The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the or...

Bacteroides (Porphyromonas) gingivalis and Bacteroides (Porphyromonas) intermedius have been implicated in the etiology of human periodontal diseases. These organisms are able to bind and degrade human fibrinogen, and these interactions may play a role in the pathogenesis of periodontal disease. In attempts to map the bacterial binding sites along the fibrinogen molecule, we have found that str...

BACKGROUND Plasma antibody measurements of antibody levels to periodontal pathogens may be used to support diagnosis, disease activity, classification, and prognosis of periodontitis. OBJECTIVE The aim of this study was to investigate the long-term stability of plasma antibody levels against Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. DESIGN Plasma immunoglobulin G (...

Yasumitsu Sakamoto1, Saori Roppongi1, Ippei Iizuka1, Yoshio Kusakabe2,3, Tomonobu Umeda2,4, Yuki Odanaka2, Satoko Matsubayashi2, Yasuyuki Kitagawa2,4, Takamasa Nonaka1 and Nobutada Tanaka2,* 1School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694, Japan 2School of Pharmacy, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan 3Faculty of Pharma...

The aim of the present study was to evaluate the ability of Porphyromonas gingivalis to degrade hyaluronic acid. No hyaluronidase activity was detected using a turbidimetric method, whereas a standard plate assay showed a positive reaction for P. gingivalis. We postulated that the high proteolytic activity of P. gingivalis may account for this observation. A modified plate assay was designed to...

Porphyromonas gingivalis is a major pathogen of chronic periodontitis and exists in a biofilm on the surface of the tooth root. Oxantel, a cholinergic anthelmintic and fumarate reductase inhibitor, significantly inhibited biofilm formation by P. gingivalis and disrupted established biofilms at concentrations below its MIC against planktonic cells. Oxantel was more effective against P. gingivali...

Approved: ____________________________________ Thesis Supervisor ____________________________________ Title and Department ____________________________________ Date 1 ORAL MUCOSAL LIPIDS ARE ANTIBACTERIAL AGAINST PORPHYROMONAS GINGIVALIS, INDUCE ULTRASTRUCTURAL DAMAGE, AND ALTER BACTERIAL LIPID AND PROTEIN COMPOSITIONS by Carol Lea Fischer A thesis submitted in partial fulfillment of the requir...

In common with many bacterial virulence genes, the fimbrillin (fimA) gene of Porphyromonas gingivalis is modulated in response to environmental fluctuation. The trans-acting components that comprise the regulatory system for transcriptional activity of the fimA gene in P. gingivalis were investigated. Three major proteins were found to bind to the upstream region of the fimA promoter. One of th...

The association between Gram negative enteric rods and Porphyromonas gingivalis in periodontal diseases has received little attention in the literature. Thus, the aim of this study was to investigate the associations between Gram negative enteric rods, Porphyromonas gingivalis and clinical parameters of periodontal disease. The prevalence of Gram-negative enteric rods and P. gingivalis were exa...

Porphyromonas gingivalis, a major periodontal pathogen, must acquire nutrients from host derived substrates, overcome oxidative stress and subvert the immune system. These activities can be coordinated via the gingipains which represent the most significant virulence factor produced by this organism. In the context of our contribution to this field, we will review the current understanding of g...