Distribution and Characteristics of<i>Escherichia coli</i>Clonal Group A1

Abstract

Among 1,102 recent Escherichia coli clinical isolates, clonal group A was identified in 17 of 20 (U.S. and non-U.S.) geographic locales, mainly among U.S. isolates (9% vs. 3%; p < 0.001) and those resistant to trimethoprim-sulfamethoxazole (10% vs. 1.7%; p < 0.001). The extensive antimicrobial resistance and virulence profiles of clonal group A may underlie its recent widespread emergence.