TABLE 1.

Emerging genomic and transcriptional mechanisms mediating carbapenem resistance mechanisms in Enterobacteriaceae

Resistance mechanism	Species	Resistance determinant(s)	Reference(s)
Narrow- and extended-spectrum β-lactamases	Enterobacter cloacae complex	AmpC	100
	Escherichia coli	AmpC	101
		ESBL	1, 54, 58
	Klebsiella pneumoniae	AmpC, ESBL	101
Carbapenemase	Citrobacter freundii	LMB-1	39
		NDM, KPC	11
		OXA	102, 103
	Escherichia coli	IMP	47
		KPC-variants	3, 37, 46
		NDM	3, 44, 45, 51, 103–109
		NDM, KPC, IMP	110
		OXA	41, 111, 112
	Enterobacter cloacae complex	FRI-3	113, 114
		FLC-1	115
		GES	116
		IMP	115
		KPC	46
		LMB	117
		MIR-17	118
		NDM	119
		OXA	102, 120
	Klebsiella pneumoniae	KPC	9, 32, 121–126
		IMP	127
		NDM-4	43, 44, 128–132
		OXA	42, 102, 111, 130, 133–136
		VIM	125, 137
	Klebsiella aerogenes	NDM	138
	Klebsiella quasipneumoniae	KHM-1	139
	E. coli, E. cloacae, and K. pneumoniae	NDM	12
Efflux pumps	Escherichia coli	AcrAB-TolC	3, 55, 59, 63, 65, 67, 140
	Klebsiella pneumoniae	AcrAB-TolC	3, 65, 67, 125
		AcrAB, RamA	141
Porin deficiency	Escherichia coli	OmpK35 and/or OmpK36	49, 51, 52, 54, 58, 67, 101, 125, 142, 143
		PhoE	144
	Enterobacter cloacae complex	OmpK35 and/or OmpK36	1, 9, 64, 100, 145
		MicC and MicF	53
	Klebsiella pneumoniae	OmpK35 and/or OmpK36	32, 33, 67, 111, 125, 136, 145–147
	Raoultella orithinolytica	OmpK35 and/or OmpK36	6
Target modifications	Escherichia coli	MdrA	148, 149