reduviidae) by trypanosomatids in two different environments in the municipality of Ouro Preto do Oeste, State of Rondônia, Brazil

INTRODUCTION: This study analyzed the occurrence and the contamination of triatomines by trypanosomatids in Orbignya speciosa (babassu) specimens in the State of Rondônia, Brazil, in two different environments (pasture and woods). METHODS: Capture of triatomines on babassus and microscopic search for trypanosomatids in their digestive tube were carried out. RESULTS: Four hundred ninety-four (494) specimens were captured (Rhodnius prolixus and R.robustus), of which 35.6% of the triatomines were positive for trypanosomatids. CONCLUSIONS: The high index of natural infection along with the abundance of triatomines points out to the necessity to create an epidemiological surveillance system to monitor vector-borne transmission and deepen the studies on the ecology of such vectors in the Amazon.

Distribuição da fauna triatomínica e infecção natural pelo Trypanosoma cruzi em diferentes municípios do semiárido do Rio Grande do Norte

The triatomine fauna distribution and the natural infection by Trypanosoma cruzi was evaluated aiming the comprehension of the transmission dynamics of this parasite in the countryside of the State of Rio Grande do Norte. Additionally, the research for Trypanosoma rangeli was also investigated. The captures of triatomines were performed at sylvatic, peridomicile and domicile environments at different municipalities of the central and western mesoregions of this state. The insects were identified and examined by direct method, xenoculture and PCR to detect T. cruzi. The detection of T. rangeli was performed by direct examination of the hemolymph and multiplex PCR of 151 positive specimens for T. cruzi. Of 824 captured insects, the species were distributed in Triatoma brasiliensis (66.4%), Triatoma pseudomaculata (18.2%), Panstrongylus lutzi (12.7%) and Rhodnius nasutus (2.7%), and T. brasiliensis was found in most of the evaluated municipalities. The species were captured at nymph and adult stages, except P. lutzi, exclusively in adult stage. In the sylvatic environment were captured T. brasiliensis (57%), P. lutzi (28%) and T. pseudomaculata (15%) species. At the peridomicile environment were identified T. brasiliensis (74%), T. pseudomaculata (21%) and R. nasutus (5.0%), while in the intradomicile was found only T. brasiliensis. The infection rate of triatomines by T. cruzi was 30.4%, P. lutzi showed highest rate (78%), followed by T. brasiliensis (24.4%), T. pseudomaculata (22.6%) and R. nasutus (4.5%). Infected triatomines indexes at silvatic, peridomicile and domicile environments were of 41.8%, 20.1% and 50.0%, respectively. T. rangeli was only detected by multiplex PCR in 2.6% (4/151) of examined insects, of these 4.4% (3/67) were T. brasiliensis and 1.5% (1/63) P. lutzi species. The data showed that the positivity of P. lutzi allied to its ability to invade domicile attracted by light, suggests a likely participation of this insect between epidemiological transmission cycles of T. cruzi. T. brasiliensis was the only specie present in all environments, what reinforces its importance related to the capacity for adapting to the domestic environment, potential as a vector, and maintenance of sylvatic and domestic transmissions cycles in the semiarid, indicating the necessity of continuous epidemiological surveillance. The presence of T. rangeli in T. brasiliensis and P. lutzi was first recorded in rural zone of this State, broadening the area of occurrence of this protozoan in northeastern Brazil.

Distribuição da fauna triatomínica e infecção natural pelo Trypanosoma cruzi em diferentes municípios do semiárido do Rio Grande do Norte

The triatomine fauna distribution and the natural infection by Trypanosoma cruzi was evaluated aiming the comprehension of the transmission dynamics of this parasite in the countryside of the State of Rio Grande do Norte. Additionally, the research for Trypanosoma rangeli was also investigated. The captures of triatomines were performed at sylvatic, peridomicile and domicile environments at different municipalities of the central and western mesoregions of this state. The insects were identified and examined by direct method, xenoculture and PCR to detect T. cruzi. The detection of T. rangeli was performed by direct examination of the hemolymph and multiplex PCR of 151 positive specimens for T. cruzi. Of 824 captured insects, the species were distributed in Triatoma brasiliensis (66.4%), Triatoma pseudomaculata (18.2%), Panstrongylus lutzi (12.7%) and Rhodnius nasutus (2.7%), and T. brasiliensis was found in most of the evaluated municipalities. The species were captured at nymph and adult stages, except P. lutzi, exclusively in adult stage. In the sylvatic environment were captured T. brasiliensis (57%), P. lutzi (28%) and T. pseudomaculata (15%) species. At the peridomicile environment were identified T. brasiliensis (74%), T. pseudomaculata (21%) and R. nasutus (5.0%), while in the intradomicile was found only T. brasiliensis. The infection rate of triatomines by T. cruzi was 30.4%, P. lutzi showed highest rate (78%), followed by T. brasiliensis (24.4%), T. pseudomaculata (22.6%) and R. nasutus (4.5%). Infected triatomines indexes at silvatic, peridomicile and domicile environments were of 41.8%, 20.1% and 50.0%, respectively. T. rangeli was only detected by multiplex PCR in 2.6% (4/151) of examined insects, of these 4.4% (3/67) were T. brasiliensis and 1.5% (1/63) P. lutzi species. The data showed that the positivity of P. lutzi allied to its ability to invade domicile attracted by light, suggests a likely participation of this insect between epidemiological transmission cycles of T. cruzi. T. brasiliensis was the only specie present in all environments, what reinforces its importance related to the capacity for adapting to the domestic environment, potential as a vector, and maintenance of sylvatic and domestic transmissions cycles in the semiarid, indicating the necessity of continuous epidemiological surveillance. The presence of T. rangeli in T. brasiliensis and P. lutzi was first recorded in rural zone of this State, broadening the area of occurrence of this protozoan in northeastern Brazil.