A Diagnostic Quandary of Escherichia Coli Pneumonia: A Case Report and Literature Review

Escherichia coli community-acquired pneumonia (CAP) is an under-recognized condition associated with higher mortality compared to the other well-studied causes of pneumonia. E. coli pneumonia is frequently associated with bacteremia. Despite the absence of abdominal or urinary symptoms, the infection may originate from an occult gastrointestinal (GI) source since it is a common commensal bacteria of the GI tract. Conditions related to extraintestinal pathogenic E. coli (ExPEC) are gaining attention, and there has been a trend toward the rise of pneumonia secondary to gram-negative bacteria. This presents a diagnostic stewardship dilemma in a patient with sepsis, E. coli bacteremia, and apparent pneumonia - to assume and treat for E. coli CAP or to look for a GI/genitourinary source which may, in turn, lead to incidental findings and further studies. We report a case of E. coli CAP in a 62-year-old patient and our approach regarding the treatment and imaging course.