IDENTIFYING VIRULENCE FACTORS OF BACTEROIDES FORSYTHUS

福赛氏拟杆菌是一种丝状、不活动、不着色、革兰氏阴性厌氧菌，已被认为是牙周病的病原体之一。然而，很少有研究研究这种口腔微生物产生的潜在毒力因素。要了解福赛斯杆菌的感染，需要在体内宿主-寄生虫相互作用的背景下确认其毒力因子的作用。一种名为体内表达技术(IVET)的创新基因技术已经被开发出来，目的是分离仅在感染过程中表达的基因。IVET在分离沙门氏菌、假单胞菌和葡萄球菌等主要医学病原体的新毒力因子方面的应用已被证明。本申请提供的初步数据表明，IVET已成功地用于检测牙周主要病原体牙龈卟啉单胞菌的基因，这些基因只在体内表达。本研究的具体目的是(1)构建连翘叶蝉的IVET系统pBFIVET，以及(2)检测pBFIVET在分离只在感染过程中表达的基因的有效性。这项研究的结果将有助于实现该实验室的长期目标：检查福赛斯杆菌在牙周感染中的作用。

Bacteroides forsythus is a filamentous, non-motile, non-pigmenting, gram-negative anaerobe that has been implicated as one of the etiologic agents of periodontal disease. Few studies, however, have examined the potential virulence factors produced by this oral microorganism. Understanding a B. forsythus infection requires that the roles of its virulence factors be confirmed in the context of an in vivo host-parasite interaction. An innovative genetic technique termed in vivo expression technology (IVET) has been developed for the purpose of isolating genes expressed only during the infectious process. The utility of IVET has been proven in isolating novel virulence factors of major medical pathogens, such as Salmonella, Pseudomonas, and Staphylococci. Preliminary data presented in this application shows that IVET has been successfully used to detect genes of Porphyromonas gingivalis, a principal periodontal pathogen, that are expressed only in vivo. The specific aims of this proposed study are (1) to construct pBFIVET, the IVET system for B. forsythus, and (2) to test pBFIVET for efficacy in isolating B. forsythus genes expressed only during the infectious process. The results obtained from this study will help achieve the long-term goal of this laboratory: to examine the role of B. forsythus in periodontal infection.