Table 3.

mcr-1 variants.

	Accession numbers	Nucleotide mutations	Amino acid variations	Locations of amino acid variations	Host strain	Source	Country	Year	Reference
mcr-1.2	KX236309	T8A	Q3L	TM domain	K. pneumoniae	Human rectal swab	Italy	2014	Di Pilato et al., 2016
mcr-1.3	KU934208	G111A, G112A	I38V	TM domain	E. coli	Chicken	China	Unknown
mcr-1.4		G1318T	D439N	α6 unit, PEA transferase domain	E. coli	Sewage	China	2015	This study
mcr-1.5	KY283125	C1354T	H452Y	Region between α6 and β7 unit, PEA transferase domain	E. coli	Human urine	Argentina	2015
mcr-1.6	KY352406	A1263G, A1607G	T215A, R536H	Region prior to β1 unit, η12 unit, PEA transferase domain
mcr-1.7		G643A	A215T	Region prior to β1 unit, PEA transferase domain	E. coli	Sewage	China	2015	This study
mcr-1, unnamed	MADL0100 0078.1	T933A, C946T, T947C, A967T, T987C, A999G	N311K, L316S, I323F	α4 and β5 unit, PEA transferase domain	E. coli	Lizard	Germany (imported from Vietnam)	2013	Unger et al., 2017
mcr-1, unnamed 2	MOFD0100 0034.1	C1396A	H466N	Region between β6 and β7 unit, PEA transferase domain	E. coli	Chicken	China	2014
mcr-1, unnamed 3	MTKG0100 0192.1	G24C	W8C	TM domain	E. coli	Seawater	Brazil	2016