The Role of PiuA, an Outer Membrane Iron Receptor, in the Pathogenesis of Pseudomonas Aeruginosa

Pseudomonas aeruginosa is a common pathogen in those with compromised immunity. It has been attributed to deaths in the majority of cases of Cystic Fibrosis. Using a strain of P. aeruginosa containing no functional piuA gene, coding for an outer membrane siderophore/iron complex receptor, we show that several virulence determinants are upregulated. These include pyocyanin production, adherence to lung epithelia, and cytotoxicity of lung epithelia. Growth was diminished in iron depleted media, suggesting that even though individual cells may be more virulent in the knockout strains, the overall resulting infection may be less severe. This may have important implications for the future when designing novel infection control strategies with P. aeruginosa.