What is the function of the bacterial capsule?

The capsule is composed of polysaccharides that cover the cell wall, which is made up of peptidoglycan and teichoic acid, characterizing the classic gram positive structure; It acts as the principal antiphagocytic and protective element that prevents access of the leukocytes to the underlying cell wall elements.

How does capsule protect the bacteria?

The bacterial capsule is also considered a virulence factor as it enhances the ability of bacteria to cause disease by preventing phagocytosis. In addition, in neutropenic patients capsule can also protect bacteria from engulfment by host macrophages [94].

What type of bacteria produce a capsule?

Capsule (also known as K antigen) is a major virulence factor of bacteria, e.g. all of the principal pathogens which cause pneumonia and meningitis, including Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Klebsiella pneumoniae, Escherichia coli, and group B streptococci have polysaccharide …

What do bacterial capsules mean?

The bacterial capsule is a large structure of many bacteria. It is a polysaccharide layer that lies outside the cell envelope , and is thus deemed part of the outer envelope of a bacterial cell. It is a well-organized layer, not easily washed off, and it can be the cause of various diseases.

What does a capsule allow a bacterium to do?

Capsules allow the bacteria to stick together, creating a larger mass that is too big for immune cells to engulf. The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign. The capsule makes the bacterium too sticky to be phagocytosed by the immune cells.

Why are bacterial capsules medically important?

Capsule in bacterial cell helps in preventing the cell from desiccation and drying as capsular polysaccharide binds significant amount of water, thus making cells resistant to drying. It also helps in protection from mechanical injury, temperature etc.

What does the capsule do on a bacterial cell?

bacterial capsule a gelatinous envelope surrounding a bacterial cell, usually polysaccharide but sometimes polypeptide in nature; it is associated with the virulence of pathogenic bacteria. Bowman’s capsule the globular dilatation forming the beginning of a renal tubule and surrounding the glomerulus.