Beetalaktaamsete

Beetalaktaamsete, commonly known as beta-lactamase, is an enzyme produced by bacteria that degrades beta-lactam antibiotics by hydrolyzing the beta-lactam ring. This enzymatic activity inactivates drugs such as penicillins, cephalosporins, monobactams, and carbapenems, making the bacteria resistant to these therapies. Beta-lactamases are a major mechanism of antibiotic resistance and are found in a range of bacteria, particularly Gram-negative species, but also in some Gram-positive organisms.

Beta-lactamases are classified by mechanism and structure into serine beta-lactamases and metallo-beta-lactamases. Serine beta-lactamases (classes A, C, and D) use a serine residue in the active site to acylate and then deacylate the beta-lactam ring. Metallo-beta-lactamases (class B) require one or more metal ions, usually zinc, to activate water that hydrolyzes the ring. Within these groups, functional categories such as narrow-spectrum beta-lactamases, extended-spectrum beta-lactamases (ESBLs), AmpC enzymes, and carbapenemases describe substrate breadth and clinical impact. ESBLs hydrolyze many penicillins and cephalosporins; carbapenemases can hydrolyze carbapenems and other beta-lactams.

In clinical practice, beta-lactamase activity limits the effectiveness of many antibiotics and drives the use of beta-lactamase inhibitors, which are co-administered with beta-lactams to restore activity. Inhibitors such as clavulanic acid, sulbactam, and tazobactam, as well as newer agents like avibactam, relebactam, and vaborbactam, expand options against certain beta-lactamase-producing pathogens. Detection of beta-lactamases guides antimicrobial choice and infection control measures to limit spread.