Class C Cephalosporinase (AmpC)

Class C cephalosporinases, also known as AmpC β-lactamases, are enzymes produced by various Gram-negative bacteria. Their primary function is to hydrolyze and inactivate a broad range of β-lactam antibiotics, particularly cephalosporins. These enzymes play a significant role in antibiotic resistance. They are typically encoded by chromosomal genes but can also be found on plasmids. Expression is often inducible. Class C cephalosporinases are widespread among Gram-negative bacteria, including Enterobacter, Citrobacter, Serratia, Proteus, Pseudomonas aeruginosa, and some strains of E. coli, making them major contributors to hospital-acquired infections with multidrug-resistant phenotypes. Classic inhibitors such as clavulanic acid do not inhibit class C enzymes effectively; however, newer agents like avibactam show inhibitory activity.

Other names

AmpC beta-lactamaseClass C β-lactamaseAmpC-type β-lactamasesGroup 1 cephalosporinases

Antibiotic inactivation