Cloning and analysis of glycosidase genes from Tannerella forsythensis

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Thesis (D.Sc.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2003 (Pediatric Dentistry).Includes bibliographic references (leaves 59-69).Periodontitis has been defined as the loss of alveolar support of the teeth. (Tanner and Stillman 1993) The progression of periodontal disease is intermittent with active and quiescent phases. (Lindhe et al. 1983; Socransky et al. 1984) The initiation and progression of periodontitis is caused by several Gram-negative bacteria accumulating in sub-gingival pockets. (Moore et al. 1985) Bacteria from dental plaque have been isolated from the human oral cavity, and several of these species have been implicated in periodontal diseases (Socransky et al. 1998). Advances in periodontal epidemiology using bacterial genomic DNA probes, show that adult chronic periodontal diseases are the result of subgingival microbial complexes, especially the red cluster that consists of three species, Tannerella forsythensis, Porphyromonas gingivalis and Treponema denticola (Socransky et al. 1998). T. forsythensis is one of the periodontal pathogens that have been frequently isolated in great numbers from periodontal pockets of patients with active periodontitis. (Dzink et al. 1985; Dzink et al. 1988; Gmur et al. 1989) T. forsythensis is a fastidious slow growing anaerobic Gram-negative rod, initially called fusiform bacteroides (Tanner et al. 1979) and was later called “Bacteroides forsythus" (Tanner et al. 1986). Recently this microorganism was renamed "Tannerella forsythensis". T. forsythensis is known to express virulence factors like sialidases, proteolytic enzymes, lipopolysaccharide and a paracrystalline protein surface layer. Identification of the virulence factors of T. forsythensis would aid in the development of preventive strategies against periodontal disease. (Sharma et al. 1998) Bacterial sialidases have been considered virulence factors in many pathogenic organisms that colonize the mucosal surfaces. The sialidase enzyme has been shown to be present in crevicular fluid from diseased but not from healthy sites. The proposed study was to clone and analyze the glycosidase genes from the T. forsythensis genomic library