Bacterial serine beta-lactamase (SBL)

Bacterial serine beta-lactamase is an enzyme produced by various bacteria that confers resistance to β-lactam antibiotics—such as penicillins, cephalosporins, monobactams, and carbapenems—by catalyzing the hydrolysis of the β-lactam ring essential for their antibacterial activity[1][5][6]. These enzymes are classified into classes A, C, and D based on sequence and mechanistic features[5]; all utilize an active-site serine for catalysis and are collectively described as serine β-lactamases, in contrast to class B metallo-β-lactamases which require zinc ions for activity[3][5][7]. The emergence and spread of serine β-lactamases in Gram-negative and Gram-positive bacteria is a primary cause of antibiotic resistance worldwide, undermining one of the most widely used classes of antimicrobials and posing a major public health challenge[1][6][8]. The clinical utility of β-lactamase inhibitors (such as clavulanic acid, tazobactam, and avibactam) can restore the effectiveness of β-lactam antibiotics by irreversibly inhibiting these enzymes, but ongoing mutation and diversity among serine β-lactamases complicate therapy and accelerate resistance development[5][6][8]. Detection of serine β-lactamase genes or their activity in clinical isolates serves as a biomarker for resistance, guiding antibiotic selection and infection control strategies.

Other names

Serine β-lactamaseSerine beta-lactamaseSerine β-lactamase enzymeClass A/C/D β-lactamaseSBLβ-lactamase (serine class)

Hydrolyzes the β-lactam ring of antibiotics, neutralizing their antimicrobial action. Covalent acylation of serine active site by β-lactam, followed by hydrolysis and antibiotic destruction.