Extracellular pathogens

Definition

Extracellular pathogens are microorganisms, such as bacteria and fungi, that reside outside the host's cells and cause infections. They elicit immune responses primarily involving antibodies and phagocytic cells.

5 Must Know Facts For Your Next Test

1. Extracellular pathogens include bacteria like Streptococcus pneumoniae and fungi like Candida albicans.
2. The immune system combats extracellular pathogens mainly through humoral immunity, which involves B cells producing antibodies.
3. Phagocytes such as neutrophils and macrophages play a crucial role in engulfing and destroying extracellular pathogens.
4. Extracellular pathogens can cause diseases ranging from mild infections to severe conditions like sepsis.
5. Patients with immunodeficiencies often have an increased susceptibility to infections by extracellular pathogens due to weakened immune responses.

Related terms

Intracellular Pathogens: Microorganisms that live inside host cells and evade the immune system by doing so.

Humoral Immunity:

A type of immune response mediated by B cells that produce antibodies against antigens in body fluids.

Phagocytosis:

The process by which certain cells, such as neutrophils and macrophages, engulf and digest microorganisms or cellular debris.