Emergence of KPC-producing Pseudomonas aeruginosa in Spain: insights into an outbreak and resistance to the novel carbapenem/β-lactamase inhibitor combinations imipenem/relebactam and meropenem/vaborbactam

Key Points

• To investigate the emergence of KPC-producing Pseudomonas aeruginosa and its resistance mechanisms.
• Outbreak investigation involving four patients and environmental samples from a hospital sink.
• Genomic analysis to identify resistance genes and plasmid characteristics.
• Functional assays to assess the interaction between KPC-2 production and porin loss.
• All isolates belonged to the ST253 clone, demonstrating significant resistance.
• Identified plasmid-encoded bla KPC-2 contributing to resistance mechanisms.
• Synergy between KPC-2 production and loss of OprD was confirmed, complicating treatment options.