Silent Invader: A Rare Case of Enterobacter aerogenes Empyema in a Hospice Patient With Complex Comorbidities.

Enterobacter aerogenes (recently renamed Klebsiella aerogenes) is an uncommon pathogen in pleural infections and empyema, typically associated with nosocomial urinary and gastrointestinal infections. This case report describes a 69-year-old male patient with chronic kidney disease, diabetes mellitus, and other comorbidities, who developed empyema despite broad-spectrum antibiotics. Pleural fluid cultures revealed E. aerogenes, known for its ability to develop resistance through beta-lactamase production and efflux pumps, which complicates treatment. Despite initial improvement with cefepime and metronidazole, the patient's respiratory status deteriorated, and due to his do not resuscitate/do not intubate (DNR/DNI) status and extensive comorbidities, no further aggressive interventions were pursued, leading to his passing. This case highlights the diagnostic and therapeutic challenges posed by E. aerogenes in pleural infections, emphasizing its rarity in pulmonary involvement and its potential for antibiotic resistance. It also underscores the importance of considering atypical pathogens in complex infections and the need for multidisciplinary management while balancing aggressive treatments with patient-centered care, particularly in end-of-life scenarios.