Candida albicans and Staphylococcus aureus dual species biofilms

描述（由申请方提供）：金黄色葡萄球菌和人类真菌病原体白色念珠菌是血流和医院获得性感染的主要病原体。由这些不同的生物体引起的大多数感染都是生物膜相关的，因为它们能够粘附在各种表面上，导致持续和慢性感染。更重要的是，C。albicans和S.金黄色葡萄球菌通常从宿主的伤口、粘膜表面和各种部位共分离。尽管它们的流行和临床推断，它们在宿主中共存，但缺乏探索它们在多微生物感染背景下相互作用的影响的研究。基于体外和体内研究的广泛初步发现，制定该建议以验证以下假设：这些微生物在宿主中相互作用，因为它们共存于粘膜表面，对其致病潜力和感染过程产生重大影响。具体而言，使用两个物种的临床菌株，该提案旨在证明由于C. albicans和S.金黄色葡萄球菌双物种生物膜。为此，建立了口腔粘膜共感染的小鼠模型，以确定高度侵袭性的C.白色念珠菌菌丝通过通常非侵入性但易逃避的S.金黄色。此外，由于初步数据似乎暗示动物模型中的共感染过程中涉及双种属生物膜诱导的蛋白表达，因此计划进行全局蛋白表达分析，以分析特定毒力因子的表达。随后，将使用基因敲除研究阐明所鉴定的蛋白质对毒力增强的直接作用。结合起来，这些新的初步发现保证了对C。albicans和S.金黄色葡萄球菌作为这些常见的病原体经常共同感染危重住院患者，导致显著的发病率和死亡率。我们期望实现这一建议的目的，作为一个范例，以进一步领域的真菌-细菌相互作用和多微生物疾病的一般。更重要的是，所产生的发现的传播将有助于设计旨在对抗真菌-细菌多微生物感染的新型治疗策略。 公共卫生相关性：细菌物种金黄色葡萄球菌和人类真菌病原体白色念珠菌能够粘附在各种表面上，引起显著的慢性生物膜相关感染。这些微生物物种也从感染患者的不同部位一起分离。然而，尽管它们的流行和发病机制，研究探索其相互作用的背景下，多微生物或混合感染的影响一直缺乏。为此，我们使用小鼠感染模型进行了广泛的初步研究，结果表明，当这些生物体在宿主中共存时，它们的毒力会增强。在本申请中，我们建议进行额外的深入分子和动物研究，以确认我们的初步发现并生成数据，以帮助我们理解导致多微生物感染的机制。我们期望这项工作的完成所产生的发现有助于设计新的治疗策略来对抗多种微生物感染。

DESCRIPTION (provided by applicant): The bacterial species Staphylococcus aureus and the human fungal pathogen Candida albicans are among the leading pathogens in bloodstream and hospital-acquired infections. Most infections caused by these diverse organisms are biofilm-associated due to their ability to adhere to a variety of surfaces causing persistent and chronic infections. More importantly, C. albicans and S. aureus are often co-isolated from wounds, mucosal surfaces and various sites in the host. Despite their prevalence and the clinical inferences of their co-existence in a host, studies exploring the implications of their interaction within the context of polymicrobial infections have been lacking. Based on extensive preliminary findings from in vitro and in vivo studies, this proposal was formulated to validate the hypothesis that these organisms interact in the host as they co-exist on mucosal surfaces with significant impact on their pathogenic potential and the infectious process. Specifically, using clinical strains of both species, this proposal aims to demonstrate infectious synergism and invasive systemic staphylococcal infection due to C. albicans and S. aureus dual species biofilms. To that end, a murine model of oral mucosal co-infection was developed in order to determine whether the penetration of the mouse oral mucosa by the highly invasive C. albicans hyphae leads to systemic infection by the normally non-invasive yet evasive S. aureus. In addition, as preliminary data seem to implicate the involvement of dual-species biofilm-induced protein expression in the co-infectious process in the animal model, global protein expression analyses are planned in order to profile the expression of specific virulence factors. Subsequently, the direct effect of the identified proteins on virulence enhancement will be elucidated using gene knockout studies. Combined, these novel preliminary findings warrant further in depth investigations into the intricate interaction between C. albicans and S. aureus as these common pathogens frequently co-infect critically-ill hospitalized patients causing significant morbidity and mortality. We expect the fulfillment of the aims of this proposal to serve as a paradigm to further the field of fungal- bacterial interactions and polymicrobial diseases in general. More importantly, the dissemination of the findings generated will aid in the design of novel therapeutic strategies aimed at combating fungal-bacterial polymicrobial infections. PUBLIC HEALTH RELEVANCE: The bacterial species Staphylococcus aureus and the human fungal pathogen Candida albicans are capable of adhering on a variety of surfaces causing significant chronic biofilm-associated infections. These microbial species are also isolated together from various sites from infected patients. Yet despite their prevalence and pathogenesis, studies exploring the implications of their interaction within the context of polymicrobial or mixed infections have been lacking. To that end, using a mouse model of infection, we performed extensive preliminary studies which demonstrated enhanced virulence for these organisms when they co-exist in a host. In this application, we propose to perform additional in depth molecular and animal studies in order to confirm our preliminary findings and generate data to contribute to our understanding of the mechanisms leading to multi-microbial infections. We expect the findings generated from the accomplishment of this work to aid in the design of novel therapeutic strategies to combat polymicrobial infections.