MINI REVIEW article

Front. Pharmacol., 15 October 2025

Sec. Translational Pharmacology

Volume 16 - 2025 | https://doi.org/10.3389/fphar.2025.1706115

Mini review: Persister cell control strategies

  • 1. Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, United States

  • 2. Deparment of Biomedical Engineering, University of Tennessee, Knoxville, TN, United States

Abstract

Bacterial persisters are growth-arrested cells with low metabolic activities, but have no genetic mutations compared to their parental cells. The dormant nature of persister cells enables them to tolerate high doses of conventional antibiotics and restart growth after the antibiotic is withdrawn, posing an important challenge to infection control. To promote more research in this important area, we present a concise review of current persister control strategies and discuss future opportunities.

What are persister cells and why are they important?

Persister cells are growth-arrested phenotypic variants found in essentially all bacterial populations (; ). Persisters can form both spontaneously () and triggered by stressors such as pH change (), nutrient limitation (), and antibiotic attack ().

Conventional antibiotics were discovered based on bacterial growth inhibition. These molecules target and corrupt growth associated cellular processes, such as cell wall synthesis, DNA replication, and protein synthesis (). These processes require energy and are rather inactive in dormant persister cells (; ); thus, conventional antibiotics commonly fail to eradicate persisters (). Persister cells play an important role in recalcitrant diseases such as chronic lung infections of cystic fibrosis patients (), medical device-associated infections (), and Lyme disease (Sharma et al., 2015). Persisters also provide a reservoir of cells for the development of antibiotic-resistant strains over time (). Thus, finding effective treatment for persister cells is a necessity for disease control.

In this mini-review, we briefly summarize the current strategies for persister control and discuss our view for future development. As a mini review, it is not a comprehensive overview with in-depth coverage of all related topics, but rather focuses on the principles and future perspectives. We are in debt to the scholars whose work is not cited here due to the limit of its scope.

What strategies have been developed for killing persister cells?

Although persister cells are dormant and tolerant to most conventional antibiotics, persister cells still need to retain cell integrity and a capability to return to normal cells upon favorable changes in the environment. Thus, some targets of antimicrobials are retained in persister cells and new strategies can be developed leveraging unique characteristics of these metabolically dormant cells (Figure 1). The major strategies of persister control are summarized in Table 1 and discussed in the sections below.

FIGURE 1

TABLE 1

StrategyFunctionAdvantagesLimitations
Direct killing of persister cellsCauses cell lysis by disrupting bacterial membranes or degrading proteinsIndependent of bacterial growth state or metabolic activityOff-target toxicity needs to be considered
Inhibiting persister formationAlters bacterial metabolism, or inhibits QSBacteria-specific targets; reduces persister formation and antibiotic toleranceMay not be effective against already-formed persisters
Synergistic killing with antibioticsDisrupts membrane integrity, enhances antibiotic uptake, alters metabolic state of persisters, or leverages other controls, e.g., electrochemical factorsCan eradicate both persister and actively growing bacterial cellsNeeds to be effective across different bacterial species
Exploiting persister dormancyBinds to intracellular targets to kill during wake-up or drives to deeper dormancySpecifically target dormant cellsLimited research; mechanisms not fully understood

Major persister control strategies, advantages, and limitations (see specific sections above for references).

Direct killing

Targeting cell membrane

Direct killing strategies attack growth-independent targets such as the cell membrane to cause cell lysis. Membrane damage can also generate lethal level of reactive oxygen species (ROS), contributing to persister killing (). Multiple agents have shown activities against persister cells or dormant cells in general by directly damaging cell membranes. Some examples include 2D-24 (), AM-0016 (), XF-70 and XF-73 (; ), SA-558 (), thymol triphenylphosphine conjugates (TPP-Thy3) (Tang et al., 2024), and tea tree essential components (). For example, SA-558 is a synthetic cation transporter. It disrupts bacterial homeostasis, leading to autolysis (). Both XF-70 and XF-73 (; ) are effective in killing non-dividing and slow-growing cells of Staphylococcus aureus by disrupting cell membranes. In addition, XF-73 generates ROS upon light activation, which oxidizes essential cellular components as a mechanism of its cidal effects ().

Additionally, synthesized cephalosporin derivatives () and red blood cell membrane-coated nanoparticles (Hb-Naf@RBCM NPs), which incorporate naftifine and oxygenated hemoglobin, effectively kill S. aureus persisters including those in biofilms (Zhu J. et al., 2024). Organo-soluble antimicrobial polymer nanocomposite () and semapimod (an anti-inflammatory drug) (Zheng et al., 2024) also exhibit anti-persister effects. Furthermore, cationic silver nanoparticle shelled nanodroplets (C-AgND) interact with the negatively charged components of the extracellular polymeric substance (EPS) layer, enabling effective killing of S. aureus persisters within biofilms ().

Other targets for direct killing

Pyrazinamide is a prodrug against Mycobacterium tuberculosis persisters. Its active form pyrazinoic acid disrupts membrane energetics, and binds to PanD (essential for coenzyme A biosynthesis) to trigger degradation of PanD by ClpC1-ClpP (; ; )Another example is ADEP4, a semi-synthetic acyldepsipeptide that binds to the ClpP protease and causes conformational changes, enabling ATP-independent protein degradation. This results in breakdown of over 400 intracellular proteins, including metabolic enzymes essential for persister wake-up. Their destruction renders the cells unable to recover and resume growth (; ).

Direct lysis of persisters is an effective approach as it does not require metabolic activities of the target cell. However, if an agent also affects mammalian membranes, it will limit its therapeutic potential due to off-target toxicity (). The field will benefit from more research on persister physiology and discovery of new persister-specific targets.

Indirect killing

Most challenges posed by persister cells stem from their dormant nature. Conceptually, persisters can be eradicated either by preventing cells from entering dormancy or by inducing them to exit the persister state. Once reactivated, these cells become more susceptible to conventional antimicrobials. Alternatively, if a cell enters a deeper dormancy from which it cannot resuscitate, it effectively results in cell death. Exploiting shifts in dormancy depth may also create synergies with other treatments such as antibiotics.

Inhibit persister formation

Although the mechanism of persister formation is still not fully understood, multiple strategies have been shown to reduce persister formation (). For example, the pheromone cCf10 inhibits Enterococcus faecalis persister formation by reducing (p)ppGpp alarmone accumulation and maintaining its metabolically active state (Zhu L. et al., 2024). Another example is potentiation of persister killing using inhibitors of H2S biogenesis. protects bacteria under stress conditions by scavenging free radicals and increasing the activity of antioxidant enzymes (). Bacterial cystathionine g-lyase (bCSE) is the primary generator of H2S in S. aureus and Pseudomonas aeruginosa. CSE inhibitors were found to reduce biofilm formation and the number of persister cells, and potentiate antibiotics against both bacteria (). Additionally, synthetic scavengers were found to sensitize S. aureus, P. aeruginosa, E. coli, and MRSA persisters to gentamicin (Sun et al., 2024).

Also effective in preventing persister formation are nitric oxide (NO) that act as a metabolic disruptor (), and pinaverium bromide (PB) that disrupts PMF and generates ROS (). In addition, some medium-chain saturated fatty acids have been shown to reduce persister formation, e.g., undecanoic acid, lauric acid, and N-tridecanoic acid ().

While persister formation is controlled at the individual cell level, signaling between bacterial cells via quorum sensing (QS) has also been shown to affect persistence. QS is a bacterial cell-cell communication system that regulates multicellular behaviors in response to increase in cell density (). showed that the QS signals phenazine pyocyanin and the N-(3-oxododecanoyl)-L-homoserine lactone increase persister formation in P. aeruginosa by inducing oxidative stress and metabolic changes. Compounds that share a benzamide-benzimidazole backbone were found to bind to the QS regulator MvfR and inhibit MvfR regulon in P. aeruginosa, reducing its persister formation without affecting growth (Starkey et al., 2014; ). Similarly, brominated furanones that are QS inhibitors reduce persister formation in P. aeruginosa ().

Synergy between antibiotics and other factors

Increasing membrane permeability has been shown to sensitize persister cells to antibiotics. For example, MB6-a potent methylazanediyl bisacetamide derivative-and two synthetic retinoids, CD437 and CD1530, bind to and embed in the MRSA lipid bilayer, thereby disrupting membrane integrity and increasing antibiotic uptake. Combined treatment of these compounds with gentamicin showed strong anti-persister activities (; ). Similarly, reported MRSA persister cell killing by cotreatment with gentamicin and membrane active compounds bithionol and nTZDpa. Also functioning through membrane disruption are IMT-P8, a cell-penetrating peptide (Singh and Nandanwar, 2024), polymyxin B nonapeptide (PMBN) (), and the polymyxin B derivative SPR741 (). Moreover, engineered the aminoglycoside antibiotic tobramycin by adding 12 amino acids to convert it to the transporter sequence. The resultant molecule (Pentobra) exhibits strong activities in persister penetration and killing. In addition, gold nanocluster adjuvant, when combined with ofloxacin, could effectively kill persister cells (). This was attributed to the ability of AuNC@CPP to hyperpolarize the cell membrane and disrupt the proton gradient (). Dihydropyrrolidone-thiadiazole disrupts biofilm integrity and cell wall homeostasis by binding to cardiolipin, leading to cell wall disruption. Consistently, it showed synergistic effects with daptomycin in persister killing (Xiong et al., 2024).

Another strategy is to combine multiple antibiotics to eradicate persisters. Colistin paired with either aminoglycosides or ciprofloxacin is effective against persisters of E. coli, K. pneumoniae, and A. baumannii. Colistin is able to disrupt the outer membrane and then facilitate penetration of other antibiotics and increase their lethality (; ).

Besides membrane disruption, antimicrobials can gain more penetration by manipulating membrane channels. An example is felodipine, an FDA approved dihydropyridine class of calcium channel blocker, which has low cytotoxicity to mammalian cells. When combined with gentamicin, the treatment dissipates MRSA membrane potential and increases cell membrane permeability. Additionally, felodipine reduces the TCA cycle and expression of aminoglycoside resistance proteins such as AacA-AphD. These led to killing MRSA persisters and biofilm cells in a mouse model (Zhang et al., 2022).

Disruption of proton motive force (PMF) also hinders efflux pump activities and increases the accumulation of certain antibiotics (). One example is econazole, an FDA approved drug that dissipates the PMF and kills persister cells when used in combination with ampicillin, gentamycin, or ciprofloxacin. Cotreatment with econazole and ceftazidime was also found to kill tolerant bacterial populations in vivo (Wang et al., 2022). Additionally, exogenous adenosine and/or guanosine were found to increase accumulation of tetracycline in Vibrio splendidus persister cells, and cause cell death during the wake-up phase ().

Contrary to the approaches to reduce membrane integrity and PMF, increase in PMF and ATP could also reduce bacterial tolerance to antibiotics by increasing membrane energetics. Higher PMF, in addition to promoting the production of ROS, powers the uptake of antibiotics, especially the aminoglycosides, increasing their lethality (). Compounds such as fumarate (; ), n-Butanol (), small molecule SA-558 (), L-lysine () have anti-persister effects through increased antibiotic uptake. It is important to note that for the approaches that increase bacterial energetics, caution should be taken so that bacteria do not resume full growth and overpower the antimicrobials and the host immune system.

Other mechanisms of synergy in persister killing

Besides chemical agents, hypoionic shock physically disrupts the cytoplasmic membrane, leading to activation of mechanosensitive channels. If effective antibiotics are applied during this process, it can result in substantial killing of persister cells (). In addition, low level electric currents have been found to increase persister killing by antibiotics. Electric currents can depolarize the cell membrane and facilitate passive diffusion of ions and antibiotics to persister cells (; ; ; Wang et al., 2020); Non-transducing phages have also been found to work in synergy with ciprofloxacin and ampicillin against cultures of uropathogenic E. coli (Vera-Mansilla et al., 2023).

Leveraging the dormant nature of persister cells

Persisters are metabolically dormant and thus have reduced efflux activities. We reported recently that the agents capable of penetrating persister cells by passive diffusion can kill persister during wake up if the intracellular targets are available and if target binding is strong (). These criteria can help guide the rational search for persister control agents. One example that fits these criteria is eravacycline, which is an amphiphilic antibiotic from the tetracycline family. It can enter persister cells through passive diffusion. Interestingly, it is more effective against persister cells than normal cells. This was attributed to the reduction of efflux in persister cells (). Using eravacycline as a lead, we recently searched a small antimicrobial compound library with a chemoinformatic model. It is encouraging that 5 out of 11 candidate compounds identified through clustering are effective against persister cells (). These findings provide helpful insights for finding new agents.

Drive persister to deeper dormancy states

Previous research suggested that persisters and the viable but non-culturable (VBNC) state are not distinct, but rather stages along a dormancy spectrum (). A key driver of the transition from dormant persistence to difficult-to-resuscitate VBNC is protein aggregation during nutrient starvation (). Thus, persister control may be achieved by driving cells to a deeper dormancy state like VBNC (Zhou et al., 2023). With more in-depth studies carried out in future, this could have major implications for antibiotic treatment strategies, chronic infection management and resuscitation protocols in the field. For example, it was found that lactate dehydrogenase (involved in pyruvate metabolism) promotes resuscitation of E. coli VBNCs, and cells with enhanced oxidative stress defense were more likely to resuscitate (Wagley et al., 2021). Finding new strategies/control agents that can stop VBNCs from resuscitation and/or going to deeper dormancy will also kill persisters. This is still a largely unexplored area.

How to find better persister control agents?

Since persister cells are growth arrested, the search for persister killing agents should be focused on targets independent of metabolic activities. This requires new knowledge and strategies to identify these targets and new leads.

Artificial intelligence (AI) and machine learning (ML) are quickly transforming drug discovery and have been used in searching for better persister control agents (Wan et al., 2024; Zheng et al., 2024). AI, particularly deep learning models, enables researchers to efficiently screen millions of chemical compounds for antibacterial activities in a fraction of the time required by traditional methods. For example, large chemical libraries with more than 107 million molecules have been screened, leading to the discovery of new antibiotics including halicin (Stokes et al., 2020). In addition, deep learning-powered virtual screens were successfully applied to search for new agents against metabolically dormant bacteria, e.g., semapimod (Zheng et al., 2024). There is no doubt that the field will see more applications of AI models to accelerate both drug screening and the development of new models.

To better combat persistent infections, there are also needs for changes in drug discovery strategies. For persister control, this requires a shift from conventional MIC based screening to more specific targets in dormant cells. It is important to identify predictors for persister penetration, target binding, and killing activities based on new mechanisms. One method to gaining significant knowledge is the utilization of microfluidic platforms to isolate and manipulate individual bacterial cells in controlled environments (). Integrating AI can automate imaging and predict cell fate, streamlining key steps in drug discovery.

To identify new targets in persister cells, we must obtain an in-depth understanding of persister formation mechanism and the true physiological stage of persister cells. There have been significant debates about the molecular mechanism of persister formation, which is partially attributed to the lack of robust methods to obtain persister cells in large quantities and the capability to separate the effects of persister formation itself from the effects of inducers applied to trigger persister formation. Heterogeneity in persister populations and the stochastic nature of formation is another challenge, which can possibly be solved by new persister isolation protocols and new technologies such as single cell RNAseq (Yan et al., 2024). To better eradicate persister cells, the drug of choice needs to bind the target strongly to overcome dormancy related slow killing kinetics. This can be achieved by modifying the drug molecule for stronger targeting including covalent binding. However, because these molecules are more active, the activity of the lead and possibility of undesired side effects must be carefully considered.

The field also need to address challenges in clinical translation of persister-targeting strategies. A central hurdle revolves around drug delivery of candidate compounds to niches where persisters reside, typically within biofilms (Wood et al., 2013), host tissues, or intracellularly within immune cells (). Off-target toxicity is also a concern if the target is not bacteria specific and/or a high dosage of treatment agent is needed. Regulatory considerations may introduce further complexities such as fitting persister therapies within existing approved frameworks or introducing new regulations to fit the relapse and chronic nature of persistent infections (). Addressing these barriers is essential to moving persister therapies from the bench into clinical practice.

By exploiting the predictive power and speed of artificial intelligence and new biotech tools, scientists are now able to discover anti-persister drugs more efficiently. This marks a significant step forward in the global effort to develop the next-generation therapeutics for persistent infections.

Statements

Author contributions

MH: Conceptualization, Data curation, Methodology, Project administration, Visualization, Writing – original draft, Writing – review and editing. YDK: Conceptualization, Methodology, Validation, Writing – original draft, Writing – review and editing. DR: Conceptualization, Data curation, Formal Analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing – review and editing.

Funding

The author(s) declare that financial support was received for the research and/or publication of this article. The research in Ren lab is supported by the U.S. National Institutes of Health (1R01EB030621, 1R21AI185651).

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The author(s) declare that no Generative AI was used in the creation of this manuscript.

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References

Summary

Keywords

persister bacteria, antibiotic, antibiotic persistence, combination therapy, AI-driven drug discovery

Citation

Hashemi MJ, Dhaouadi Khattab Y and Ren D (2025) Mini review: Persister cell control strategies. Front. Pharmacol. 16:1706115. doi: 10.3389/fphar.2025.1706115

Received

15 September 2025

Accepted

07 October 2025

Published

15 October 2025

Volume

16 - 2025

Edited by

Jessica Amber Jennings, University of Memphis, United States

Reviewed by

Butool Durrani, University of Minnesota Twin Cities, United States

Updates

Copyright

*Correspondence: Dacheng Ren,

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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