Pyoverdine expression on Pseudomonas aeruginosa swarming cells

Abstract

The gamma-proteobacterium Pseudomonas aeruginosa is an opportunistic pathogen frequently associated with patients with cystic fibrosis or severe burns. The infection establishment is dependent on a number of factors that contribute to virulence, including siderophores and iron uptake systems. Pyoverdine is the main siderophore produced by P. aeruginosa and strains deficient in its production are not able to establish infection in animal models. The conditions necessary for swarming motility appear to mimic those found in the mucus layer associated with epithelium, such as the lung epithelium. Mutant strains in prlC or PA14_00800, derived from P. aeruginosa PA14, have irregular pyoverdine production under conditions that favour swarming motility. The mutant in PA14_00800 apparently produces pyoverdine solely at the extremities of the swarming colony, suggesting a regulation associated with cell differentiation at these sites. PrlC is an oligopeptidase and PA14_00800 a small protein with an unknown function domain, encoded by a gene immediately downstream of PrlC. There are few studies in the literature on PrlC function and no information about PA14_00800. Therefore, this project aims at understanding the role of the prlC-PA14_00800 locus in producing pyoverdine, focusing on the production of this siderophore in swarming colonies. The regulatory mechanism of pyoverdine production and the comprehension of the dynamics of the proteins involved in the process are important and can help the rational design of new drugs to combat infections caused by P. aeruginosa. (AU)