Larval stress alters dengue virus susceptibility in Aedes aegypti (L.) adult females

Abstract

In addition to genetic history, environmental conditions during larval stages are critical to the development, success and phenotypic fate of the Aedes aegypti mosquito. In particular, previous studies have shown a strong genotype-by-environment component to adult mosquito body size in response to optimal vs stressed larval conditions. Here, we expand upon those results by investigating the effects of larval-stage crowding and nutritional limitation on the susceptibility of a recent field isolate of Aedes aegypti to dengue virus serotype-2. Interestingly, female mosquitoes from larvae subjected to a stressed regime exhibited significantly reduced susceptibility to disseminated dengue infection 14 days post infection compared to those subjected to optimal regimes. Short term survivorship post-infected blood feeding was not significantly different. As with body size, dengue virus susceptibility of a mosquito population is determined by a combination of genetic and environmental factors and is likely maintained by balancing selection. Here, we provide evidence that under different environmental conditions, the innate immune response of field-reared mosquitoes exhibits a large range of phenotypic variability with regard to dengue virus susceptibility. Further, as with body size, our results suggest that mosquitoes reared under optimal laboratory conditions, as employed in all mosquito-pathogen studies to date, may not always be realistic proxies for natural populations.

Arbovirus Vectors of Epidemiological Concern in the Americas: A Scoping Review of Entomological Studies on Zika, Dengue and Chikungunya Virus Vectors

“…Three studies examined the effects of larval competition on dengue vector competence [142,143,172]. Bara et al [142] found that Ae.…”

“…albopictus larval competition resulted in significantly longer development times, lower emergence rates, and smaller adults, but did not significantly affect the extrinsic incubation period of DENV-2 virus. Kang et al [172] found that larval-stage crowding and nutritional limitation led to lower survival rates until pupation, lower blood feeding success, slower development, smaller adult body size, and lower susceptibility to DENV-2 infection. Four studies examined a variety of blood meal characteristics on arboviral infection rate [122,123,147,173].…”

“…Six studies examined the infectivity of different dengue viral strains, and the impact of co-infection [148,172,197–200]. Quintero-Gil et al [198] found that the DENV-2 serotype performed with a thousand-fold greater efficiency than the DENV-3 serotype, upon co-infection.…”

“…aegypti were significantly less susceptible to secondary dengue infection, after having been challenged with an inactive version of the virus. Kang et al [172] modelled interactions between dengue viral serotypes. Quiner et al [197] studied the infectivity of different isolates of DENV-2, and found NI-2B to have a replicative advantage over NI-1 until 12 days following infection, after which the advantage had dissipated.…”

Chemical Characterization and Larvicidal Activity of Essential Oil from Aniba duckei Kostermans against Aedes aegypti

“…Dengue, chikungunya and zika are all transmitted by the same vector, Aedes aegypti mosquito [8,10,[14][15] . Because there are still no validated vaccines against dengue or a specific antiviral for treatment of those diseases [16][17][18] , the best control method is prevention, by attacking its vector [19] . Vector control is done by eliminating propitious locations for oviposition or by fighting these mosquito larvae.…”