Effect of Chikungunya virus infection on the locomotor activity of Aedes aegypti (Diptera: Culicidae)

• Grant number: 19/11152-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2019
• End date: June 30, 2020
• Field of knowledge: Biological Sciences - Parasitology - Entomology and Malacology of Parasites and Vectors
• Principal Investigator: Tamara Nunes de Lima Camara
• Grantee: Marcela Mori Menzato
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In general, insects are characterized as diurnal, nocturnal and crepuscular because they restrict their daily activities, such as flight, oviposition and feeding, at certain times of the day. Aedes aegypti Linnaeus, 1762 is considered a diurnal mosquito, with main peaks of activity at dawn and dusk. However, some physiological variations may alter the activity of this species, such as insemination, blood feeding and arbovirus infection. The great importance of Ae. aegypti for public health relies on the fact that it is considered the main vector of the dengue, chikungunya and Zika viruses in Brazil and in other countries of the world. One of the ways to study the interaction between vector / pathogen is to evaluate the effect of the infection on the locomotor activity of the mosquito and, despite the importance, there is a huge knowledge gap about the effect of dengue, Zika and chikungunya virus infection on the locomotor activity of Ae. aegypti. The objective of this project is to evaluate, under laboratory conditions, the effect of chikungunya virus infection (CHIKV) on the locomotor activity of Ae. aegypti, under 12 hours of light and 12 hours of dark (LD 12:12), at 25 ° C. The eggs of this species will be placed to hatch and the immature forms will be raised under regime of LD 12:12, at 25ºC. Adult females of Ae. aegypti will be individually infected through intrathoracic inoculation with solution containing chikungunya virus at an infecting concentration for the female. Control females will also be injected intratoracically with the same volume of the same solution but without the presence of the virus. The locomotor activity analysis system used will be the Drosophila Activity Monitor (Trikinetics) and, to quantify the activity, the "DAMSystem data collection" program will be used, which will record, at regular intervals, the number of times each mosquito interrupts the infrared light. All females that survive after infection with the virus, in addition to some alive females of the control group, will be stored in freezer -80 ° C for further viral detection by PCR.