Pseudomonas-derived cephalosporinase (PDC) (PDC)

Pseudomonas-derived cephalosporinases (PDCs) are chromosomal Class C beta-lactamases naturally produced by the opportunistic pathogen Pseudomonas aeruginosa (Livermore, 1995). These enzymes, traditionally known as AmpC beta-lactamases, are primary mediators of intrinsic and acquired resistance to a wide range of beta-lactam antibiotics, including penicillins and most cephalosporins, by catalyzing the hydrolysis of the drug's amide bond (Rodriguez-Martinez et al., 2009). PDC-3 is one of the most common clinical variants, while PDC-88 represents an evolved allele often associated with reduced susceptibility to modern therapeutic combinations (Beta-Lactamase DataBase). The expression of PDC is typically inducible but can become constitutively high through mutations in regulatory genes such as ampD, leading to high-level clinical resistance (Zamorano et al., 2010). Therapeutic strategies to overcome PDC-mediated resistance involve the use of advanced beta-lactamase inhibitors like avibactam and relebactam, which form a stable covalent bond with the active-site serine of the enzyme to prevent substrate degradation (Lahiri et al., 2015). However, the emergence of extended-spectrum AmpC (ESAC) variants with specific structural mutations continues to pose a significant challenge in treating multidrug-resistant Pseudomonas infections (Barnes et al., 2018).

Other names

AmpC beta-lactamasePseudomonas aeruginosa AmpCPDC-3PDC-88Class C beta-lactamaseblaPDC

Covalent inhibition of the active-site serine by beta-lactamase inhibitors to prevent the hydrolysis of co-administered beta-lactam antibiotics.