Department of Biology, Emory Universitygrid.189967.8, Atlanta, Georgia, USA.
Department of Biological Sciences, Southern Illinois University Edwardsvillegrid.263857.d, Edwardsville, Illinois, USA.
Appl Environ Microbiol. 2022 Jan 11;88(1):e0155021. doi: 10.1128/AEM.01550-21. Epub 2021 Oct 20.
Many insects harbor microbial symbiotic partners that offer protection against pathogens, parasitoids, and other natural enemies. Mounting evidence suggests that these symbiotic microbes can play key roles in determining infection outcomes in insect vectors, making them important players in the quest to develop novel vector control strategies. Using the squash bug , we investigated how the presence of symbionts affected the persistence and intensity of phytopathogenic Serratia marcescens within the insect vector. We reared insects aposymbiotically and with different isolates, infected them with S. marcescens, and then sampled the insects periodically to assess the intensity and persistence of pathogen infection. Squash bugs harboring consistently had much lower-intensity infections and cleared S. marcescens significantly faster than their aposymbiotic counterparts. These patterns held even when we reversed the timing of exposure to symbiont and pathogen. Taken together, these results indicate that symbionts play an essential role in S. marcescens infection outcomes in squash bugs and could be used to alter vector competence to enhance agricultural productivity in the future. Insect-microbe symbioses have repeatedly been shown to profoundly impact an insect's ability to vector pathogens to other hosts. The use of symbiotic microbes to control insect vector populations is of growing interest in agricultural settings. Our study examines how symbiotic microbes affect the dynamics of a plant pathogen infection within the squash bug vector , a well-documented pest of squash and other cucurbit plants and a vector of Serratia marcescens, the causative agent of cucurbit yellow vine disease. We provide evidence that the symbiont prevents successful, long-term establishment of S. marcescens in the squash bug. These findings give us insight into symbiont-pathogen dynamics within the squash bug that could ultimately determine its ability to transmit pathogens and be leveraged to interrupt disease transmission in this system.
许多昆虫体内都携带有微生物共生伙伴，这些伙伴可以为其提供抵御病原体、寄生蜂和其他天敌的保护。越来越多的证据表明，这些共生微生物在决定昆虫媒介物的感染结果方面发挥着关键作用，使它们成为开发新型媒介物控制策略的重要参与者。本研究以南瓜实蝇为例，探讨了共生体的存在如何影响植物病原菌粘质沙雷氏菌在昆虫媒介物体内的持续存在和感染强度。我们对无菌和不同分离株感染的昆虫进行了饲养，然后定期取样以评估病原体感染的强度和持续时间。携带共生体的南瓜实蝇感染强度明显较低，且清除粘质沙雷氏菌的速度明显快于无菌对照。即使我们改变了暴露于共生体和病原体的时间顺序，这些模式仍然成立。总的来说，这些结果表明，共生体在南瓜实蝇感染粘质沙雷氏菌的结果中起着至关重要的作用，可以用来改变媒介物的适应性，以提高未来农业生产力。昆虫-微生物共生关系已多次被证明会深刻影响昆虫将病原体传播给其他宿主的能力。在农业环境中，利用共生微生物来控制昆虫媒介物种群的方法越来越受到关注。本研究考察了共生微生物如何影响南瓜实蝇媒介物体内植物病原菌感染的动态，南瓜实蝇是南瓜和其他葫芦科植物的一种已被充分研究的害虫，也是粘质沙雷氏菌的媒介物，后者是导致葫芦科黄萎病的病原体。我们提供的证据表明，共生体可防止粘质沙雷氏菌在南瓜实蝇体内成功建立长期感染。这些发现使我们深入了解了南瓜实蝇体内共生体-病原体的动态，这最终可能决定其传播病原体的能力，并可用于中断该系统中的疾病传播。
