blaCTX-M-carrying Escherichia coli of the O25b ST131 clonal group have emerged in China

Six Escherichia coli O25b ST131 isolates, which were mostly hospital-acquired but from various types of samples, were found to carry blaCTX-M-3a,blaCTX-M-14, or blaCTX-M-65 genes, demonstrating that such isolates have emerged in China. The blaCTX-M genes were mostly carried by IncFII-related conjugative plasmids. All isolates were also resistant to ciprofloxacin and gentamicin and had substitutions in GyrA and carried an aac(3)-II gene.