Department of Veterinary Pathobiology, University of Missouri, Columbia, MO.
Department of Biological Sciences, University of Missouri, Columbia, MO.
J Med Entomol. 2019 Apr 16;56(3):832-843. doi: 10.1093/jme/tjy241.
Mayaro virus (MAYV; Togaviridae; Alphavirus) has drawn increasing attention as an arthropod-borne virus with potential to cause outbreaks among the human populations of the Western Hemisphere. In the tropical regions of Central and South America, the virus exists in sylvatic cycles between mosquitoes and primate reservoirs such as marmosets. Although forest-dwelling mosquitoes are regarded as important vectors for MAYV, it has been shown previously that the virus can infect and potentially be transmitted by the mosquitoes, Aedes aegypti and Aedes albopictus (Diptera: Culicidae). Here, we compare the infection and transmission efficiencies of two MAYV strains, IQT 4235 from Iquitos, Peru ('IQT') and the type strain of MAYV from Trinidad, TRVL 4675 ('TRVL') in two laboratory-adapted Ae. aegypti strains, Higgs White Eye and Orlando. The TRVL strain was less efficiently transmitted by both mosquito strains than MAYV IQT. Based on the full-length nucleotide sequences of the two viral genomes, we show that the TRVL prototype strain of MAYV is phylogenetically ancestral and more distantly related to the IQT strain. The TRVL strain efficiently infected wild-type Ae. albopictus from Missouri and readily disseminated in those. Considering scenarios in which natural MAYV transmission cycles may overlap with those of chikungunya virus (CHIKV; Togaviridae; Alphavirus), we assessed the effects of mixed infections of the two viruses in mosquitoes based on coinfection or superinfection. Although coinfection had no measurable effect on the transmission potential of either virus, we observed superinfection exclusion for CHIKV in MAYV-infected mosquitoes but not for MAYV in CHIKV-infected mosquitoes.
马亚罗病毒（MAYV；披膜病毒科；甲病毒属）作为一种具有在西半球人群中引发暴发潜力的虫媒病毒，引起了越来越多的关注。在中美洲和南美洲的热带地区，该病毒在蚊子和灵长类动物（如狨猴）等野生动物宿主之间存在循环。尽管森林栖蚊子被认为是 MAYV 的重要传播媒介，但此前已表明该病毒可感染并可能由埃及伊蚊和白纹伊蚊（双翅目：库蚊科）传播。在此，我们比较了来自秘鲁伊基托斯的 IQT 4235 株（IQT）和特立尼达的 MAYV 原型株 TRVL 4675（“TRVL”）两种 MAYV 株在两种实验室适应的埃及伊蚊品系（Higgs 白眼和奥兰多）中的感染和传播效率。与 IQT 相比，TRVL 株在两种蚊子中传播效率都较低。基于两个病毒基因组的全长核苷酸序列，我们表明 MAYV 的 TRVL 原型株在系统发育上是祖先的，与 IQT 株的亲缘关系更远。TRVL 株可有效感染来自密苏里州的野生型白纹伊蚊，并在其中迅速传播。考虑到自然 MAYV 传播周期可能与基孔肯雅病毒（CHIKV；披膜病毒科；甲病毒属）重叠的情况，我们根据混合感染或重复感染评估了两种病毒在蚊子中的混合感染的影响。尽管混合感染对两种病毒的传播潜力均无明显影响，但我们观察到 MAYV 感染的蚊子中 CHIKV 的重复感染排斥，但 CHIKV 感染的蚊子中 MAYV 则无此现象。
