IDENTIFYING VIRULENCE FACTORS OF BACTEROIDES FORSYTHUS

福赛斯拟杆菌是一种丝状、非运动性、非色素性、革兰氏阴性厌氧菌，被认为是牙周病的病原体之一。 然而，很少有研究检查这种口腔微生物产生的潜在毒力因子。 了解福赛斯拟杆菌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。一种被称为体内表达技术（IVET）的创新遗传技术已被开发出来，用于分离仅在感染过程中表达的基因。 IVET 在分离主要医学病原体（例如沙门氏菌、假单胞菌和葡萄球菌）的新型毒力因子方面的实用性已得到证实。 本申请中提供的初步数据表明，IVET 已成功用于检测仅在体内表达的主要牙周病原体牙龈卟啉单胞菌的基因。本研究的具体目的是 (1) 构建 pBFIVET，即福赛斯拟杆菌的 IVET 系统，以及 (2) 测试 pBFIVET 在分离仅在感染过程中表达的福赛斯拟杆菌基因方面的功效。 这项研究获得的结果将有助于实现该实验室的长期目标：研究福赛斯芽孢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.