Moraxella catarrhalis is typically a commensal organism in the human respiratory tract but can act as a pathogen under certain conditions. It is a major cause of otitis media (middle ear infection) in children and contributes to lower respiratory tract infections in adults (Murphy & Parameswaran 2009, Karalus & Campagnari 2000)
Murphy, T. F., & Parameswaran, G. I. (2009). Moraxella catarrhalis, a human respiratory tract pathogen. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 49(1), 124–131. https://doi.org/10.1086/599375
Karalus, R., & Campagnari, A. (2000). Moraxella catarrhalis: a review of an important human mucosal pathogen. Microbes and infection, 2(5), 547–559. https://doi.org/10.1016/s1286-4579(00)00314-2
