Laboratório de Ecologia de Doenças Transmissíveis na Amazônia, Instituto Leônidas e Maria Deane-Fiocruz Amazônia, Manaus, Brasil.
Programa de Pós-Graduação em Biologia Parasitária, Instituto Oswaldo Cruz (IOC), Rio de Janeiro, Brasil.
PLoS Negl Trop Dis. 2024 Oct 3;18(10):e0012547. doi: 10.1371/journal.pntd.0012547. eCollection 2024 Oct.
Ae. aegypti mosquitoes are considered a global threat to public health due to its ability to transmit arboviruses such as yellow fever, dengue, Zika and Chikungunya to humans. The lack of effective arboviral vaccines and etiological treatments make vector control strategies fundamental in interrupting the transmission cycle of these pathogens. This study evaluated Ae. aegypti mosquito populations pre- and post-intervention period with disseminating stations of the larvicide pyriproxyfen to understand its potential influence on the genetic structure and population diversity of these vectors.
METHODOLOGY/PRINCIPAL FINDINGS: This study was conducted in Manacapuru city, Amazonas, Brazil, where 1,000 pyriproxyfen dissemination stations were deployed and monitored from FEB/2014 to FEB/2015 (pre-intervention) and AUG/2015 to JAN/2016 (post-intervention). Low-coverage whole genome sequencing of 36 individuals was performed, revealing significant stratification between pre- and post-intervention groups (pairwise FST estimate of 0.1126; p-value < 0.033). Tajima's D estimates were -3.25 and -3.07 (both p-value < 0.01) for pre- and post-intervention groups, respectively. Molecular diversity estimates (Theta(S) and Theta(Pi)) also showed divergences between pre- and post-intervention groups. PCA and K-means analysis showed clustering for SNP frequency matrix and SNP genotype matrix, respectively, being both mainly represented by the first principal component. PCA and K-means clustering also showed significant results that corroborate the impact of pyriproxyfen intervention on genetic structure populations of Ae. aegypti mosquitoes.
CONCLUSIONS/SIGNIFICANCE: The results revealed a bottleneck effect and reduced mosquito populations during intervention, followed by reintroduction from adjacent and unaffected populations by this vector. We highlighted that low-coverage whole genome sequencing can contribute to genetic and structure population data, and also generate important information to aid in genomic and epidemiological surveillance.
埃及伊蚊被认为是全球公共卫生的威胁，因为它能够将黄热病、登革热、寨卡和基孔肯雅热等虫媒病毒传播给人类。缺乏有效的虫媒病毒疫苗和病因治疗方法使得病媒控制策略成为阻断这些病原体传播周期的基础。本研究通过投放幼虫杀蚊剂吡丙醚的传播站，在干预前后评估埃及伊蚊种群，以了解其对这些病媒遗传结构和种群多样性的潜在影响。
方法/主要发现：本研究在巴西亚马逊州的马纳卡普鲁市进行，2014 年 2 月至 2015 年 2 月（干预前）和 2015 年 8 月至 2016 年 1 月（干预后）期间，共部署和监测了 1000 个吡丙醚传播站。对 36 个人进行了低覆盖率全基因组测序，结果显示干预前后组之间存在显著分层（成对 FST 估计值为 0.1126；p 值<0.033）。干预前和干预后组的 Tajima's D 估计值分别为-3.25 和-3.07（均 p 值<0.01）。分子多样性估计值（Theta(S)和 Theta(Pi)）也显示出干预前后组之间的差异。PCA 和 K-means 分析分别显示 SNP 频率矩阵和 SNP 基因型矩阵的聚类，第一主成分主要代表这两个矩阵。PCA 和 K-means 聚类也显示出显著的结果，证实了吡丙醚干预对埃及伊蚊种群遗传结构的影响。
结论/意义：结果显示，在干预期间，蚊群出现瓶颈效应和数量减少，随后由该蚊种从邻近和未受影响的种群中重新引入。我们强调，低覆盖率全基因组测序可以为遗传和结构群体数据做出贡献，并生成有助于基因组和流行病学监测的重要信息。
