1
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Niu H, Gu J, Zhang Y. Bacterial persisters: molecular mechanisms and therapeutic development. Signal Transduct Target Ther 2024; 9:174. [PMID: 39013893 PMCID: PMC11252167 DOI: 10.1038/s41392-024-01866-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 05/06/2024] [Accepted: 05/13/2024] [Indexed: 07/18/2024] Open
Abstract
Persisters refer to genetically drug susceptible quiescent (non-growing or slow growing) bacteria that survive in stress environments such as antibiotic exposure, acidic and starvation conditions. These cells can regrow after stress removal and remain susceptible to the same stress. Persisters are underlying the problems of treating chronic and persistent infections and relapse infections after treatment, drug resistance development, and biofilm infections, and pose significant challenges for effective treatments. Understanding the characteristics and the exact mechanisms of persister formation, especially the key molecules that affect the formation and survival of the persisters is critical to more effective treatment of chronic and persistent infections. Currently, genes related to persister formation and survival are being discovered and confirmed, but the mechanisms by which bacteria form persisters are very complex, and there are still many unanswered questions. This article comprehensively summarizes the historical background of bacterial persisters, details their complex characteristics and their relationship with antibiotic tolerant and resistant bacteria, systematically elucidates the interplay between various bacterial biological processes and the formation of persister cells, as well as consolidates the diverse anti-persister compounds and treatments. We hope to provide theoretical background for in-depth research on mechanisms of persisters and suggest new ideas for choosing strategies for more effective treatment of persistent infections.
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Affiliation(s)
- Hongxia Niu
- School of Basic Medical Science and Key Laboratory of Blood-stasis-toxin Syndrome of Zhejiang Province, Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China
| | - Jiaying Gu
- School of Basic Medical Science and Key Laboratory of Blood-stasis-toxin Syndrome of Zhejiang Province, Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China
| | - Ying Zhang
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003, Zhejiang, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250022, Shandong, China.
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2
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Zhu L, Yang X, Fu X, Yang P, Lin X, Wang F, Shen Z, Wang J, Sun F, Qiu Z. Pheromone cCF10 inhibits the antibiotic persistence of Enterococcus faecalis by modulating energy metabolism. Front Microbiol 2024; 15:1408701. [PMID: 39040910 PMCID: PMC11260814 DOI: 10.3389/fmicb.2024.1408701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/24/2024] [Indexed: 07/24/2024] Open
Abstract
Introduction Bacterial resistance presents a major challenge to both the ecological environment and human well-being, with persistence playing a key role. Multiple studies were recently undertaken to examine the factors influencing the formation of persisters and the underlying process, with a primary focus on Gram-negative bacteria and Staphylococcus aureus (Gram-positive bacteria). Enterococcus faecalis (E. faecalis) is capable of causing a variety of infectious diseases, but there have been few studies of E. faecalis persisters. Previous studies have shown that the sex pheromone cCF10 secreted by E. faecalis induces conjugative plasmid transfer. However, whether the pheromone cCF10 regulates the persistence of E. faecalis has not been investigated. Methods As a result, we investigated the effect and potential molecular mechanism of pheromone cCF10 in regulating the formation of persisters in E. faecalis OG1RF using a persistent bacteria model. Results and discussion The metabolically active E. faecalis OG1RF reached a persistence state and temporarily tolerated lethal antibiotic concentrations after 8 h of levofloxacin hydrochloride (20 mg/mL) exposure, exhibiting a persistence rate of 0.109 %. During the growth of E. faecalis OG1RF, biofilm formation was a critical factor contributing to antibiotic persistence, whereas 10 ng/mL cCF10 blocked persister cell formation. Notably, cCF10 mediated the antibiotic persistence of E. faecalis OG1RF via regulating metabolic activity rather than suppressing biofilm formation. The addition of cCF10 stimulated the Opp system and entered bacterial cells, inhibiting (p)ppGpp accumulation, thus maintaining the metabolically active state of bacteria and reducing persister cell generation. These findings offer valuable insights into the formation, as well as the control mechanism of E. faecalis persisters.
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Affiliation(s)
- Li Zhu
- School of Environmental and Chemical Engineering, Xi’an Polytechnic University, Xi’an, China
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xiaobo Yang
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Xinyue Fu
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
- College of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai, China
| | - Panpan Yang
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
- School of Public Health, North China University of Science and Technology, Tangshan, China
| | - Xiaoli Lin
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
- Key Laboratory of Karst Geological Resources and Environment, Guizhou University, Guizhou, China
| | - Feng Wang
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
- College of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai, China
| | - Zhiqiang Shen
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Jingfeng Wang
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
| | - Feilong Sun
- School of Environmental and Chemical Engineering, Xi’an Polytechnic University, Xi’an, China
| | - Zhigang Qiu
- Key Laboratory of Risk Assessment and Control for Environment and Food Safety, Tianjin Institute of Environmental and Operational Medicine, Tianjin, China
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Hirsch P, Molano LA, Engel A, Zentgraf J, Rahmann S, Hannig M, Müller R, Kern F, Keller A, Schmartz G. Mibianto: ultra-efficient online microbiome analysis through k-mer based metagenomics. Nucleic Acids Res 2024; 52:W407-W414. [PMID: 38716863 PMCID: PMC11223814 DOI: 10.1093/nar/gkae364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/03/2024] [Accepted: 04/24/2024] [Indexed: 07/06/2024] Open
Abstract
Quantifying microbiome species and composition from metagenomic assays is often challenging due to its time-consuming nature and computational complexity. In Bioinformatics, k-mer-based approaches were long established to expedite the analysis of large sequencing data and are now widely used to annotate metagenomic data. We make use of k-mer counting techniques for efficient and accurate compositional analysis of microbiota from whole metagenome sequencing. Mibianto solves this problem by operating directly on read files, without manual preprocessing or complete data exchange. It handles diverse sequencing platforms, including short single-end, paired-end, and long read technologies. Our sketch-based workflow significantly reduces the data volume transferred from the user to the server (up to 99.59% size reduction) to subsequently perform taxonomic profiling with enhanced efficiency and privacy. Mibianto offers functionality beyond k-mer quantification; it supports advanced community composition estimation, including diversity, ordination, and differential abundance analysis. Our tool aids in the standardization of computational workflows, thus supporting reproducibility of scientific sequencing studies. It is adaptable to small- and large-scale experimental designs and offers a user-friendly interface, thus making it an invaluable tool for both clinical and research-oriented metagenomic studies. Mibianto is freely available without the need for a login at: https://www.ccb.uni-saarland.de/mibianto.
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Affiliation(s)
- Pascal Hirsch
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
| | | | - Annika Engel
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
| | - Jens Zentgraf
- Algorithmic Bioinformatics, Center for Bioinformatics Saar and Saarland University, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Saarbrücken Graduate School of Computer Science, Saarland Informatics Campus, 66123 Saarbrücken, Germany
| | - Sven Rahmann
- Algorithmic Bioinformatics, Center for Bioinformatics Saar and Saarland University, Saarland Informatics Campus, 66123 Saarbrücken, Germany
| | - Matthias Hannig
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, Saarland University Hospital, Saarland University, Kirrberger Str. 100, Building 73, 66421 Homburg, Saar, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, 66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), Standort Hannover-Braunschweig, 38124 Braunschweig, Germany
- PharmaScienceHub, 66123 Saarbrücken, Germany
| | - Fabian Kern
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, 66123 Saarbrücken, Germany
| | - Andreas Keller
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, 66123 Saarbrücken, Germany
- PharmaScienceHub, 66123 Saarbrücken, Germany
| | - Georges P Schmartz
- Chair for Clinical Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
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Méndez LR, Rodríguez-Cornejo T, Rodríguez-Ramos T, Al-Hussinee L, Velázquez J, Campbell JH, Carpio Y, Estrada MP, Dixon B. PACAP sequence modifications modulate the peptide antimicrobial activity against bacterial pathogens affecting aquaculture. FISH & SHELLFISH IMMUNOLOGY 2024; 148:109512. [PMID: 38499216 DOI: 10.1016/j.fsi.2024.109512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/05/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
The global aquaculture industry has significant losses each year due to disease outbreaks. Antibiotics are one of the common methods to treat fish infections, but prolonged use can lead to the emergence of resistant strains. Aeromonas spp. Infections are a common and problematic disease in fish, and members of this genera can produce antibiotic resistant strains. Antimicrobial peptides (AMPs) have emerged as an alternative method to treat and prevent infections and pituitary adenylate cyclase activating polypeptide (PACAP) is a prominent member of this family. The objective of this research was to study PACAP's direct antimicrobial activity and its toxicity in fish cells. Four synthetic variants of the natural PACAP from Clarias gariepinus were tested in addition to the natural variant. The experimental results show a different antimicrobial activity against A. salmonicida and A. hydrophila of each PACAP variant, and for the first time show dependence on the culture broth used. Furthermore, the results suggest that the underlying mechanism of PACAP antimicrobial activity includes a bacterial membrane permeabilizing effect, classifying PACAP as a membrane disruptive AMP. This study also demonstrated that the five PACAP variants evaluated showed low toxicity in vitro, at concentrations relevant for in vivo applications. Therefore, PACAP could be a promising alternative to antibiotics in the aquaculture sector.
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Affiliation(s)
- Laura Rivera Méndez
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | | | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Lowia Al-Hussinee
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada; Animal Health Laboratory, OVC, Guelph University, Canada
| | - Janet Velázquez
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - James Hugh Campbell
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Yamila Carpio
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - Mario Pablo Estrada
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada.
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5
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Dadole I, Blaha D, Personnic N. The macrophage-bacterium mismatch in persister formation. Trends Microbiol 2024:S0966-842X(24)00049-0. [PMID: 38443279 DOI: 10.1016/j.tim.2024.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
Many pathogens are hard to eradicate, even in the absence of genetically detectable antimicrobial resistance mechanisms and despite proven antibiotic susceptibility. The fraction of clonal bacteria that temporarily elude effective antibiotic treatments is commonly known as 'antibiotic persisters.' Over the past decade, there has been a growing body of research highlighting the pivotal role played by the cellular host in the development of persisters. In parallel, this research has also sought to elucidate the molecular mechanisms underlying the formation of intracellular antibiotic persisters and has demonstrated a prominent role for the bacterial stress response. However, questions remain regarding the conditions leading to the formation of stress-induced persisters among a clonal population of intracellular bacteria and despite an ostensibly uniform environment. In this opinion, following a brief review of the current state of knowledge regarding intracellular antibiotic persisters, we explore the ways in which macrophage functional heterogeneity and bacterial phenotypic heterogeneity may contribute to the emergence of these persisters. We propose that the degree of mismatch between the macrophage permissiveness and the bacterial preparedness to invade and thrive intracellularly may explain the formation of stress-induced nonreplicating intracellular persisters.
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Affiliation(s)
- Iris Dadole
- CIRI - Centre International de Recherche en Infectiologie, CNRS, INSERM, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Group Persistence and single-cell dynamics of respiratory pathogens, CIRI, Lyon, France
| | - Didier Blaha
- CIRI - Centre International de Recherche en Infectiologie, CNRS, INSERM, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Group Persistence and single-cell dynamics of respiratory pathogens, CIRI, Lyon, France
| | - Nicolas Personnic
- CIRI - Centre International de Recherche en Infectiologie, CNRS, INSERM, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Group Persistence and single-cell dynamics of respiratory pathogens, CIRI, Lyon, France.
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6
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Goormaghtigh F, Van Bambeke F. Understanding Staphylococcus aureus internalisation and induction of antimicrobial tolerance. Expert Rev Anti Infect Ther 2024; 22:87-101. [PMID: 38180805 DOI: 10.1080/14787210.2024.2303018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/04/2024] [Indexed: 01/07/2024]
Abstract
INTRODUCTION Staphylococcus aureus, a human commensal, is also one of the most common and serious pathogens for humans. In recent years, its capacity to survive and replicate in phagocytic and non-phagocytic cells has been largely demonstrated. In these intracellular niches, bacteria are shielded from the immune response and antibiotics, turning host cells into long-term infectious reservoirs. Moreover, neutrophils carry intracellular bacteria in the bloodstream, leading to systemic spreading of the disease. Despite the serious threat posed by intracellular S. aureus to human health, the molecular mechanisms behind its intracellular survival and subsequent antibiotic treatment failure remain elusive. AREA COVERED We give an overview of the killing mechanisms of phagocytes and of the impressive arsenal of virulence factors, toxins and stress responses deployed by S. aureus as a response. We then discuss the different barriers to antibiotic activity in this intracellular niche and finally describe innovative strategies to target intracellular persisting reservoirs. EXPERT OPINION Intracellular niches represent a challenge in terms of diagnostic and treatment. Further research using ad-hoc in-vivo models and single cell approaches are needed to better understand the molecular mechanisms underlying intracellular survival and tolerance to antibiotics in order to identify strategies to eliminate these persistent bacteria.
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Affiliation(s)
- Frédéric Goormaghtigh
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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7
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Cotten KL, Davis KM. Bacterial heterogeneity and antibiotic persistence: bacterial mechanisms utilized in the host environment. Microbiol Mol Biol Rev 2023; 87:e0017422. [PMID: 37962348 PMCID: PMC10732018 DOI: 10.1128/mmbr.00174-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023] Open
Abstract
SUMMARYAntibiotic persistence, or the ability of small subsets of bacteria to survive prolonged antibiotic treatment, is an underappreciated cause of antibiotic treatment failure. Over the past decade, researchers have discovered multiple different stress responses and mechanisms that can promote antibiotic persistence. However, many of these studies have been completed in culture-based systems that fail to truly replicate the complexities of the host environment, and it is unclear whether the mechanisms defined in in vitro studies are applicable during host infection. In this review, we focus our discussion on recent studies that utilize a mixture of ex vivo culture systems and animal models to understand what stressors in the host environment are important for inducing antibiotic persistence. Different host stressors are involved depending on the anatomical niche the bacteria reside in and whether the host immune system is primed to generate a more robust response against bacteria, which can result in differing downstream effects on antibiotic susceptibility. Bacterial pathogens can also utilize specific strategies to reprogram their metabolism, which is vital for transitioning into an antibiotic-persistent state within host tissues. Importantly, we highlight that more attention is needed to establish guidelines for in vivo work on antibiotic persistence, particularly when identifying antibiotic-persistent subpopulations and distinguishing these phenotypes from antibiotic tolerance. Studying antibiotic persistence in the context of the host environment will be crucial for developing tools and strategies to target antibiotic-persistent bacteria and increase the efficacy of antibiotic treatment.
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Affiliation(s)
- Katherine L. Cotten
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Kimberly Michele Davis
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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Franzini M, Valdenassi L, Pandolfi S, Tirelli U, Ricevuti G, Chirumbolo S. The Role of Ozone as an Nrf2-Keap1-ARE Activator in the Anti-Microbial Activity and Immunity Modulation of Infected Wounds. Antioxidants (Basel) 2023; 12:1985. [PMID: 38001838 PMCID: PMC10669564 DOI: 10.3390/antiox12111985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Ozone is an allotrope of oxygen, widely known to exert an anti-oxidant potential. The ability of low, controlled and standardized doses of ozone in the ozone adjunct treatment of bacterial infections, which occur in wounds, is engaging clinical research to deepen the role of ozone in eradicating even multidrug-resistant bacteria. Ozone activates the nuclear factor erythroid 2-related factor 2 (Nrf2), and this activation triggers a complex cascade of events, which ultimately leads to macrophage training and an improvement in their ability to operate a clearance of bacteria in the patient's anatomical districts. In this review, we try to elucidate the recent evidence about the mechanisms with which ozone can actually remove bacteria and even multi-drug-resistant (MDR) bacteria, accounting on its complex ability in modulating immunity.
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Affiliation(s)
- Marianno Franzini
- Italian Scientific Society of Oxygen-Ozone Therapy (SIOOT), 24020 Bergamo, Italy; (M.F.); (L.V.); (S.P.)
| | - Luigi Valdenassi
- Italian Scientific Society of Oxygen-Ozone Therapy (SIOOT), 24020 Bergamo, Italy; (M.F.); (L.V.); (S.P.)
| | - Sergio Pandolfi
- Italian Scientific Society of Oxygen-Ozone Therapy (SIOOT), 24020 Bergamo, Italy; (M.F.); (L.V.); (S.P.)
| | | | - Giovanni Ricevuti
- Department of Drug Science, University of Pavia, 27100 Pavia, Italy;
| | - Salvatore Chirumbolo
- Department of Engineering for Innovation Medicine, University of Verona, 37125 Verona, Italy
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9
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Chen E, Shaffer MG, Bilodeau RE, West RE, Oberly PJ, Nolin TD, Culyba MJ. Clinical rel mutations in Staphylococcus aureus prime pathogen expansion under nutrient stress. mSphere 2023; 8:e0024923. [PMID: 37750686 PMCID: PMC10597345 DOI: 10.1128/msphere.00249-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 07/31/2023] [Indexed: 09/27/2023] Open
Abstract
Persistent infection by Staphylococcus aureus has been linked to the bacterial stringent response (SR), a conserved stress response pathway regulated by the Rel protein. Rel synthesizes (p)ppGpp "alarmones" in response to amino acid starvation, which enables adaptation to stress by modulating bacterial growth and virulence. We previously identified five novel protein-altering mutations in rel that arose in patients with persistent methicillin-resistant S. aureus bacteremia. The mutations mapped to both the enzymatic and regulatory protein domains of Rel. Here, we set out to characterize the phenotype of these mutations to understand how they may have been selected in vivo. After introducing each mutation into S. aureus strain JE2, we analyzed growth, fitness, and antibiotic profiles. Despite being located in different protein domains, we found that all of the mutations converged on the same phenotype. Each shortened the time of lag phase growth and imparted a fitness advantage in nutritionally depleted conditions. Through quantification of intracellular (p)ppGpp, we link this phenotype to increased SR activation, specifically during the stationary phase of growth. In contrast to two previously identified clinical rel mutations, we find that our rel mutations do not cause antibiotic tolerance. Instead, our findings suggest that in vivo selection was due to an augmented SR that primes cells for growth in nutrient-poor conditions, which may be a strategy for evading host-imposed nutritional immunity. Importance Host and pathogen compete for available nutrition during infection. For bacteria, the stringent response (SR) regulator Rel responds to amino acid deprivation by signaling the cell to modulate its growth rate, metabolism, and virulence. In this report, we characterize five rel mutations that arose during cases of persistent methicillin-resistant Staphylococcus aureus bacteremia. We find that all of the mutations augmented SR signaling specifically under nutrient-poor conditions, enabling the cell to more readily grow and survive. Our findings reveal a strategy used by bacterial pathogens to evade the nutritional immunity imposed by host tissues during infection.
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Affiliation(s)
- Edwin Chen
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Marla G. Shaffer
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Robert E. Bilodeau
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Raymond E. West
- Small Molecule Biomarker Core, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Patrick J. Oberly
- Small Molecule Biomarker Core, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Thomas D. Nolin
- Small Molecule Biomarker Core, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - Matthew J. Culyba
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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10
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Beam JE, Wagner NJ, Lu KY, Parsons JB, Fowler VG, Rowe SE, Conlon BP. Inflammasome-mediated glucose limitation induces antibiotic tolerance in Staphylococcus aureus. iScience 2023; 26:107942. [PMID: 37790275 PMCID: PMC10543182 DOI: 10.1016/j.isci.2023.107942] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/27/2023] [Accepted: 09/13/2023] [Indexed: 10/05/2023] Open
Abstract
Staphylococcus aureus is a leading human pathogen that frequently causes relapsing infections. The failure of antibiotics to eradicate infection contributes to infection relapse. Host-pathogen interactions have a substantial impact on antibiotic susceptibility and the formation of antibiotic tolerant cells. In this study, we interrogate how a major S. aureus virulence factor, α-toxin, interacts with macrophages to alter the microenvironment of the pathogen, thereby influencing its susceptibility to antibiotics. We find α-toxin-mediated activation of the NLRP3 inflammasome induces antibiotic tolerance. Induction of tolerance is driven by increased glycolysis in the host cells, resulting in glucose limitation and ATP depletion in S. aureus. Additionally, inhibition of NLRP3 activation improves antibiotic efficacy in vitro and in vivo, suggesting that this strategy has potential as a host-directed therapeutic to improve outcomes. Our findings identify interactions between S. aureus and the host that result in metabolic crosstalk that can determine the outcome of antimicrobial therapy.
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Affiliation(s)
- Jenna E. Beam
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikki J. Wagner
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kuan-Yi Lu
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Joshua B. Parsons
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC, USA
| | - Vance G. Fowler
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC, USA
| | - Sarah E. Rowe
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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11
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Freiberg JA, Ruiz VMR, Green ER, Skaar EP. Restriction of Arginine Induces Antibiotic Tolerance in Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.12.561972. [PMID: 37873095 PMCID: PMC10592767 DOI: 10.1101/2023.10.12.561972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Staphylococcus aureus is responsible for a substantial number of invasive infections globally each year. These infections are problematic because they are frequently recalcitrant to antibiotic treatment, particularly when they are caused by Methicillin-Resistant Staphylococcus aureus (MRSA). Antibiotic tolerance, the ability for bacteria to persist despite normally lethal doses of antibiotics, is responsible for most antibiotic treatment failure in MRSA infections. To understand how antibiotic tolerance is induced, S. aureus biofilms exposed to multiple anti-MRSA antibiotics (vancomycin, ceftaroline, delafloxacin, and linezolid) were examined using both quantitative proteomics and transposon sequencing. These screens indicated that arginine metabolism is involved in antibiotic tolerance within a biofilm and led to the hypothesis that depletion of arginine within S. aureus communities can induce antibiotic tolerance. Consistent with this hypothesis, inactivation of argH, the final gene in the arginine synthesis pathway, induces antibiotic tolerance under conditions in which the parental strain is susceptible to antibiotics. Arginine restriction was found to induce antibiotic tolerance via inhibition of protein synthesis. Finally, although S. aureus fitness in a mouse skin infection model is decreased in an argH mutant, its ability to survive in vivo during antibiotic treatment with vancomycin is enhanced, highlighting the relationship between arginine metabolism and antibiotic tolerance during S. aureus infection. Uncovering this link between arginine metabolism and antibiotic tolerance has the potential to open new therapeutic avenues targeting previously recalcitrant S. aureus infections.
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Affiliation(s)
- Jeffrey A. Freiberg
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Valeria M. Reyes Ruiz
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Erin R. Green
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Microbiology, University of Chicago, Chicago, IL 60637
| | - Eric P. Skaar
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
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12
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Bollen C, Louwagie E, Verstraeten N, Michiels J, Ruelens P. Environmental, mechanistic and evolutionary landscape of antibiotic persistence. EMBO Rep 2023; 24:e57309. [PMID: 37395716 PMCID: PMC10398667 DOI: 10.15252/embr.202357309] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/07/2023] [Accepted: 06/16/2023] [Indexed: 07/04/2023] Open
Abstract
Recalcitrant infections pose a serious challenge by prolonging antibiotic therapies and contributing to the spread of antibiotic resistance, thereby threatening the successful treatment of bacterial infections. One potential contributing factor in persistent infections is antibiotic persistence, which involves the survival of transiently tolerant subpopulations of bacteria. This review summarizes the current understanding of antibiotic persistence, including its clinical significance and the environmental and evolutionary factors at play. Additionally, we discuss the emerging concept of persister regrowth and potential strategies to combat persister cells. Recent advances highlight the multifaceted nature of persistence, which is controlled by deterministic and stochastic elements and shaped by genetic and environmental factors. To translate in vitro findings to in vivo settings, it is crucial to include the heterogeneity and complexity of bacterial populations in natural environments. As researchers continue to gain a more holistic understanding of this phenomenon and develop effective treatments for persistent bacterial infections, the study of antibiotic persistence is likely to become increasingly complex.
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Affiliation(s)
- Celien Bollen
- Centre of Microbial and Plant GeneticsKU LeuvenLeuvenBelgium
- Center for Microbiology, VIBLeuvenBelgium
| | - Elen Louwagie
- Centre of Microbial and Plant GeneticsKU LeuvenLeuvenBelgium
- Center for Microbiology, VIBLeuvenBelgium
| | - Natalie Verstraeten
- Centre of Microbial and Plant GeneticsKU LeuvenLeuvenBelgium
- Center for Microbiology, VIBLeuvenBelgium
| | - Jan Michiels
- Centre of Microbial and Plant GeneticsKU LeuvenLeuvenBelgium
- Center for Microbiology, VIBLeuvenBelgium
| | - Philip Ruelens
- Centre of Microbial and Plant GeneticsKU LeuvenLeuvenBelgium
- Center for Microbiology, VIBLeuvenBelgium
- Laboratory of Socioecology and Social EvolutionKU LeuvenLeuvenBelgium
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13
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Ronneau S, Michaux C, Helaine S. Decline in nitrosative stress drives antibiotic persister regrowth during infection. Cell Host Microbe 2023; 31:993-1006.e6. [PMID: 37236190 DOI: 10.1016/j.chom.2023.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 04/01/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023]
Abstract
Internalization of pathogenic bacteria by macrophages results in formation of antibiotic-tolerant persisters. These cells are maintained in a non-growing state for extended periods of time, and it is assumed that their growth resumption causes infection relapse after cessation of antibiotic treatment. Despite this clinical relevance, the signals and conditions that drive persister regrowth during infection are not yet understood. Here, we found that after persister formation in macrophages, host reactive nitrogen species (RNS) produced in response to Salmonella infection lock persisters in growth arrest by intoxicating their TCA cycle, lowering cellular respiration and ATP production. Intracellular persisters resume growth when macrophage RNS production subsides and functionality of their TCA cycle is regained. Persister growth resumption within macrophages is slow and heterogeneous, dramatically extending the time the persister reservoir feeds infection relapse. Using an inhibitor of RNS production, we can force recalcitrant bacteria to regrow during antibiotic treatment, thereby facilitating their eradication.
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Affiliation(s)
- Séverin Ronneau
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Charlotte Michaux
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Sophie Helaine
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
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14
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Schrader SM, Botella H, Vaubourgeix J. Reframing antimicrobial resistance as a continuous spectrum of manifestations. Curr Opin Microbiol 2023; 72:102259. [PMID: 36608373 DOI: 10.1016/j.mib.2022.102259] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 01/06/2023]
Abstract
To fight antimicrobial resistance (AMR), we must recognize and target all its manifestations. In this review, we briefly summarize the history that led to recognition of the various manifestations of AMR in bacterial pathogens and the ways in which they interrelate. We emphasize the importance of distinguishing between AMR arising from genetic alterations versus induction of endogenous machinery in response to environmental triggers, including - paradoxically - stresses from host immunity and antimicrobial therapy. We present an integrated view of AMR by reframing it as a spectrum of phenotypes within a continuous three-dimensional space defined by the growth rate, prevalence, and kill rate of cells displaying AMR. Finally, we reflect on strategies that may help stem the emergence of AMR.
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Affiliation(s)
- Sarah M Schrader
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA
| | - Hélène Botella
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK
| | - Julien Vaubourgeix
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.
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15
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Personnic N, Doublet P, Jarraud S. Intracellular persister: A stealth agent recalcitrant to antibiotics. Front Cell Infect Microbiol 2023; 13:1141868. [PMID: 37065203 PMCID: PMC10102521 DOI: 10.3389/fcimb.2023.1141868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/06/2023] [Indexed: 04/03/2023] Open
Abstract
The bulk of bacteria transiently evading appropriate antibiotic regimes and recovered from non-resolutive infections are commonly refer to as persisters. In this mini-review, we discuss how antibiotic persisters stem from the interplay between the pathogen and the cellular defenses mechanisms and its underlying heterogeneity.
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Affiliation(s)
- Nicolas Personnic
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Persistence and Single-Cell Dynamics of Respiratory Pathogens, Lyon, France
- *Correspondence: Nicolas Personnic,
| | - Patricia Doublet
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Legionella Pathogenesis, Lyon, France
| | - Sophie Jarraud
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Legionella Pathogenesis, Lyon, France
- National Reference Centre for Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France
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16
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Arastehfar A, Daneshnia F, Cabrera N, Penalva-Lopez S, Sarathy J, Zimmerman M, Shor E, Perlin DS. Macrophage internalization creates a multidrug-tolerant fungal persister reservoir and facilitates the emergence of drug resistance. Nat Commun 2023; 14:1183. [PMID: 36864040 PMCID: PMC9981703 DOI: 10.1038/s41467-023-36882-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/22/2023] [Indexed: 03/04/2023] Open
Abstract
Candida glabrata is a major fungal pathogen notable for causing recalcitrant infections, rapid emergence of drug-resistant strains, and its ability to survive and proliferate within macrophages. Resembling bacterial persisters, a subset of genetically drug-susceptible C. glabrata cells can survive lethal exposure to the fungicidal echinocandin drugs. Herein, we show that macrophage internalization induces cidal drug tolerance in C. glabrata, expanding the persister reservoir from which echinocandin-resistant mutants emerge. We show that this drug tolerance is associated with non-proliferation and is triggered by macrophage-induced oxidative stress, and that deletion of genes involved in reactive oxygen species detoxification significantly increases the emergence of echinocandin-resistant mutants. Finally, we show that the fungicidal drug amphotericin B can kill intracellular C. glabrata echinocandin persisters, reducing emergence of resistance. Our study supports the hypothesis that intra-macrophage C. glabrata is a reservoir of recalcitrant/drug-resistant infections, and that drug alternating strategies can be developed to eliminate this reservoir.
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Affiliation(s)
- Amir Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Farnaz Daneshnia
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
- Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, 1012 WX, The Netherlands
| | - Nathaly Cabrera
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Suyapa Penalva-Lopez
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - Jansy Sarathy
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, USA
| | - Matthew Zimmerman
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, USA
| | - Erika Shor
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA.
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, USA.
| | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA.
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, USA.
- Georgetown University Lombardi Comprehensive Cancer Center, Washington, DC, 20057, USA.
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17
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Cho YY, Ko KS. ColE-type plasmid bearing bla OXA-232 increases persister cell formation. J Glob Antimicrob Resist 2023; 32:113-117. [PMID: 36806700 DOI: 10.1016/j.jgar.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/25/2023] [Accepted: 02/05/2023] [Indexed: 02/19/2023] Open
Abstract
OBJECTIVES Bacterial persister cells are a sub-population of cells that are tolerant to high concentrations of antibiotics. In this study, we investigated the effect of plasmids bearing carbapenemase genes on persister cell formation. METHODS Three plasmids, IncX3-type plasmid with blaNDM-1, IncN-type plasmid with blaKPC-2, and ColE-type plasmid with blaOXA-232, were transformed into Escherichia coli MG1655. For the ColE-type plasmid (pM5_OXA232), gene-deletion plasmids were constructed and transformed into the MG1655. Persister assays were performed against ciprofloxacin and amikacin, and expression levels of relA and spoT were measured for the wild-type E. coli and all transformants. RESULTS Unlike the other two plasmids, transformation of ColE-type plasmid (pM5_OXA232) caused a significant increase in the formation of persister cells. Compared with transformants that harboured intact pM5_OXA232, transformants that harboured plasmids with deletions of gene(s), vbhA, hypothetical gene, or a mobile gene cassette showed decreased persister cell formation. Expression levels of relA and spoT exhibited patterns similar to those of persister cell formation rates, particularly against ciprofloxacin. CONCLUSION In this study, we showed that a small ColE-type plasmid bearing blaOXA-232 has an effect on persister cell formation, possibly contributing to the dissemination of low-level carbapanemase.
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Affiliation(s)
- Yun Young Cho
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Kwan Soo Ko
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.
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18
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Lu KY, Wagner NJ, Velez AZ, Ceppe A, Conlon BP, Muhlebach MS. Antibiotic Tolerance and Treatment Outcomes in Cystic Fibrosis Methicillin-Resistant Staphylococcus aureus Infections. Microbiol Spectr 2023; 11:e0406122. [PMID: 36519944 PMCID: PMC9927320 DOI: 10.1128/spectrum.04061-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent in U.S. cystic fibrosis (CF) patients and is associated with worse clinical outcomes in CF. These infections often become chronic despite repeated antibiotic therapy. Here, we assessed whether bacterial phenotypes, including antibiotic tolerance, can predict the clinical outcomes of MRSA infections. MRSA isolates (n = 90) collected at the incident (i.e., acute) and early infection states from 57 patients were characterized for growth rates, biofilm formation, hemolysis, pigmentation, and vancomycin tolerance. The resistance profiles were consistent with those in prior studies. Isolates from the early stage of infection were found to produce biofilms, and 70% of the isolates exhibited delta-hemolysis, an indicator of agr activity. Strong vancomycin tolerance was present in 24% of the isolates but was not associated with intermediate vancomycin susceptibility. There were no associations between these phenotypic measures, antibiotic tolerance, and MRSA clearance. Our research suggests that additional factors may be relevant for predicting the clearance of MRSA. IMPORTANCE Chronic MRSA infections remain challenging to treat in patients with cystic fibrosis (CF). The ability of the bacterial population to survive high concentrations of bactericidal antibiotics, including vancomycin, despite lacking resistance is considered one of the main reasons for treatment failures. The connection between antibiotic tolerance and treatment outcomes remains unexplored and can be crucial for prognosis and regimen design toward eradication. In this study, we measured the capacity of 90 MRSA isolates from CF patients to form vancomycin-tolerant persister cells and evaluated their correlation with the clinical outcomes. Additionally, various traits that could reflect the metabolism and/or virulence of those MRSA isolates were systematically phenotyped and included for their predictive power. Our research highlights that despite the importance of antibiotic tolerance, additional factors need to be considered for predicting the clearance of MRSA.
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Affiliation(s)
- Kuan-Yi Lu
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Nikki J. Wagner
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Amanda Z. Velez
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Agathe Ceppe
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Marianne S. Muhlebach
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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19
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Meredith EM, Harven LT, Berti AD. Antimicrobial Efficacy against Antibiotic-Tolerant Staphylococcus aureus Depends on the Mechanism of Antibiotic Tolerance. Antibiotics (Basel) 2022; 11:antibiotics11121810. [PMID: 36551467 PMCID: PMC9774428 DOI: 10.3390/antibiotics11121810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/22/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022] Open
Abstract
Bacteria can adapt to a changing environment by adopting alternate metabolic states favoring small molecule synthesis and resilience over growth. In Staphylococcus aureus, these states are induced by factors present during infection, including nutritional limitations, host responses and competition with other bacteria. Isogenic "tolerant" populations have variable responses to antibiotics and can remain viable. In this study, we compared the capability of antibiotics to reduce the viability of S. aureus made tolerant by different mechanisms. Tolerance was induced with mupirocin, HQNO, peroxynitrite or human serum. Tolerant cultures were exposed to ceftaroline, daptomycin, gentamicin, levofloxacin, oritavancin or vancomycin at physiological concentrations, and the viability was assessed by dilution plating. The minimum duration for 3-log viability reduction and 24 h viability reduction were calculated independently for each of three biological replicates. Each tolerance mechanism rendered at least one antibiotic ineffective, and each antibiotic was rendered ineffective by at least one mechanism of tolerance. Further studies to evaluate additional antibiotics, combination therapy and different tolerance inducers are warranted.
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Affiliation(s)
- Emily M. Meredith
- Department of Pharmacy Practice, College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Lauren T. Harven
- Department of Pharmacy Practice, College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Andrew D. Berti
- Department of Pharmacy Practice, College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, Wayne State University, Detroit, MI 48201, USA
- Correspondence: ; Tel.: +1-313-577-3565
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20
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Intracellular Habitation of Staphylococcus aureus: Molecular Mechanisms and Prospects for Antimicrobial Therapy. Biomedicines 2022; 10:biomedicines10081804. [PMID: 36009351 PMCID: PMC9405036 DOI: 10.3390/biomedicines10081804] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections pose a global health threat, especially with the continuous development of antibiotic resistance. As an opportunistic pathogen, MRSA infections have a high mortality rate worldwide. Although classically described as an extracellular pathogen, many studies have shown over the past decades that MRSA also has an intracellular aspect to its infectious cycle, which has been observed in vitro in both non-professional as well as professional phagocytes. In vivo, MRSA has been shown to establish an intracellular niche in liver Kupffer cells upon bloodstream infection. The staphylococci have evolved various evasion strategies to survive the antimicrobial environment of phagolysosomes and use these compartments to hide from immune cells and antibiotics. Ultimately, the host cells get overwhelmed by replicating bacteria, leading to cell lysis and bacterial dissemination. In this review, we describe the different intracellular aspects of MRSA infection and briefly mention S. aureus evasion strategies. We discuss how this intracellular niche of bacteria may assist in antibiotic tolerance development, and lastly, we describe various new antibacterial strategies that target the intracellular bacterial niche.
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21
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Beam JE, Maiocchi S, Cartaya A, Rowe SE, Bahnson ESM, Conlon BP. The Use of Acute Immunosuppressive Therapy to Improve Antibiotic Efficacy against Intracellular Staphylococcus aureus. Microbiol Spectr 2022; 10:e0085822. [PMID: 35575507 PMCID: PMC9241675 DOI: 10.1128/spectrum.00858-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/16/2022] [Indexed: 12/28/2022] Open
Abstract
Interactions between Staphylococcus aureus and the host immune system can have significant impacts on antibiotic efficacy, suggesting that targeting and modulating the immune response to S. aureus infection may improve antibiotic efficacy and improve infection outcome. As we've previously shown, high levels of reactive oxygen species (ROS), associated with an M1-like proinflammatory macrophage response, potently induce antibiotic tolerance in S. aureus. Although the proinflammatory immune response is critical for initial control of pathogen burden, recent studies demonstrate that modulation of the macrophage response to an anti-inflammatory, or M2-like, response facilitates resolution of established S. aureus skin and soft tissue infections, arthritis, and bacteremia. Here, we evaluated the impact of host-directed immunosuppressive chemotherapeutics and anti-inflammatory agents on antibiotic efficacy against S. aureus. IMPORTANCE Staphylococcus aureus is the leading cause of hospital-acquired infections in the United States with high rates of antibiotic treatment failure. Macrophages represent an important intracellular niche in experimental models of S. aureus bacteremia. Although a proinflammatory macrophage response is critical for controlling infection, previous studies have identified an antagonistic relationship between antibiotic treatment and the proinflammatory macrophage response. Reactive oxygen species, produced by macrophages during respiratory burst, coerce S. aureus into an antibiotic tolerant state, leading to poor treatment outcome. Here, we aimed to determine the potential of host-directed immunomodulators that reduce the production of reactive oxygen species to improve antibiotic efficacy against intracellular S. aureus.
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Affiliation(s)
- Jenna E. Beam
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sophie Maiocchi
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Curriculum in Toxicology & Environmental Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for Nanotechnology in Drug Delivery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ana Cartaya
- Center for Nanotechnology in Drug Delivery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sarah E. Rowe
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Edward S. M. Bahnson
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Curriculum in Toxicology & Environmental Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Center for Nanotechnology in Drug Delivery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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22
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Ledger EVK, Mesnage S, Edwards AM. Human serum triggers antibiotic tolerance in Staphylococcus aureus. Nat Commun 2022; 13:2041. [PMID: 35440121 PMCID: PMC9018823 DOI: 10.1038/s41467-022-29717-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/30/2022] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus frequently causes infections that are challenging to treat, leading to high rates of persistent and relapsing infection. Here, to understand how the host environment influences treatment outcomes, we study the impact of human serum on staphylococcal antibiotic susceptibility. We show that serum triggers a high degree of tolerance to the lipopeptide antibiotic daptomycin and several other classes of antibiotic. Serum-induced daptomycin tolerance is due to two independent mechanisms. Firstly, the host defence peptide LL-37 induces tolerance by triggering the staphylococcal GraRS two-component system, leading to increased peptidoglycan accumulation. Secondly, GraRS-independent increases in membrane cardiolipin abundance are required for full tolerance. When both mechanisms are blocked, S. aureus incubated in serum is as susceptible to daptomycin as when grown in laboratory media. Our work demonstrates that host factors can significantly modulate antibiotic susceptibility via diverse mechanisms, and combination therapy may provide a way to mitigate this.
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Affiliation(s)
- Elizabeth V K Ledger
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK.
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23
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Li J, Claudi B, Fanous J, Chicherova N, Cianfanelli FR, Campbell RAA, Bumann D. Tissue compartmentalization enables Salmonella persistence during chemotherapy. Proc Natl Acad Sci U S A 2021; 118:e2113951118. [PMID: 34911764 PMCID: PMC8713819 DOI: 10.1073/pnas.2113951118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2021] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial chemotherapy can fail to eradicate the pathogen, even in the absence of antimicrobial resistance. Persisting pathogens can subsequently cause relapsing diseases. In vitro studies suggest various mechanisms of antibiotic persistence, but their in vivo relevance remains unclear because of the difficulty of studying scarce pathogen survivors in complex host tissues. Here, we localized and characterized rare surviving Salmonella in mouse spleen using high-resolution whole-organ tomography. Chemotherapy cleared >99.5% of the Salmonella but was inefficient against a small Salmonella subset in the white pulp. Previous models could not explain these findings: drug exposure was adequate, Salmonella continued to replicate, and host stresses induced only limited Salmonella drug tolerance. Instead, antimicrobial clearance required support of Salmonella-killing neutrophils and monocytes, and the density of such cells was lower in the white pulp than in other spleen compartments containing higher Salmonella loads. Neutrophil densities declined further during treatment in response to receding Salmonella loads, resulting in insufficient support for Salmonella clearance from the white pulp and eradication failure. However, adjunctive therapies sustaining inflammatory support enabled effective clearance. These results identify uneven Salmonella tissue colonization and spatiotemporal inflammation dynamics as main causes of Salmonella persistence and establish a powerful approach to investigate scarce but impactful pathogen subsets in complex host environments.
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Affiliation(s)
- Jiagui Li
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | | | - Joseph Fanous
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | | | | | | | - Dirk Bumann
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
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24
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Antibiotic persistence and tolerance: not just one and the same. Curr Opin Microbiol 2021; 64:76-81. [PMID: 34634678 DOI: 10.1016/j.mib.2021.09.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/23/2021] [Accepted: 09/28/2021] [Indexed: 12/11/2022]
Abstract
Distinguished by their penetrance within a population, antibiotic tolerance and persistence are superficially similar phenomena by which growth-restricted bacteria survive treatment with bactericidal antibiotics. Owing to their apparent similarity, it is often assumed that the same physiological states and molecular mechanisms underlie the ability of individual antibiotic tolerant and persistent bacteria to survive treatment. Experimentally, antibiotic persistence is an extremely challenging phenomenon to study due to both its transience and the co-existence of persisters with non-persisters in the population of interest. In contrast, antibiotic tolerance operates at the whole population level as a result of bacteria acquiring genetic mutations or encountering environmental conditions that result in growth restriction. Therefore, studying antibiotic tolerance is often used as a convenient way to understand the molecular mechanisms governing antibiotic persistence. In this opinion, we discuss our current understanding of these two phenomena, outlining how tolerance and persistence can be distinguished experimentally. We argue that this approach will help avoid controversies in the field, especially in instances where the two phenomena co-exist. Finally, we evaluate the clinical evidence implicating tolerance and persistence in recalcitrance and relapse of bacterial infections.
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