Specific bla CTX-M-8 /IncI1 Plasmid Transfer among Genetically Diverse Escherichia coli Isolates between Humans and Chickens.

We investigated the genetic backbones of 14 bla CTX-M-8 -positive Escherichia coli isolates recovered from human stool samples and chicken meat. All isolates carried IncI1 plasmids with bla CTX-M-8 ( bla CTX-M-8 /IncI1), and most (9/14) belonged to a specific genetic lineage, namely, plasmid sequence type 113 (pST113). The genetic contexts of the nine bla CTX-M-8 /IncI1 pST113 plasmids were similar, regardless of the source. These results suggest the probable local transfer of bla CTX-M-8 /IncI1 between humans and chickens with genetically diverse E. coli .