Related Experiment Video

Updated: May 27, 2026

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens
13:47

Opsono-Adherence Assay to Evaluate Functional Antibodies in Vaccine Development Against Bacillus anthracis and Other Encapsulated Pathogens

Published on: May 19, 2020

Staphylococcus epidermidis polysaccharide intercellular adhesin activates complement

Elizabeth G Aarag Fredheim1, Hildegunn Norbakken Granslo, Trond Flægstad

  • 1Paediatric Research Group, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway. elizabeth.aarag@uit.no

FEMS Immunology and Medical Microbiology
|November 15, 2011
PubMed

Insights

Staphylococcus epidermidis polysaccharide intercellular adhesin (PIA) strongly activates the complement system, contributing to inflammation. However, PIA biofilms may hinder immune cell activation, potentially aiding bacterial survival.

Area of Science:

  • Microbiology
  • Immunology
  • Infectious Diseases

Background:

  • Staphylococcus epidermidis is a major cause of hospital-acquired infections.
  • Biofilm formation, mediated by polysaccharide intercellular adhesin (PIA), is a key virulence factor.
  • PIA and biofilms are linked to immune evasion strategies.

Purpose of the Study:

  • To investigate the impact of S. epidermidis PIA on the host inflammatory response.
  • To specifically examine the role of PIA in complement activation.
  • To compare the immune-modulating effects of PIA-positive and PIA-negative S. epidermidis strains.

Main Methods:

  • Utilized a human whole-blood ex vivo infection model.
  • Compared a PIA-positive strain (SE1457) with its PIA-negative isogenic mutant (M10).
  • Investigated the independent effect of purified PIA on complement activation.

Main Results:

  • SE1457 formed a PIA-rich biofilm, while the mutant formed a proteinaceous, DNA-rich biofilm.
  • PIA-positive strain induced stronger complement system activation compared to the mutant.
  • Purified PIA independently triggered significant complement activation.
  • The PIA-negative mutant induced greater granulocyte activation (CD11b) and cytokine secretion.

Conclusions:

  • S. epidermidis PIA possesses potent pro-inflammatory properties via complement activation.
  • The reduced granulocyte and cytokine activation by PIA biofilms may impede bacterial clearance.
  • A complex interplay exists between PIA-mediated complement activation and other immune responses in S. epidermidis infections.

More Related Videos

In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells05:57

In Vitro Assay of Bacterial Adhesion onto Mammalian Epithelial Cells

Published on: May 16, 2011

Invasion of Human Cells by a Bacterial Pathogen07:15

Invasion of Human Cells by a Bacterial Pathogen

Published on: March 21, 2011

Related Concept Videos

Complement System01:27

Complement System

The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a membrane...
Staphylococcal Skin Infections01:29

Staphylococcal Skin Infections

Staphylococcus aureus is a Gram-positive coccus that resides harmlessly on the skin and mucous membranes of healthy individuals. When the skin barrier is breached, it can shift from a commensal to an opportunistic pathogen. This transition is facilitated by surface adhesins, such as clumping factor B and S. aureus surface protein G (SasG), which bind to structural proteins, including loricrin and cytokeratin, in the damaged epidermis. Protein A, another key factor, binds the Fc region of...
Adherens Junctions01:24

Adherens Junctions

Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types –  adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as  epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as  heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
The endothelial cells...
Cell Adhesion in Plants01:14

Cell Adhesion in Plants

Plants have rigid cell walls that are made up of cell wall polysaccharides that mediate cell-cell adhesion. The primary cell walls of plants consist of two independent and interacting polysaccharide networks: a pectin matrix that embeds the second network comprising cellulose and hemicelluloses.
Pectins are complex heteropolymers mainly composed of negatively-charged α-D-glucopyranosyl uronic acid and some neutral glycosyl residues such as α-L-rhamnopyranose, α-L-arabinofuranose, and...
Selectins01:25

Selectins

Cell adhesion is  an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain, which...
Outer Layers of the Cell Envelope01:18

Outer Layers of the Cell Envelope

The outermost layers of prokaryotic cells play a critical role in their survival, virulence, and interaction with the environment. These layers, often composed of polysaccharides, polypeptides, or proteins, form protective and adhesive structures that vary in organization and function.Capsules and Slime LayersCapsules are highly organized, tightly bound layers that firmly attach to the bacterial cell wall. Capsules are usually made of polysaccharides, though some are made of polypeptides. These...