Betalaktamaz

Betalaktamaz, also known as beta-lactamase, refers to enzymes produced by certain bacteria that hydrolyze the beta-lactam ring found in many penicillins, cephalosporins, monobactams, and related antibiotics. By breaking the core structure of these drugs, betalaktamaz enzymes inactivate them and confer resistance to the producing organism.

Beta-lactamases are categorized by their molecular structure and mechanism. Serine beta-lactamases (classes A, C, and D) use a serine residue to break the beta-lactam ring, while metallo-beta-lactamases (class B) require zinc for activity. Some enzymes, known as extended-spectrum beta-lactamases (ESBLs), broaden hydrolysis to newer cephalosporins; AmpC beta-lactamases provide resistance to cephamycins and other beta-lactams. Carbapenemases, including certain class A, B, and D enzymes, can hydrolyze carbapenems, posing major treatment challenges.

Genetically, betalaktamaz genes (bla genes) are often carried on plasmids, transposons, or other mobile elements, enabling rapid horizontal transfer between bacteria. This contributes to the spread of resistance across species and geographic regions, particularly among Enterobacterales and other Gram-negative pathogens, though beta-lactamases are also found in some Gram-positive bacteria.

Clinical impact and management rely on surveillance, rapid detection, and appropriate antibiotic choices. Phenotypic tests and molecular assays help identify specific enzymes. Treatment strategies include using beta-lactam antibiotics in combination with beta-lactamase inhibitors (such as clavulanic acid, tazobactam, or sulbactam) and employing newer inhibitor combinations like avibactam, relebactam, or vaborbactam. In some cases, non-beta-lactam antibiotics or last-resort agents are needed. Ongoing research aims to develop novel inhibitors and beta-lactam antibiotics less susceptible to degradation by these enzymes.