Bacteremia Caused by Moraxella Osloensis: a Fatal Case of an Immunocompromised Patient and Literature Review.

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.