Date of Award

Summer 6-13-2023

Degree Type


Degree Name

Master of Science in Integrative Biology (MSIB)



Major Professor

Melanie Griffin

First Committee Member

Thomas McElroy

Second Committee Member

Tsai-Tien Tseng


Pseudomonas aeruginosa infections make up 10% of nosocomial infections, and these infections are increasing in antibiotic resistance. Virulence factors such as pyocyanin and siderophores contribute to this resistance as they help with virulence and nutrient acquisition. Previously, Lrp has been shown to bind to PQS in P. aeruginosa, a key player in quorum sensing, and when lrp is knocked out, there is a reduction in these quorum sensing virulence factors. Leucine-responsive regulatory protein (Lrp) is a known global regulator in E. coli and if proven to be a global regulator in P. aeruginosa, it could be a potential new target in P. aeruginosa infections. The virulence factors pyocyanin, pyoverdine, and pyochelin, which are important in infection, are investigated in this study, where we determine the role of Lrp in their regulation and production. The results of this study suggest that Lrp plays an indirect role in regulating these factors through quorum sensing, potentially PQS specifically. RNAseq suggests Lrp also plays a role in regulating other important systems such as swarming motility and biofilm formation. In nutrient limited environments, Lrp may regulate an estimated 4-14% of the genome.

Available for download on Friday, July 21, 2028