Analysis of Secreted Metabolites During Predation of Myxococcus xanthus on Pseudomonas aeruginosa
Disciplines
Microbiology
Abstract (300 words maximum)
Pseudomonas aeruginosa is categorized by the World Health Organization as one of the most multidrug-resistant pathogens in need of control. Myxobacteria is a single-celled predatory soil bacterium and a potential source of novel antibiotics. They are social and seen to hunt in “wolf” packs cooperatively. Under starvation conditions they will aggregate in compact structures filled with spores known as fruiting bodies; only germinating when nutrients become available. In our research group we have shown that Myxococcus xanthus (predator) is able to predate on isolated Pseudomonas aeruginosa (prey) cells. This is supported by our observations in microscopic mixed cell assays using fluorescent tags to track prey cell death. However, a unique resistance response to predation is observed in a population of P. aeruginosa when predator and prey are spotted side-by-side. P. aeruginosa blocks M. xanthus advancement and resists predation. To determine if there are any metabolites associated with the resistance response we performed a side-by-side spot predation assay with M. xanthus and P. aeruginosa. We used a bilayer of partial-starvation agar plates, with a porous cellophane layer between the two layers of agar. After incubating for 48-hrs, bacterial spots as well as agar blocks from the lower agar layer corresponding to the spot placement were collected and placed into a 60:40 ratio of methanol and water mixture to be analyzed using Liquid Chromatography Mass Spectrometry (LCMS). This is to determine the role of secreted metabolites in the predation evasion response of P. aeruginosa. We expect to see differential expression of metabolites during predation of M. xanthus on P. aeruginosa in comparison to the control spots. Determining the evasion strategies of this bacterium could lead to the development of alternative methods to combat this pathogen
Academic department under which the project should be listed
CSM - Molecular and Cellular Biology
Primary Investigator (PI) Name
Ramya Rajagopalan
Analysis of Secreted Metabolites During Predation of Myxococcus xanthus on Pseudomonas aeruginosa
Pseudomonas aeruginosa is categorized by the World Health Organization as one of the most multidrug-resistant pathogens in need of control. Myxobacteria is a single-celled predatory soil bacterium and a potential source of novel antibiotics. They are social and seen to hunt in “wolf” packs cooperatively. Under starvation conditions they will aggregate in compact structures filled with spores known as fruiting bodies; only germinating when nutrients become available. In our research group we have shown that Myxococcus xanthus (predator) is able to predate on isolated Pseudomonas aeruginosa (prey) cells. This is supported by our observations in microscopic mixed cell assays using fluorescent tags to track prey cell death. However, a unique resistance response to predation is observed in a population of P. aeruginosa when predator and prey are spotted side-by-side. P. aeruginosa blocks M. xanthus advancement and resists predation. To determine if there are any metabolites associated with the resistance response we performed a side-by-side spot predation assay with M. xanthus and P. aeruginosa. We used a bilayer of partial-starvation agar plates, with a porous cellophane layer between the two layers of agar. After incubating for 48-hrs, bacterial spots as well as agar blocks from the lower agar layer corresponding to the spot placement were collected and placed into a 60:40 ratio of methanol and water mixture to be analyzed using Liquid Chromatography Mass Spectrometry (LCMS). This is to determine the role of secreted metabolites in the predation evasion response of P. aeruginosa. We expect to see differential expression of metabolites during predation of M. xanthus on P. aeruginosa in comparison to the control spots. Determining the evasion strategies of this bacterium could lead to the development of alternative methods to combat this pathogen