Laktamaser

Laktamaser are a family of enzymes produced by many bacteria that hydrolyze the beta-lactam ring found in penicillins, cephalosporins, and related antibiotics. By breaking this chemical structure, laktamaser inactivate the drugs and enable bacterial survival in the presence of beta-lactam antibiotics. They are a primary mechanism of antibiotic resistance in clinical settings.

Beta-lactamases operate through two main catalytic strategies: serine-based hydrolysis and metal-dependent hydrolysis. Based on amino acid sequence and mechanism, they are grouped into Ambler classes A, B, C and D. Class B comprises metallo-beta-lactamases that require zinc for activity, while Classes A, C and D are serine beta-lactamases. Some laktamaser have broad or extended-spectrum activity, while others are capable of carbapenem hydrolysis, posing particular treatment challenges.

Notable families and examples include TEM, SHV and CTX-M enzymes (Class A, many ESBLs), KPC and OXA-48-like enzymes (Class A and Class D carbapenemases), and NDM, VIM and IMP (Class B metallo-beta-lactamases). The distribution and prevalence of specific laktamaser vary by geography and facility, contributing to local resistance patterns and shaping antibiotic choices.

Detection typically combines phenotypic tests, such as nitrocefin-based assays, with molecular methods that identify specific beta-lactamase genes. Surveillance and antimicrobial stewardship programs monitor spread and guide interventions. Treatment and containment rely on beta-lactamase inhibitors (for example, clavulanic acid, sulbactam, tazobactam and newer agents like avibactam, relebactam, vaborbactam) used in combination therapies, as well as non-beta-lactam antibiotics when appropriate. Preventing dissemination involves rigorous infection control and prudent antibiotic use.