Clinical and Molecular Epidemiology of Extended-Spectrum Beta-Lactamase-Producing Escherichia Coli Infections in Metro Detroit: Early Dominance of the ST-131 Clone

INTRODUCTION Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli infections have become endemic worldwide. We aimed to describe the molecular and clinical epidemiology of ESBL-producing E. coli infections during a period of rising global prevalence. METHODS Three hundred sixty-nine consecutive ESBL-producing E. coli infections in Detroit from 2010-2011 were analyzed. Sequence typing (ST) and CH typing were performed. Clinical characteristics and outcomes were compared between patients infected with ST131 and non-ST131 isolates. RESULTS Ninety-six percent of isolates were ST 131, and 78.6% of ST 131 isolates produced blaCTX-M-15. Median time to effective therapy was 48 h vs. 35 h (P = 0.38) in the ST131 vs. non-ST131 groups. Ninety-day mortality rates (8% vs. 8%, P = 1.0) were similar between the two groups. CONCLUSION blaCTX-M-15 ST131 E. coli predominated in Detroit during an early period of global ST131 dissemination. Patients with ST131 E. coli infections had similar clinical outcomes to those with non-ST131 E. coli infections.