RESUMO
Aedes aegypti mosquitoes are vectors for arboviruses of medical importance such as dengue (DENV) and Zika (ZIKV) viruses. Different innate immune pathways contribute to the control of arboviruses in the mosquito vector including RNA interference, Toll and Jak-STAT pathways. However, the role of cellular responses mediated by circulating macrophage-like cells known as hemocytes remains unclear. Here we show that hemocytes are recruited to the midgut of Ae. aegypti mosquitoes in response to DENV or ZIKV. Blockade of the phagocytic function of hemocytes using latex beads induced increased accumulation of hemocytes in the midgut and a reduction in virus infection levels in this organ. In contrast, inhibition of phagocytosis by hemocytes led to increased systemic dissemination and replication of DENV and ZIKV. Hence, our work reveals a dual role for hemocytes in Ae. aegypti mosquitoes, whereby phagocytosis is not required to control viral infection in the midgut but is essential to restrict systemic dissemination. Further understanding of the mechanism behind this duality could help the design of vector-based strategies to prevent transmission of arboviruses.
Assuntos
Aedes/citologia , Aedes/virologia , Vírus da Dengue/fisiologia , Hemócitos/imunologia , Hemócitos/virologia , Zika virus/fisiologia , Aedes/anatomia & histologia , Animais , Feminino , Hemócitos/fisiologia , Mosquitos Vetores , Fagócitos/virologia , FagocitoseRESUMO
The mosquito community from remote locations toward the southern border of the Brazilian State of Amazonas, in four localities along the Liberdade and Gregório Rivers, was sampled using CDC and Malaise traps, complemented with net sweeping and immature collections. During May 2011, 190 collections yielded 13,012 mosquitoes, from 15 genera and 112 different species, together with 10 morphospecies, which may represent new undescribed taxa. Among the species collected, there are two new geographical distribution records for the State of Amazonas. Culex, the most abundant genus, also had the highest number of species. Both Aedes and Uranotaenia had the second highest number of species, although they were the second and seventh most abundant, respectively. The most abundant species were Aedes (Ochlerotatus) fulvus (Wiedemann), Aedes (Ochlerotatus) nubilus (Theobald), Culex (Culex) mollis Dyar & Knab, Nyssorhynchus (Nyssorhynchus) oswaldoi sensu lato, Culex (Melanoconion) pedroi Sirivanakarn & Belkin, and Culex (Melanoconion) gnomatos Sallum, Hutchings & Ferreira. The epidemiological implications of mosquito species are discussed and compared with other mosquito inventories from the Amazon region. These results represent the first standardized mosquito inventories of the Liberdade and Gregório Rivers, with the identification of 112 species and 10 morphospecies, within the municipalities of Ipixuna and Eirunepé, from which we have only few records in the published literature.
Assuntos
Biota , Culicidae/fisiologia , Animais , Brasil , Culicidae/crescimento & desenvolvimento , Feminino , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Pupa/crescimento & desenvolvimento , Pupa/fisiologia , RiosRESUMO
Resumo Introdução Estudos que aperfeiçoam e/ou aferem a capacidade de armadilhas na detecção de vetores auxiliam sobremaneira o processo de controle das doenças causadas por eles. Objetivo Objetivou-se comparar quatro tipos de armadilhas para captura/coleta de A. aegypti em condições de campo e avaliar a influência da temperatura e precipitação na eficiência destas armadilhas. Método Armadilhas ovitrampas (papel-filtro e paleta), mosquitéricas e MosquiTRAP ® foram instaladas em 10 quarteirões, que recebiam, em cada uma de suas faces, um tipo destas armadilhas. Foram calculados índices entomológicos qualitativos e quantitativos para todas as armadilhas. Resultados A armadilha mosquitérica apresentou o menor índice de positividade (3%). Apenas os índices IPAaegypti e IDAaegypti demonstraram relação positiva com a temperatura e a precipitação, respectivamente. As armadilhas ovitrampas tiveram até 6,6 vezes maiores chances de positividade para A. aegypti quando comparadas com as MosquiTRAP ®, sem diferença significante entre os substratos papel-filtro e paleta. Conclusão As armadilhas ovitrampas apresentaram os melhores índices para serem utilizadas na vigilância do A. aegypti. É recomendado de forma imperativa o uso do papel-filtro como substrato para oviposição, pelo seu menor custo, maior facilidade de confecção, transporte e armazenamento, além da melhor visibilidade dos ovos depositados.
Abstract Background Studies that improve and/or assess the ability of traps in vector detection, facilitate the control of diseases caused by these vectors. Objective The objective of this study was to compare four types of traps for A. aegypti capture and collection under field conditions, and to evaluate the influences of temperature and precipitation on the efficiency of these traps. Method Ovitraps (filter paper and palette), "mosquitéricas" and MosquiTRAP® were installed in 10 city blocks, which received on each face, one type of trap. Qualitative and quantitative entomological indices were calculated for all traps. Results The "mosquitéricas" trap had the lowest positivity index (3%). Only the IPAaegypti and IDAaegypti indices showed a positive relationship with temperature and precipitation, respectively. The ovitraps had up to 6.6 times more chances of positivity for A. aegypti when compared to MosquiTRAP®, with no significant difference between the filter paper and the palette substrates. Conclusion The ovitraps presented the best indices to be used in the surveillance of A. aegypti . The recommendation to use filter paper as a substrate for oviposition is imperative because of its lower cost, easier manufacturing, transport and storage, as well as better visibility of the deposited eggs.