https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-023-01693-0
2023年9月13日，南方医科大学热带医学研究所陈晓光教授团队在国际期刊BMC Biology（一区）发表题为“The dynamics of deltamethrin resistance evolution in Aedes albopictus has an impact on fitness and dengue virus type-2 vectorial capacity”的研究论文。
白纹伊蚊（Aedes albopictus）是登革热等蚊媒传染病的重要传播媒介。主要依赖化学杀虫剂的媒介控制是蚊媒传染病预防控制的主要策略。然而，化学杀虫剂的滥用和不恰当使用已经导致蚊虫产生广泛的抗药性，如何实施科学的杀虫剂抗性管理，直接影响媒介种群和蚊媒传染病的有效控制。
该研究利用代表性杀虫剂溴氰菊酯建立敏感品系来源的白纹伊蚊抗药性演化模型，揭示了白纹伊蚊对溴氰菊酯抗性演化的分子机制；利用媒介能量方程综合分析抗性水平、适合度代价以及对登革病毒的易感性，发现白纹伊蚊对溴氰菊酯抗性的演化会增大其对登革病毒的传播风险。该研究成果将对媒介蚊虫的杀虫剂使用、抗药性监测和管理以及蚊媒传染病防控提供科学指引。
Worldwide invasion and expansion of Aedes albopictus, an important vector of dengue, chikungunya, and Zika viruses, has become a serious concern in global public health. Chemical insecticides are the primary means currently available to control the mosquito populations. However, long-term and large-scale use of insecticides has selected for resistance in the mosquito that is accompanied by a genetic load that impacts fitness.
A number of laboratory strains representing different resistance mechanisms were isolated and identified from laboratory-derived, deltamethrin-resistant Ae. albopictus recovered in previous work. Resistance levels and fitness costs of the strains were evaluated and compared to characterize the evolution of the resistance genotypes and phenotypes. The heterozygous F1534S mutation (1534F/S) in the voltage gated sodium channel (vgsc) gene product (VGSC), first detected in early stages of resistance evolution, not only confers high-level resistance, but also produces no significant fitness costs, leading to the rapid spread of resistance in the population. This is followed by the increase in frequency of homozygous F1534S (1534S/S) mosquitoes that have significant fitness disadvantages, prompting the emergence of an unlinked I1532T mutation with fewer side effects and a mating advantage better adapted to the selection and reproductive pressures imposed in the experiments. Metabolic resistance with no significant fitness cost and mediating a high-tolerance resistance phenotype may play a dominant role in the subsequent evolution of resistance. The different resistant strains had similar vector competence for dengue virus type-2 (DENV-2). Furthermore, a comparative analysis of vectorial capacity revealed that increased survival due to deltamethrin resistance balanced the negative fitness cost effects and contributed to the risk of dengue virus (DENV) transmission by resistant populations. The progressive evolution of resistance results in mosquitoes with both target-site insensitivity and metabolic resistance with lower fitness costs, which further leads to resistant populations with both high resistance levels and vectorial capacity.
This study reveals a possible mechanism for the evolution of deltamethrin resistance in Aedes albopictus. These findings will help guide practical strategies for insecticide use, resistance management and the prevention and control of mosquito-borne disease.
