Sialidase-Enhanced Lectin-Like Mechanism for
            <i>Actinomyces viscosus</i>
            and
            <i>Actinomyces naeslundii</i>
            Hemagglutination

In this paper, it is suggested that specificity and non‐specificity in (oral) microbial adhesion are different expressions for the same phenomena. It is argued that the same basic, physico‐chemical forces are responsible for so‐called ‘non‐specific’ and ‘specific’ binding and that from a physico‐chemical point of view the distinction between the two is an artificial one. Non‐specific interactions arise from Van der Waals and electrostatic forces and hydrogen bonding, and originate from the entire cell. A specific bond consists of a combination of the same type of Van der Waals and electrostatic forces and hydrogen bonding, now originating from highly localized chemical groups, which together form a stereo‐chemical combination. The absence or presence of specific receptor sites on microbial cell surfaces must therefore be reflected in the overall, non‐specific surface properties of cells as well. This point is illustrated by showing that glucanbinding lectins on mutans streptococcal strains may determine the pH dependence of the zeta potentials of these cells. When studying microbial adhesion, a non‐specific approach may be better suited to explain adhesion to inert substrata, whereas a specific approach may be preferred in case of adhesion to adsorbed protein films. Adhesion is, however, not as important in plaque formation in the human oral cavity as is retention, because low shear force periods. during which adhesion presumably occurs, are followed by high shear force periods, during which adhering cells must withstand these detachment forces. Evidence is provided that such detachment will be through cohesive failure in the pellicle mass, the properties of which are conditioned by the overall, non‐specific substratum properties. Therefore, in vivo plaque formation may be more readily explained by a non‐specific approach.

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“…Type 2 fimbriae Mammalian cells Galactose residues [10] Actinomyces naeslundii [ 14] Actinomyces viscosus Type 2 fimbriae…”

Section: Actinomyces Viscosusmentioning

confidence: 99%

On the relative importance of specific and non-specific approaches to oral microbial adhesion

Busscher

Cowan

Mei

1992

FEMS Microbiology Letters

117

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“…Various pathogenic bacteria possess lectins which allow adherence to host cells. Most commonly, this adherence has been studied by testing hapten inhibition of hemagglutination by bacteria such as Escherichia coli (13,14), Vibrio cholerae (28), Pseudomonas aeruginosa (21), and Actinomyces viscosus or Actinomyces naeslundii (9,15,39). It is often difficult to discern all of the factors contributing to the specificity of the lectin because of the complexity of the erythrocyte membrane.…”

mentioning

confidence: 99%

“…It adheres either to previously colonized organisms such as streptococci (4, 7) or to epithelial cells (16) by means by a lectin-like interaction. A. viscosus T14V secretes neuraminidase and agglutinates erythrocytes in a neuraminidase-dependent, lactoseinhibitable manner (9,15,35,39) by two sequential steps: (i) action of neuraminidase to unmask galactose termini, and (ii) binding of exposed galactose residues to bacterial lectin. In spite of the indirect evidence for the involvement of galactose termini, it has not been possible to alter galactose residues of asialo erythrocyte membranes by treatment with galactose oxidase or P-galactosidase and thereby prevent agglutination (R P. Ellen, E. D. Fillery, K. H. Chan, and D. H. Grove, J. Dent.…”

mentioning

confidence: 99%

Characterization of a Galactose-Specific Lectin from Actinomyces viscosus by a Model Aggregation System

1982

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A simple model system has been developed in which lectin-mediated aggregation of glycoprotein-coated beads can be monitored by following the decrease in light scattering at 650 nm. Aggregation has been characterized with the lectin of Actinomyces viscosus T14V. Its dependence on pH, temperature, and stirring rate was examined, and the number of bacterial cells in relation to the number of latex beads resulting in optimal aggregation was established. This system has the advantage of permitting the study of a single ligand of defined structure. The ligand density was determined with radiolabeled glycoproteins. Under the conditions of the assay, ligand leakage was less than 3%, and ligands were not displaced from the beads by various proteins, glycoproteins, or by other components present in the assay mixture. Latex beads coated with asialofetuin aggregate upon the addition of A. viscosus T14V cells. By contrast, when asialofetuin was first extensively treated with purified galactose oxidase, no aggregation occurred. Only after reduction with NaBH4 was aggregation restored, demonstrating that galactose termini of asialofetuin are essential for the binding of A. viscosus lectin. An absolute requirement for calcium was also demonstrated. Various sugars inhibited aggregation in the following order, starting with the most effective: lactose, methyl-p-D-galactopyranoside, galactose, N-acetylgalactosamine, methyl-ot-D-galactopyranoside. Beads coated with fimbriae from A. viscosus coaggregated with neuraminidase-treated human erythrocytes and with Streptococcus sanguis cells. In each instance the aggregation was inhibited by lactose, indicating that the A. viscosus lectin is located in the fimbriae. Cells grown under different conditions differed in their effectiveness in aggregating glycoprotein-coated beads, suggesting differences in lectin density or accessibility. Two different experimental designs were used to establish the minimum ligand density for aggregation to occur. In one type of experiment, a threshold concentration was found for asialo a1-acid glycoprotein, but not for asialofetuin. With an alternate approach in which a different population of galactose residues was exposed, a threshold phenomenon was also demonstrated for asialofetuin. The importance of structural ligand features in the aggregation assay is discussed in view of these findings.

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“…After laboratory culture for only the one or two passages needed to confirm purity, each strain was grown in batch broth culture and frozen at -70°C on serum-coated glass beads (Feltham et al 1978) which could be used to inoculate growth media for experimentation while avoiding further laboratory passage. For agglutination experiments, Actinomyces cultures were grown aerobically for 3 days in tryptic soy broth (Difco) (McBride & Bourgeau 1975).…”

Section: Bacterial Strains and Cullural Conditionsmentioning

confidence: 99%

Infrequent polysaccharide cohesion among Actinomyces viscosus and Actinomyces naeslundii fresh isolates of human origin

Ellen¹,

Fillery²,

Seckington³

1983

J of Periodontal Research

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Dextran‐mediated agglutination has been both proposed and opposed as a mechanism for cohesive interactions between Actinomyces viscosus and streptococci in dental plaques. In their Studies, opponents of this mechanism used laboratory strains subcultured in vitro for unknown periods, whereas its proponents had previously shown that laboratory passage of Actinomyces strains weakened this trait. To clarify this issue, eighty‐eight strains of A. viscosus and Actinomyces naeslundii freshly isolated from the human oral cavity and hardly subcultured in vitro, were studied for enhancement of agglutination by commercially obtained polysaccharides including dextran, inulin, agarose, and starch and polysaccharides isolated from sucrose‐grown Streptococcus mutans, Streptococcus sanguis, and Streptococcus salivarius. Few of the strains exhibited higher agglutination scores in buffer containing any of the various polysaccharides than in control buffer free of the polysaccharides. Infrequent polysaccharide agglutinability of these human isolates, even by polysaccharides likely to be encountered in dental plaques, casts doubt on this explanation for Actinomyces’cohesive interactions in plaque formation.

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Sialidase-Enhanced Lectin-Like Mechanism for Actinomyces viscosus and Actinomyces naeslundii Hemagglutination

Cited by 83 publications

References 24 publications

On the relative importance of specific and non-specific approaches to oral microbial adhesion

On the relative importance of specific and non-specific approaches to oral microbial adhesion

Characterization of a Galactose-Specific Lectin from Actinomyces viscosus by a Model Aggregation System

Infrequent polysaccharide cohesion among Actinomyces viscosus and Actinomyces naeslundii fresh isolates of human origin

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