MRC-University of Glasgow Centre for Virus Research, Glasgow, UK.
Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.
mBio. 2021 Dec 21;12(6):e0025021. doi: 10.1128/mBio.00250-21. Epub 2021 Nov 9.
Environmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of symbionts for the control of dengue arboviruses. The potential of to invade, persist, and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains Mel and AlbB, two strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity, and dengue inhibition capacity were observed for Mel. In contrast, AlbB-carrying maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, Mel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures. In the past decades, dengue incidence has dramatically increased all over the world. An emerging dengue control strategy utilizes Aedes aegypti mosquitoes artificially transinfected with the bacterial symbiont , with the ultimate aim of replacing wild mosquito populations. However, the rearing temperature of mosquito larvae is known to impact on some strains. In this study, we compared the effects of a temperature cycle mimicking natural breeding sites in tropical climates on two strains, currently used for open field trials. When choosing the strain to be used in a dengue control program it is important to consider the effects of environmental temperatures on invasiveness and virus inhibition. These results underline the significance of understanding the impact of environmental factors on released mosquitoes, in order to ensure the most efficient strategy for dengue control.
环境因素在节肢动物内共生体的种群动态中起着至关重要的作用，因此也影响着共生体在登革热病毒防控中的应用。入侵、持续存在和阻断病毒传播的潜力在一定程度上取决于其细胞内密度。最近的几项研究强调了幼虫饲养温度在调节成年个体中密度的重要性，表明高温会严重影响某些菌株，而对其他菌株几乎没有影响。使用携带 Mel 和 AlbB 两种目前用于登革热防控的菌株的埃及伊蚊品系来评估热带热循环对密度和病毒阻断水平的影响。观察到 Mel 对细胞内密度、母系传播保真度和登革热抑制能力的影响。相比之下，携带 AlbB 的在高温下保持相对稳定的细胞内密度，并保持其抑制登革热的能力。经过幼虫热处理后，Mel 在老化成虫中表现出一定程度的密度恢复，但这因空气温度升高而受到影响。在过去的几十年中，登革热的发病率在全球范围内急剧上升。一种新兴的登革热防控策略是利用人工感染了细菌共生体的埃及伊蚊，最终目标是取代野生蚊群。然而，已知幼虫的饲养温度会影响某些菌株。在这项研究中，我们比较了模拟热带自然繁殖地温度周期对两种目前用于野外试验的菌株的影响。在选择用于登革热防控计划的菌株时，考虑环境温度对入侵性和病毒抑制的影响非常重要。这些结果强调了了解释放蚊子所受环境因素影响的重要性，以确保登革热防控的最有效策略。
