Emergence of colistin resistance gene mcr-1 in Cronobacter sakazakii producing NDM-9 and Escherichia coli from the same animal.

ABSTRACT We report the presence of mcr-1 in Escherichia coli and carbapenem-resistant Cronobacter sakazakii from the same diseased chicken. The mcr-1 gene linked with IS Apl1 was located on two different IncI2 plasmids, including one multidrug plasmid in E. coli, whereas fosA3-bla NDM-9 was on an IncB/O plasmid in C. sakazakii. The development of the fosA3-bla NDM-9 resistance region was mediated by IS 26 . The colocation of mcr-1 or bla NDM-9 with other resistance genes will accelerate the dissemination of the two genes.