Nanoscale interactions of candida species with oral bacteria and surfaces

人类口腔中含有许多不同类型的微生物，这些微生物通常以称为生物膜的“粘性”群落的形式附着在口腔表面。这些微生物被保持在很近的距离，因此可能会影响彼此的行为。这种影响可能导致微生物生长增加，一些微生物转移到其他位置，基因表达改变，并可能使微生物引起感染。卡迪夫大学牙科学院的梅根·威廉姆斯女士正在进行一个博士研究项目，她一直在探索一种名为白色念珠菌的真菌是如何与丙烯酸表面（用于制造假牙）以及白色念珠菌周围常见的细菌相互作用的。到目前为止，这项工作已经表明，涂有不同液体的丙烯酸定植，包括吸烟产生的液体，可能会改变白色念珠菌的生长方式。白色念珠菌可以生长为称为酵母的圆形细胞，也可以生长为称为菌丝的丝状细胞。通常认为，在感染期间，菌丝形式对人体组织表面的破坏更大。此外，研究表明，当某些细菌与白色念珠菌一起生长在丙烯酸表面时，也会引发菌丝的发育。这很重要，因为这可能意味着白色念珠菌感染的发生至少部分取决于与念珠菌一起存在的细菌的群落组成。迄今为止，用于研究这些影响的方法包括荧光显微镜，其中念珠菌被染色以对细菌和附着表面发出不同颜色的荧光。虽然这种方法可以量化不同生长形式的附着和成像，但它不能确定细胞-细胞表面相互作用的强度。原子力显微镜（AFM）是一种通过测量运动探针和表面之间的作用力来提供图像的方法。可以将不同的分子甚至整个细菌附着在AFM探针上，这样我们就可以测量细菌之间发生的相互作用，假丝酵母或菌丝作为底物。多伦多大学的Laurent Bozec博士和他的团队是AFM使用方面的专家，卡迪夫牙科学院没有AFM。因此，交流为博士生提供了学习新的实验技术，为博士学位生成重要数据的机会，并从独特的网络体验中受益。此提案所产生的结果将大大提高研究成果，并补充博士现有的研究成果。最终，这可以帮助确定细菌如何与白色念珠菌物理相互作用，并触发菌丝的发展，以促进感染。

The human mouth contains many different types of microorganisms that are often found attached to oral surfaces in 'sticky' communities called biofilms. These microorganisms are held in close proximity and will therefore likely influence the behaviour of each other. The effects of this could result in increased microbial growth, the displacement of some microorganisms to other sites, the alteration of gene expression and potentially, the enabling of microorganisms to cause infection.A PhD research project being done by Ms Megan Williams at the School of Dentistry, Cardiff University has been exploring how a fungus called Candida albicans can interact both with acrylic surfaces (used to manufacture dentures) and also with bacterial species often found alongside Candida albicans. To date, the work has indicated that colonisation of acrylic coated with different fluids, including those generated from tobacco smoking, may change the way Candida albicans grows. Candida albicans can grow as round cells called yeast, or as filamentous forms called hyphae. It is the hyphal forms that are often considered more damaging to human tissue surfaces during infection. In addition, the research shows that when certain bacteria are grown on acrylic surfaces with Candida albicans, hyphal development is also triggered. This is important, as it may mean that occurrence of infection by Candida albicans is at least in part determined by the community composition of the bacteria present alongside Candida. To date, the methods used to study these effects have included fluorescent microscopy, where the Candida is stained to fluoresce a different colour to bacteria and the surface of attachment. Whilst this approach allows quantification of attachment and imaging of the different growth forms, it cannot determine strength of cell-cell-surface interactions. Atomic Force Microscopy (AFM) is a method that provides images through measuring forces acting between a moving probe and a surface. It is possible to attach different molecules and even whole bacteria to the AFM probe, and in doing so, we can measure interactions occurring between bacteria, and either Candida yeast or hyphae serving as the substrate. Dr Laurent Bozec and his team at the University of Toronto are experts in use of AFM, which is not available in the School of dentistry, Cardiff. The exchange therefore offers the PhD student the opportunity to learn a new experimental technique, generate important data for the PhD and benefit from unique networking experiences. The results generated from this proposal will greatly enhance the research output and complement existing findings of the PhD. Ultimately, this could help determine how bacteria physically interact with Candida albicans and trigger the development of hyphal filaments to facilitate infection.