Abstract
Raoultella ornithinolytica is a bacterium that belongs to the Enterobacteriaceae family. The most frequently reported infections are gastrointestinal and hepatobiliary. Urinary tract infections are very rarely reported and bloodstream infections are usually reported without an identified source. This bacterium is responsible for an increasing number of infections, especially in immunocompromised patients. The authors describe the first case ever reported of an immunocompromised patient due to non-Hodgkin lymphoma MALT type and corticotherapy, who developed urinary tract infection and subsequently bacteriemia due to this pathogen. LEARNING POINTS: Raoultella ornithinolytica is a virulent pathogen causing community-acquired and hospital-acquired infection, especially in immunocompromised populations.Although most cases of R. ornithinolytica infection are susceptible to standard antibiotic regimens, multi-drug resistant strains have been reported, which may pose a severe risk to the immunocompromised patient.Physicians should be aware that some treatments may increase immunosuppression, thus enabling infection by opportunistic agents such as R. ornithinolytica.