Adaptation to anaerobiosis in H influenzae pathogenesis

描述(申请人提供)：流感嗜血杆菌是一种常见的 无症状的上呼吸道定殖者，但也引起范围 侵袭性疾病，如中耳炎，中耳感染会导致 儿童的急性疼痛、痛苦和暂时性或永久性听力损失。这个 中耳存在专性厌氧菌群与流感嗜血杆菌 中耳炎患者的分泌物和鼻咽标本显示流感嗜血杆菌 在体内遇到低氧条件。流感嗜血杆菌 在其他几种细菌病原体中发现了氧化还原反应系统。这个 这些氧化还原反应系统参与改变全球基因 对缺氧反应的表达将通过 硝酸盐和亚硝酸盐还原酶的表达谱特征。 初步数据表明，在H。 流感病毒受环境信号的影响，例如底物的可用性。 和环境中的氧气水平。此外，还对其体外特性进行了研究 硝酸盐和亚硝酸盐还原酶的表达谱允许发展 还原酶编码基因作为H。 幼鼠感染期间的流感病毒。因此，这项研究的重要性 不仅是为了深入了解氧化还原感应的监管过程 流感嗜血杆菌，也是为了表征这一生理状态 宿主生态位内的细菌。

DESCRIPTION (provided by applicant): Haemophilus influenzae is a common asymptomatic colonizer of the upper respiratory tract, yet also causes a range of invasive diseases such as otitis media, a middle ear infection that produces acute pain, distress and temporary or permanent hearing loss in children. The presence of obligate anaerobic species with H. influenzae in the middle ear fluid and the nasopharynx of otitis media patients indicates that H. influenzae encounters low oxygen conditions in vivo. H. influenzae possesses redox-responsive systems found in several other bacterial pathogens. The participation of these redox-responsive systems in altering global gene expression in response to oxygen deprivation will be investigated by characterizing the expression profiles of the nitrate and nitrite reductases. Preliminary data indicate that nitrate and nitrite reductase expression in H. influenzae is mediated by environmental signals, such as substrate availability and environmental oxygen levels. Additionally, the in vitro characterization of the nitrate and nitrite reductase expression profiles permits the development of the reductase-encoding genes as reporters for the physiological state of H. influenzae during infant rat infection. Therefore, the importance of this study is to not only yield insight into the regulatory processes of redox sensing in H. influenzae, but also to characterize the physiological state of this bacterium within host niches.