Pseudomonas-derived cephalosporinase (PDC)

Pseudomonas-derived cephalosporinase is a **class C β-lactamase enzyme** produced chromosomally by *Pseudomonas aeruginosa*. It is also commonly referred to as **AmpC β-lactamase** or simply **PDC**, with numerous allelic variants described. This enzyme hydrolyzes a broad range of cephalosporins and other β-lactams, rendering these antibiotics ineffective. Overexpression or structural mutations in this enzyme are major contributors to multidrug resistance in *P. aeruginosa*, particularly against expanded-spectrum cephalosporins like cefepime and ceftazidime. The presence of more than 400 allelic variants highlights its evolutionary adaptability; certain mutations enhance catalytic efficiency for specific drugs or confer broader substrate specificity[4]. Newer therapeutic strategies combine antipseudomonal agents with novel non–β-lactams inhibitors such as taniborbactam, avibactam, or relebactam to overcome this resistance mechanism; these inhibitors bind covalently but reversibly to the active site serine residue on the enzyme, blocking its hydrolytic activity and restoring antibiotic efficacy[1][2][3]. The rapid evolution and diversity of this target present ongoing challenges for clinical management of resistant infections.

Other names

AmpC β-lactamasechromosomal AmpCPDC (with specific variants such as PDC-3, PDC-88)blaPDC gene product

Hydrolyzes and inactivates cephalosporins and other β-lactams by breaking the β-lactam ring[1][2][3]. Inhibition by novel non–β-lactams such as taniborbactam or avibactam restores activity of partner antibiotics[1][2][3].