The Bactericidal Effect of MA-T for Factitiously Contaminated and Used Masks.

Matching transformation system (MA-T), an on-demand aqueous chlorine dioxide solution, is an excellent safety disinfectant, because chlorine dioxide is not detected during storage or before use. The production of chlorine dioxide in MA-T is induced by a catalytic reaction in the presence of target microorganisms. In this study, we investigated MA-T disinfection of masks as a reuse method to eliminate mask shortages.

A screening system using minimal media identifies a flavin-competing inhibitor of Porphyromonas gingivalis growth.

Chronic periodontitis is caused by dysbiosis of human oral commensals and especially by increase in Porphyromonas gingivalis. Inhibitors of P. gingivalis growth are expected to serve as effective drugs for the periodontal therapy.

Enzymatic kinetics of the quinol peroxidase of an aggressive periodontopathic bacterium.

Aggregatibacter actinomycetemcomitans is an oral pathogen for aggressive periodontitis, and encodes a triheme c-containing membrane-bound enzyme, quinol peroxidase (QPO) that catalyzes peroxidase activity using quinol in the respiratory chain. In the previous work, we have characterized recombinant QPO purified from the membrane fraction of Escherichia coli harboring a plasmid containing QPO gene. Irreversible inactivation of QPO by high concentration of H2O2 exhibited pseudo-first order kinetics.

Contribution of Streptococcus gordonii Hsa Adhesin to Biofilm Formation.

Adhesion of oral mitis group streptococci, such as Streptococcus gordonii, to acquired pellicle on the tooth surface is the first step in oral biofilm formation. S. gordonii strain DL1 possesses an Hsa adhesin, which recognizes the terminal sialic acid of host sialoglycoconjugates.

Correction: Two Arginine Residues of Streptococcus gordonii Sialic Acid-Binding Adhesin Hsa Are Essential for Interaction to Host Cell Receptors.

[This corrects the article DOI: 10.1371/journal.pone.

Two Arginine Residues of Streptococcus gordonii Sialic Acid-Binding Adhesin Hsa Are Essential for Interaction to Host Cell Receptors.

Hsa is a large, serine-rich protein of Streptococcus gordonii DL1 that mediates binding to α2-3-linked sialic acid termini of glycoproteins, including platelet glycoprotein Ibα, and erythrocyte membrane protein glycophorin A, and band 3. The binding of Hsa to platelet glycoprotein Ibα contributes to the pathogenesis of infective endocarditis. This interaction appears to be mediated by a second non-repetitive region (NR2) of Hsa.

Effects of surface reaction-type pre-reacted glass ionomer on oral biofilm formation of Streptococcus gordonii.

Streptococcus gordonii, a bacterium involved in the initial colonization of tooth surfaces, contributes to dental biofilm formation and is an important cause of infective endocarditis. This study aimed to investigate the influence of surface reaction-type pre-reacted glass ionomer (S-PRG) filler on oral bacterial growth and aggregation of S. gordonii.

Relationship between oral bacteria count and pneumonia onset in elderly nursing home residents.

Aim: Oral bacteria, which are a source of infection for aspiration pneumonia, were examined in frail older adults with the aim of establishing a standard bacteria count that indicates the risk of pneumonia onset in this group.

Methods: A survey of bacteria count in the saliva using a simple instrument for measurement of the number of oral bacteria, along with factors including swallowing function and nutritional status, was carried out in 691 elderly individuals requiring care (137 men; mean age 82.6 ± 8.

Cementogenic potential of multipotential mesenchymal stem cells purified from the human periodontal ligament.

The periodontal ligament (PDL) consists of a group of specialized connective tissue fibers embedded in the alveolar bone and cementum that are believed to contain progenitors for mineralized tissue-forming cell lineages. These progenitors may contribute to regenerative cell therapy or tissue engineering methods aimed at recovery of tissue formation and functions lost in periodontal degenerative changes. Some reports using immortal clonal cell lines of cementoblasts, which are cells containing mineralized tissue-forming cell lineages, have shown that their phenotypic alteration and gene expression are associated with mineralization.

Identification and characterization of prokaryotic dipeptidyl-peptidase 5 from Porphyromonas gingivalis.

Porphyromonas gingivalis, a Gram-negative asaccharolytic anaerobe, is a major causative organism of chronic periodontitis. Because the bacterium utilizes amino acids as energy and carbon sources and incorporates them mainly as dipeptides, a wide variety of dipeptide production processes mediated by dipeptidyl-peptidases (DPPs) should be beneficial for the organism. In the present study, we identified the fourth P.

[Adhesins of oral streptococci].

Oral streptococci comprise a numerically prominent group of oral bacteria that occur primarily on the human tooth surface as members of the biofilm community, commonly referred to as dental plaque. These streptococci are not only causative of dental caries and are primers for colonization of periodontopathic bacteria, but also well known for their ability to colonize damaged heart valves, identified most frequently as primary etiological agents of infective endocarditis. A number of streptococcal cell surface components are known to contribute to colonization of the tooth surface including putative adhesins recognizing host sialic acid (sialic acid-binding adhesins).

Streptococcus gordonii promotes rapid differentiation of monocytes into dendritic cells through interaction with the sialic acid-binding adhesin.

Infective endocarditis is frequently attributed to oral streptococci. Although the pathogenetic mechanisms are not well understood, interaction between streptococci and phagocytes is thought to be important for infective endocarditis. In this study, HL-60 cell-derived monocytes were characterized following interaction with Streptococcus gordonii DL1.

A novel rapid oral bacteria detection apparatus for effective oral care to prevent pneumonia.

Objective: To clarify the oral environment, we evaluated the usefulness and clinical applicability of a new apparatus developed for the simple and rapid quantification of oral bacteria.

Background: Professional oral health care can reduce the number of oral bacteria and days of fever and inhibit the development of pneumonia. A novel detection apparatus was developed by applying the dielectrophoretic impedance measurement method.

Contribution of phosphoglucosamine mutase to determination of bacterial cell morphology in Streptococcus gordonii.

Phosphoglucosamine mutase (GlmM; EC 5.4.2.

Identification of a novel Porphyromonas gingivalis outer membrane protein, PG534, required for the production of active gingipains.

Gingipains are secreted endopeptidases important for the virulence and proliferation of Porphyromonas gingivalis; however, their secretion and biogenesis process is not yet fully elucidated. The PG0534 gene of P. gingivalis W83 encodes a novel protein, PG534, of unknown function.

The role of Sov protein in the secretion of gingipain protease virulence factors of Porphyromonas gingivalis.

Porphyromonas gingivalis transports Arg-gingipains and Lys-gingipain across the outer membrane via an unknown pathway. Recently, we found that the sov gene of P. gingivalis W83 was required for this step.

Recombinant expression and redox properties of triheme c membrane-bound quinol peroxidase.

The qpo gene of Aggregatibacter actinomycetemcomitans encodes a triheme c-containing membrane-bound enzyme, quinol peroxidase (QPO) that catalyzes peroxidation reaction in the respiratory chain and uses quinol as the physiological electron donor. The QPO of A. actinomycetemcomitans is the only characterized QPO, but homologues of the qpo gene are widely distributed among many gram-negative bacteria, including Haemophils ducreii, Bacteroides fragilis, and Escherichia coli.

Contribution of phosphoglucosamine mutase to the resistance of Streptococcus gordonii DL1 to polymorphonuclear leukocyte killing.

Phosphoglucosamine mutase (GlmM; EC 5.4.2.

PG27 is a novel membrane protein essential for a Porphyromonas gingivalis protease secretion system.

Porphyromonas gingivalis secretes endopeptidase gingipains, which are important virulence factors of this bacterium. Gingipains are transported across the inner membrane via the Sec system, followed by transport across the outer membrane via an unidentified pathway. The latter transport step is suggested to be mediated via a novel protein secretion pathway.

Binding of the Streptococcus gordonii DL1 surface protein Hsa to the host cell membrane glycoproteins CD11b, CD43, and CD50.

Infective endocarditis is frequently attributed to oral streptococci. The mechanisms of pathogenesis, however, are not well understood, although interaction between streptococci and phagocytes are thought to be very important. A highly expressed surface component of Streptococcus gordonii, Hsa, which has sialic acid-binding activity, contributes to infective endocarditis in vivo.

Characterization of a quinol peroxidase mutant in Aggregatibacter actinomycetemcomitans.

Aggregatibacter actinomycetemcomitans is an oral pathogen causing localized aggressive periodontitis (LAP). Recently, we characterized for the first time a quinol peroxidase (QPO) that catalyzes peroxidase activity using quinol in the respiratory chain of A. actinomycetemcomitans for the reduction of hydrogen peroxide.

Identification of the Streptococcus gordonii glmM gene encoding phosphoglucosamine mutase and its role in bacterial cell morphology, biofilm formation, and sensitivity to antibiotics.

Phosphoglucosamine mutase (EC 5.4.2.

Hsa, an adhesin of Streptococcus gordonii DL1, binds to alpha2-3-linked sialic acid on glycophorin A of the erythrocyte membrane.

Bacterial recognition of host sialic acid-containing receptors plays an important role in microbial colonization of the human oral cavity. The aggregation of human platelets by Streptococcus gordonii DL1 is implicated in the pathogenesis of infective endocarditis. In addition, we consider that hemagglutination of this organism may act as an additive factor to increase the severity of this disease.

Association of odor from infected root canal analyzed by an electronic nose with isolated bacteria.

Infected root canals usually cause foul odor. On sensory testing, objective evaluation of the odor is difficult because of the subjectivity of the examiner. In this study, the odor of the canal content was analyzed by an electronic nose.

Identification of a Porphyromonas gingivalis novel protein sov required for the secretion of gingipains.

Gingipains are extracellular proteases important for the virulence of Porphyromonas gingivalis; however, the mechanism for the secretion of gingipains is poorly understood. In this report, we found that insertion mutants for PG0809 (83K1 and 83K2) were defective in black pigmentation and hemolysis. We cloned and sequenced PG0809 and found that PG0809 contains two additional nucleotides that are not deposited in the W83 genome database.