Table 2.

Resistance mechanisms of carbapenemase producing Enterobacteriaceae

Class	Genetic mutation	Clavulanic acid inhibition
Class A	Chromosomal encoded (NmcA, Sme, IMI-1, SFC-1)	Partially inhibited
	Plasmid encoded (IMI-2, GES, KPC)
Class B	Metallo-β-lactamase (IMP, VIM and NDM-1, SIM, GIM, SPM)	Resistant to clavulanic acid
Class D	Plasmid encoded oxa-48	Resistant to clavulanic aci

KPC: K. pneumoniae carbapenemases; OXA: Oxacillin-hydrolising; NDM: New Delhi metallo-beta-lactamase. Table was modified from the ref.[22].