Plasmids of diverse Inc groups disseminate the fosfomycin resistance gene fosA3 among Escherichia coli from pigs, chickens and dairy cows in Northeast China.

Thirty-nine fosfomycin-resistant Escherichia coli isolates carrying fosA3 were obtained from pigs, chickens, dairy cows, and staff in four northeastern provinces of China between June 2015 and April 2016. The fosA3 gene was colocated with bla(CTX-M) genes on conjugative plasmids of the incompatibility groups IncN (n = 12), IncN-F33:A(-):B- (n = 2), IncF33:A(-):B-(n = 14), IncF14:A(-):B- (n = 2), and IncI1/sequence type 136 (ST136) (n = 9). Four different genetic contexts of fosA3 were detected among the 39 E. coli isolates. Three potential epidemic plasmids circulated among E. coli strains from this region.