IncI1 plasmids associated with the spread of CMY-2, CTX-M-1 and SHV-12 in Escherichia coli of animal and human origin

Fourteen plasmids carrying blaCTX-M-1, blaSHV-12 or blaCMY-2 genes from Escherichia coli of both avian and human origin were analysed. IncI1 plasmids were largely predominant. Plasmid mutilocus sequence typing and comparative analysis revealed that the blaCMY-2-ST12-IncI1 plasmids from avian E.coli were identical to those previously found in Salmonella from humans, but different to those associated with human E.coli. The IncI1-ST3 plasmids carrying blaCTX-M-1 or blaSHV-12 were related to those previously identified in avian E.coli, but different to those identified in human E.coli. Overall, no plasmids shared by E.coli of both origin (human/avian) were identified; however, further investigations are needed.