key term - Haemophilus influenzae

Definition

Haemophilus influenzae is a Gram-negative bacterium that can cause various infections, particularly in the respiratory tract. It is known for causing severe diseases such as meningitis and pneumonia, especially in young children and immunocompromised individuals.

5 Must Know Facts For Your Next Test

1. Haemophilus influenzae type b (Hib) is the most pathogenic strain and a leading cause of bacterial meningitis in children.
2. It can evade the immune system through its polysaccharide capsule, which inhibits phagocytosis.
3. Hib infections are preventable by vaccination, significantly reducing incidence rates where vaccines are used.
4. Non-typeable Haemophilus influenzae (NTHi) strains lack a capsule and primarily cause respiratory tract infections like otitis media and bronchitis.
5. Diagnosis often involves culturing the bacteria from bodily fluids like blood, cerebrospinal fluid, or sputum.

Review Questions

Related terms

Meningitis:

Inflammation of the protective membranes covering the brain and spinal cord, often caused by an infection.

Phagocytosis:

The process by which certain cells engulf and digest microorganisms or cellular debris.

Otitis Media: An infection or inflammation of the middle ear commonly caused by bacteria or viruses.