Comparison of the efficiencies of transfer of IncFII- and IncX3-type plasmids harboring blaNDM. The effect of incubation temperature on the efficiency of transfer of IncFII- or IncX3-type plasmids from their transformants to a recipient, E. coli ML4909, was assessed by a conjugation assay. E. coli HST08 transformed with IncFII plasmids harboring blaNDM-5 (pM214_FII, pM217_FII, or pM412_FII) and IncX3 plasmids harboring blaNDM-4 (pM216_X3 or pM507_X3) or blaNDM-7 (pW046BW) was used as the donor. Measurements were performed in triplicate (n = 3). *, P < 0.05 (t test).