Master Moraxella catarrhalis with Picmonic for Medicine

Moraxella Catarrhalis is gram negative, meaning it does not retain crystal violet stain. This is because it has a thin peptidoglycan layer, which is sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane.

Under microscopy, Moraxella catarrhalis exists as diplococci, or round bacteria (cocci) that typically occur in the form of two joined cells.

This bacterium is oxidase-positive, meaning it can produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. This means Moraxella catarrhalis can use oxygen as a terminal electron acceptor in respiration.

Moraxella is catalase-positive. This means that it catalyzes the decomposition of hydrogen peroxide to water and oxygen, which is important for preventing oxidative damage by reactive oxygen species.

This bacterium is a common cause of otitis media in children.

Adults and children may be colonized with Moraxella catarrhalis, and can develop sinusitis because of this bacteria. This is more commonly seen in children.

Moraxella catarrhalis is the second most common cause of bacteria-induced COPD exacerbation. The most common cause is H. influenzae.

When the bronchi in the lungs become inflamed, this leads the patient to suffer irritation in the form of coughing that often produces mucus. In addition, patients may suffer from chest pain, shortness of breath, and wheezing. This is referred to as bronchitis and decreases expiratory airflow in patients. Important to note, bronchitis is further specified as either acute or chronic. Chronic bronchitis is one of the lung diseases included in the umbrella term of COPD, in addition to emphysema.

Patients can also develop laryngitis due to Moraxella catarrhalis infection, which is one of the most common bacterial causes of laryngitis. This is more common in adults, but children can also be affected.