Bacterial class D β-lactamase

Bacterial class D β-lactamase is an enzyme produced by a variety of bacteria, most commonly Gram-negative pathogens but also some Gram-positive species, that confers resistance to β-lactam antibiotics by hydrolyzing the β-lactam ring critical for antibiotic activity[1][3][4]. Class D β-lactamases, also called OXA-type β-lactamases, are serine hydrolases within the molecular family of β-lactamase enzymes (EC 3.5.2.6), and act by rapidly inactivating antibiotics such as penicillins (especially oxacillin), cephalosporins, and in some cases carbapenems[2][3]. They are structurally and mechanistically distinct from other β-lactamase classes (A, B, C), sharing significant homology with DD-peptidases but with differences in substrate binding and catalysis[2][1]. The clinical significance of these enzymes lies in their ability to confer multidrug resistance, complicating treatment of infections caused by organisms such as *Acinetobacter baumannii*, *Enterobacteriaceae*, and certain Gram-positive bacilli[1][4]. Genes encoding these enzymes can rapidly spread via plasmids among bacterial populations, and their identification is a key biomarker of antibiotic resistance[1][2][4]. They pose a public health threat due to the scarcity of effective β-lactamase inhibitors, especially those that work against the evolving spectrum of OXA-type enzymes[4].

Other names

β-lactamase DOXA-type β-lactamaseClass D beta-lactamaseOXA β-lactamaseserine beta-lactamase (class D)

Hydrolysis of the β-lactam ring of antibiotics, rendering them inactive[3][2][1] Prevents antibiotics from binding to and inhibiting penicillin-binding proteins essential for bacterial cell wall synthesis[2]