Beta-lactamase, class A (serine beta-lactamase) and class C (AmpC beta-lactamase) (TEM, SHV, CTX-M, KPC, AmpC)

Class A and C beta-lactamases are bacterial enzymes responsible for resistance to a wide range of beta-lactam antibiotics by hydrolyzing the four-membered beta-lactam ring. Class A enzymes (serine beta-lactamases) are common in Gram-negative bacteria and include well-known types such as TEM, SHV, CTX-M, and KPC, with the ability to hydrolyze penicillins, cephalosporins, and sometimes carbapenems. Class C enzymes (AmpC beta-lactamases) preferentially inactivate cephalosporins and are less susceptible to inhibition by traditional beta-lactamase inhibitors. Both are major contributors to hospital- and community-acquired bacterial resistance, posing critical challenges in infectious disease management. Detection of their activity or genes is a key biomarker for guiding appropriate antibiotic therapy.

Other names

Serine beta-lactamaseTEM beta-lactamaseSHV beta-lactamaseCTX-M beta-lactamaseKPC beta-lactamaseAmpC beta-lactamasecephalosporinase

Enzymatic hydrolysis of the beta-lactam ring, rendering beta-lactam antibiotics inactive