Spread of CTX-M-15 Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates through Household Contact and Plasmid Transfer

ABSTRACT We document the household spread of extended-spectrum β-lactamase-producing Escherichia coli. One isolate belonged to sequence type 1193 and caused urinary tract infection in a 4-month-old female, and the other isolate belonged to sequence type 131 and colonized three family members, including the index patient. These isolates carried similar Inc-I1-Iγ plasmids, harboring bla CTX-M-15 .