TABLE 2

Broth microdilution polymyxin susceptibility testing of cloned mcr-3-like and mcr-4.2 expressed in E. coli BL21(DE3) host

E. coli BL21(DE3) strainaMIC (mg/liter)
ColistinPolymyxin B
pET48b—mcr-3-like11
pET48b—mcr-4.211
pET48b10.5
No vector0.51
  • a Expression of mcr was induced by the addition of 1 mM isopropyl β-d-1-thiogalactopyranoside (IPTG) to cation-adjusted Mueller-Hinton broth media.