Moraxella catarrhalis endocarditis: case report and review of the literature.

A case of bacterial endocarditis caused by Moraxella catarrhalis in an apparently immunocompetent Greek male is presented, which was diagnosed after a 2-month history of low-grade fever of unknown origin. The agent seems to be a rare pathogen, but due to the high mortality rate, it should always be considered in the differential diagnosis of relevant cases. Beta-lactamase production by many strains complicates the choice of antibiotic.