RESUMO
Aedes aegypti is the main vector of dengue in the Americas and is also a transmitter of urban yellow fever arboviruses, Zika, and Chikungunya, all of which have substantial economic impacts on the affected countries. Through mathematical models, the influence of climatic factors on the oviposition of Ae. aegypti was determined. The data were collected in the city of Apucarana, Paraná State, using oviposition traps. Daily data were submitted to a negative binomial regression model (p < 0.05). The analyses were performed using the R statistical program to determine the climatic factors that most influenced oviposition. A Poisson regression showed that the variables temperature, atmospheric pressure, humidity, and precipitation significantly increased the number of eggs. However, using the semi-normal probability graph with a simulation envelope, it was determined that the Poisson regression model was not adequate to explain the relationships between the variables. Thus, a negative binomial regression model was used, which overcame the problem of overdispersion, and showed that only temperature affected the increase in the number of eggs, where an increase of 1 °C was expected to result in a 54.03% increase in the number of Ae. aegypti eggs.
RESUMO
Phlebotomine sand flies are haematophagous dipterans of primary medical importance. They represent the only proven vectors of leishmaniasis worldwide and are involved in the transmission of various other pathogens. Studying the ecology of sand flies is crucial to understand the epidemiology of leishmaniasis and further control this disease. A major limitation in this regard is that traditional morphological-based methods for sand fly species identifications are time-consuming and require taxonomic expertise. DNA metabarcoding holds great promise in overcoming this issue by allowing the identification of multiple species from a single bulk sample. Here, we assessed the reliability of a short insect metabarcode located in the mitochondrial 16S rRNA for the identification of Neotropical sand flies, and constructed a reference database for 40 species found in French Guiana. Then, we conducted a metabarcoding experiment on sand flies mixtures of known content and showed that the method allows an accurate identification of specimens in pools. Finally, we applied metabarcoding to field samples caught in a 1-ha forest plot in French Guiana. Besides providing reliable molecular data for species-level assignations of phlebotomine sand flies, our study proves the efficiency of metabarcoding based on the mitochondrial 16S rRNA for studying sand fly diversity from bulk samples. The application of this high-throughput identification procedure to field samples can provide great opportunities for vector monitoring and eco-epidemiological studies.
Assuntos
Código de Barras de DNA Taxonômico/métodos , Insetos Vetores , Metagenômica/métodos , Psychodidae/classificação , Psychodidae/genética , Animais , Análise por Conglomerados , DNA Mitocondrial/química , DNA Mitocondrial/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Guiana Francesa , Filogenia , Psychodidae/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
A construção de represas geralmente causa modificações na composição da fauna em sua área de influência. Na área de implantação da Usina Hidrelétrica de Rosal, Estados do Espírito Santo e Rio de Janeiro, foram avaliadas modificações na abundância de anofelinos, planorbídeos e flebotomíneos antes (1998-2000) e após (2000-2005) o represamento. Foram definidos nove pontos de coleta, cada qual representado por uma moradia e seus anexos, abrigos de animais domésticos e coleções hídricas num raio de 150m. Coletaram-se 103 anofelinos adultos antes do represamento e 313 depois, 200 imaturos antes e 708 depois, 868 planorbídeos antes e 486 depois, e 2.979 flebotomíneos antes e 912 depois. O registro de vetores dentre anofelinos, planorbídeos e flebotomíneos revela o potencial da área para transmissão de malária, esquistossomose e leishmaniose tegumentar. As transformações ambientais ocorridas, no entanto, não aumentaram o risco para ocorrência dessas doenças.
The construction of dams usually changes the composition of the fauna within their areas of influence. In the area where the Rosal hydroelectric power station has been installed, in the States of Espírito Santo and Rio de Janeiro, changes to the abundance of anophelinae, planorbidae and phlebotominae were evaluated before (1998-2000) and after (2000-2005) the damming. Nine sample collection points were defined, each represented by a home and its outbuildings, shelters for domestic animals and water collection points within a radius of 150m. One hundred and three adult anophelinae were collected before the damming and 313 afterwards; 200 immature anophelinae before and 708 afterwards; 868 planorbidae before and 486 afterwards; and 2,979 phlebotominae before and 912 afterwards. The vector record, consisting of anophelinae, planorbidae and phlebotominae, shows the potential of this area for transmission of malaria, schistosomiasis and American cutaneous leishmaniasis. However, the environmental changes did not increase the risk of the occurrence of these diseases.