Tables & Figures: Table 1.7: Different Classes of Carbapenemase

Tables

Table 1.7: Different Classes of Carbapenemase

	Class A	Metallo-β-lactamase	OXA carbapenemase
Molecular class	Class A	Class B	Class D
Functional class	2f	3	2d
Gene location	Usually transposon	Usually plasmid	Usually plasmid
Examples	KPC¹ GES SME IMI/NMC-A¹	IMP¹ VIM¹ NDM¹	OXA-23, 24, 51, 58 (types in Acinetobacter spp.)² OXA-48, 181, 232 (types in Enterobacterales)¹
Found in	Enterobacterales	Non-fermenters and Enterobacterales	Non-fermenters and Enterobacterales
Inhibited by	Clavulanate and tazobactam	EDTA	No effective inhibitor
Active site	Serine	Zinc ion	Serine
Carbapenem	Hydrolysed	Hydrolysed	Hydrolysed
Aztreonam	Hydrolysed	Not hydrolysed	Not hydrolysed
Early β-lactam	Hydrolysed	Hydrolysed	Hydrolysed
Extended spectrum cephalosporin	Hydrolysed (except SME)	Hydrolysed	Hydrolysed poorly
¹ Seen in Hong Kong
² Common in Hong Kong