Complete Sequencing of Plasmids Containing blaOXA-163 and blaOXA-48 in Escherichia coli Sequence Type 131.

OXA-48-like enzymes have emerged as important extended-spectrum β-lactamases/carbapenemases in Escherichia coli sequence type 131 (ST131). We report the structures of the first fully sequenced blaOXA-163 plasmid and of two other blaOXA-48 plasmids in this lineage. blaOXA-163 was located on a 71-kb IncN plasmid with other resistance genes. blaOXA-48 was present on IncL/M plasmids, genetically similar to other blaOXA-48 plasmid sequences, and consistent with interspecies/interlineage spread. The presence of blaOXA-48-like genes on epidemic plasmids in ST131 is of concern.