Bacterial community composition in the salivary glands of triatomines (Hemiptera: Reduviidae).

BACKGROUND: Chagas disease is caused by the parasite Trypanosoma cruzi and is transmitted through triatomines (Hemiptera: Reduviidae). In the last year, many studies of triatomine gut microbiota have outlined its potential role in modulating vector competence. However, little is known about the microbiota present in the salivary glands of triatomines. Bacterial composition of salivary glands in selected triatomine species was investigated, as well as environmental influences on the acquisition of bacterial communities. METHODOLOGY/PRINCIPAL FINDINGS: The diversity of the bacterial communities of 30 pairs of salivary glands of triatomines was studied by sequencing of the V1- V3 variable region of the 16S rRNA using the MiSeq platform (Illumina), and bacteria isolated from skin of three vertebrate hosts were identified based on 16S rRNA gene sequence analysis (targeting the V3-V5 region). In a comparative analysis of microbiota in the salivary glands of triatomine species, operational taxonomic units belonging to Arsenophonous appeared as dominant in Triatoma spp (74% of the total 16S coverage), while these units belonging to unclassified Enterobacteriaceae were dominant in the Rhodnius spp (57% of the total 16S coverage). Some intraspecific changes in the composition of the triatomine microbiota were observed, suggesting that some bacteria may have been acquired from the environment. CONCLUSIONS AND SIGNIFICANCE: Our study revealed the presence of a low-diversity microbiota associated to the salivary glands of the evaluated triatomines. The predominant bacteria genera are associated with triatomine genera and the bacteria can be acquired in the environment in which the insects reside. Further studies are necessary to determine the influence of bacterial communities on vector competence.

Triatoma infestans relies on salivary lysophosphatidylcholine to enhance Trypanosoma cruzi transmission.

Triatoma infestans is a mandatory haematophagous vector of Chagas disease in Brazil. Despite a large number of studies on the anti-haemostatic molecules present in its saliva, the role of its salivary components on parasite transmission is poorly understood. Here, we show that the bioactive lipid molecule, lysophosphatidylcholine (LPC), is present in the salivary gland of T. infestans. We characterized the lipid profiles of each unit of the T. infestans salivary gland. We noticed that LPC is present in the three units of the salivary gland and that the insect feeding state does not influence its proportion. T. infestans saliva and LPC can enhance T. cruzi transmission to mice by dramatically altering the profile of inflammatory cells at the site of inoculation on mouse skin, facilitating the transmission of T. cruzi to the vertebrate host. Consequently, the mortality curves of either saliva- or LPC-injected mice display significant higher mortality rates than the control. Altogether, these results implicate LPC as one of key salivary molecule involved in Chagas disease transmission.

Description of the feeding preferences of triatominae in the Chagas disease surveillance study for the State of Pernambuco, Brazil (Hemiptera: Reduviidae).

INTRODUCTION:: Studying the feeding preferences of triatomines is an important entomological surveillance tool, since continuous surveillance of the disease is necessary. METHODS:: The precipitin reaction was used to describe the feeding preferences of triatomines along with their natural infection by flagellates similar to Tyrpanosoma cruzi. Six hundred eighty-seven insects were examined, including Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus lutzi. RESULTS:: Sixty-nine (10%) of 687 triatomines examined tested positive for flagellates similar to T. cruzi, and 8 (1.2%) of these fed on human blood. CONCLUSIONS:: This study found potential transmitters of Chagas disease both inside and outside the domiciliar environment.

Description of the feeding preferences of triatominae in the Chagas disease surveillance study for the State of Pernambuco, Brazil (Hemiptera: Reduviidae)

Abstract INTRODUCTION: Studying the feeding preferences of triatomines is an important entomological surveillance tool, since continuous surveillance of the disease is necessary. METHODS: The precipitin reaction was used to describe the feeding preferences of triatomines along with their natural infection by flagellates similar to Tyrpanosoma cruzi. Six hundred eighty-seven insects were examined, including Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus lutzi. RESULTS: Sixty-nine (10%) of 687 triatomines examined tested positive for flagellates similar to T. cruzi, and 8 (1.2%) of these fed on human blood. CONCLUSIONS: This study found potential transmitters of Chagas disease both inside and outside the domiciliar environment.

Mitochondrial Gene Confirms the Specific Status of Triatoma pintodiasi Jurberg, Cunha, and Rocha, 2013 (Hemiptera, Triatominae), an Endemic Species in Brazil.

Chagas disease is most frequently transmitted to humans through contact with feces of insects from the Triatominae subfamily. In Brazil, there are 65 species of triatomines distributed throughout the country's 27 states. Among the species in the state of Rio Grande do Sul, Triatoma rubrovaria, Triatoma oliveirai, Triatoma pintodiasi, Triatoma klugi, Triatoma carcavalloi, and Triatoma circummaculata (with the addition Triatoma limai, which is endemic to Argentina) form the T. rubrovaria subcomplex. The last species described and grouped into this subcomplex was T. pintodiasi Thus, this study characterized the genetic distance between T. pintodiasi and of the other members of the T. rubrovaria subcomplex to evaluate the specific status of T. pintodiasi The genetic distance observed between T. pintodiasi and the other species of the T. rubrovaria subcomplex was large, a finding which highlights the specific status of the species considered to be cryptic of T. circummaculata.

Registration of new geographical distribution of Panstrongylus geniculatus (Latreille) 1811 (Hemiptera, Reduviidae, Triatominae) in Brazil

The first report of the occurrence of Panstrongylus geniculatus (Latreille) 1811 was reported in the state of Pernambuco. Therefore its distribution was amplified, and now, such as P. megistus, is the most widely distributed species in Brazil. P. geniculatus was found by health workers in intradomiciliary environments in Vitória de Santo Antão, testing positive for flagellates observed by direct examination of intestinal contents, and Giemsa staining

Triatominae (Hemiptera, Reduviidae) in the Pantanal region: association with Trypanosoma cruzi, different habitats and vertebrate hosts.

INTRODUCTION: The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection. METHODS: The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads. RESULTS: In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests. CONCLUSIONS: Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.

Triatominae (Hemiptera, Reduviidae) in the Pantanal region: association with Trypanosoma cruzi, different habitats and vertebrate hosts

ABSTRACTINTRODUCTION: The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection.METHODS: The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads.RESULTS: In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests.CONCLUSIONS: Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.

Genes encoding defensins of important Chagas disease vectors used for phylogenetic studies.

Insects possess both cellular and humoral immune responses. The latter makes them capable to recognize and control invading pathogens after synthesis of a variety of small proteins, also known as antimicrobial peptides. Defensins, cysteine-rich cationic peptides with major activity against Gram-positive bacteria, are one ubiquitous class of antimicrobial peptides, widely distributed in different animal and plant taxa. Regarding triatomines in each of the so far analyzed species, various defensin gene isoforms have been identified. In the present study, these genes were sequenced and used as a molecular marker for phylogenetic analysis. Considering the vectors of Chagas disease the authors are reporting for the first time the presence of these genes in Triatoma sordida (Stål, 1859), Rhodnius nasutus (Stål, 1859), and Panstrongylus megistus (Burmeister, 1835). Members of the Triatoma brasiliensis species complex were included into the study to verify the genetic variability within these taxa. Mainly in their mature peptide, the deduced defensin amino acid sequences were highly conserved. In the dendrogram based on defensin encoding nucleotide, sequences the Triatoma Def3/4 genes were separated from the rest. In the dendrogram based on deduced amino acid sequences the Triatoma Def2/3/4 together with Rhodnius DefA/B pre-propeptides were separated from the rest. In the sub-branches of both the DNA and amino acid dendrograms, the genus Triatoma was separated from the genus Rhodnius as well as from P. megistus.

Trypanosoma cruzi Infection through the Oral Route Promotes a Severe Infection in Mice: New Disease Form from an Old Infection?

Oral transmission of Chagas disease has been documented in Latin American countries. Nevertheless, significant studies on the pathophysiology of this form of infection are largely lacking. The few studies investigating oral route infection disregard that inoculation in the oral cavity (Oral infection, OI) or by gavage (Gastrointestinal infection, GI) represent different infection routes, yet both show clear-cut parasitemia and heart parasitism during the acute infection. Herein, BALB/c mice were subjected to acute OI or GI infection using 5x10(4) culture-derived Trypanosoma cruzi trypomastigotes. OI mice displayed higher parasitemia and mortality rates than their GI counterparts. Heart histopathology showed larger areas of infiltration in the GI mice, whereas liver lesions were more severe in the OI animals, accompanied by higher Alanine Transaminase and Aspartate Transaminase serum contents. A differential cytokine pattern was also observed because OI mice presented higher pro-inflammatory cytokine (IFN-γ, TNF) serum levels than GI animals. Real-time PCR confirmed a higher TNF, IFN-γ, as well as IL-10 expression in the cardiac tissue from the OI group compared with GI. Conversely, TGF-ß and IL-17 serum levels were greater in the GI animals. Immunolabeling revealed macrophages as the main tissue source of TNF in infected mice. The high mortality rate observed in the OI mice paralleled the TNF serum rise, with its inhibition by an anti-TNF treatment. Moreover, differences in susceptibility between GI versus OI mice were more clearly related to the host response than to the effect of gastric pH on parasites, since infection in magnesium hydroxide-treated mice showed similar results. Overall, the present study provides conclusive evidence that the initial site of parasite entrance critically affects host immune response and disease outcome. In light of the occurrence of oral Chagas disease outbreaks, our results raise important implications in terms of the current view of the natural disease course and host-parasite relationship.

List of the type-specimens of Reduviidae (Hemiptera: Heteroptera) in the Triatomines Collection of the Oswaldo Cruz Institute, Brazil.

The Triatomines Collection of the Oswaldo Cruz Institute (CTIOC) holds 90 holotypes, seven syntypes, and 619 paratypes of the family Reduviidae, distributed in 44 genera and nine subfamilies: Chryxinae, Emesinae, Hammacerinae, Harpactorinae, Peiratinae, Reduviinae, Stenopodainae, Triatominae, and Vesciinae. A detailed list containing nomenclatural, taxonomic, and locality information about all these types is herein presented for the first time.

Importância da distribuição geográfica dos vetores da doença de chagas em Pernambuco, Brasil, em 2012 / The importance of the geographical distribution of Chagas disease vectors in Pernambuco during 2012

Objetivos: Ressaltar a importância da distribuição geográfica e do comportamento dos vetores dadoença de Chagas no estado de Pernambuco. Métodos: O material analisado incluiu 100 por cento dosinsetos infectados por Trypanosoma sp. e 40 por cento dos insetos negativos, examinados no Laboratório deEndemias para confirmação taxonômica, pesquisa do parasito nas fezes dos triatomíneos e Controleda Qualidade na confirmação do diagnóstico. Resultados: Foram examinados 3.323 triatomíneos.A infecção natural por tripanossomatídeos foi detectada em 21,3 por cento dos exemplares. Triatomabrasiliensis foi a espécie mais frequente no intradomicílio (24,3 por cento), Triatoma pseudomaculata(14,9 por cento) e Panstrongylus megistus apresentaram proporcionalmente taxa de infecção naturalsuperior às demais (40,8 por cento) no peridomicílio. Conclusão: O conhecimento atualizado da distribuiçãogeográfica dos vetores da doença de Chagas é importante para fundamentar ações integradas entreos serviços de saúde, o que contribui para a vigilância entomológica no controle dos triatomíneos.

Objectives: To underscore the importance of geographic distribution and behavior of vectors ofChagas disease in the state of Pernambuco. Methods: The material analyzed included 100 percent of theinsects infected with Trypanosoma spp., and 40 percent of negative insects, examined at the EndemicDisease Laboratory for taxonomic confirmation, searching for the parasite in feces of the insects,with Quality Control to confirm the diagnosis. Results: A total of 3,323 triatomines. Naturalinfection by trypanosomes was detected in 21.3 percent of the specimens. Triatoma brasiliensis wasthe most frequent intradomiciliary species (24.3 percent), outside the home Triatoma pseudomaculata(14.9 percent) and Panstrongylus megistus had a natural infection rate proportionally superior to the others(40.8 percent). Conclusion: The current knowledge of the geographical distribution of Chagas diseasevectors is important as a platform to integrate actions between health services, contributing to theentomological surveillance and control of the insects.

Atlas iconográfico dos triatomíneos do Brasil (vetores da doença de Chagas) / Iconographic atlas of triatomine Brazil (vectors of Chagas' disease)

O material conta com ilustrações e informações sobre a morfologia dos insetos, tamanho, habitat, ciclo de vida, além de mapas sobre a diversidade e distribuição geográfica das 66 espécies de barbeiros registradas até o momento...

Synanthropic triatomines (Hemiptera, Reduviidae) in the state of Pernambuco, Brazil: geographical distribution and natural Trypanosoma infection rates between 2006 and 2007.

INTRODUCTION: The present study shows a descriptive analysis of triatomine occurrence and its natural Trypanosoma infection rates in the state of Pernambuco, Brazil, between 2006 and 2007. METHODS: Entomological data for the species, such as specimens captured in both intra and peridomiciles and natural infection index, were obtained via domiciliary capture in 147 municipalities from 11 Regional Managements of Health. The database was obtained from a sample of insects (100% infected and 20% non-infected) sent to the Central Laboratory of Pernambuco. RESULTS: A total of 18,029 triatomines were analyzed from 138 municipalities of the state. Triatoma pseudomaculata (35%), Triatoma brasiliensis (34%), and Panstrongylus lutzi (25%) were the most captured species. These species also showed a widespread geographical distribution in the state. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus, and Triatoma infestans showed more limited geographical distribution and lower relative abundance. The parasitological research showed that 8.8% of the triatomines were naturally infected with flagellates morphologically similar to Trypanosoma cruzi and 91.3% of them were captured inside houses in 113 municipalities. P. lutzi showed the highest rates of natural infection. CONCLUSIONS: After the control of T. infestans, synanthropic species, such as T. brasiliensis, T. pseudomaculata, and P. lutzi, maintain the risk of T. cruzi transmission to humans in the state of Pernambuco. These species are widely distributed, and infected specimens have been found inside houses. Thus, an enhanced surveillance and vector control of Chagas disease is recommended in Pernambuco.

Synanthropic triatomines (Hemiptera, Reduviidae) in the state of Pernambuco, Brazil: geographical distribution and natural Trypanosoma infection rates between 2006 and 2007 / Triatomíneos sinantrópicos (Hemiptera, Reduviidae) no estado de Pernambuco, Brasil: distribuição geográfica e índices de infecção natural por Trypanosoma entre 2006 e 2007

INTRODUCTION: The present study shows a descriptive analysis of triatomine occurrence and its natural Trypanosoma infection rates in the state of Pernambuco, Brazil, between 2006 and 2007. METHODS: Entomological data for the species, such as specimens captured in both intra and peridomiciles and natural infection index, were obtained via domiciliary capture in 147 municipalities from 11 Regional Managements of Health. The database was obtained from a sample of insects (100 percent infected and 20 percent non-infected) sent to the Central Laboratory of Pernambuco. RESULTS: A total of 18,029 triatomines were analyzed from 138 municipalities of the state. Triatoma pseudomaculata (35 percent), Triatoma brasiliensis (34 percent), and Panstrongylus lutzi (25 percent) were the most captured species. These species also showed a widespread geographical distribution in the state. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus, and Triatoma infestans showed more limited geographical distribution and lower relative abundance. The parasitological research showed that 8.8 percent of the triatomines were naturally infected with flagellates morphologically similar to Trypanosoma cruzi and 91.3 percent of them were captured inside houses in 113 municipalities. P. lutzi showed the highest rates of natural infection. CONCLUSIONS: After the control of T. infestans, synanthropic species, such as T. brasiliensis, T. pseudomaculata, and P. lutzi, maintain the risk of T. cruzi transmission to humans in the state of Pernambuco. These species are widely distributed, and infected specimens have been found inside houses. Thus, an enhanced surveillance and vector control of Chagas disease is recommended in Pernambuco.

INTRODUÇÃO: O presente estudo apresenta uma análise descritiva da ocorrência de triatomíneos e seus índices de infecção natural por Trypanosoma no Estado de Pernambuco, entre 2006 e 2007. MÉTODOS: Dados entomológicos para as espécies de triatomíneos, tais como espécimes capturados no intra e peridomicílio, e índice de infecção natural foram obtidos por meio da captura domiciliar em 147 municípios das 11 Gerências Regionais de Saúde. A pequisa foi baseada em uma amostra de insetos (100 por cento dos infectados e 20 por cento dos não infectados) enviados para o Laboratório Central de Pernambuco. RESULTADOS: No total, 18.029 triatomíneos foram analisados provenientes de 138 municípios. Triatoma pseudomaculata (35 por cento), Triatoma brasiliensis (34 por cento) e Panstrongylus lutzi (25 por cento) foram as espécies mais capturadas. Estas espécies também apresentaram ampla distribuição geográfica no estado. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus e Triatoma infestans apresentaram distribuição geográfica mais restrita e menores valores de abundância relativa. A pesquisa parasitológica mostrou que 8,8 por cento dos triatomíneos estavam infectados por flagelados morfologicamente similares a Trypanosoma cruzi e 91,3 por cento deles foram capturados no interior das habitações em 113 municípios. P. lutzi apresentou as maiores taxas de infecção natural. CONCLUSÕES: Após o controle do T. infestans, as espécies sinantrópicas T. brasiliensis, T. pseudomaculata e P. lutzi mantêm o risco de transmissão do T. cruzi ao homem no Estado de Pernambuco. Estas espécies são amplamente distribuídas e espécimes infectados foram encontrados dentro das casas. Assim, nossos resultados recomendam reforçar a vigilância e controle vetorial da doença de Chagas em Pernambuco.

Avaliação em laboratório da atividade de voo de Rhodnius brethesi Matta, 1919, potencial vetor silvestre do Trypanosoma cruzi na Amazônia Brasileira(Hemiptera: Reduviidae: Triatominae) / Laboratory analysis of the flight of Rhodnius brethesi Matta, 1919, potential wild vector of Trypanosoma cruzi in the Brazilian Amazon. (Hemiptera: Reduviidae: Triatominae)

A partir de observações realizadas em laboratório, foi avaliada a capacidade de voo de Rhodnius brethesi, correlacionando esta atividade a fatores como quantidade de sangue ingerida, gênero e período de jejum. Foram observados 27 machos e 38 fêmeas. O período médio de sobrevida foi de 17,8 e 22,3 dias para machos e fêmeas, respectivamente. A maioria dos insetos necessitou em média de 13 dias para iniciar o voo.

The flight ability of Rhodnius brethesi was evaluated through laboratory observations, and it was correlated with the quantity of blood ingested, gender and fasting period. A total of 65 insects were analyzed: 27 males and 38 females; their mean survival period was 17.8 and 22.3 days, respectively. Most of the insects started flying after 13 days.

Resistência ao jejum de Rhodnius stali Lent, Jurberg & Galvão, 1993 (Hemiptera, Reduviidae, Triatominae) em condições de laboratório / Resistance of Rhodnius stali Lent, Jurberg & Galvão, 1993 (Hemiptera, Reduviidae, Triatominae) to fasting under laboratory conditions

O objetivo deste estudo é avaliar a capacidade de resistência à privação alimentar de Rhodnius stali Lent, Jurberg, & Galvão, 1993, em condições de laboratório sob temperatura e umidade média ambiental registrada. Ovos recém colocados, de casais previamente separados, foram transferidos para tubos de polipropileno com tampa de rosca, com capacidade para 50 mL, forrados com papel filtro e, em seu interior, foi colocada uma tira do mesmo papel, dobrada, para aumentar a área de contato dos insetos e remover o excesso de umidade. A seguir, os espécimes foram individualizados, identificados e, após a eclosão, observados até a sua morte depois de uma única alimentação. A médiada resistência à privação alimentar observada, em dias, foi de 23, 45 ± 6, 42; 40,52 ± 22,57; 70,39 ± 38,46; 119, 6 ± 51, 44 e 160, 0 ± 49, 44 para os estádios de 1º ao 5º, respectivamente, enquanto as formas adultas resistiram 52, 65 ± 12, 16 dias para os machos e 46, 50 ± 18, 05 dias para as fêmeas.

The objective of this study was to evaluate the resistance of Rhodnius stali Lent, Jurberg & Galvão, 1993 to food deprivation under laboratory conditions at mean environmental temperature and humidity rates. Recently laid eggs from previously separated pairs were transferred to 50 mL propylene assay tubes with screw caps wrapped with filter paper. A strip of filterpaper was included inside to increase the insects' contact area and remove excess humidity. Specimens were isolated, identified, and observed after hatching until they died, having received only one feeding. The mean resistance to food deprivation was 23. 45 ± 6. 42; 40.52 ± 22. 57; 70. 39 ± 38.46; 119. 6 ± 51. 44, and 160. 0 ± 49. 44 days for the 1st to 5th stages, respectively. Adult males resisted for 52. 65 ± 12.16 days, and females resisted for 46.50 ± 18.05 days.