Genetic Control of C. albicans Biofilm Formation

描述（由申请方提供）：白色念珠菌是一种主要的人类真菌病原体，可引起粘膜和深部组织感染。一个重要的危险因素C。白色念珠菌感染是存在植入的医疗装置，其提供用于生物膜形成的表面。生物膜为病原体的生存创造了受保护的微环境。本文提出的研究的近期目标是确定关键C。白念珠菌的基因和调控途径，支配生物膜的形成，与发展新的治疗策略的长期目标基于这一认识。我们已经实施了一种新的策略来分析独特的C。白念珠菌性状：转录因子功能调查。通过这种策略，我们创建了每个转录因子基因都有缺陷的菌株，并测试了菌株的表型缺陷。然后，我们使用微阵列分析，以确定目标基因有一个直接的作用，在研究中的表型。迄今为止，我们已经测试了生物膜缺陷的84个转录因子基因中的每一个中的纯合插入突变体。锌指蛋白Bcr1 p是生物膜形成和一组表面蛋白基因和粘附素表达所必需的。我们将分析单个和多个靶基因突变体以及生物膜形成试验中的过表达菌株。此外，我们将确定我们在筛选中定义的其他生物膜调节剂的靶基因。将对靶基因进行功能分析。最后，我们将用大鼠中心静脉导管模型在体内测试我们的体外结果，用于生物膜形成。将监测包括活菌负荷、生物膜结构和基因表达谱在内的属性。

DESCRIPTION (provided by applicant): Candida albicans is a major human fungal pathogen, causing both mucosal and deep tissue infections. A significant risk factor for C. albicans infection is the presence of an implanted medical device, which provides a surface for biofilm formation. The biofilm creates a protected microenvironment for survival of the pathogen. The immediate goal of studies here proposed is to define the key C. albicans genes and regulatory pathways that govern biofilm formation, with the long-term objective of developing new treatment strategies based upon this understanding. We have implemented a new strategy for analysis of unique C. albicans traits: a transcription factor function survey. With this strategy, we create strains with defects in each transcription factor gene and test the strains for phenotypic defects. We then use microarray analysis to identify target genes that have a direct role in phenotype under study. We have thus far tested homozygous insertion mutants in each of 84 transcription factor genes for biofilm defects. Zinc-finger protein Bcr1 p is required for biofilm formation and for expression of a group of surface protein genes and adhesins. We will analyze single and multiple target gene mutants as well as over-expressing strains in assays for biofilm formation. In addition, we will identify target genes for additional biofilm regulators that we define in our screen. Target genes will be subjected to functional analysis. Finally, we will test our in vitro results with a rat central venous catheter model for biofilm formation in vivo. Attributes including viable burden, biofilm architecture, and gene expression profiles will be monitored.