Final answer:
Moraxella catarrhalis causes otitis media by inducing an inflammatory response in the middle ear, which is worsened by fluid accumulation due to eustachian tube blockages, common in young children.
Step-by-step explanation:
Moraxella catarrhalis and Otitis Media:
Moraxella catarrhalis causes otitis media primarily through inducing an inflammatory response rather than direct tissue damage. In older infants and children, it is one of the common bacterial causes alongside Streptococcus pneumoniae and Haemophilus influenzae. These bacteria can proliferate due to fluid trapped in the middle ear because of eustachian tube blockages, commonly observed in children.
The process of infection typically begins with a blockage, which collects fluid leading to otitis media with effusion (OME), presenting an ideal environment for microbes. Subsequently, this can cause secondary infections, often resulting in chronic earaches. For Moraxella catarrhalis, which is a gram-negative bacterium, components like lipopolysaccharide (LPS) play a vital role in triggering the immune response that culminates in swelling, pus formation, and tissue damage within the middle ear.