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Properties of hemagglutination by Prevotella melaninogenica
Gunnsteinn Haraldsson1, Jukka H Meurman, Eija Könönen
1Faculty of Odontology, University of Iceland, Reykjavík, Iceland. gah@hi.is
Abstract:
Although Prevotella melaninogenica belongs to the commensal oral microbiota, some strains possess putative virulence factors. For example, we have previously described fimbriated, hemagglutinating strains of P. melaninogenica, isolated from patients with periodontal disease. The aim of this investigation was to compare some chemical and physical properties of hemagglutination (HA) of P. melaninogenica with those of other pigmented gram-negative anaerobes. HA of 13 P. melaninogenica strains proved to be considerably weaker than that of the major periodontal pathogen, Porphyromonas gingivalis. Vigorous shaking reduced HA of shaken cells but the shaken supernatant had the same hemagglutinating activity as non-shaken cells. The hemagglutinating agent on P. melaninogenica seemed to be a protein, which can be separated from the cell and binds to lactose-, galactose-, and raffinose-containing carbohydrates on the erythrocytes. Adherence to epithelial cells did not differ significantly between the hemagglutinating and non-hemagglutinating strains of P. melaninogenica. Although P. melaninogenica is able to agglutinate erythrocytes, this potential virulence factor is of a considerably lower magnitude than that of major periodontal pathogens.
Insights
Prevotella melaninogenica exhibits hemagglutination (HA), a potential virulence factor, but it is significantly weaker than that of periodontal pathogens like Porphyromonas gingivalis. This protein-based hemagglutination binds to erythrocyte carbohydrates.
Area of Science:
- Oral microbiology
- Bacteriology
- Periodontal disease research
Background:
- Prevotella melaninogenica is a commensal oral bacterium.
- Some strains of P. melaninogenica possess virulence factors, including hemagglutination (HA).
- Fimbriated, hemagglutinating strains have been isolated from periodontal disease patients.
Purpose of the Study:
- To compare the chemical and physical properties of P. melaninogenica hemagglutination (HA).
- To compare HA of P. melaninogenica with other pigmented gram-negative anaerobes.
- To investigate the nature and binding characteristics of the hemagglutinating agent.
Main Methods:
- Hemagglutination assays on 13 P. melaninogenica strains.
- Comparison of HA activity with Porphyromonas gingivalis.
- Analysis of HA after cell shaking.
- Separation and characterization of the hemagglutinating agent.
- Erythrocyte binding studies with specific carbohydrates.
- Epithelial cell adherence assays.
Main Results:
- HA of P. melaninogenica strains was considerably weaker than that of P. gingivalis.
- Shaking reduced cell-associated HA, but the supernatant retained activity.
- The hemagglutinating agent is a separable protein.
- This protein binds to lactose-, galactose-, and raffinose-containing carbohydrates on erythrocytes.
- No significant difference in epithelial cell adherence between hemagglutinating and non-hemagglutinating strains.
Conclusions:
- P. melaninogenica possesses a protein-based hemagglutinating factor.
- This factor exhibits weaker hemagglutination activity compared to major periodontal pathogens.
- The hemagglutinating potential of P. melaninogenica is a minor virulence factor.
- The binding specificity suggests interactions with erythrocyte surface carbohydrates.
