The outer membrane protein OlpA contributes to Moraxella catarrhalis serum resistance via interaction with factor H and the alternative pathway.
Factor H is an important complement regulator of the alternative pathway commonly recruited by pathogens for increased survival in the human host. The respiratory pathogen Moraxella catarrhalis that resides in the mucosa is highly serum resistant and causes otitis media in children and respiratory tract infections in individuals with underlying diseases. In this study, we show that M. catarrhalis