Conditions that Determine the Induction of the Predation Resistance in Pseudomonas aeruginosa
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 cells when the predator and prey are spotted side-by-side. P. aeruginosa blocks Myxococcal advancement and resists predation. To determine the spatial conditions where the resistance response is induced, we performed assays where predator and prey cells were spotted on agar surface in different orientations. A 10-fold reduction was observed in prey cell counts when spatial constraints prevented prey cells from mounting a resistance response, suggesting coordinated behavior. Previous data collected observed that mutated strains of certain Quorum Sensing pathways are unable to mount a similar resistance response, suggesting a key role for Quorum Sensing in predation resistance. To verify this hypothesis, we will perform differential gene expression analysis using qRT-PCR under predation and solitary conditions. This information could potentially lead to alternative ways to counter the infectious Pseudomonas aeruginosa.
Academic department under which the project should be listed
CSM - Molecular and Cellular Biology
Primary Investigator (PI) Name
Ramya Rajagopalan
Conditions that Determine the Induction of the Predation Resistance in 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 cells when the predator and prey are spotted side-by-side. P. aeruginosa blocks Myxococcal advancement and resists predation. To determine the spatial conditions where the resistance response is induced, we performed assays where predator and prey cells were spotted on agar surface in different orientations. A 10-fold reduction was observed in prey cell counts when spatial constraints prevented prey cells from mounting a resistance response, suggesting coordinated behavior. Previous data collected observed that mutated strains of certain Quorum Sensing pathways are unable to mount a similar resistance response, suggesting a key role for Quorum Sensing in predation resistance. To verify this hypothesis, we will perform differential gene expression analysis using qRT-PCR under predation and solitary conditions. This information could potentially lead to alternative ways to counter the infectious Pseudomonas aeruginosa.