The Influence of Dengue Virus Serotype-2 Infection on Aedes aegypti (Diptera: Culicidae) Motivation and Avidity to Blood Feed
The Influence of Dengue Virus Serotype-2 Infection on Aedes aegypti (Diptera: Culicidae) Motivation and Avidity to Blood Feed
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DOI：
10.1371/journal.pone.0065252
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发表时间：
2013-06-03
期刊：
影响因子：
3.7
通讯作者：
Koella, Jacob C.
中科院分区：
文献类型：
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作者：
Maciel-de-Freitas, Rafael;Sylvestre, Gabriel;Koella, Jacob C.
背景：登革热病毒（DENV）由埃及伊蚊传播，这是一种与人类住所密切相关的物种。登革热病毒感染后的蚊虫行为有待进一步研究，特别是登革热病毒对蚊虫叮咬动机和贪婪度的潜在影响。方法/主要发现：我们对4-5日龄的Ae进行了口头挑战。低传代DENV血清型2 （DENV-2）的埃及伊蚊雌性，以测试该病毒是否影响进食动机（蚊子获得血粉的可能性及其血粉的大小）和贪婪度（在中断的第一次血粉后重新进食的可能性）。为了检测蚊子的进食动机，我们在第一次血餐后7天或14天分别给蚊子麻醉小鼠2、3、4或5分钟，并测量它们开始进食的时间。60.5%的未暴露的蚊子以老鼠为食，但只有40.5%的阳性蚊子以老鼠为食。暴露但阴性的蚊子与未暴露的蚊子行为相似（55.0%进食）。因此，DENV-2感染降低了蚊子的进食动机。为了测定蚊子的贪婪度，我们在第一轮喂食后两小时给同样的蚊子一只老鼠，并测量它们开始探查的时间。暴露的蚊子（阳性或阴性）比未暴露的蚊子更有可能重新进食，特别是，先前阻止蚊子重新进食的血餐在暴露的蚊子中比在未暴露的蚊子中更大。因此，DENV-2感染增加了蚊子的贪欲。结论/意义：DENV-2显著降低了蚊子的进食动机，但增加了蚊子的贪婪度（即使考虑了之前的吸血量）。由于这些是传播的重要组成部分，我们预计吸血行为的改变会影响伊蚊的媒介能力。埃及伊蚊感染登革热。
Background: Dengue virus (DENV) is transmitted by Aedes aegypti, a species that lives in close association with human dwellings. The behavior of DENV-infected mosquitoes needs further investigation, especially regarding the potential influence of DENV on mosquito biting motivation and avidity.Methodology/Principal findings: We orally challenged 4-5 day-old Ae. aegypti females with a low passage DENV serotype 2 (DENV-2) to test whether the virus influences motivation to feed (the likelihood that a mosquito obtains a blood-meal and the size of its blood meal) and avidity (the likelihood to re-feed after an interrupted first blood-meal). To assay motivation, we offered mosquitoes an anesthetized mouse for 2, 3, 4 or 5 minutes 7 or 14 days after the initial blood meals and measured the time they started feeding. 60.5% of the unexposed mosquitoes fed on the mouse, but only 40.5% of the positive ones did. Exposed but negative mosquitoes behaved similarly to unexposed ones (55.0% feeding). Thus DENV-2 infection decreased the mosquitoes' motivation to feed. To assay avidity, we offered the same mosquitoes a mouse two hours after the first round of feeding, and we measured the time at which they started probing. The exposed (positive or negative) mosquitoes were more likely to re-feed than the unexposed ones and, in particular, the size of the previous blood-meal that kept mosquitoes from re-feeding was larger in the exposed than in the unexposed mosquitoes. Thus, DENV-2 infection increased mosquito avidity.Conclusions/Significance: DENV-2 significantly decreased the mosquitoes' motivation to feed, but increased their avidity (even after taking account the amount of blood previously imbibed). As these are important components of transmission, we expect that the changes of the blood-feeding behaviour impact the vectorial capacity Ae. aegypti for dengue.