Table 2.

Primers and conditions used for the amplification of the mcr genes.

Target	Primer	Sequence (5′–3′)	Amplicon Size (bp)	Conditions
mcr-1	mcr-1-Fw	CGGTCAGTCCGTTTGTTC	309	20 cycles of amplification at 94 °C for 30 s, 58 °C for 90 s, 72 °C for 1 min and final 72 °C for 10 min
	mcr-1-Rv	CTTGGTCGGTCTGTAGGG
mcr-2	mcr-2-Fw	TGTTGCTTGTGCCGATTGGA	567	33 cycles of amplification at 95 °C for 3 min, 65 °C for 30 s, 72 °C for 1 min and final 72 °C for 10 min.
	mcr-2-Rv	AGATGGTATTGTTGGTTGCTG
mcr-3	mcr-3-Fw	TTGGCACTGTATTTTGCATTT	542	30 cycles of amplification at 95 °C for 30 s, 50 °C for 30 s, 72 °C for 45 s and final 72 °C for 7 min.
	mcr-3-Rv	TTAACGAAATTGGCTGGAACA
mcr-4	mcr-4-Fw	ATTGGGATAGTCGCCTTTTT	487	20 cycles of amplification at 94 °C for 30 s, 58 °C for 90 s, 72 °C for 1 min and final 72 °C for 10 min
	mcr-4-Rv	TTACAGCCAGAATCATTATCA
mcr-5	mcr-5-Fw	ATGCGGTTGTCTGCATTTATC	1644	30 cycles of amplification at 95 °C for 30 s, 50 °C for 30 s, 72 °C for 95 s and final 72 °C for 5 min.
	mcr-5-Rv	TCATTGTGGTTGTCCTTTTCTG

Fw: Forward, Rv: Reverse.