Bacteroides gingivalis-Actinomyces viscosus cohesive interactions as measured by a quantitative binding assay

Adherence of Porphyromonas gingivalis to early plaque bacteria, such as Streptococcus gordonii, is considered an important colonization mechanism. The molecules that mediate this interspecies binding have not been determined. Fimbriae were prepared from P. gingivalis 33277 by mild agitation, ammonium sulfate precipitation and DEAE-Sepharose chromatography. In a nitrocellulose blot adherence assay, purified fimbriae inhibited S. gordonii G9B-P. gingivalis 33277 binding by up to 54%. In addition, fimbriae bound to S. gordonii cells in a dot-blot assay. Incubation of fimbriae with S. gordonii cells followed by washing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), electroblotting and probing with P. gingivalis antibodies also revealed that the fimbriae bind to S. gordonii. In contrast, S. gordonii did not interact with fimbriae that were first subjected to SDS-PAGE and electroblotting or deposited on a nitrocellulose membrane, suggesting that conformational determinants of the fimbriae may be important in binding. The results indicate that binding between P. gingivalis and S. gordonii is mediated, at least in part, by the porphyromonads' fimbriae.

Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Involvement of Porphyromonas gingivalis fimbriae in adherence to Streptococcus gordonii

Lamont

Bevan

Gil

et al. 1993

“…We were then able to study the micrographs for physical changes in the fimbriae due to acoustic exposure. Additionally, scanning electron microscopy (SEM) has been used to demonstrate the presence of oral bacteria adhering to saliva-treated hydroxyapatite (3,17,18). In our study, SEM was used to provide physical evidence for the effects of acoustic energy on bacteria bound to saliva-treated hydroxyapatite disks.…”

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confidence: 99%

Fimbria damage and removal of adherent bacteria after exposure to acoustic energy

McInnes

Engel

Martin

1993

The physical effects of low-frequency acoustic energy on Actinomyces viscosus were studied with electron microscopy to explore both acoustically induced damage to fimbriae on the surface of these bacteria and acoustic removal of bacteria from saliva-treated hydroxyapatite disks. A bacterial suspension was exposed to acoustic energy from a laboratory acoustic generator (50 kPa, 200 Hz) and from a new electronic toothbrush, the Sonicare. The exposed bacteria were examined with electron microscopy after negative staining. A decrease in both the percentage of bacterial surface covered with fimbriae and the fimbria length was observed after acoustic exposure. To study the acoustic effects on adherent bacteria, A. viscosus bound to hydroxyapatite disks were exposed to acoustic energy and examined with scanning electron microscopy. Quantitative evaluation of the micrographs for the number of bacteria present after exposure revealed that acoustic energy removed both bacteria adherent to the hydroxyapatite surface and adherent to each other. The results support the concept that an electronic toothbrush employing low-frequency acoustic energy may help prevent and control periodontal diseases by altering bacterial adherence.

“…The nature of the binding sites on teeth and oral tissues to which periodontopathic bacteria, including B. gingivalis attach has not been well established. In vitro, B. gingivalis can attach to and agglutinate erythrocytes (19,20,21,(27)(28)(29), ad-here in high numbers to human buccal epithelial cells (18), to crevicular epithelial cells derived from periodontal pockets (29), and to surfaces of Gram positive bacteria present in plaque (23,29). In addition, this species will adhere to untreated and saliva-treated hydroxyapatite (SHA), but in comparatively low numbers (29).…”

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confidence: 99%

The expression and function of a Bacteroides gingivalis hemagglutinin gene in Escherichia coll

Progulske‐Fox

Tumwasorn

Holt

1989

Eight Escherichia coli JM 109 transformants generated from a clone bank of Bacteroides gingivalis 381 genomic DNA, were found to express B. gingivalis antigens. Quantitation of antigen expression by ELISA indicated that isopropyl-beta-D-thiogalactopyranoside (IPTG) was not necessary for antigen expression for any of the clones but that expression in 2 of the clones, ST 2 and ST 3, was increased in cells grown in the presence of IPTG. Western blot analysis revealed that the expressed protein of clone ST 2 has a molecular weight of 125,000 Dal. and that clone ST 3 contains multiple bands of 30 to 50 kdal which react with the anti-B. gingivalis antiserum. Three of the transformants were found to agglutinate sheep erythrocytes. Polyclonal monospecific antiserum to one of the transformants, clone ST 2, was found to react to 2 major bands of MWs 43,000 and 38,000 and minor bands of 115,000, 105,000, 32,000, and 30,000 Dal. present in B. gingivalis cell lysate preparations. Adsorption of anti B. gingivalis antiserum with cells of clone ST 2 reduced the hemagglutination inhibition activity of the antiserum 4-fold whereas antiserum to the clone itself inhibited B. gingivalis hemagglutination at a titer of 8 times that of normal rabbit serum. Immunoelectronmicroscopic studies using the antiserum to clone ST 2 indicate that the product of the cloned gene (hemagglutinin) is located on the B. gingivalis cell surface. A restriction map generated of the cloned B. gingivalis DNA fragment confirms the insert to be 3.2 kbases and indicates the possibility of a repeated sequence in the fragment.