Analysis of Molecules secreted during Myxococcal Predation on Pseudomonas aeruginosa

The search for alternative therapeutics is on the rise due to the threat of multi-drug resistant bacteria. One avenue of exploration to combat this issue is observing the hunting strategy of bacterial micropredators. One such micropredator is Myxococcus xanthus. This bacterium is a soil predator with a wide prey range. Using Myxococcus xanthus as a predator, we observed a novel predation evasion behavior in Pseudomonas aeruginosa strain PAO1. P. aeruginosa is an opportunistic pathogen responsible for 10% of all hospital acquired infections. P. aeruginosa is also classified as an ESKAPE pathogen. These pathogens are the leading cause of nosocomial infections throughout the world, and most of them are multi drug resistant. This strain of Pseudomonas aeruginosa was originally isolated from a burn wound and exhibits resistance to multiple antibiotics. In effort to gain a deeper understanding of this predation evasion behavior, we are using Liquid Chromatography Mass Spectrometry (LCMS) in order to see what products are excreted when P. aeruginosa is in predation by M. xanthus. Spots of Myxococcus and Pseudomona are spotted 1 mm apart on a bilayer agar with a porous cellophane layer between the two agar layers to prevent bacterial migration. After incubating, the cellophane layer is removed, and the agar underneath is cut out and mixed with 60:40 ratio of methanol and water in order to extract diffused compounds. The samples are then analyzed using LCMS. We expect that different compounds will be excreted by P. aeruginosa and M. xanthus when they are in contact with one another through a predation assay compared to when they are growing separately as controls. With further analysis to identify differentially secreted products, we hope to discover the mechanism behind the predation evasion behavior of PAO1