Carbapenemases: A worldwide threat to antimicrobial therapy

Table 1 Carbapenemase classification

Bush-Jacoby	Bush-Jacoby-Medeiros	Molecular	Distinctive	Inhibited by		Characteristics	Representative
(2010)	(1995)	class	substrate	CA or TZB	EDTA		enzyme
2f	2f	A	Carbapenems	Variable	No	Increased hydrolysis of carbapenems, oxyamino-β-lactams, cephamycins	KPC-2, IMI-1, SME-1
2df		D	Carbapenems	Variable	No	Hydrolizes oxacillin and carbapenems	OXA-23, OXA-48
1e		C	Cephalosporins	No	No	Increased hydrolysis of ceftazidime and often other oxyimino-β-lactams	CMY-10
3a	3	B1	Carbapenems	No	Yes	Broad.spectrum hydrolysis including carbapenems but not monobactams	IMP-1, VIM-1, CcrA, IND-1
3a	3	B3	Cephalosporins	No	Yes	Broad.spectrum hydrolysis including carbapenems but not monobactams	L1, CAU-1, GOB-1, FEZ-1
3b	3	B2	Carbapenems	No	Yes	Preferential hydrolysis of carbapenems	CphA, SFh-1

CA: Clavulanic acid; TZB: Tazobactam; KPC: Klebsiella pneumoniae carbapenemase; IMI: Imipenem hydrolyzing Β-lactamase; SME: Serratia marcescens enzyme; VIM: Verona integron-encoded metallo-β-lactamase; EDTA: Ethylenediaminetetraacetic acid.