-Moraxella catarrhalis are gram-negative cocci that pair as kidney-shaped diplococci and thus morphologically similar to Neisseria
-In contrast to pathogenic Neisseria, Moraxella lacks antiphagocytic capsules and IgA proteases.
-It is found only in humans and is transmitted by respiratory aerosol.
Symptoms & Signs
-It causes otitis media and sinusitis primarily in children
-it causes bronchitis and pneumonia, primarily in older people with chronic obstructive pulmonary disease
-in culture, it grows as round, opaque colonies on blood and chocolate agar, which typically turn pink after 48 hours
-A characteristic feature of M. catarrhalis: its colonies slide across agar without disruption (hockey puck sign)
-Antibiotics: amoxicillin-clavulanate, ampicillin-sulbactam, trimethoprim-sulfamethoxazole, macrolides (azithromycin, clarithromycin) fluoroquinolones (ciprofloxacin), and cephalosporins
-M.catarrhalis produces a β-lactamase and is resistant to ampicillin.