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


Corresponding author: Dr A. Carattoli, Department of Infectious, Parasitic and Immuno-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161 Rome, Italy



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.