Question

what are three mechanisms for bacterial adhesion to surface?

Answer 1

Adhesion is the ability of bacteria to attach to the surface of the host cell to gain entry into the host. Adhesion is carrioed out by proteins adhesins or invasins and fimbrae, hair like structure on bacterial surface allows bacteria to attach to the host cells surface. The adhesion process involves lectin-like adhesion proteins on the bacteria with binding specificity for carbohydrates on the tissue surfaces.

1. Attachement through hydrophobic interactions - Surface molecules on bacteria, adhesins or ligands binds specifically with complementary surface receptors on cells through hydrophobic interactions, followed by adhesive interactions such as hydrogen bonding, cation bridg­ing. Adhesin molecules present on bacterial surface are responsible for adhesion.
2. Bacteria possess surface structures like fimbriae (or pilli), fibrils, flagella, capsule and S layer that help in adhesion of cells. All these structures consist of adhesins.
3. Proteins present bacterial cell surface act as adhesins and facilitate the attachment of bacteria to host cell surface. Lectins, a glycoprotein present at end of pilli;  lipoteichoic acid (LTA) acts as adhesin and triggers the adhesion to fibronectin. Carbohydrates produced by bacteria also helps in adhesion like exopolysaccharide (alginate), Lipopolysaccharide (LPS)