Emergence of mcr-1 in Raoultella ornithinolytica and Escherichia coli Isolates from Retail Vegetables in China.

The presence of mcr-1 among Enterobacteriaceae isolates collected from retail vegetables in China between 2015 and 2016 was investigated. Two Raoultella ornithinolytica and seven Escherichia coli strains recovered from lettuce and tomato samples were identified as MCR-1-producers. Similar to isolates from animals and humans, the mcr-1 gene was located on the IncHI2/ST3, IncI2, or IncX4 plasmids. The presence of MCR-1-producing organisms in ready-to-eat food samples represents a serious risk for human health.