[A rare case of sepsis from Citrobacter koseri in adults]

We describe the case of a 53-year-old man, recently diagnosed with decompensated type II diabetes mellitus, admitted to our Department for fever, asthenia, and detection of multiple lung abscesses and pulmonary embolism at chest tomography.His clinical history revealed just a recent orthopedic surgery of osteosynthesis on the left wrist with normal clinical and instrumental post-surgical evolution. Empirical antibiotic therapy with piperacillin/tazobactam and clindamycin was initiated. During hospital stay, swelling and functional impotence in the right knee occurred. They were investigated by arthrocentesis and magnetic resonance, and diagnosed as septic arthritis.Blood culture performed at admission tested positive for Citrobacter koseri on several samples where meropenem was added according to antibiogram. On the other hand, the cultures of bronchoaspirate, pulmonary fine needle aspiration, and arthrocentesis were negative.Antibiotic therapy was administered up to two weeks after discharge and radiological and physical features progressively improved.