Related Experiment Video
Updated: Aug 12, 2026
07:15
Invasion of Human Cells by a Bacterial Pathogen
Published on: March 21, 2011
The collagen-binding adhesin is a virulence factor in Staphylococcus aureus keratitis
M N Rhem1, E M Lech, J M Patti
1Sid W. Richardson Ocular Microbiology Laboratory, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.
Infection and Immunity
|May 19, 2000
Summary
Staphylococcus aureus uses collagen-binding adhesins to infect corneas, causing bacterial keratitis in contact lens wearers. Blocking this adhesin reduced bacterial adherence, suggesting a new therapeutic target.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Bacterial keratitis is a serious eye infection, often associated with contact lens wear.
- Staphylococcus aureus is a common causative agent of bacterial keratitis.
- The mechanisms by which S. aureus adheres to and infects the cornea are not fully understood.
Purpose of the Study:
- To investigate the role of collagen-binding adhesins in Staphylococcus aureus pathogenesis of bacterial keratitis.
- To evaluate the potential of targeting collagen-binding adhesins as a therapeutic strategy.
Main Methods:
- A rabbit model of soft contact lens-associated bacterial keratitis was used.
- Collagen-binding and collagen-binding-negative isogenic mutant strains of S. aureus were compared.
- The effect of a collagen-binding peptide on bacterial adherence was assessed.
Main Results:
- A collagen-binding strain of S. aureus caused more suppurative inflammation than its mutant.
- Reintroducing the collagen adhesin gene (cna) restored corneal adherence and infectivity.
- Topical collagen-binding peptide application reduced S. aureus adherence to damaged corneas.
Conclusions:
- Collagen-binding adhesins play a significant role in the pathogenesis of S. aureus corneal infections.
- Targeting these adhesins may offer a novel approach for treating bacterial keratitis.
More Related Videos
Related Concept Videos
01:11Fibril-associated Collagen
Fibril-associated collagens are a type of collagens present in the extracellular matrix with interrupted triple helices or FACIT (Fibril-associated collagens interrupted triple-helices). FACIT help connect and attach the collagen fibrils with each other as well as with other proteins of the extracellular matrix.
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
01:17Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
01:24Adherens 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...
Adherens Junctions are Dynamic
The endothelial cells...
01:31Immunoglobulin-like Cell Adhesion Molecules
Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
01:20Determinants of Bacterial Pathogenicity and Virulence
Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...
01:29Staphylococcal 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...