Table 2.

Genetic and phenotypic characteristics of E. coli isolated from fecal samples at different dates and the corresponding transconjugants that have acquired the mcr-1-borne plasmid (strain number with a suffix of C)

Strain ID	Isolation date	Species	AMR genes	mcr-1 plasmids	MIC (μg/ml)									MLST	PFGE
					IMP	MEM	FEP	CAZ	AMK	LEV	CST	SCF	ATM
EC-J53	–	E. coli	–	–	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	1	≤0.5	≤0.5
EC1–1	20/11/2014	E. coli	–	–	<0.25	<0.25	<0.5	<0.5	4	128	0.25	2	<0.5	224	EC1
EC1–2	09/05/2015	E. coli	–	–	<0.25	<0.25	<0.5	<0.5	4	128	0.25	1	<0.5	224	UT
EC2	13/07/2015	E. coli	mcr-1	N/A	0.5	0.25	<0.5	<0.5	2	8	8	<0.5	<0.5	58	EC2
EC2C		EC-J53	mcr-1	~33 kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5
EC3	15/07/2015	E. coli	mcr-1	N/A	<0.25	<0.25	<0.5	<0.5	>256	4	8	<0.5	<0.5	607	EC3
EC3C		EC-J53	mcr-1	~33 kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5
EC4	20/07/2015	M. morganii	mcr-1		<0.25	<0.25	<0.5	<0.5	1	4	>64	2	<0.5	58	NT
EC5	24/07/2015	C. freundii	mcr-1		0.5	0.25	<0.5	<0.5	4	64	16	1	<0.5		NT
EC5C		EC-J53	mcr-1	~ 60kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	4	≤0.5	≤0.5
EC6	10/08/2015	E. coli	mcr-1		<0.25	<0.25	<0.5	<0.5	2	8	8	<0.5	<0.5	58	EC4
EC6C		EC-J53	mcr-1	~ 33kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5
EC7	18/08/2015	E. coli	mcr-1		<0.25	<0.25	<0.5	<0.5	8	8	8	<0.5	<0.5	58	UT
EC7C		EC-J53	mcr-1	~ 33kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5
EC8	18/08/2015	E. coli	mcr-1		<0.25	<0.25	<0.5	<0.5	8	2	8	<0.5	<0.5	46	EC5
EC8C		EC-J53	mcr-1	~ 33kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5
EC9	13/11/2015	E. coli	mcr-1		<0.25	<0.25	>256	>256	>256	128	8	4	32	3944	UT
EC9C		EC-J53	mcr-1	~ 60kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5
EC10	25/11/2015	E. coli	mcr-1		<0.25	<0.25	>256	>256	>256	128	8	4	32	3944	UT
EC10C		EC-J53	mcr-1	~ 33kb	≤0.25	≤0.25	≤0.5	≤0.5	1	≤0.125	8	≤0.5	≤0.5

AMR antimicrobial resistance genes, IPM imipenem, MEM meropenem, FEP cefepime, CAZ ceftazidime, AMK amikacin, LEV levofloxacin, CST colistin, SCF cefperazone/sulbactam, ATM aztreonam, UT untypable, NT not determined