Pneumonia involving Legionella pneumophila and Listeria monocytogenes in an immunocompromised patient: an unusual coinfection

Abstract

Recently, empirical therapy has been recommended for severe community-acquired pneumonia. We report the case of a 68-year-old prednisone-treated man with multiple myeloma who developed a fatal pneumonia due to Legionella pneumophila and Listeria monocytogenes confirmed by immunohistochemistry on postmortem lung sampling. Involvement of the latter bacteria and association of two different pathogens are both highly uncommon features in pneumonia. The route of infection with L. monocytogenes is discussed and the literature on respiratory infections with L. monocytogenes is briefly reviewed. This case highlights the need to consider unusual pathogens when facing pneumonia in immunocompromised patients, and to perform extensive microbiological investigations even if broadspectrum antibiotic therapy is the treatment of choice.