A case of lobar pneumonia and sepsis with death caused by invasive Klebsiella rhinoscleromatis infection

Klebsiella pneumoniae often causes pneumonia and other infections in heavy drinkers and patients with diabetes. Pneumonia caused by Klebsiella rhinoscleromatis, a subspecies of K. pneumoniae, has not been previously reported. We report a case of pneumonia caused by K. rhinoscleromatis. A 68-year-old man with type 2 diabetes visited our department complaining fever and fatigue for 10 days and cough and bloody sputum for two days. His Japan Coma Scale score was I-1, body temperature 38.3 °C, blood pressure 85/51 mmHg, pulse 135 bpm, and peripheral capillary oxygen saturation level 92% (room air). He had no abnormal breathing sounds. His white blood cell count had decreased to 2600/μL, and his C-reactive protein level was high, at 35.9 mg/dL. Chest computed tomography revealed lobar pneumonia in the right upper lobe and pneumonia in the left upper division. Klebsiella was suspected based on the result of a sputum smear examination. He was diagnosed with septic shock due to pneumonia and was immediately admitted. Intravenous antibacterial (levofloxacin) treatment was initiated, however, he died 13 h after presenting at the hospital. Subsequently, K. rhinoscleromatis was detected in sputum and blood culture. Additional testing determined the bacteria to be a highly pathogenic hypermucoviscosity phenotype and the cause of the fatal lobar pneumonia. Although cases of rhinoscleroma and bacteremia caused by K. rhinoscleromatis infection have been reported, this is the first report of a case with sepsis caused by fulminant pneumonia.