Identification of Porphyromonas gingivalis genes required for iron/haem acquisition and biofilm formation

牙周病是人类最常见的细菌性疾病之一，沿着龋齿，约占澳大利亚人口所有牙齿脱落的90%。澳大利亚最近的一项口腔健康调查发现，在30-34岁年龄组中，超过20%的人患有中度至重度牙周病，这表明牙周炎是一个主要的公共卫生问题。特定的细菌，特别是牙龈卟啉单胞菌，作为细菌生物膜（牙菌斑）生长会导致牙周病。在这项研究中，我们将利用现有的最新技术来确定细菌的哪些基因对动物模型中的生物膜生长，铁获得和毒力很重要。我们将研究细菌如何获得铁，因为通常很少有铁可用于人体组织上的细菌生长，而细菌摆脱这种铁限制的能力与致病性有关。确定铁在细菌生物膜形成和毒力中的作用将有助于我们了解疾病发生的变化，并可能制定早期干预策略。这项工作的意义在于，我们将了解这种细菌如何作为一种机会性人类病原体发挥作用。我们将确定哪些基因是必不可少的生长作为一个生物膜，并在动物模型中产生疾病。这将使针对产生疾病所需的特定细菌基因产物的治疗性和预防性干预措施的开发成为可能。

Periodontal diseases are some of the most common bacterial diseases of humans and along with dental caries, account for approximately 90% of all tooth loss in the Australian population. A recent survey of oral health in Australia found that in the 30-34 age group over 20% of people had moderate to severe periodontal disease, indicating that periodontitis is a major public health problem. Specific bacteria, especially Porphyromonas gingivalis, that grow as bacterial biofilms (dental plaque) cause periodontal disease. In this study we will utilise the latest technology available to determine which genes of the bacterium are important for biofilm growth, iron acquisition and virulence in an animal model. We will investigate how the bacterium acquires iron, as there is usually little available iron for bacterial growth on human tissues and the ability of the bacterium to free itself from this iron limitation is associated with pathogenicity. The determination of the role of iron availability in biofilm formation and virulence of the bacterium will help us to understand the changes that occur in the initiation of disease and may allow the development of early intervention strategies. The significance of this work is that we will gain an understanding of how this bacterium functions as an opportunistic human pathogen. We will determine which genes are essential for growth as a biofilm and to produce disease in an animal model. This will enable the development of therapeutic and prophylactic interventions targeted to specific bacterial gene products required to produce disease.