Table 1.

Characteristics of mcr-1-producing Escherichia coli GB110, Klebsiella pneumoniae GB015 and their transconjugants isolated from market retail fruits in China

Isolate code	Source	Isolation site	MLST	Plasmid replicon type	Encoding genes of resistance	MICs
E. coli GB110	Apple	Market retail fruits	ST189	IncHI1,IncFIA	aadA2, aadA1, mcr-1, floR, cmlA1, sul2, sul3, tetA, tetM, dfrA12, mdfA	CL (16), PB (8), TGC (≤1), AMP (4), AMC (8), CTX (≤0.125), CAZ (≤0.125), FEP (0.25), GEN (≤1), AMK (4), ETP (≤0.125), IPM (≤0.125), MEM (≤0.125), FOS (≤8), NIT (≤8), CIP (≤0.03)
K. pneumoniae	Orange	Market	ST442	IncHI1,	bla, mcr-1, SHV-110	CL (64), PB (64), TGC (≤1), AMP (64), AMC (8),
GB015		retail fruits		IncFIB	qnrS1, oqxA, oqxB, fosA6, sul1, tetA, dfrA1	CTX (≤0.125), CAZ (0.5), FEP (≤0.125), GEN (≤1), AMK (4), ETP (≤0.125), IPM (0.5), MEM (≤0.125), FOS (16), NIT (64), CIP (1)
E. coli C600 (transconjugant of E. coli GB110)	–	–	–	IncFIA	mcr-1	CL (16), PB (8), TGC (≤1), AMP (4), AMC (8), CTX (≤0.125), CAZ (≤0.125), FEP (≤0.125), GEN (≤1), AMK (4), ETP (≤0.125), IPM (≤0.125), MEM (≤0.125), FOS (≤8), NIT (8), CIP (≤0.03)
E. coli C600 (transconjugant of K. pneumoniae GB015)	–	–	–	IncHI1	mcr-1	CL (16), PB (16), TGC (≤1), AMP (4), AMC (8), CTX (≤0.125), CAZ (≤0.125), FEP (≤0.125), GEN (≤1), AMK (4), ETP (≤0.125), IPM (≤0.125), MEM (≤0.125), FOS (≤8), NIT (≤8), CIP (≤0.03)

Abbreviations: AMC, amoxicillin–clavulanic acid; AMK, amikacin; AMP, ampicillin; CAZ, ceftazidime; CIP, ciprofloxacin; CL, colistin; CTX, cefotaxime; ETP, ertapenem; FEP, cefepime; FOS, fosfomycin; GEN, gentamicin; IPM, imipenem; MEM, meropenem; MIC, minimum inhibitory concentration; MLST, multilocus sequence typing; NIT, nitrofurantoin; PB, polymyxin B; TGC, tigecycline.