EVALUATION OF AN WECA MUTANT IN EXPERIMENTAL HUMAN INFECTION WITH HAEMOPHILUS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 杜热氏嗜血杆菌是生殖器溃疡下巴疾病的病原体。最近，Munson和他的同事发现了与H.ducreyi ECA(肠杆菌共同抗原)类似途径对应的基因，该途径应该组装一个表面糖脂。该途径中的第一个基因，WECA与大肠杆菌WECA突变体互补，使其能够组装ECA糖脂。构建了杜氏乳杆菌WECA突变体35000HPwecA。在体外培养时，35000HPwecA与其亲本35000HPwecA的表型没有什么不同。最近，斯皮诺拉实验室在人类志愿者的脓肿中捕获了细菌转录本。这些实验旨在识别体内比体外更丰富的转录本。从病变中捕获的转录本中有两个位于H.ducreyi ECA样通路中。杜氏杆菌Eca样通路可能只在体内上调或表达。测试Eca样通路在杜氏杆菌致病中是否重要的最直接方法是在人类志愿者身上测试Eca样通路突变体。这项研究的目的是检验这一假设，即35000HPwecA与其等基因亲本相比，其感染人类皮肤的能力受到损害。为了验证这一假设，我们将比较父母和突变人在人类受试者中导致实验性感染的能力。这些研究将确定杜氏嗜血杆菌是否需要WECA的表达才能引起脓疱疮，并可能为开发杜氏嗜血杆菌疫苗提供理论基础。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Haemophilus ducreyi is the etiologic agent of the genital ulcer disease chancroid. Recently, the genes corresponding to an H. ducreyi ECA (Enterobacterial Common Antigen)-like pathway, which should assemble a surface glycolipid, were identified by Munson and colleagues. The first gene in the pathway, wecA complements an E. coli wecA mutant so that it can assemble the ECA glycolipid. An H. ducreyi wecA mutant, 35000HPwecA, was constructed. When grown in vitro, 35000HPwecA, does not appear to be phenotypically different than its parent, 35000HP. Recently, the Spinola laboratory captured bacterial transcripts in pustules of human volunteers. These experiments were designed to identify transcripts that are more abundant in vivo than in vitro. Two of the transcripts that were captured from the lesions are in the H. ducreyi ECA-like pathway. It is possible that the H. ducreyi ECA-like pathway is upregulated or expressed only in vivo. The most direct way to test whether ECA-like pathway is important in H. ducreyi pathogenesis is to test an ECA-like pathway mutant in human volunteers. The purpose of this study is to test the hypothesis that 35000HPwecA is impaired in its ability to infect human skin when compared to its isogenic parent. To test this hypothesis, we will compare the ability of the parent and the mutant to cause experimental infection in human subjects. These studies will establish whether expression of wecA is required for H. ducreyi to cause pustules, and may provide a rationale to develop a vaccine against H. ducreyi.