Molecular physiological characterization of the dynamics of persister formation inStaphylococcus aureus

Abstract

Bacteria possess the ability to enter a growth arrested state known as persistence in order to survive antibiotic exposure. Clinically, persisters are regarded as the main causative agents for chronic and recurrent infectious diseases. To combat this antibiotic-tolerant population, a better understanding of the molecular physiology of persisters is required. In this study, we collected samples at different stages of the biphasic kill curve to reveal the dynamics of the cellular molecular changes that occur in the process of persister formation. After exposure to antibiotics with different modes of action, namely vancomycin and enrofloxacin, similar persister levels were obtained. Both shared and distinct stress responses were enriched for the respective persister populations. However, the dynamics of the presence of proteins linked to the persister phenotype throughout the biphasic kill curve and the molecular profiles in a stable persistent population did show large differences depending on the antibiotic used. This suggests that persisters at the molecular level are highly stress specific, emphasizing the importance of characterizing persisters generated under different stress conditions. Additionally, although generated persisters exhibited cross-tolerance toward tested antibiotics, combined therapies were demonstrated to be a promising approach to reduce persister levels. In conclusion, this investigation sheds light on the stress-specific nature of persisters, highlighting the necessity of tailored treatment approaches and the potential of combined therapy. Importance: By monitoring proteome and metabolites during Staphylococcus aureus persister formation under vancomycin and enrofloxacin exposure, we revealed the dynamic information of the molecular physiology of persister formation upon exposure to two different antibiotics with different modes of action. The data shows that cells that phenotypically are similarly classified as persisters, do have several molecular characteristics in common but, remarkably so, differ substantially in a significant number of other aspects of their molecular makeup. These contrasts provided valuable insights into persister eradication, which holds considerable clinical relevance.

A high-throughput assay identifies molecules with antimicrobial activity against persister cells

“…By arresting growth, slowing metabolism and activating protective mechanisms, persister cells tolerate extremely high concentrations of antibiotics because antibiotics typically target processes involved in growth or require a certain level of metabolic activity to exert their antimicrobial effect [9][10][11]. Furthermore, it has been hypothesized that the molecular mechanism of persister formation is stress-specific and that there is not one global mechanism [12]. The persister phenotype is often associated with bacterial biofilms, where persister cells exist as a sub-population.…”