PA0328 Is Associated with Virulence and Immune Evasion in Carbapenem-resistant Pseudomonas aeruginosa

Pseudomonas aeruginosa is a major nosocomial pathogen. Its persistence in hospital environments and ability to evade host immune responses are closely linked to multiple virulence factors. This study aimed to investigate the regulatory role of PA0328 in controlling key pathogenic traits of carbapenem-resistant Pseudomonas aeruginosa (CRPA), particularly its interactions with host immune cells. An extensively drug-resistant CRPA isolate from a COPD patient (BALF sample) was colistin-resistant and biofilm-proficient. It served as the basis for transposon mutagenesis. We identified PA0328 as a critical regulator of virulence. Functional assays confirmed its role in modulating pyocyanin production, biofilm formation, bacterial motility, and macrophage interaction. The gene expression analysis were used to explore its regulatory targets, especially quorum sensing-associated pathways. PA0328 was identified as a pivotal regulator of multiple virulence processes. It modulates pyocyanin synthesis, biofilm dynamics, and motility. Notably, PA0328 fine-tunes macrophage interactions by balancing bacterial adhesion and resistance to phagocytosis, which was essential for CRPA survival and dissemination in the host. Mechanistically, PA0328 repressed quorum sensing-related genes, unveiling a regulatory axis controlling CRPA virulence. PA0328 plays a central role in orchestrating CRPA pathogenicity by regulating multiple virulence-related processes and macrophage responses. It represents a promising target for anti-virulence therapies against CRPA infections.