Meningoencephalitis Caused by Escherichia coli in an Adult With No Known Immunocompromising Conditions: A Case Report

BACKGROUND E. coli is one of the most common causative agents of neonatal meningitis. However, it rarely affects the central nervous system (CNS) in immunocompetent adults or adults with no known immunocompromising conditions, with less than 1 case per year. Gram-negative community-acquired bacillary meningitis seldom occurs without pre-existing conditions such as trauma, organ dysfunction, and immunocompromised state, and there have been very few case reports with E. coli. CASE REPORT In this report, we present a case of a 69-year-old man who was proven to have meningoencephalitis caused by E. coli. The patient was admitted to the Intensive Care Unit (ICU) in a severe general condition with fever, headache, confusion, delirium, and psychomotor agitation. Analysis of cerebrospinal fluid (CSF) and urine identified E. coli. After intensive therapy with anti-edema agents, appropriate antibiotics, and symptomatic agents, the patient's condition improved significantly, and he was discharged from the hospital on day 14 with no signs of E. coli in CSF and urine. On follow-up 1 month after discharge, the patient's sterile urine again tested positive for E. coli in significant quantity, and it was multidrug-resistant to antibiotics. Nitrofurantoin was administered, and the isolated strain was the only susceptible strain. Two months after persistent treatment, the patient's urine was sterile, and he had no further concerns. CONCLUSIONS This case highlights the possibility that E. coli can cause CNS involvement even in an adult with no known immunocompromising conditions with an existing urinary tract infection with this pathogen.