Relationship analysis between molecular mechanisms of persister formation and environmental stress

When bacterial population is exposed to antibiotics, only small subpopulation could survive and cause the recurrence of infections. Surviving persisters are different from antibiotic resistant mutant, because their tolerances arise from phenotypic variants. This phenotypic heterogeneity provides population with advantageous properties to prevent the extinction. From previous research, mechanisms of persister formation are highly redundant and they are influenced by growth phase, stressed environment, and immune system. In order to investigate persister, we developed a marker for E.coli persisters, and identified novel gene expression which leads to switch into the persister phenotype. Although the gene knockdown decreased persister level at exponential phase in LB medium, it was not reproduced in stressed conditions. The objective of this project is to reveal relationships between stressed conditions and mechanisms of persister formation.