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Updated: Aug 26, 2026
In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells
Published on: May 16, 2011
Demonstration of adherence properties of Porphyromonas gingivalis outer membrane vesicles using a new microassay
P Duchesne1, D Grenier, D Mayrand
1Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire, Université Laval, Quebec, Canada.
Abstract:
Vesicles made by Porphyromonas gingivalis possess several biological activities, including the ability to adhere to oral surfaces and to bacteria. In this study, a new and simple method was developed to measure the adherence capability of outer membrane vesicles from P. gingivalis. Vesicles were conjugated to fluorescent microspheres (0.7 micron) and added to wells of a Teflon-coated microscope slide previously covered with a variety of soluble ligands. After incubation and washes, the number of fluorescent microspheres per microscopic field were counted. Vesicle-coated microspheres attached best to gelatin (> 200 per field), whereas other compounds (such as fibronectin, fibrinogen, collagen and laminin) provided moderate attachment, and no attachment was observed to bovine serum albumin. Adherence to any of the tested ligands was not observed when fluorescent microspheres were conjugated to bovine serum albumin or lipopolysaccharides from P. gingivalis. The adherence of vesicle-coated microspheres to ligands was not significantly affected when the pH of the reaction mixture was between 4 and 10. None of the tested carbohydrates lowered the attachment capability of vesicle-coated microspheres to substrates. When vesicle-coated microspheres were treated with trypsin and chymotrypsin or heated, this resulted in a significant loss of attachment, suggesting a possible involvement of proteinaceous molecules in the process. The present study confirms that vesicles of P. gingivalis are capable of attachment to various molecules and indicate their potential role in colonization.
Insights
Porphyromonas gingivalis outer membrane vesicles (OMVs) can adhere to various molecules, particularly gelatin. This adherence, crucial for colonization, is mediated by proteins and is unaffected by pH or carbohydrates.
Area of Science:
- Microbiology
- Oral Biology
- Biochemistry
Background:
- Porphyromonas gingivalis outer membrane vesicles (OMVs) exhibit biological activities, including adherence to oral surfaces and other bacteria.
- Understanding OMV adherence mechanisms is vital for comprehending P. gingivalis colonization and pathogenesis.
Purpose of the Study:
- To develop a novel, straightforward method for quantifying the adherence of P. gingivalis OMVs to various ligands.
- To investigate the molecular basis of OMV adherence to different substrates.
Main Methods:
- Conjugating P. gingivalis OMVs to fluorescent microspheres.
- Incubating microsphere-conjugated OMVs with Teflon-coated slides coated with diverse soluble ligands (gelatin, fibronectin, etc.).
- Quantifying OMV adherence by counting fluorescent microspheres under microscopy.
Main Results:
- Vesicle-coated microspheres demonstrated strongest attachment to gelatin, moderate attachment to fibronectin, fibrinogen, collagen, and laminin, and no attachment to bovine serum albumin.
- Adherence was not observed with microspheres conjugated to bovine serum albumin or P. gingivalis lipopolysaccharides.
- Attachment remained stable across a pH range of 4-10 and was not inhibited by tested carbohydrates.
- Proteolytic treatment (trypsin, chymotrypsin) or heating significantly reduced OMV adherence, indicating the involvement of proteinaceous components.
Conclusions:
- P. gingivalis OMVs possess a significant capacity to adhere to a range of molecules, with a notable preference for gelatin.
- The adherence mechanism appears to be protein-dependent.
- These findings support the role of P. gingivalis OMVs in bacterial colonization of oral surfaces.
