plasmids carrying ESBL and mcr-1 genes. Epidemic plasmids carrying ESBL and mcr-1 genes in Escherichia coli from healthy broilers, Lebanon

The objective of the present study was to investigate the mobile genetic supports responsible for the spread of these resistance genes among Escherichia coli in healthy broilers in Lebanon.Twenty-nine conjugative IncFII plasmids harboured the extended-spectrum beta-lactamase genes blaCTX-M-3 or blaCTX-M-55.The mobile colistin resistance genes mcr-1.1 and mcr-1.26 were carried by IncX4 and IncI2 plasmids. One E. coli isolate, the ISEcp1-blaCTX-M-55 transposable unit was found integrated in a mcr-1.26-carrying IncX4 plasmid.