H. influenzae Genes Associated with Acute Otitis Media

描述（由申请人提供）：急性中耳炎是宿主防御、环境因素和细菌毒力特性复杂相互作用的结果。以前的研究表明，流感嗜血杆菌（Hi）是儿童急性中耳炎的一个重要病因，它具有独特的基因，在这种感染的发病机制中起重要作用。在这个项目中，我们将确定中耳炎特异性的潜在毒力因素。使用减法杂交技术，我们将鉴定出Hi中耳炎分离株中存在的DNA片段和Hi喉部分离株中不存在的DNA片段。减去的DNA片段将被克隆、测序，并用于确定它们在按各种流行病学参数分组的大组Hi菌株中的流行程度。我们收集的大量Hi菌株将使用基于基因检测的微阵列筛选中耳炎相关基因，该微阵列包括Hi菌株的基因组以及这些基因之间以及这些基因与确定的流行病学因素之间的关联。该项目的具体目标是：

DESCRIPTION (provided by applicant): Acute otitis media results from a complex interplay of host defenses, environmental factors, and virulence characteristics of bacteria. Previous studies suggest that Haemophilus influenzae (Hi), an important cause of acute otitis media in children, possess unique genes important in the pathogenesis of this infection. In this project, we will identify potential virulence factors specific for Hi otitis media. Using a subtractive hybridization technique, we will identify DNA fragments present in Hi otitis media isolates and absent in Hi throat isolates. The subtracted DNA fragments will be cloned, sequenced and used to determine their prevalence among large panels of Hi strains grouped by various epidemiologic parameters. Our large collection of Hi strains will be screened for the otitis media associated genes using a gene detection-based microarray consisting of genomes of the Hi strains and associations among these genes as well as between these genes and epidemiologic factors established. The Specific Aims of this project are: 1. Characterize Hi isolated from middle ear effusions of children with acute otitis media and from nasopharyngeal throat specimens of children by biotype, serotype, b-lactamase production and genotype by pulsed field gel electrophoresis. 2. Identify candidate Hi otitis media associated genes through subtractive hybridization. 3. Describe associations among candidate Hi otitis media associated genes and between Hi otitis media associated genes and epidemiologic parameters, including site of isolation, geographic location, persistence of nasopharyngeal colonization and ability to be transmitted child to child, using a microarray of Hi genomic DNA from each strain in our collections. 4. Characterize the Hi otitis media associated genes by size, predicted function, and location in the Hi chromosome. Identification of unique Hi otitis media virulence factors will facilitate the development of novel approaches to the prevention and treatment of Hi otitis media.