Unexpected Origins: A Case Report of Escherichia coli-Linked Cerebral Abscess in an Adult.

Brain abscesses in patients with congenital heart disease (CHD), particularly cyanotic CHD, present significant morbidity and mortality risks. While Escherichia coli is a known neonatal meningitis pathogen, its involvement in adult intracranial abscesses is rare. This report details a 36-year-old female with an uncorrected ventricular septal defect (VSD) and Eisenmenger syndrome, presenting with neurological symptoms. Imaging identified a left cerebral hemisphere ring-enhancing lesion indicative of a brain abscess, and stereotactic aspiration confirmed E. coli as the pathogen. Treatment with antibiotics resulted in substantial clinical improvement. This case highlights the rarity of E. coli brain abscesses in adults and emphasizes the necessity for early diagnosis and precise microbiological identification to guide effective treatment strategies.