How microbe–microbe interactions dictate microbial complexity in the mosquito gut is unclear. Previously we found that, Serratia, a gut symbiont that alters vector competence and is being considered for vector control, poorly colonized Aedes aegypti yet was abundant in Culex quinquefasciatus reared under identical conditions. To investigate the incompatibility between Serratia and Ae. aegypti, we characterized two distinct strains of Serratia marcescens from Cx. quinquefasciatus and examined their ability to infect Ae. aegypti. Both Serratia strains poorly infected Ae. aegypti, but when microbiome homeostasis was disrupted, the prevalence and titers of Serratia were similar to the infection in its native host. Examination of multiple genetically diverse Ae. aegypti lines found microbial interference to S. marcescens was commonplace, however, one line of Ae. aegypti was susceptible to infection. Microbiome analysis of resistant and susceptible lines indicated an inverse correlation between Enterobacteriaceae bacteria and Serratia, and experimental co-infections in a gnotobiotic system recapitulated the interference phenotype. Furthermore, we observed an effect on host behavior; Serratia exposure to Ae. aegypti disrupted their feeding behavior, and this phenotype was also reliant on interactions with their native microbiota. Our work highlights the complexity of host–microbe interactions and provides evidence that microbial interactions influence mosquito behavior.

微生物-微生物相互作用如何决定蚊子肠道中微生物的复杂性尚不清楚。以前我们发现，沙雷氏菌是一种改变载体能力并被考虑用于载体控制的肠道共生体，但在相同条件下饲养的库蚊中大量繁殖的埃及伊蚊。调查Serratia和Ae之间的不相容性。aegypti，我们表征了来自Cx 的两种不同的粘质沙雷氏菌菌株。quinquefasciatus并检查了它们感染Ae的能力。埃及人。两种沙雷氏菌菌株感染Ae都很差。埃及，但是当微生物组稳态被破坏时，沙雷氏菌的流行率和滴度与其原生宿主的感染相似。检查多种遗传多样的Ae。aegypti线发现微生物对S. marcescens 的干扰是司空见惯的，但是，Ae 的一个线。埃及人很容易受到感染。对抗性和易感品系的微生物组分析表明，肠杆菌科细菌和沙雷氏菌之间呈负相关，并且无菌系统中的实验性共感染重现了干扰表型。此外，我们观察到对宿主行为的影响；沙雷氏菌暴露于Ae。埃及扰乱了它们的进食行为，这种表型也依赖于与它们的原生微生物群的相互作用。我们的工作突出了宿主-微生物相互作用的复杂性，并提供了微生物相互作用影响蚊子行为的证据。