Class D serine beta-lactamase (OXA-type beta-lactamase) (OXA)

Class D serine beta-lactamases, also known as OXA-type enzymes or oxacillinases, are a diverse group of bacterial enzymes that confer resistance to a wide range of beta-lactam antibiotics, including penicillins, cephalosporins, and carbapenems (StatPearls, 2023). These enzymes utilize a serine residue in their active site to catalyze the hydrolysis of the beta-lactam ring, thereby inactivating the drug before it can reach its target, the penicillin-binding proteins (UniProt, 2024). Class D enzymes are particularly notorious for their role in carbapenem resistance among Gram-negative pathogens such as Acinetobacter baumannii and Klebsiella pneumoniae (PubMed, 2022). Unlike Class A and C enzymes, Class D beta-lactamases are often poorly inhibited by classical inhibitors like clavulanic acid or tazobactam, necessitating the development of next-generation inhibitors like avibactam and durlobactam (Nature Reviews Microbiology, 2021). The clinical significance of these enzymes is profound, as they are frequently encoded on mobile genetic elements, facilitating their rapid spread across different bacterial species in healthcare settings (CDC, 2023). Targeting these enzymes is a critical strategy in overcoming multidrug-resistant infections and preserving the utility of existing antibiotic classes.

Other names

OXA-type beta-lactamaseOxacillinaseAmbler Class D beta-lactamaseSerine-type beta-lactamase class D

Inhibition of the serine-based catalytic site of the enzyme, preventing the hydrolysis of beta-lactam antibiotics and restoring their bactericidal activity (StatPearls, 2023).