Tables & Figures: Table 1.6: Characteristics of ESBL and AmpC β-Lactamases

Tables

Table 1.6: Characteristics of ESBL and AmpC β-Lactamases

	ESBL	AmpC β-lactamase
Bush-Jacoby-Medeiros functional class	2be
Ambler molecular classification	A	C
Plasmid mediated	Almost always (responsible for the spread)	Most are chromosomal Plasmid increasingly reported
Inhibition by clavulanate, tazobactam, sulbactam*	Inhibited	Not inhibited
Cephamycins - cefoxitin - cefmetazole	Not hydrolysed	Hydrolysed
Oxyimino-β-lactams - cefotaxime - ceftriaxone - ceftazidime	Hydrolysed	Hydrolysed
Cefepime	Variable	Not hydrolysed
Carbapenem	Not hydrolysed	Not hydrolysed
Examples	TEM, SHV and CTX-M	Enterobacter, Citrobacter and Serratia possess inducible AmpC β-lactamase encoded in their chromosomes
*β-lactamase inhibitor