Expression of hemolytic activity of Tannerella forsythensis in E Coli
Date
2003
DOI
Authors
Tankkunnasombut, Sarinthron
Version
OA Version
Citation
Abstract
Oral bacteria exist in complexes within the subgingival milieu. A bacterial complex that has been implicated in periodontal disease consist of Bacteroides forsythus, Treponema denticola and Porphyromonas gingivalis. Hemolysis by bacteria is a virulence factor for many pathogens. Hemolysins may have toxic effects on other eukaryotic cells and provide iron sources during infection.
Objectives: The aim of this study was to isolate and characterize genes that encode hemolysins expressed by T. forsythensis.
Methods: A lambda ZAP II phagemid library of T. forsythensis ATCC 43037 was screened for hemolytic activity using LB agar containing 5% sheep blood. Hemolytic activity of each of the phagemids isolated was quantified using a spectrometric in vitro hemolysin assay. The hemolytic activities were localized to unique open reading frames (ORF) using EZ::TN transposon mutagenesis and DNA sequencing.
Results: Four phagemids that exhibited hemolytic activity both on LB agar containing sheep blood and in the in vitro hemolysin assay were isolated. One phagemid contained the previously reported prtH gene coding for a serine protease with hemolytic activity (Saito et al., 1997). The remaining three phagemids were studied to identify additional genes coding for hemolytic activities in T. forsythensis. The three putative hemolysin genes showed limited homologies to regions of different proteins. One was homologous to the perfringolysin O gene from Clostridium perfringens, the second to an isopropylmalate dehydratase from Escherichia coli and the third to a hypothetical protein from Pseudomonas aeruginosa. All three ORFs showed no other significant homologies to any other proteins in the databases.
Conclusions: Three putative hemolysins were identified from T. forsythensis, which may play a role in the pathogenesis of periodontal disease.
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Thesis (M.S.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2003 (Pediatric Dentistry).
Includes bibliographical references (leaves 71-76).
Thesis (M.S.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2003 (Pediatric Dentistry).
Includes bibliographical references (leaves 71-76).
License
This work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.