Beta-lactamases identified in clinical isolates of Pseudomonas aeruginosa.

The increased prevalence of beta-lactamases in Pseudomonas aeruginosa has begun to reduce the clinical efficacy of beta-lactams against the most common opportunistic pathogen. Of over 800 beta-lactamases identified from Gram-negative bacilli, at least 120 beta-lactamases have been detected in P. aeruginosa. IMPs and VIMs are predominantly found in P. aeruginosa and like Acinetobacter spp., P. aeruginosa is also a predominant source of OXAs, indicating that P. aeruginosa is a crucial reservoir of beta-lactam resistance determinants. This review summarizes the beta-lactamases identified in clinical isolates of P. aeruginosa, with a particular focus on AmpC-type beta-lactamases, extended-spectrum beta-lactamases, and carbapenemases.