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Updated: Apr 29, 2026
Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells
Published on: December 17, 2015
[Analysis of capsule related surface properties of Porphyromonas gingivalis isolates]
Yanbin Zhou1, Dali Liu1, Yunpeng Li1
1Department of Periodontology, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine & Shanghai Research Institute of Stomatology & Shanghai Key Laboratory of Stomatology, Shanghai 200011, China.
Objective:
To analyze the capsule related surface properties of Porphyromonas gingivalis (Pg) isolates.
Methods:
The transmission electron microscopy (TEM) was used to observe the capsule structure and the capsule thickness of 2 type of strains and 5 clinical isolates. Microbial adhesion to hydrocarbons (MATH) assay was used to qualitatively assess the hydrophobicity of each strain, and the capacities of these strains were investigated by autoaggregation assay.Ninety-six well biofilm assay and confocal laser scanning microscopy (CLSM) were applied to quantify and observe the biofilm produced by each strain.
Results:
TEM showed the variety of capsule thickness of these strains.Virulent type strain W83 possessed thicker capsular structure than less-virulent type strain ATCC33277. The SJD4 possessed thicker capsule than other clinical isolates, followed by SJD11, SJD5, SJD2, and SJD12.Strains W83, SJD4, SJD11, with thicker capsule, were much more hydrophilic with lower MATH percentage, in accordance with a slow autoaggregation in incubation during a period of 240 min. Compared with W83, the hydrophobicity of strains ATCC33277, SJD5, SJD2, and SJD12, with thinner capsule, showed increased MATH percentage and autoaggregations. All clinical strains developed biofilm with different absorbance compared with type strains. The CLSM observation showed biofilm thickness of each strain, ranged from (14.74 ± 4.99) to (24.13 ± 5.45) µm. Strain W83 and SJD11 showed notable poor biofilm formation, while others developed dense and mature biofilm.
Conclusions:
There was a certain degree of linkage between the Pg capsule thickness and surface properties diversity.
Insights
Porphyromonas gingivalis capsule thickness influences surface properties like hydrophobicity and biofilm formation. Thicker capsules correlated with increased hydrophilicity and reduced biofilm development in clinical isolates.
Area of Science:
- Microbiology
- Oral Health
- Bacterial Pathogenesis
Background:
- Porphyromonas gingivalis (Pg) is a key pathogen in periodontitis.
- The bacterial capsule is a virulence factor influencing host interactions.
- Understanding capsule properties is crucial for targeting Pg.
Purpose of the Study:
- To investigate the relationship between the capsule structure and surface properties of Porphyromonas gingivalis isolates.
- To analyze how capsule thickness affects hydrophobicity, autoaggregation, and biofilm formation.
Main Methods:
- Transmission electron microscopy (TEM) for capsule structure and thickness.
- Microbial adhesion to hydrocarbons (MATH) assay for hydrophobicity.
- Autoaggregation assay for cell surface properties.
- Biofilm assays and confocal laser scanning microscopy (CLSM) for biofilm quantification and visualization.
Main Results:
- Capsule thickness varied among P. gingivalis strains; virulent strain W83 had a thicker capsule than ATCC33277.
- Thicker capsules were associated with increased hydrophilicity (lower MATH %) and slower autoaggregation.
- Biofilm formation varied, with strains W83 and SJD11 showing poor biofilm development despite thicker capsules.
Conclusions:
- A correlation exists between P. gingivalis capsule thickness and diverse surface properties.
- Capsule characteristics play a significant role in P. gingivalis pathogenicity and biofilm lifestyle.
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