A49-05 A Rare Case of Escherichia Coli Causing Community-acquired Cavitary Pneumonia Without Bacteremia

Abstract Introduction E. Coli is a gram-negative bacterium found in the gastrointestinal or genitourinary tract in the human body. Rarely, it can also cause cavitary pneumonia through hematogenous dissemination from GI or GU infection. This case report describes a case of community-acquired pneumonia caused by E. Coli in an immunocompromised patient without bacteremia. Case Presentation A 42-year-old female with a history of neuroectodermal tumor, Adriamycin-induced cardiomyopathy, orthotopic heart transplantation on mycophenolate, prednisone, and tacrolimus, renal cell carcinoma with left nephrectomy, ESRD on HD, presented to the hospital with several weeks of productive cough and new onset right-sided pleuritic chest pain. On arrival, she was afebrile, normotensive, tachycardic, and tachypneic with desaturation to 80% on room air, requiring 4 L oxygen. The initial laboratory testing was notable for leukocytosis of 16x103/mm3. Her CT chest scan demonstrated multiple new cavitary lesions in the right upper lobe that were not previously seen, right-sided pleural effusion, and segmental pulmonary embolus in the right upper lobe. The patient was initially admitted to the Heart Failure service but soon transferred to the cardiac ICU after rapid decompensation in her respiratory status, requiring FiO2 of 80% on high flow nasal cannula. Her workup for infectious endocarditis was negative with sterile blood culture, TTE, and TEE. She was put on empiric antibiotic treatment and underwent bronchoscopy with bronchoalveolar lavage. A few days later, the bacterial culture from the bronchoscopy grew Escherichia coli, and she was discharged home with a 6-week course of IV cefepime therapy. Discussion : Cavitary pneumonia can result from a variety of mycobacterial, non-mycobacterial, and fungal organisms in immunocompromised patients. E. coli remains a rare cause of Community-acquired pneumonia (CAP) as it is typically acquired via hematogenous spread from the gastrointestinal or genitourinary tract. CAP caused by E. coli without bacteremia is exceedingly uncommon (1); our patient presented to the hospital with E. coli pneumonia without hematogenous dissemination, likely from oropharyngeal microaspirations in the setting of an immunocompromised state. This case highlights the importance of considering E. coli as an emerging pathogen that can cause CAP without bacteremia and the need for timely diagnostic investigation and treatment, especially in immunocompromised patients. Reference: Jonas M, Cunha BA. Bacteremic Escherichia coli pneumonia. Arch Intern Med. 1982;142(12):2157-2159. This abstract is funded by: None