The Role of Novel Bacteria in Male Urethritis

描述（由申请人提供）：尿道炎是最常见的男性生殖道综合征，然而一旦考虑到淋病，高达50%的非淋球菌性尿道炎（NGU）病例没有已知的病因，这表明存在隐性病原体。新的宏基因组方法在识别以前未识别的生物体方面非常有效。广谱核糖体RNA基因PCR是发现细菌病原体的一种强有力的技术，但其敏感性低于靶向物种特异性PCR；因此，两种方法都是必需的。利用这些技术，Fredricks和他的同事最近通过广谱rRNA基因PCR在细菌性阴道病（BV）女性中鉴定出16种新发现的细菌。通过更灵敏的物种特异性定量PCR （qPCR）检测，这些新型细菌中有7种与BV显著相关（Fredricks, NEJM 2005）， 5种（BV相关细菌[BVAB] 2、BVAB3、Leptotrichia/Sneathia、Atopobium vaginae和Megasphaera 1型）与宫颈炎相关，成为强有力的尿道病原体候选。鉴于NGU的相对常见性质，不明原因病例的高比例以及多种病因的可能性，我们在最近完成的病例对照研究中提出了一种两层方法来识别新型尿道病原体。在病原体发现活动中，我们建议使用宽范围16S rRNA基因PCR与焦磷酸测序来描述和比较136例特发性尿道炎男性和136例非尿道炎男性尿道细菌生物群。在更直接的方法中，我们建议使用种特异性qPCR方法描述5种新的候选细菌病原体（BVAB2, BVAB3， Leptotrichia/Sneathia种，Megasphaera 1型，a . vaginae）在男性中的流行病学，重点评估它们与NGU的关系。我们还将评估与新细菌检测相关的行为和临床特征，包括与NGU相关的任何生物体对NGU标准抗菌治疗的临床反应。

DESCRIPTION (provided by applicant): Urethritis is the most common male reproductive tract syndrome, yet once gonorrhea is accounted for, up to 50% of non-gonococcal urethritis (NGU) cases have no known etiology, suggesting the presence of occult pathogens. New metagenomic approaches have been extremely effective in identifying previously unidentified organisms. Broad range ribosomal RNA gene PCR is a powerful technique for bacterial pathogen discovery, but is less sensitive than targeted species-specific PCR; thus both approaches are required. Using these techniques, Fredricks and colleagues recently identified 16 newly recognized bacteria among women with bacterial vaginosis (BV) by broad range rRNA gene PCR. Using more sensitive species-specific quantitative PCR (qPCR) assays, 7 of these novel bacteria were significantly associated with BV (Fredricks, NEJM 2005) and 5 (BV-associated bacterium [BVAB] 2, BVAB3, Leptotrichia/Sneathia, Atopobium vaginae, and Megasphaera type 1) were associated with cervicitis, making them strong candidate urethral pathogens. Given the relatively common nature of NGU, the high proportion of unexplained cases and the possibility of multiple etiologies, we propose a 2-tiered approach to identify novel urethral pathogens within a recently completed case-control study. In pathogen discovery activities we propose to use broad range 16S rRNA gene PCR with pyrosequencing to describe and compare the urethral bacterial biota in 136 men with idiopathic urethritis to that in 136 men without urethritis. In a more directed approach, we propose to describe the epidemiology of 5 novel candidate bacterial pathogens (BVAB2, BVAB3, Leptotrichia/Sneathia species, Megasphaera type 1, A. vaginae) in men using species-specific qPCR assays, focusing on evaluating their association with NGU. We will also evaluate behavioral and clinical characteristics associated with detection of novel bacteria, including the clinical response of any organisms associated with NGU to the standard antimicrobial therapies for NGU.