Effect of Arginine Metabolism on Biofilm Formation in the Staphyloccoci

葡萄球菌是我们社会的主要负担，导致显著的发病率、死亡率和成本增加 在医疗保健方面。增加这种疾病负担的是它们在生物材料上形成生物膜的能力， 增加对抗菌剂的耐受性和免疫系统的作用。进一步研究发展和 葡萄球菌生物膜的成熟可能导致导致其破坏的新疗法。 已知葡萄球菌生物膜显示包含几种生理状态的空间异质性 包括需氧和厌氧区域。维持这些生理状态对于 形成成熟的生物膜。据推测，精氨酸催化剂是至关重要的发展， 以及金黄色葡萄球菌和S.表皮生物膜事实上， 两个S.金黄色葡萄球菌和表皮含有两个完整的精氨酸拷贝， 脱亚胺酶（ADI）操纵子，其中之一是获得的致病岛。ADI操纵子合成 分解精氨酸产生ATP和氨的蛋白质。在生物膜的某些微环境中 在环境中，所产生的ATP可用于代谢目的，而氨可用于 pH稳态。研究表明，精氨酸代谢在生物膜发育过程中被诱导， 获得的（即来自致病性岛）ADI操纵子作为生物膜最具转录活性 成熟精氨酸代谢的重要性将通过首先探索ArcR的调节作用来研究， 生物膜生长期间ADI表达的已知调节剂。据推测，最大诱导的 获得的ADI操纵子发生在生物膜生长期间，并且在这些条件下的诱导是ArcR。 其次，通过使用荧光基因融合，我们将检查时间和空间的 ADI基因在S. epidermidis和S.金黄色葡萄球菌生物膜，并将这些数据与 已知的生物膜的厌氧和需氧区域。Lasfiy，通过小鼠异物感染模型， ADI突变体与野生型S.金黄色葡萄球菌和确定表皮细胞。 ADI突变体对抗生素的敏感性将在豚鼠裂笼模型中进行检测。 相关性（参见说明）：

Staphylococci are a major burden on our society causing significant morbidity, mortality, and increased cost in healthcare. Increasing this disease burden is their ability to form biofilms on biomaterials resulfing in increased tolerance to anfibiofics and action of the immune system. Further study on the development and maturation of staphylococcal biofilms may lead to novel therapeufics that lead to their disruption. Staphylococcal biofilms are known to display spatial heterogeneity containing several physiological states including aerobic and anaerobic regions. Maintenance of these physiological states is imperative to the development of a mature biofilm. It is hypothesized that arginine catabolism is crucial for the development and maturation of anaerobic regions within both a Staphylococcus aureus and S. epidermidis biofilm. In fact, several backgrounds of both S. aureus and S. epidermidis contain two complete copies of the arginine deiminase (ADI) operon, one of which is acquired on a pathogenicity island. The ADI operon synthesizes proteins which catabolize arginine resulfing in ATP and ammonia. Within certain microniches of a biofllm environment, the resulting ATP can be used for metabolic purposes whereas the ammonia may be used for pH homeostasis. Studies demonstrate that arginine metabolism is induced during biofilm development and that the acquired (i.e. from pathogenicity island) ADI operon is most transcriptionally active as the biofilm matures. The importance of arginine metabolism will be studied by first exploring the regulatory role of ArcR, a known regulator of ADI expression, during biofilm growth. It is hypothesized that maximal inducfion of the acquired ADI operon occurs during biofilm growth and that Induction under these conditions is ArcR- dependent Secondly, through the use of fluorescent gene fusions, we will examine the temporal and spafial pattern of ADI gene expression within a S. epidermidis and S. aureus biofilm and compare those data to known anaerobic and aerobic regions of a biofilm. Lasfiy, through a mouse foreign body infection model, the relative virulence of ADI mutants in comparison to wild type S. aureus and S. epidermidis w'\\\ be determined. Suscepfibility of ADI mutants to anfibiotics will be tested in a guinea pig fissue cage model. RELEVANCE (See instructions):