Background: Moraxella osloensis rarely causes infection in humans, and most of the reported cases are not fatal. It is often difficult to identify M. osloensis using conventional biochemical methods.
Methods: Here, we report a bacteremia case caused by M. osloensis in a patient with advanced lung cancer who initially presented symptoms of fever.
Results: Blood culture revealed growth of a gram-negative bacterium, which was identified as M. osloensis through 16S rRNA gene sequencing and MALDI-TOF analyses. The patient could not recover from sepsis with empirical treatment.
Conclusions: As M. osloensis can cause serious infections in immunocompromised patients, its prompt identification is important.