Intensive care unit-acquired complicated necrotizing pneumonia caused by Enterobacter cloacae: A case report.

A 58-year-old man with a history of diabetes mellitus and end-stage renal disease acquired pneumonia with acute respiratory failure during his stay in an intensive care unit (ICU). Empirical antimicrobial therapy with ceftazidime and vancomycin was initiated, and imipenem replaced ceftazidime 2 days later due to the patients pulmonary condition failed to improve. However, within 5 days, pulmonary consolidation rapidly progressed to necrotizing pneumonia complicated by lung abscess, empyema, pyopneumothorax, and tension pneumothorax, leading to the patient's death. After the patient had died, all bacterial isolates from cultures of pleural effusion, blood, and tracheal aspirate were identified as Enterobacter cloacae (E. cloacae), which was susceptible to imipenem but resistant to ceftazidime. E. cloacae should be considered in the differential diagnosis of complicated necrotizing pneumonia with lung abscess, empyema, pyopneumothorax, and tension pneumothorax. Carbapenem therapy should be immediately initiated until the pathogen in such rapidly progressive ICU-acquired pneumonia is confirmed. Increased awareness among physicians regarding E. cloacae-induced complicated necrotizing pneumonia acquired in ICUs could enable earlier detection and appropriate antimicrobial therapy for this invasive disease.