Kluyvera ascorbata Strain from Hospital Sewage Carrying the mcr-1 Colistin Resistance Gene

The newly identified plasmid-borne colistin resistance gene mcr-1 was found in a Kluyvera ascorbata isolate from hospital sewage in China. mcr-1 was carried by a 57-kb self-transmissible IncI2 plasmid. Unlike in a previous report, mcr-1 was not associated with ISApl1 and was inserted into a gene encoding a putative membrane protein by an unknown mechanism. This study highlights that mcr-1 has spread to multiple bacterial species.