Micro| Moraxella Catarrhalis

3.13 Moraxella Catarrhalis Microbiology review for the USMLE Step 1 exam Moraxella Catarrhalis is a gram negative diplococcus that is part of normal upper respiratory tract flora Mainly causes three different types of infections: otitis media in children, lower respiratory tract infections in COPD patients, and pneumonia in elderly patients Otitis media is the most common bacterial infectious disease in childhood and the most common reason for which children receive antibiotics. M. catarrhalis causes about 15-20% of otitis media cases. Symptoms of otitis media in children include pulling or tugging at the ears, irritability, headache, disturbed or restless sleep, poor feeding, anorexia, vomiting, or diarrhea. In COPD patients, exacerbations are often due to bacterial and viral infections. M. catarrhalis is a bug to keep in mind and symptoms of a COPD exacerbation caused by this bug are very similar to those caused by other bacteria, including increased sputum production, sputum purulence, and dyspnea. Pneumonia due to M. catarrhalis is a cause of pneumonia in elderly patients, especially in elderly patients with an underlying cardiopulmonary disease like COPD. These infections are usually treated empirically with broad spectrum antibiotics such as 3rd generation cephalosporins and amoxicillin-clavulonic acid.