Díaz Sebastián, Avila Frank W, Coon Kerri L
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA; Max Planck Tandem Group in Mosquito Reproductive Biology, Universidad de Antioquia, Medellín, 050010, Antioquia, Colombia.
Max Planck Tandem Group in Mosquito Reproductive Biology, Universidad de Antioquia, Medellín, 050010, Antioquia, Colombia.
Acta Trop. 2025 May;265:107615. doi: 10.1016/j.actatropica.2025.107615. Epub 2025 Apr 12.
The development of axenic (microbiota-free) and gnotobiotic (fully defined and controlled microbiota) mosquito models has opened an opportunity to resolve current questions regarding mosquito-microbiota interactions, including fitness effects, microbiota acquisition, and tissue tropism. In this work, we introduced each of two focal bacterial strains - Enterobacter sp. and Asaia sp. originally isolated from Aedes aegypti midguts and reproductive tracts, respectively - into axenic Ae. aegypti larvae or adults to evaluate the effects of bacterial source and inoculation route on mosquito fitness. Asaia inoculated into mosquitoes at the first instar larval stage resulted in elevated larval and pupal mortality and surviving adults with reduced body and egg clutch sizes compared to adults from Enterobacter-inoculated larvae and conventional controls. In contrast, although inoculation of Asaia into newly emerged axenic adults resulted in lower survival among gnotobiotic females, no differences were observed in body or egg clutch sizes between Asaia- and Enterobacter-inoculated adults compared to axenic and conventional controls. These results suggest that the influence of bacteria on mosquito fitness is greater during the larval stage than in the adult stage, with bacteria isolated from distinct adult tissues differentially affecting host fitness. Source tissue and inoculation methods should be considered when evaluating the feasibility of bacterial candidates for microbiota-based vector control approaches.
无菌（无微生物群）和悉生（完全确定且可控的微生物群）蚊子模型的发展为解决当前有关蚊子与微生物群相互作用的问题提供了契机，这些问题包括适应性影响、微生物群获取以及组织嗜性。在这项研究中，我们将两种重点细菌菌株——分别最初从埃及伊蚊中肠和生殖道分离出的肠杆菌属细菌和亚细亚菌属细菌——引入无菌埃及伊蚊幼虫或成虫体内，以评估细菌来源和接种途径对蚊子适应性的影响。与接种肠杆菌属细菌的幼虫发育成的成虫以及传统对照相比，在一龄幼虫阶段接种亚细亚菌属细菌的蚊子，其幼虫和蛹的死亡率升高，存活成虫的体型和卵块大小减小。相比之下，虽然将亚细亚菌属细菌接种到新羽化的无菌成虫体内会导致悉生雌蚊的存活率降低，但与无菌对照和传统对照相比，接种亚细亚菌属细菌的成虫与接种肠杆菌属细菌的成虫在体型或卵块大小上没有差异。这些结果表明，细菌对蚊子适应性的影响在幼虫阶段比在成虫阶段更大，从不同成虫组织分离出的细菌对宿主适应性的影响也不同。在评估基于微生物群的病媒控制方法中候选细菌的可行性时，应考虑来源组织和接种方法。
