Investigating the Metabolic Mechanisms of Bacterial Persistence
Abstract
Bacterial persisters comprise a small population of bacteria that temporarily cease to replicate allowing them to survive antibiotic treatment. Persisters do not arise from genetic mutation; rather they exist as phenotypic variants. While numerous studies have elucidated the pathways and metabolic steps that lead to a persister phenotype, little is known about the metabolism of persisters OJice they are "switched" into this state. The objective of this proposal is to study the persister metabolic program in E.coli. This study will specifically elucidate the metabolic steps that lead to persister formation, the metabolic state of persisters during stasis, and the metabolic steps that exist once persisters are reactivated to normal growth. Ultimately, the goal of this project is to sufficiently understand the metabolic program of persisters so that rational means can be developed to sabotage the program. There are a number of different genetic loci in E.coli that comprise coupled toxin-antitoxin (TA) systems that provide effectors that can drive the stochastic switch from a normal to persister state. Entry into persistence is marked by accumulation of free toxin. In this study, three mechanistically-distinct model persisters will be employed to examine the breadth and robustness of the persister metabolic program. To generate model persisters, strains have been constructed that allow controlled orthogonal induction of toxins and antitoxins (entry into persistence will be initiated by toxin accumulation and exit from persister state by induction of antitoxin). To meet the objectives of the proposal, extra- and intracellular metabolite levels, enzyme activities, and protein levels will be measured. The data will be analyzed in the context of the metabolic network and with the use of genetics, targeted events of the metabolic program will be perturbed and assessed for their impact on persistence. Particular attention will be paid to those steps in the metabolic pathway important to all three model persisters as they will likely provide the potential as broad spectrum anti-persister targets.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510173
Entities
People
- Mark Brynildsen
Organizations
- Army Contracting Command
- Princeton University
- United States Army