Natural vertical cotransmission of Dengue virus and Chikungunya virus from Aedes aegypti in Brumado, Bahia, Brazil

ABSTRACT Background: Arthropod-borne viruses have recently emerged and are pathogens of various human diseases, including dengue, zika, and chikungunya viruses. Methods: We collectedAedes aegyptilarvae (N = 20) from Brumado, Bahia, Brazil, and treated and individually preserved the specimens. We analyzed the samples for dengue, zika, and chikungunya viruses using molecular biology methods. Results: We found that 25% (N = 5) and 15% (N = 3) were positive exclusively for dengue and chikungunya viruses, respectively; 15% (N = 3) were coinfected with both. Conclusions: This is the first report of dengue and chikungunya virus coinfection in A. aegypti larvae.

Typology and distribution of antennal sensory organs of adults Haematobia irritans of the Midwest Region of Brazil / Tipologia e distribuição de órgãos sensilares de Haematobia irritans adultas do Centro-Oeste do Brasil

Considering the great economic and sanitarian importance of Haematobia irritans − the development of resistance of this species to the main chemical insecticides used in its control, in several other localities of the world; as well as that different strains of the same species frequently present different types and distribution patterns −, the present aim study was to investigate the typology and distribution of different types of sensillae of H. irritans adults, from populations of this fly present in Brazilian Midwest, with emphasis on olfactory sensillae. This study provides new data on the typology and sensillary distribution of antennal sensilla of this fly. In the antennal segments were found non-innervated spinules and ten subtypes of sensilla: long bristles sensillum, long basiconic sensillum, blunt coeloconic sensillum, clavate coeloconic sensilla − single-tip and double-tip subtypes −, grooved coeloconic sensillum, long grooved coeloconic sensillum, trichoid sensillum, coeloconic sensillum, and smaller basiconic sensillum. A slight sexual dimorphism was observed in the antennal sensillae of H. irritans. These results provide a morphological basis for future investigations on olfactory-mediated behavior of this species, and could assist future studies for the development of alternative measures to the monitoring and control of this fly populations, with less environmental impact.(AU)

Considerando a grande importância econômica e sanitária de Haematobia irritans, o desenvolvimento de resistência desta espécie aos principais inseticidas químicos utilizados em seu controle, em diversas outras localidades do mundo, bem como que diferentes cepas de uma mesma espécie frequentemente apresentam diferentes tipos e padrões de distribuição sensilares, objetivou-se no presente trabalho investigar a tipologia e a distribuição dos diferentes tipos e subtipos sensilares de adulttos de H. irritans, oriunda de populações desta mosca presentes no centro-oeste brasileiro, com ênfase nas sensilas olfatórias. Este estudo apresenta novos dados sobre a tipologia e distribuição sensilar da antenna desta mosca. Em seus segmentos antenais foram observados pilosidades não enervadas e dez subtipos de sensilas, sendo: long bristles sensillum, long basiconic sensillum, blunt coeloconic sensillum, clavate coeloconic sensilla - single-tip and double-tip subtypes -, grooved coeloconic sensillum, long grooved coeloconic sensillum, trichoid sensillum, coeloconic sensillum, e smaller basiconic sensillum. Leve dimorfismo sexual foi observado em relação às sensilas antenais de H. irritans. Estes resultados fornecem uma base morfológica para futuras investigações sobre o comportamento mediado pelo olfato desta espécie, e poderão fomentar futuros estudos para desenvolvimento de medidas alternativas de monitoramento e controle de populações dessa mosca, com menor impacto.(AU)

Metagenomics, paratransgenesis and the Anopheles microbiome: a portrait of the geographical distribution of the anopheline microbiota based on a meta-analysis of reported taxa

Anophelines harbour a diverse microbial consortium that may represent an extended gene pool for the host. The proposed effects of the insect microbiota span physiological, metabolic and immune processes. Here we synthesise how current metagenomic tools combined with classical culture-dependent techniques provide new insights in the elucidation of the role of the Anopheles-associated microbiota. Many proposed malaria control strategies have been based upon the immunomodulating effects that the bacterial components of the microbiota appear to exert and their ability to express anti-Plasmodium peptides. The number of identified bacterial taxa has increased in the current “omics” era and the available data are mostly scattered or in “tables” that are difficult to exploit. Published microbiota reports for multiple anopheline species were compiled in an Excel® spreadsheet. We then filtered the microbiota data using a continent-oriented criterion and generated a visual correlation showing the exclusive and shared bacterial genera among four continents. The data suggested the existence of a core group of bacteria associated in a stable manner with their anopheline hosts. However, the lack of data from Neotropical vectors may reduce the possibility of defining the core microbiota and understanding the mosquito-bacteria interactive consortium.

A comparative study of fat body morphology in five mosquito species

The insect fat body plays major roles in the intermediary metabolism, in the storage and transport of haemolymph compounds and in the innate immunity. Here, the overall structure of the fat body of five species of mosquitoes (Aedes albopictus, Aedes fluviatilis, Culex quinquefasciatus, Anopheles aquasalis and Anopheles darlingi) was compared through light, scanning and transmission electron microscopy. Generally for mosquitoes, the fat body consists of lobes projecting into the haemocoel and is formed by great cell masses consisting of trophocytes and oenocytes. Trophocytes are rich in lipid droplets and protein granules. Interestingly, brown pigment granules, likely ommochromes, were found exclusively in the trophocytes located within the thorax and near the dorsal integument of Anopheles, which is suggestive of the role these cells play in detoxification via ommochrome storage. This study provides a detailed comparative analysis of the fat body in five different mosquito species and represents a significant contribution towards the understanding of the structural-functional relationships associated with this organ.

Insights into the transcriptome of oenocytes from Aedes aegypti pupae

Oenocytes are ectodermic cells present in the fat body of several insect species and these cells are considered to be analogous to the mammalian liver, based on their role in lipid storage, metabolism and secretion. Although oenocytes were identified over a century ago, little is known about their messenger RNA expression profiles. In this study, we investigated the transcriptome of Aedes aegypti oenocytes. We constructed a cDNA library from Ae. aegypti MOYO-R strain oenocytes collected from pupae and randomly sequenced 687 clones. After sequences editing and assembly, 326 high-quality contigs were generated. The most abundant transcripts identified corresponded to the cytochrome P450 superfamily, whose members have roles primarily related to detoxification and lipid metabolism. In addition, we identified 18 other transcripts with putative functions associated with lipid metabolism. One such transcript, a fatty acid synthase, is highly represented in the cDNA library of oenocytes. Moreover, oenocytes expressed several immunity-related genes and the majority of these genes were lysozymes. The transcriptional profile suggests that oenocytes play diverse roles, such as detoxification and lipid metabolism, and increase our understanding of the importance of oenocytes in Ae. aegypti homeostasis and immune competence.

Prevenção domiciliar da dengue: avaliação preliminar de tela protetora para pratos de vasos de planta / Prevención domiciliar de la dengue: evaluación preliminar de tela protectora para platos de macetas de planta / Dengue prevention at the household level: preliminary evaluation of a mesh cover for flowerpot saucers

Avaliou-se em laboratório a eficácia de um protótipo de capa de tela de poliéster (evidengue®) destinada a vedar o acesso de fêmeas do mosquito Aedes aegypti a pratos de vasos de planta. Dois pratos de vasos com água foram envolvidos individualmente com a capa e colocados com os seus respectivos vasos em duas gaiolas entomológicas, um em cada gaiola. Numa terceira gaiola foi colocado um conjunto idêntico de prato e vasos sem a capa. Cada gaiola recebeu 20 fêmeas copuladas do mosquito, alimentadas com sangue de camundongo. Os resultados mostram que a capa foi eficaz como barreira ao acesso de fêmeas. Novos testes são necessários para se avaliar a eficácia da capa como dispositivo de prevenção da ovipostura nos pratos.

The effectiveness of a polyester mesh cover (evidengue®), aimed at preventing the access of female Aedes aegypti mosquitoes to flowerpot saucers, was evaluated in laboratory. Two saucers of flowerpot with water were individually wrapped with the cover was placed with their respective pots in two entomological cages. One identical set of flowerpot and saucer was placed in a third cage. In each cage, 20 gravid females, fed on mouse blood, were released. Results show that the cover was effective to prevent access of females. Further tests are necessary to assess cover effectiveness as a device to prevent saucer oviposition.

Se evaluó en laboratorio la eficiencia de una cubierta de tela de polyester (evidengue®) con el objetivo de vedar el acceso de hembras del mosquito Aedes aegypti a platos de macetas de planta. Fueron utilizadas tres jaulas entomológicas, dos de ellas con evidengue® y una para control. En cada jaula fueron colocados dos conjuntos de macetas de planta y platos y 20 hembras copuladas, alimentadas con sangre de ratón. Los resultados muestran que la cubierta fue eficaz como barrera al acceso de hembras. Nuevas pruebas son necesarias para evaluar la eficiencia de la cubierta como dispositivo de prevención de la oviposición en los platos.