Novel Plasmid-Mediated Colistin Resistance Gene mcr-3 in Escherichia coli

ABSTRACT The mobile colistin resistance gene mcr-1 has attracted global attention, as it heralds the breach of polymyxins, one of the last-resort antibiotics for the treatment of severe clinical infections caused by multidrug-resistant Gram-negative bacteria. To date, six slightly different variants of mcr-1 , and a second mobile colistin resistance gene, mcr-2 , have been reported or annotated in the GenBank database. Here, we characterized a third mobile colistin resistance gene, mcr-3 . The gene coexisted with 18 additional resistance determinants in the 261-kb IncHI2-type plasmid pWJ1 from porcine Escherichia coli . mcr-3 showed 45.0% and 47.0% nucleotide sequence identity to mcr-1 and mcr-2 ,…

• NN
  National Natural Science Foundation of China

  Awards: 2013CB127200, 31422055, 81661138002
• MO
  Ministry of Science and Technology of the People's Republic of China

  Award: 2013CB127200
• MR
  Medical Research Council

  Awards: MR/P007295/1, MR/P007295/1