Class C serine beta-lactamase (AmpC) (AmpC)

Class C serine beta-lactamases, commonly referred to as AmpC enzymes, are bacterial hydrolases that represent a major mechanism of resistance against beta-lactam antibiotics in Gram-negative pathogens (Bush & Jacoby, 2010). These enzymes are characterized by a catalytic serine residue that facilitates the hydrolysis of the beta-lactam ring in cephalosporins, penicillins, and monobactams (Jacoby, 2009). Unlike Class A beta-lactamases, AmpC enzymes are generally resistant to inhibition by classical inhibitors such as clavulanic acid, sulbactam, and tazobactam (Tamma et al., 2019). They are frequently encoded on the chromosomes of organisms like Pseudomonas aeruginosa and Enterobacter species, where their expression can be induced by exposure to certain antibiotics or become constitutive through mutations (Meini et al., 2019). In clinical settings, the presence of AmpC enzymes complicates the treatment of serious infections, often necessitating the use of carbapenems or novel inhibitor combinations (Tamma et al., 2019). Modern therapeutic strategies involve the use of diazabicyclooctane inhibitors like avibactam or boronate-based inhibitors like vaborbactam, which effectively target the AmpC active site to restore antibiotic efficacy (Papp-Wallace et al., 2020).

Other names

AmpC beta-lactamaseAmbler Class C beta-lactamaseCephalosporinaseSerine-type beta-lactamase Group 1

Inhibition of the enzyme's catalytic activity through covalent or non-covalent binding to the active site serine residue, preventing the hydrolysis of beta-lactam antibiotics.