Novel Collective Prey Evasion Response of Pseudomonas Aeruginosa PAO1 to Soil Micropredator Myxococcus Xanthus DK1622
Disciplines
Bacteriology | Integrative Biology | Other Microbiology
Abstract (300 words maximum)
The search for alternative therapeutics is on the rise because of the threat of multi-drug resistant bacteria. Looking at the hunting strategy of soil based bacterial micropredators is one avenue of exploration. Myxobacteria are soil predators with a wide prey range including Gram-negative and Gram-positive bacteria, fungi, and archaea. We discovered a distinct and novel predation evasion behavior in Pseudomonas aeruginosa PAO1. P. aeruginosa is an opportunistic and nosocomial pathogen responsible for 10% of all hospital acquired infections. P. aeruginosa is part of the ESKAPE group, which are leading causes of nosocomial infections throughout the world, and they are often multi-drug resistant. When standardized concentrations of Myxococcus xanthus DK1622 and prey were spotted on partial starvation media, most prey displayed a three-log reduction in surviving cell counts following 48 hours of myxobacterial predation. However, under the same conditions PAO1 showed no reduction in surviving cells when compared to non-predation controls. Concurrently, we observed a retreat of prey cells at the junction between advancing M. xanthus front and the PAO1 spot, resembling a “fold.” This distinct evasion response was not observed in another P. aeruginosa strain, PA14, nor in other closely related pseudomonads we tested. We also observed a multi-log reduction in prey cell counts of the pseudomonads following myxococcal predation, indicating that the flight response might be linked to successful predation evasion. Various mutants of the quorum sensing (QS) operon in PAO1 displayed aberrant phenotypes of this evasion response in crude predation assays. We will conduct standardized predation assays of the strains to more thoroughly investigate the link between certain QS and motility pathways in successful predation evasion. We will subsequently create knockout mutants in select regulatory pathways based on these results. We hope that this will eventually lead to the discovery of alternative pathways to better control and eradicate Pseudomonas aeruginosa infections.
Academic department under which the project should be listed
CSM - Molecular and Cellular Biology
Primary Investigator (PI) Name
Ramya Rajagopalan
Novel Collective Prey Evasion Response of Pseudomonas Aeruginosa PAO1 to Soil Micropredator Myxococcus Xanthus DK1622
The search for alternative therapeutics is on the rise because of the threat of multi-drug resistant bacteria. Looking at the hunting strategy of soil based bacterial micropredators is one avenue of exploration. Myxobacteria are soil predators with a wide prey range including Gram-negative and Gram-positive bacteria, fungi, and archaea. We discovered a distinct and novel predation evasion behavior in Pseudomonas aeruginosa PAO1. P. aeruginosa is an opportunistic and nosocomial pathogen responsible for 10% of all hospital acquired infections. P. aeruginosa is part of the ESKAPE group, which are leading causes of nosocomial infections throughout the world, and they are often multi-drug resistant. When standardized concentrations of Myxococcus xanthus DK1622 and prey were spotted on partial starvation media, most prey displayed a three-log reduction in surviving cell counts following 48 hours of myxobacterial predation. However, under the same conditions PAO1 showed no reduction in surviving cells when compared to non-predation controls. Concurrently, we observed a retreat of prey cells at the junction between advancing M. xanthus front and the PAO1 spot, resembling a “fold.” This distinct evasion response was not observed in another P. aeruginosa strain, PA14, nor in other closely related pseudomonads we tested. We also observed a multi-log reduction in prey cell counts of the pseudomonads following myxococcal predation, indicating that the flight response might be linked to successful predation evasion. Various mutants of the quorum sensing (QS) operon in PAO1 displayed aberrant phenotypes of this evasion response in crude predation assays. We will conduct standardized predation assays of the strains to more thoroughly investigate the link between certain QS and motility pathways in successful predation evasion. We will subsequently create knockout mutants in select regulatory pathways based on these results. We hope that this will eventually lead to the discovery of alternative pathways to better control and eradicate Pseudomonas aeruginosa infections.