adherence to host cell-capsule hindrance

[biology_06er]

Question, and sorry if it sounds dumb!

If a bacterium is covered by a capsule, and you have a possible adhesin embedded in the cell membrane, does the capsule not hinder the ability of the adhesin to adhere to the host cell?

[PsycoCarrot]

From what I understand about pathogenic microbiology, I think that the capsule will indeed act as a physical barrier. The host's complement system, which acts as a passive response against invading organisms, attracts phagocytes and is directly cytolytic on its own (via membrane attack complex). Bacteria with capsules resist attachment of complement to their cellular surfaces, and can evade these mechanisms of the host immune system.

However, the bacterial polysaccharide is directly antigenic, so antibody response against different capsular polysaccharides will eventually be built by the host, rendering certain strains vulnerable.


Sorry, I went off on an immunology tangent, but hopefully this helps.