An Anopheles aquasalis GATA factor Serpent is required for immunity against Plasmodium and bacteria.

Innate immunity is an ancient and conserved defense system that provides an early effective response against invaders. Many immune genes of Anopheles mosquitoes have been implicated in defense against a variety of pathogens, including plasmodia. Nevertheless, only recent work identified some immune genes of Anopheles aquasalis mosquitoes upon P. vivax infection. Among these was a GATA transcription factor gene, which is described here. This is an ortholog of GATA factor Serpent genes described in Drosophila melanogaster and Anopheles gambiae. Gene expression analyses showed an increase of GATA-Serpent mRNA in P. vivax-infected A. aquasalis and functional RNAi experiments identified this transcription factor as an important immune gene of A. aquasalis against both bacteria and P. vivax. Besides, we were able to identify an effect of GATA-Serpent knockdown on A. aquasalis hemocyte proliferation and differentiation. These findings expand our understanding of the poorly studied A. aquasalis-P. vivax interactions and uncover GATA-Serpent as a key player of the mosquito innate immune response.

Aedes (Stegomyia) albopictus' dynamics influenced by spatiotemporal characteristics in a Brazilian dengue-endemic risk city.

Brazil reported the majority of the dengue cases in Americas during the last two decades, where the occurrence of human dengue cases is exclusively attributed to the Aedes (Stegomyia) aegypti (Linnaeus). Nowadays, other recognized Dengue virus (DENV) vector in Asian countries, Aedes (Stegomyia) albopictus (Skuse), has been detected in more than half of the 5565 Brazilian municipalities. Therefore, the aim of the present study was to investigate the presence of, and determine the Ae. albopictus' dynamics influenced by spatiotemporal characteristics in a dengue-endemic risk city of Belo Horizonte, Minas Gerais State's capital. Aedes albopictus were collected across four consecutive DENV transmission seasons from 2010 to 2014. These mosquitoes were caught in three selected districts, which had been reported in the previous ten years as having high mosquito densities and an elevated concentration of human dengue cases during epidemic seasons. All field-caught Ae. albopictus was individually processed by real-time RT-PCR, to research the DENV presence. The third season (p<0.05) and the Pampulha district (p<0.05) had the highest proportions of field-caught Ae. albopictus, respectively. The second season had the highest proportion of DENV-infected field-caught females (p<0.05), but there was no difference among the proportions of DENV-infected Ae. albopictus when comparing the collection in the three districts (p=0.98). Minimum (p=0.004) and maximum (p<0.0001) temperature were correlated with the field-caught Ae. albopictus in four different periods and districts. In the generalized linear model of Poisson, the field-caught DENV-infected Ae. albopictus (p=0.005), East district (p=0.003), minimum temperature (p<0.0001) and relative humidity (p=0.001) remained associated with the total number of human dengue cases. Our study demonstrated that the number of field-caught DENV-infected Ae. albopictus was inversed correlated with the number of human dengue cases. Our study raises the possibility that the DENV circulating in mosquitoes Ae. albopictus is happening in non-epidemic periods, showing that this species may be keeping only the presence of the virus in nature. Further long-term studies are necessary to better understand the role of Ae. albopictus in DENV transmission and or its vectorial competence in Belo Horizonte and in other endemic cities in Brazil and in the New World countries.

Distinct variation in vector competence among nine field populations of Aedes aegypti from a Brazilian dengue-endemic risk city.

BACKGROUND: In Brazil, dengue epidemics erupt sporadically throughout the country and it is unclear if outbreaks may initiate a sustainable transmission cycle. There are few studies evaluating the ability of Brazilian Aedes aegypti populations to transmit dengue virus (DENV). The aim of this study was to compare DENV susceptibility of field-captured Ae. aegypti populations from nine distinct geographic areas of the city of Belo Horizonte in 2009 and 2011. Infection Rate (IR), Vector Competence (VC) and Disseminated Infection Rate (DIR) were determined. METHODS: Aedes aegypti eggs from each region were collected and reared separately in an insectary. Adult females were experimentally infected with DENV-2 and the virus was detected by qPCR in body and head samples. Data were analyzed with the Statistical Package for the Social Sciences version 17. RESULTS: IR varied from 40.0% to 82.5% in 2009 and 60.0% to 100.0% in 2011. VC ranged from 25.0% to 77.5% in 2009 and 25.0% to 80.0% in 2011. DIR oscillated from 68.7% to 100.0% in 2009 and 38.4% to 86.8 in 2011. When the results were evaluated by a logistic model using IR as covariate, North, Barreiro, South-Central and Venda Nova showed the strongest association in 2009. In 2011, a similar association was observed for South-Central, Venda Nova, West and Northeast regions. Using VC as covariate, South-Central and Venda Nova showed the most relevant association in 2009. In 2011, South-Central, Venda Nova and Barreiro presented the greatest revelation associations. When DIR data were analyzed by logistic regression models, Pampulha, South-Central, Venda Nova, West, Northeast and East (2009) as well as South-Central, Venda Nova and West (2011) were the districts showing the strongest associations. CONCLUSIONS: We conclude that Ae. aegypti populations from Belo Horizonte exhibit wide variation in vector competence to transmit dengue. Therefore, vector control strategies should be adapted to the available data for each region. Further analysis should be conducted to better understand the reasons for this large variability in vector competence and how these parameters correlate with epidemiological findings in subsequent years.

[Phlebotomine sandflies in Parque Nacional Cavernas do Peruaçu, Minas Gerais state, Brazil]. / Flebotomíneos do Parque Nacional Cavernas do Peruaçu, MG.

We surveyed the phlebotomine fauna in the Parque Nacional Cavernas do Peruaçu, Minas Gerais, Brazil, aiming to associate the presence of vector with the risk of leishmaniasis transmission. Field captures were performed with CDC light traps between February and March 2003. A total of 436 sand flies were captured, belonging to 14 species. The predominant species (28.7%) was Lutzomyia ischnacantha Martins, Souza e Falcão, followed by L. renei (27,06%) and L. cavernicola (13,07%). The finding of L. intermedia, a species that is incriminated as vector of cutaneous leishmaniasis, has to be taken into account.

Flebotomíneos do Parque Nacional Cavernas do Peruaçu, MG / Phlebotomine sandflies in Parque Nacional Cavernas do Peruaçu, Minas Gerais state, Brazil

O presente trabalho teve como objetivo conhecer a fauna flebotomínica na Gruta do Caboclo, localizada no Parque Nacional Cavernas do Peruaçu, MG, e associá-la ao risco de transmissão das leishmanioses. As capturas foram realizadas utilizando-se armadilhas luminosas tipo CDC, nos meses de fevereiro e março de 2003. O total de 436 flebotomíneos foi capturado, pertencendo a 14 espécies. A espécie predominante foi Lutzomyia ischnacantha Martins, Souza & Falcão, com 28,7 por cento, seguida por L. renei (27,06 por cento) e L. cavernicola (13,07 por cento). O encontro de L. intermedia, espécie incriminada como vetora de leishmaniose cutânea, deve ser levado em consideração.

We surveyed the phlebotomine fauna in the Parque Nacional Cavernas Do Peruaçu, Minas Gerais, Brazil, aiming to associate the presence of vector with the risk of leishmaniasis transmission. Field captures were performed with CDC light traps between February and March 2003. A total of 436 sand flies were captured, belonging to 14 species. The predominant species (28.7 percent) was Lutzomyia ischnacantha Martins, Souza e Falcão, followed by L. renei (27,06 percent) and L. cavernicola (13,07 percent). The finding of L. intermedia, a species that is incriminated as vector of the cutaneous leishmaniasis, has to be taken into account.