Molecular basis of niche adaptation and competition by Streptococcus pyogenes

这项NSERC发现拨款旨在了解不同的遗传系统如何有助于化脓性链球菌在鼻咽内生存的能力。已知这种细菌只自然地生活在人类体内，尽管它可以引起一系列重要的人类疾病，但化脓性链球菌的“自然”生命周期是一种定植状态，在这种状态下，该有机体不会导致活动性疾病。因此，由于化脓性链球菌只有一个自然宿主，它一定进化出了非常有效的方法来使其在这种环境中生存。这项工作旨在了解两个基因系统如何进化为化脓性链球菌的生存做出贡献。第一个系统由感染细菌的病毒(称为噬菌体)组成，并将它们的病毒DNA添加到化脓性链球菌的DNA中，以及这些噬菌体如何使化脓性链球菌更有效地定植。第二个系统由小的抗菌分子组成，这些分子的功能可能会让化脓性链球菌与其他微生物竞争。该应用程序将利用一些遗传方法来改变化脓性链球菌，然后评估这些遗传系统在细菌之间调动的能力或有助于化脓性链球菌持续存在的能力。

This NSERC Discovery grant is designed to understand how different genetic systems contribute to the ability of the bacterium Streptococcus pyogenes to survive within the nasopharynx. This bacterium is only known to live naturally in humans, and although it can cause a range of important human diseases, the 'natural' lifecycle of S. pyogenes is a state of colonization where the organism does not cause active disease. Thus, because S. pyogenes only has one natural host, it must have evolved very efficient ways to allow it to survive in this environment. The work is designed to understand how two genetic systems have evolved to contribute to the survival of S. pyogenes. The first system consists of viruses that infect bacteria (called bacteriophages) and have added their viral DNA to the DNA of S. pyogenes, and how these bacteriophages can make S. pyogenes more efficient at colonizing. The second system consists of small, anti-bacterial molecules that likely function to allow S. pyogenes to compete with other microorganisms. The application will utilize a number of genetic approaches to alter S. pyogenes and then assess the ability of these genetic systems to mobilize between bacteria or contribute to the ability of S. pyogenes to persist.