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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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Guan J, Jakob U. The Protein Scaffolding Functions of Polyphosphate. J Mol Biol 2024; 436:168504. [PMID: 38423453 DOI: 10.1016/j.jmb.2024.168504] [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: 12/05/2023] [Revised: 01/31/2024] [Accepted: 02/21/2024] [Indexed: 03/02/2024]
Abstract
Inorganic polyphosphate (polyP), one of the first high-energy compound on earth, defies its extreme compositional and structural simplicity with an astoundingly wide array of biological activities across all domains of life. However, the underlying mechanism of such functional pleiotropy remains largely elusive. In this review, we will summarize recent studies demonstrating that this simple polyanion stabilizes protein folding intermediates and scaffolds select native proteins. These functions allow polyP to act as molecular chaperone that protects cells against protein aggregation, as pro-amyloidogenic factor that accelerates both physiological and disease-associated amyloid formation, and as a modulator of liquid-liquid phase separation processes. These activities help to explain polyP's known roles in bacterial stress responses and pathogenicity, provide the mechanistic foundation for its potential role in human neurodegenerative diseases, and open a new direction regarding its influence on gene expression through condensate formation. We will highlight critical unanswered questions and point out potential directions that will help to further understand the pleiotropic functions of this ancient and ubiquitous biopolymer.
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Affiliation(s)
- Jian Guan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA; Biological Chemistry Department, University of Michigan Medical School, Ann Arbor, MI, USA.
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3
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Bacon EE, Myers KS, Iruegas-López R, Banta AB, Place M, Ebersberger I, Peters JM. Physiological Roles of an Acinetobacter-specific σ Factor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.602572. [PMID: 39026751 PMCID: PMC11257525 DOI: 10.1101/2024.07.08.602572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
The Gram-negative pathogen Acinetobacter baumannii is considered an "urgent threat" to human health due to its propensity to become antibiotic resistant. Understanding the distinct regulatory paradigms used by A. baumannii to mitigate cellular stresses may uncover new therapeutic targets. Many γ-proteobacteria use the extracytoplasmic function (ECF) σ factor, RpoE, to invoke envelope homeostasis networks in response to stress. Acinetobacter species contain the poorly characterized ECF "SigAb;" however, it is unclear if SigAb has the same physiological role as RpoE. Here, we show that SigAb is a metal stress-responsive ECF that appears unique to Acinetobacter species and distinct from RpoE. We combine promoter mutagenesis, motif scanning, and ChIP-seq to define the direct SigAb regulon, which consists of sigAb itself, the stringent response mediator, relA, and the uncharacterized small RNA, "sabS." However, RNA-seq of strains overexpressing SigAb revealed a large, indirect regulon containing hundreds of genes. Metal resistance genes are key elements of the indirect regulon, as CRISPRi knockdown of sigAb or sabS resulted in increased copper sensitivity and excess copper induced SigAb-dependent transcription. Further, we found that two uncharacterized genes in the sigAb operon, "aabA" and "aabB", have anti-SigAb activity. Finally, employing a targeted Tn-seq approach that uses CRISPR-associated transposons, we show that sigAb, aabA, and aabB are important for fitness even during optimal growth conditions. Our work reveals new physiological roles for SigAb and SabS, provides a novel approach for assessing gene fitness, and highlights the distinct regulatory architecture of A. baumannii.
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Affiliation(s)
- Emily E. Bacon
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Kevin S. Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Rubén Iruegas-López
- Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Germany
| | - Amy B. Banta
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Michael Place
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Ingo Ebersberger
- Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Germany
- Senckenberg Biodiversity and Climate Research Centre (S-BIKF), Frankfurt, Germany
- LOEWE Center for Translational Biodiversity Genomics (TBG), Frankfurt, Germany
| | - Jason M. Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA
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4
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Khan M, Alkhathlan HZ, Adil SF, Shaik MR, Siddiqui MRH, Khan M, Khan ST. Secondary metabolite profile of Streptomyces spp. changes when grown with the sub-lethal concentration of silver nanoparticles: possible implication in novel compound discovery. Antonie Van Leeuwenhoek 2024; 117:95. [PMID: 38967683 DOI: 10.1007/s10482-024-01991-9] [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: 02/25/2024] [Accepted: 06/18/2024] [Indexed: 07/06/2024]
Abstract
The decline of new antibiotics and the emergence of multidrug resistance in pathogens necessitates a revisit of strategies used for lead compound discovery. This study proposes to induce the production of bioactive compounds with sub-lethal concentrations of silver nanoparticles (Ag-NPs). A total of Forty-two Actinobacteria isolates from four Saudi soil samples were grown with and without sub-lethal concentration of Ag-NPs (50 µg ml-1). The spent broth grown with Ag-NPs, or without Ag-NPs were screened for antimicrobial activity against four bacteria. Interestingly, out of 42 strains, broths of three strains grown with sub-lethal concentration of Ag-NPs exhibit antimicrobial activity against Staphylococcus aureus and Micrococcus luteus. Among these, two strains S4-4 and S4-21 identified as Streptomyces labedae and Streptomyces tirandamycinicus based on 16S rRNA gene sequence were selected for detailed study. The change in the secondary metabolites profile in the presence of Ag-NPs was evaluated using GC-MS and LC-MS analyses. Butanol extracts of spent broth grown with Ag-NPs exhibit strong antimicrobial activity against M. luteus and S. aureus. While the extracts of the controls with the same concentration of Ag-NPs do not show any activity. GC-analysis revealed a clear change in the secondary metabolite profile when grown with Ag-NPs. Similarly, the LC-MS patterns also differ significantly. Results of this study, strongly suggest that sub-lethal concentrations of Ag-NPs influence the production of secondary metabolites by Streptomyces. Besides, LC-MS results identified possible secondary metabolites, associated with oxidative stress and antimicrobial activities. This strategy can be used to possibly induce cryptic biosynthetic gene clusters for the discovery of new lead compounds.
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Affiliation(s)
- Merajuddin Khan
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, 11451, Riyadh, Saudi Arabia
| | - Hamad Z Alkhathlan
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, 11451, Riyadh, Saudi Arabia
| | - Syed Farooq Adil
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, 11451, Riyadh, Saudi Arabia
| | - Mohammed Rafi Shaik
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, 11451, Riyadh, Saudi Arabia
| | | | - Mujeeb Khan
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, 11451, Riyadh, Saudi Arabia.
| | - Shams Tabrez Khan
- Department of Agricultural Microbiology, Faculty of Agricultural Science, Aligarh Muslim University, Aligarh, U.P., 202002, India.
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Elbediwi M, Rolff J. Metabolic pathways and antimicrobial peptide resistance in bacteria. J Antimicrob Chemother 2024; 79:1473-1483. [PMID: 38742645 DOI: 10.1093/jac/dkae128] [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] [Indexed: 05/16/2024] Open
Abstract
Antimicrobial resistance is a pressing concern that poses a significant threat to global public health, necessitating the exploration of alternative strategies to combat drug-resistant microbial infections. Recently, antimicrobial peptides (AMPs) have gained substantial attention as possible replacements for conventional antibiotics. Because of their pharmacodynamics and killing mechanisms, AMPs display a lower risk of bacterial resistance evolution compared with most conventional antibiotics. However, bacteria display different mechanisms to resist AMPs, and the role of metabolic pathways in the resistance mechanism is not fully understood. This review examines the intricate relationship between metabolic genes and AMP resistance, focusing on the impact of metabolic pathways on various aspects of resistance. Metabolic pathways related to guanosine pentaphosphate (pppGpp) and guanosine tetraphosphate (ppGpp) [collectively (p)ppGpp], the tricarboxylic acid (TCA) cycle, haem biosynthesis, purine and pyrimidine biosynthesis, and amino acid and lipid metabolism influence in different ways metabolic adjustments, biofilm formation and energy production that could be involved in AMP resistance. By targeting metabolic pathways and their associated genes, it could be possible to enhance the efficacy of existing antimicrobial therapies and overcome the challenges exhibited by phenotypic (recalcitrance) and genetic resistance toward AMPs. Further research in this area is needed to provide valuable insights into specific mechanisms, uncover novel therapeutic targets, and aid in the fight against antimicrobial resistance.
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Affiliation(s)
- Mohammed Elbediwi
- Evolutionary Biology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
- Animal Health Research Institute, Agriculture Research Centre, 12618 Cairo, Egypt
| | - Jens Rolff
- Evolutionary Biology, Institute for Biology, Freie Universität Berlin, 14195 Berlin, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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Malik A, Oludiran A, Poudel A, Alvarez OB, Woodward C, Purcell EB. RelQ-mediated alarmone signalling regulates growth, stress-induced biofilm formation and spore accumulation in Clostridioides difficile. MICROBIOLOGY (READING, ENGLAND) 2024; 170. [PMID: 39028551 DOI: 10.1099/mic.0.001479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm formation in the presence of sublethal stress, the ΔrelQ strain cannot upregulate biofilm production in response to stress. Deletion of relQ slows spore accumulation in planktonic cultures but accelerates it in biofilms. This work establishes biofilm formation and spore accumulation as alarmone-mediated processes in C. difficile and reveals the importance of RelQ in stress-induced biofilm regulation.
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Affiliation(s)
- Areej Malik
- Biomedical Sciences Program, Old Dominion University, Norfolk, Virginia, 23529, USA
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Adenrele Oludiran
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Asia Poudel
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Orlando Berumen Alvarez
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Charles Woodward
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Erin B Purcell
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
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Barman S, Kurnaz LB, Leighton R, Hossain MW, Decho AW, Tang C. Intrinsic antimicrobial resistance: Molecular biomaterials to combat microbial biofilms and bacterial persisters. Biomaterials 2024; 311:122690. [PMID: 38976935 DOI: 10.1016/j.biomaterials.2024.122690] [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: 12/03/2023] [Revised: 05/13/2024] [Accepted: 06/26/2024] [Indexed: 07/10/2024]
Abstract
The escalating rise in antimicrobial resistance (AMR) coupled with a declining arsenal of new antibiotics is imposing serious threats to global public health. A pervasive aspect of many acquired AMR infections is that the pathogenic microorganisms exist as biofilms, which are equipped with superior survival strategies. In addition, persistent and recalcitrant infections are seeded with bacterial persister cells at infection sites. Together, conventional antibiotic therapeutics often fail in the complete treatment of infections associated with bacterial persisters and biofilms. Novel therapeutics have been attempted to tackle AMR, biofilms, and persister-associated complex infections. This review focuses on the progress in designing molecular biomaterials and therapeutics to address acquired and intrinsic AMR, and the fundamental microbiology behind biofilms and persisters. Starting with a brief introduction of AMR basics and approaches to tackling acquired AMR, the emphasis is placed on various biomaterial approaches to combating intrinsic AMR, including (1) semi-synthetic antibiotics; (2) macromolecular or polymeric biomaterials mimicking antimicrobial peptides; (3) adjuvant effects in synergy; (4) nano-therapeutics; (5) nitric oxide-releasing antimicrobials; (6) antimicrobial hydrogels; (7) antimicrobial coatings. Particularly, the structure-activity relationship is elucidated in each category of these biomaterials. Finally, illuminating perspectives are provided for the future design of molecular biomaterials to bypass AMR and cure chronic multi-drug resistant (MDR) infections.
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Affiliation(s)
- Swagatam Barman
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, United States; Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, 29208, United States
| | - Leman Buzoglu Kurnaz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, United States
| | - Ryan Leighton
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, 29208, United States
| | - Md Waliullah Hossain
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, United States
| | - Alan W Decho
- Department of Environmental Health Sciences, University of South Carolina, Columbia, SC, 29208, United States.
| | - Chuanbing Tang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, United States.
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Zheng R, Wu R, Liu Y, Sun Z, Xue Z, Bagheri Y, Khajouei S, Mi L, Tian Q, Pho R, Liu Q, Siddiqui S, Ren K, You M. Multiplexed sequential imaging in living cells with orthogonal fluorogenic RNA aptamer/dye pairs. Nucleic Acids Res 2024:gkae551. [PMID: 38922685 DOI: 10.1093/nar/gkae551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 06/01/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
Detecting multiple targets in living cells is important in cell biology. However, multiplexed fluorescence imaging beyond two-to-three targets remains a technical challenge. Herein, we introduce a multiplexed imaging strategy, 'sequential Fluorogenic RNA Imaging-Enabled Sensor' (seqFRIES), which enables live-cell target detection via sequential rounds of imaging-and-stripping. In seqFRIES, multiple orthogonal fluorogenic RNA aptamers are genetically encoded inside cells, and then the corresponding cell membrane permeable dye molecules are added, imaged, and rapidly removed in consecutive detection cycles. As a proof-of-concept, we have identified in this study four fluorogenic RNA aptamer/dye pairs that can be used for highly orthogonal and multiplexed imaging in living bacterial and mammalian cells. After further optimizing the cellular fluorescence activation and deactivation kinetics of these RNA/dye pairs, the whole four-color semi-quantitative seqFRIES process can be completed in ∼20 min. Meanwhile, seqFRIES-mediated simultaneous detection of critical signalling molecules and mRNA targets was also achieved within individual living cells. We expect our validation of this new seqFRIES concept here will facilitate the further development and potential broad usage of these orthogonal fluorogenic RNA/dye pairs for multiplexed and dynamic live-cell imaging and cell biology studies.
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Affiliation(s)
- Ru Zheng
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Rigumula Wu
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Yuanchang Liu
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Zhining Sun
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Zhaolin Xue
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Yousef Bagheri
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Sima Khajouei
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Lan Mi
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Qian Tian
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Raymond Pho
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA 01003, USA
| | - Qinge Liu
- Department of Chemistry, Mount Holyoke College, Holyoke, MA 01075, USA
| | - Sidrat Siddiqui
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Kewei Ren
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Mingxu You
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, MA 01003, USA
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Rs N, Sinha SK, Batra S, Regatti PR, Syal K. Promoter characterization of relZ-bifunctional (pp)pGpp synthetase in mycobacteria. Genes Cells 2024. [PMID: 38923083 DOI: 10.1111/gtc.13135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024]
Abstract
The second messenger guanosine 3',5'-bis(diphosphate)/guanosine tetraphosphate (ppGpp) and guanosine 3'-diphosphate 5'-triphosphate/guanosine pentaphosphate (pppGpp) ((p)ppGpp) has been shown to be crucial for the survival of mycobacteria under hostile conditions. Unexpectedly, deletion of primary (p)ppGpp synthetase-Rel did not completely diminish (p)ppGpp levels leading to the discovery of novel bifunctional enzyme-RelZ, which displayed guanosine 5'-monophosphate,3'-diphosphate (pGpp), ppGpp, and pppGpp ((pp)pGpp) synthesis and RNAseHII activity. What conditions does it express itself under, and does it work in concert with Rel? The regulation of its transcription and whether the Rel enzyme plays a role in such regulation remain unclear. In this article, we have studied relZ promoter and compared its activity with rel promoter in different growth conditions. We observed that the promoter activity of relZ was constitutive; it is weaker than rel promoter, lies within 200 bp upstream of translation-start site, and it increased under carbon starvation. Furthermore, the promoter activity of relZ was compromised in the rel-knockout strain in the stationary phase. Our study unveils the dynamic regulation of relZ promoter activity by SigA and SigB sigma factors in different growth phases in mycobacteria. Importantly, elucidating the regulatory network of RelZ would enable the development of the targeted interventions for treating mycobacterial infections.
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Affiliation(s)
- Neethu Rs
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
| | - Shubham Kumar Sinha
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
| | - Sakshi Batra
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
- Department of Pulmonary Medicine, Malla Reddy Institute of Medical Sciences, Hyderabad, Telangana, India
| | - Pavan Reddy Regatti
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
| | - Kirtimaan Syal
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
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Xu M, Liu M, Liu T, Pan X, Ren Q, Han T, Gou L. HigA2 (Rv2021c) Is a Transcriptional Regulator with Multiple Regulatory Targets in Mycobacterium tuberculosis. Microorganisms 2024; 12:1244. [PMID: 38930627 PMCID: PMC11205783 DOI: 10.3390/microorganisms12061244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2024] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
Toxin-antitoxin (TA) systems are the major mechanism for persister formation in Mycobacterium tuberculosis (Mtb). Previous studies found that HigBA2 (Rv2022c-Rv2021c), a predicted type II TA system of Mtb, could be activated for transcription in response to multiple stresses such as anti-tuberculosis drugs, nutrient starvation, endure hypoxia, acidic pH, etc. In this study, we determined the binding site of HigA2 (Rv2021c), which is located in the coding region of the upstream gene higB2 (Rv2022c), and the conserved recognition motif of HigA2 was characterized via oligonucleotide mutation. Eight binding sites of HigA2 were further found in the Mtb genome according to the conserved motif. RT-PCR showed that HigA2 can regulate the transcription level of all eight of these genes and three adjacent downstream genes. DNA pull-down experiments showed that twelve functional regulators sense external regulatory signals and may regulate the transcription of the HigBA2 system. Of these, Rv0903c, Rv0744c, Rv0474, Rv3124, Rv2603c, and Rv3583c may be involved in the regulation of external stress signals. In general, we identified the downstream target genes and possible upstream regulatory genes of HigA2, which paved the way for the illustration of the persistence establishment mechanism in Mtb.
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Affiliation(s)
- Mingyan Xu
- Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, North China University of Science and Technology, Tangshan 063210, China; (M.X.); (M.L.); (T.L.); (X.P.); (Q.R.)
| | - Meikun Liu
- Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, North China University of Science and Technology, Tangshan 063210, China; (M.X.); (M.L.); (T.L.); (X.P.); (Q.R.)
| | - Tong Liu
- Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, North China University of Science and Technology, Tangshan 063210, China; (M.X.); (M.L.); (T.L.); (X.P.); (Q.R.)
| | - Xuemei Pan
- Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, North China University of Science and Technology, Tangshan 063210, China; (M.X.); (M.L.); (T.L.); (X.P.); (Q.R.)
| | - Qi Ren
- Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, North China University of Science and Technology, Tangshan 063210, China; (M.X.); (M.L.); (T.L.); (X.P.); (Q.R.)
| | - Tiesheng Han
- Hebei Province Key Laboratory of Occupational Health and Safety for Coal Industry, School of Public Health, North China University of Science and Technology, Tangshan 063210, China; (M.X.); (M.L.); (T.L.); (X.P.); (Q.R.)
| | - Lixia Gou
- School of Life Science, North China University of Science and Technology, Tangshan 063210, China
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11
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Watanabe S, Nsofor CA, Thitiananpakorn K, Tan XE, Aiba Y, Takenouchi R, Kiga K, Sasahara T, Miyanaga K, Veeranarayanan S, Shimamori Y, Lian AYS, Nguyen TM, Nguyen HM, Alessa O, Kumwenda GP, Jayathilake S, Revilleza JEC, Baranwal P, Nishikawa Y, Li FY, Kawaguchi T, Sankaranarayanan S, Arbaah M, Zhang Y, Maniruzzaman, Liu Y, Sarah H, Li J, Sugano T, Ho TMD, Batbold A, Nayanjin T, Cui L. Metabolic remodeling by RNA polymerase gene mutations is associated with reduced β-lactam susceptibility in oxacillin-susceptible MRSA. mBio 2024; 15:e0033924. [PMID: 38988221 PMCID: PMC11237739 DOI: 10.1128/mbio.00339-24] [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: 02/01/2024] [Accepted: 03/27/2024] [Indexed: 07/12/2024] Open
Abstract
The emergence of oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA) has imposed further challenges to the clinical management of MRSA infections. When exposed to β-lactam antibiotics, these strains can easily acquire reduced β-lactam susceptibility through chromosomal mutations, including those in RNA polymerase (RNAP) genes such as rpoBC, which may then lead to treatment failure. Despite the increasing prevalence of such strains and the apparent challenges they pose for diagnosis and treatment, there is limited information available on the actual mechanisms underlying such chromosomal mutation-related transitions to reduced β-lactam susceptibility, as it does not directly associate with the expression of mecA. This study investigated the cellular physiology and metabolism of six missense mutants with reduced oxacillin susceptibility, each carrying respective mutations on RpoBH929P, RpoBQ645H, RpoCG950R, RpoCG498D, RpiAA64E, and FruBA211E, using capillary electrophoresis-mass spectrometry-based metabolomics analysis. Our results showed that rpoBC mutations caused RNAP transcription dysfunction, leading to an intracellular accumulation of ribonucleotides. These mutations also led to the accumulation of UDP-Glc/Gal and UDP-GlcNAc, which are precursors of UTP-associated peptidoglycan and wall teichoic acid. Excessive amounts of building blocks then contributed to the cell wall thickening of mutant strains, as observed in transmission electron microscopy, and ultimately resulted in decreased susceptibility to β-lactam in OS-MRSA. IMPORTANCE The emergence of oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA) strains has created new challenges for treating MRSA infections. These strains can become resistant to β-lactam antibiotics through chromosomal mutations, including those in the RNA polymerase (RNAP) genes such as rpoBC, leading to treatment failure. This study investigated the mechanisms underlying reduced β-lactam susceptibility in four rpoBC mutants of OS-MRSA. The results showed that rpoBC mutations caused RNAP transcription dysfunction, leading to an intracellular accumulation of ribonucleotides and precursors of peptidoglycan as well as wall teichoic acid. This, in turn, caused thickening of the cell wall and ultimately resulted in decreased susceptibility to β-lactam in OS-MRSA. These findings provide insights into the mechanisms of antibiotic resistance in OS-MRSA and highlight the importance of continued research in developing effective treatments to combat antibiotic resistance.
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Affiliation(s)
- Shinya Watanabe
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Chijioke A Nsofor
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
- Department of Biotechnology, School of Biological Sciences, Federal University of Technology Owerri Nigeria, Owerri, Nigeria
| | - Kanate Thitiananpakorn
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Xin-Ee Tan
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Yoshifumi Aiba
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Remi Takenouchi
- School of Medicine, Jichi Medical University, Tochigi, Japan
| | - Kotaro Kiga
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo, Japan
| | - Teppei Sasahara
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Kazuhiko Miyanaga
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Srivani Veeranarayanan
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Yuzuki Shimamori
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Adeline Yeo Syin Lian
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Thuy Minh Nguyen
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Huong Minh Nguyen
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Ola Alessa
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | | | - Sarangi Jayathilake
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | | | - Priyanka Baranwal
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Yutaro Nishikawa
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Feng-Yu Li
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Tomofumi Kawaguchi
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Sowmiya Sankaranarayanan
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Mahmoud Arbaah
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Yuancheng Zhang
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Maniruzzaman
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Yi Liu
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Hossain Sarah
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Junjie Li
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Takashi Sugano
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Thi My Duyen Ho
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Anujin Batbold
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Tergel Nayanjin
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
| | - Longzhu Cui
- Division of Bacteriology, Department of Infection and Immunity, Jichi Medical University, Tochigi, Japan
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12
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He L, Lidstrom ME. Utilisation of low methane concentrations by methanotrophs. Adv Microb Physiol 2024; 85:57-96. [PMID: 39059823 DOI: 10.1016/bs.ampbs.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
The growing urgency regarding climate change points to methane as a key greenhouse gas for slowing global warming to allow other mitigation measures to take effect. One approach to both decreasing methane emissions and removing methane from air is aerobic methanotrophic bacteria, those bacteria that grow on methane as sole carbon and energy source and require O2. A subset of these methanotrophs is able to grow on methane levels of 1000 parts per million (ppm) and below, and these present an opportunity for developing both environmental- and bioreactor-based methane treatment systems. However, relatively little is known about the traits of such methanotrophs that allow them to grow on low methane concentrations. This review assesses current information regarding how methanotrophs grow on low methane concentrations in the context of developing treatment strategies that could be applied for both decreasing methane emissions and removing methane from air.
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Affiliation(s)
- Lian He
- Department of Chemical Engineering, University of Washington, Seattle, WA United States
| | - Mary E Lidstrom
- Department of Chemical Engineering, University of Washington, Seattle, WA United States; Department of Microbiology, University of Washington, Seattle, WA United States.
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13
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da Silva CV, Velikkakam T, de Oliveira ECM, Silveira ACA, de Lima Júnior JP, Uombe NPI, da Silva PHR, Borges BC. Cellular dormancy: A widespread phenomenon that perpetuates infectious diseases. J Basic Microbiol 2024; 64:e2300389. [PMID: 38064123 DOI: 10.1002/jobm.202300389] [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: 07/11/2023] [Revised: 11/05/2023] [Accepted: 11/21/2023] [Indexed: 05/03/2024]
Abstract
Under adverse environmental conditions, microorganisms are able to enter a state of cellular dormancy which consists of cell cycle arrest and interruption of multiplication. This process ensures their perpetuation in the infected host organism and enables the spread of disease. Throughout biological evolution, dormancy allowed microorganisms to persist in a harsh niche until favorable conditions for their reactivation were re-established. Here, we propose to discuss the dormancy of bacteria and protozoa pathogens focusing on the potential mechanisms and components associated with dormancy.
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Affiliation(s)
- Claudio V da Silva
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Teresiama Velikkakam
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Elida C M de Oliveira
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Anna C A Silveira
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Joed P de Lima Júnior
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Nelsa P I Uombe
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Paulo H R da Silva
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - Bruna C Borges
- Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Uberlândia, Brazil
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14
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Qi W, Jonker MJ, de Leeuw W, Brul S, ter Kuile BH. Role of RelA-synthesized (p)ppGpp and ROS-induced mutagenesis in de novo acquisition of antibiotic resistance in E. coli. iScience 2024; 27:109579. [PMID: 38617560 PMCID: PMC11015494 DOI: 10.1016/j.isci.2024.109579] [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: 01/22/2024] [Revised: 03/06/2024] [Accepted: 03/25/2024] [Indexed: 04/16/2024] Open
Abstract
The stringent response of bacteria to starvation and stress also fulfills a role in addressing the threat of antibiotics. Within this stringent response, (p)ppGpp, synthesized by RelA or SpoT, functions as a global alarmone. However, the effect of this (p)ppGpp on resistance development is poorly understood. Here, we show that knockout of relA or rpoS curtails resistance development against bactericidal antibiotics. The emergence of mutated genes associated with starvation and (p)ppGpp, among others, indicates the activation of stringent responses. The growth rate is decreased in ΔrelA-resistant strains due to the reduced ability to synthesize (p)ppGpp and the persistence of deacylated tRNA impeding protein synthesis. Sluggish cellular activity causes decreased production of reactive oxygen species (ROS), thereby reducing oxidative damage, leading to weakened DNA mismatch repair, potentially reducing the generation of mutations. These findings offer new targets for mitigating antibiotic resistance development, potentially achieved through inhibiting (p)ppGpp or ROS synthesis.
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Affiliation(s)
- Wenxi Qi
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Martijs J. Jonker
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Wim de Leeuw
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Stanley Brul
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Benno H. ter Kuile
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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15
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Rachedi R, Risoul V, Foglino M, Aoudache Y, Lang K, Champ S, Kaplan E, Orelle C, Douzi B, Jault JM, Latifi A. Unravelling HetC as a peptidase-based ABC exporter driving functional cell differentiation in the cyanobacterium Nostoc PCC 7120. Microbiol Spectr 2024; 12:e0405823. [PMID: 38358282 PMCID: PMC10986499 DOI: 10.1128/spectrum.04058-23] [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: 11/30/2023] [Accepted: 01/30/2024] [Indexed: 02/16/2024] Open
Abstract
The export of peptides or proteins is essential for a variety of important functions in bacteria. Among the diverse protein-translocation systems, peptidase-containing ABC transporters (PCAT) are involved in the maturation and export of quorum-sensing or antimicrobial peptides in Gram-positive bacteria and of toxins in Gram-negative organisms. In the multicellular and diazotrophic cyanobacterium Nostoc PCC 7120, the protein HetC is essential for the differentiation of functional heterocysts, which are micro-oxic and non-dividing cells specialized in atmospheric nitrogen fixation. HetC shows similarities to PCAT systems, but whether it actually acts as a peptidase-based exporter remains to be established. In this study, we show that the N-terminal part of HetC, encompassing the peptidase domain, displays a cysteine-type protease activity. The conserved catalytic residues conserved in this family of proteases are essential for the proteolytic activity of HetC and the differentiation of heterocysts. Furthermore, we show that the catalytic residue of the ATPase domain of HetC is also essential for cell differentiation. Interestingly, HetC has a cyclic nucleotide-binding domain at its N-terminus which can bind ppGpp in vitro and which is required for its function in vivo. Our results indicate that HetC is a peculiar PCAT that might be regulated by ppGpp to potentially facilitate the export of a signaling peptide essential for cell differentiation, thereby broadening the scope of PCAT role in Gram-negative bacteria.IMPORTANCEBacteria have a great capacity to adapt to various environmental and physiological conditions; it is widely accepted that their ability to produce extracellular molecules contributes greatly to their fitness. Exported molecules are used for a variety of purposes ranging from communication to adjust cellular physiology, to the production of toxins that bacteria secrete to fight for their ecological niche. They use export machineries for this purpose, the most common of which energize transport by hydrolysis of adenosine triphosphate. Here, we demonstrate that such a mechanism is involved in cell differentiation in the filamentous cyanobacterium Nostoc PCC 7120. The HetC protein belongs to the ATP-binding cassette transporter superfamily and presumably ensures the maturation of a yet unknown substrate during export. These results open interesting perspectives on cellular signaling pathways involving the export of regulatory peptides, which will broaden our knowledge of how these bacteria use two cell types to conciliate photosynthesis and nitrogen fixation.
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Affiliation(s)
- Raphaël Rachedi
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | - Véronique Risoul
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | - Maryline Foglino
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | | | - Kevin Lang
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | - Stéphanie Champ
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | - Elise Kaplan
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | - Cédric Orelle
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | | | - Jean-Michel Jault
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | - Amel Latifi
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
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16
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Reber AS, Baluška F, Miller WB, Slijepčević P. The sensual cell: Feeling and affect in unicellular species. Biosystems 2024; 238:105197. [PMID: 38556108 DOI: 10.1016/j.biosystems.2024.105197] [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: 02/18/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/02/2024]
Abstract
Our previous efforts to probe the complex, rich experiential lives of unicellular species have focused on the origins of consciousness (Reber, 2019) and the biomolecular processes that underlie sentience (Reber et al., 2023). Implied, but unexplored, was the assumption that these cognitive functions and associated unicellular organismal behaviors were linked with and often driven by affect, feelings, sensual experiences. In this essay we dig more deeply into these valenced (We're using the term valence here to cover the aspects of sensory experiences that have evaluative elements, are experienced as positive or negative ─ those where this affective, internal representation is an essential element in how the input is interpreted and responded to.) self-referencing features. In the first part, we examine the empirical evidence for various sensual experiences that have been identified. In the second part, we look at other features of prokaryote life that appear to also have affective, valenced elements but where the data to support the proposition aren't as strong. We engage in some informed speculation about these phenomena.
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Affiliation(s)
- Arthur S Reber
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada.
| | - František Baluška
- Institute of Cellular and Molecular Botany, University of Bonn, Germany.
| | | | - Predrag Slijepčević
- Department of Life Sciences, College of Health, Medicine and Life Sciences, University of Brunel, UK.
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17
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Mandel CG, Sanchez SE, Monahan CC, Phuklia W, Omsland A. Metabolism and physiology of pathogenic bacterial obligate intracellular parasites. Front Cell Infect Microbiol 2024; 14:1284701. [PMID: 38585652 PMCID: PMC10995303 DOI: 10.3389/fcimb.2024.1284701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 02/01/2024] [Indexed: 04/09/2024] Open
Abstract
Bacterial obligate intracellular parasites (BOIPs) represent an exclusive group of bacterial pathogens that all depend on invasion of a eukaryotic host cell to reproduce. BOIPs are characterized by extensive adaptation to their respective replication niches, regardless of whether they replicate within the host cell cytoplasm or within specialized replication vacuoles. Genome reduction is also a hallmark of BOIPs that likely reflects streamlining of metabolic processes to reduce the need for de novo biosynthesis of energetically costly metabolic intermediates. Despite shared characteristics in lifestyle, BOIPs show considerable diversity in nutrient requirements, metabolic capabilities, and general physiology. In this review, we compare metabolic and physiological processes of prominent pathogenic BOIPs with special emphasis on carbon, energy, and amino acid metabolism. Recent advances are discussed in the context of historical views and opportunities for discovery.
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Affiliation(s)
- Cameron G. Mandel
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Savannah E. Sanchez
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, United States
| | - Colleen C. Monahan
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Weerawat Phuklia
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People’s Democratic Republic
| | - Anders Omsland
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
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18
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Liu Y, LaBonte S, Brake C, LaFayette C, Rosebrock AP, Caudy AA, Straight PD. MOB rules: Antibiotic Exposure Reprograms Metabolism to Mobilize Bacillus subtilis in Competitive Interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.585991. [PMID: 38562742 PMCID: PMC10983992 DOI: 10.1101/2024.03.20.585991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Antibiotics have dose-dependent effects on exposed bacteria. The medicinal use of antibiotics relies on their growth-inhibitory activities at sufficient concentrations. At subinhibitory concentrations, exposure effects vary widely among different antibiotics and bacteria. Bacillus subtilis responds to bacteriostatic translation inhibitors by mobilizing a population of cells (MOB-Mobilized Bacillus) to spread across a surface. How B. subtilis regulates the antibiotic-induced mobilization is not known. In this study, we used chloramphenicol to identify regulatory functions that B. subtilis requires to coordinate cell mobilization following subinhibitory exposure. We measured changes in gene expression and metabolism and mapped the results to a network of regulatory proteins that direct the mobile response. Our data reveal that several transcriptional regulators coordinately control the reprogramming of metabolism to support mobilization. The network regulates changes in glycolysis, nucleotide metabolism, and amino acid metabolism that are signature features of the mobilized population. Among the hundreds of genes with changing expression, we identified two, pdhA and pucA, where the magnitudes of their changes in expression, and in the abundance of associated metabolites, reveal hallmark metabolic features of the mobilized population. Using reporters of pdhA and pucA expression, we visualized the separation of major branches of metabolism in different regions of the mobilized population. Our results reveal a regulated response to chloramphenicol exposure that enables a population of bacteria in different metabolic states to mount a coordinated mobile response.
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Affiliation(s)
- Yongjin Liu
- Biochemistry and Biophysics Department, Texas A&M University, AgriLife Research, College Station, Texas, USA
| | - Sandra LaBonte
- Biochemistry and Biophysics Department, Texas A&M University, AgriLife Research, College Station, Texas, USA
- Interdisciplinary Program in Genetics and Genomics,Texas A&M University, College Station, Texas, USA
| | - Courtney Brake
- Department of Visualization, Institute for Applied Creativity, Texas A&M University, College Station, Texas, USA
| | - Carol LaFayette
- Department of Visualization, Institute for Applied Creativity, Texas A&M University, College Station, Texas, USA
| | | | - Amy A. Caudy
- Maple Flavored Solutions, LLC, Indianapolis, Indiana, USA
| | - Paul D. Straight
- Biochemistry and Biophysics Department, Texas A&M University, AgriLife Research, College Station, Texas, USA
- Interdisciplinary Program in Genetics and Genomics,Texas A&M University, College Station, Texas, USA
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19
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Ding S, Liu C, Zhu Y, Li J, Shi G, Zhu A. Rare Earth-Carbon Dots Nanocomposite-Modified Glass Nanopipettes: Electro-Optical Detection of Bacterial ppGpp. Anal Chem 2024; 96:4521-4527. [PMID: 38442333 DOI: 10.1021/acs.analchem.3c05211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
As an important alarmone nucleotide, guanosine 3'-diphosphate-5'-diphosphate (ppGpp) can regulate the survival of bacteria under strict environmental conditions. Direct detection of ppGpp in bacteria with high sensitivity and selectivity is crucial for elucidating the role of ppGpp in bacterial stringent response. Herein, the terbium-carbon dots nanocomposite (CDs-Tb) modified glass nanopipet was developed for the recognition of ppGpp. The CDs-Tb in glass nanopipette preserved their fluorescence properties as well as the coordination capacity of Tb3+ toward ppGpp. The addition of ppGpp not only led to the fluorescence response of CDs-Tb but also triggered variations of surface charge inside the glass nanopipet, resulting in the ionic current response. Compared with nucleotides with similar structures, this method displayed good selectivity toward ppGpp. Moreover, the dual signals (fluorescence and ionic current) offered a built-in correction for potential interference. Apart from the high selectivity, the proposed method can determine the concentration of ppGpp from 10-13 to 10-7 M. Taking advantage of the significant analytical performance, we monitored ppGpp in Escherichia coli under different nutritional conditions and studied the relationship between ppGpp and DNA repair, which is helpful for overcoming antibiotic resistance and promoting the development of potential drugs for antibacterial treatment.
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Affiliation(s)
- Shushu Ding
- School of Pharmacy, Nantong University, 19 Qixiu Road, Nantong 226001, People's Republic of China
| | - Chunyan Liu
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai 200241, People's Republic of China
| | - Yue Zhu
- School of Pharmacy, Nantong University, 19 Qixiu Road, Nantong 226001, People's Republic of China
| | - Jinlong Li
- School of Pharmacy, Nantong University, 19 Qixiu Road, Nantong 226001, People's Republic of China
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai 200241, People's Republic of China
| | - Anwei Zhu
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai 200241, People's Republic of China
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20
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Ortiz de la Rosa JM, Martín-Gutiérrez G, Casimiro-Soriguer CS, Gimeno-Gascón MA, Cisneros JM, de Alarcón A, Lepe JA. C-terminal deletion of RelA protein is suggested as a possible cause of infective endocarditis recurrence with Enterococcus faecium. Antimicrob Agents Chemother 2024; 68:e0108323. [PMID: 38349158 PMCID: PMC10923276 DOI: 10.1128/aac.01083-23] [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: 08/21/2023] [Accepted: 01/16/2024] [Indexed: 03/07/2024] Open
Abstract
Infective endocarditis (IE) caused by Enterococcus spp. represents the third most common cause of IE, with high rates of relapse compared with other bacteria. Interestingly, late relapses (>6 months) have only been described in Enterococcus faecalis, but here we describe the first reported IE relapse with Enterococcus faecium more than a year (17 months) after the initial endocarditis episode. Firstly, by multi locus sequence typing (MLST), we demonstrated that both isolates (EF646 and EF641) belong to the same sequence type (ST117). Considering that EF641 was able to overcome starvation and antibiotic treatment conditions surviving for a long period of time, we performed bioinformatic analysis in identifying potential genes involved in virulence and stringent response. Our results showed a 13-nucleotide duplication (positions 1638-1650) in the gene relA, resulting in a premature stop codon, with a loss of 167 amino acids from the C-terminal domains of the RelA enzyme. RelA mediates the stringent response in bacteria, modulating levels of the alarmone guanosine tetraphosphate (ppGpp). The relA mutant (EF641) was associated with lower growth capacity, the presence of small colony variants, and higher capacity to produce biofilms (compared with the strain EF646), but without differences in antimicrobial susceptibility patterns according to standard procedures during planktonic growth. Instead, EF641 demonstrated tolerance to high doses of teicoplanin when growing in a biofilm. We conclude that all these events would be closely related to the long-term survival of the E. faecium and the late relapse of the IE. These data represent the first clinical evidence of mutations in the stringent response (relA gene) related with E. faecium IE relapse.
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Affiliation(s)
- José Manuel Ortiz de la Rosa
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Guillermo Martín-Gutiérrez
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
- Department of Health Sciences, Loyola Andalucía University, Sevilla, Spain
| | - Carlos S. Casimiro-Soriguer
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - María Adelina Gimeno-Gascón
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - José Miguel Cisneros
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
- Faculty of Medicine, University of Seville, Seville, Spain
| | - Arístides de Alarcón
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - José Antonio Lepe
- Clinical Unit of Infectious Diseases, Microbiology and Parasitology, University Hospital Virgen del Rocío, Seville, Spain
- Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
- Department of Microbiology, University of Seville, Seville, Spain
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21
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Voedts H, Anoyatis-Pelé C, Langella O, Rusconi F, Hugonnet JE, Arthur M. (p)ppGpp modifies RNAP function to confer β-lactam resistance in a peptidoglycan-independent manner. Nat Microbiol 2024; 9:647-656. [PMID: 38443580 DOI: 10.1038/s41564-024-01609-w] [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: 02/21/2023] [Accepted: 01/16/2024] [Indexed: 03/07/2024]
Abstract
(p)ppGpp is a nucleotide alarmone that controls bacterial response to nutrient deprivation. Since elevated (p)ppGpp levels confer mecillinam resistance and are essential for broad-spectrum β-lactam resistance as mediated by the β-lactam-insensitive transpeptidase YcbB (LdtD), we hypothesized that (p)ppGpp might affect cell wall peptidoglycan metabolism. Here we report that (p)ppGpp-dependent β-lactam resistance does not rely on any modification of peptidoglycan metabolism, as established by analysis of Escherichia coli peptidoglycan structure using high-resolution mass spectrometry. Amino acid substitutions in the β or β' RNA polymerase (RNAP) subunits, alone or in combination with the CRISPR interference-mediated downregulation of three of seven ribosomal RNA operons, were sufficient for resistance, although β-lactams have no known impact on the RNAP or ribosomes. This implies that modifications of RNAP and ribosome functions are critical to prevent downstream effects of the inactivation of peptidoglycan transpeptidases by β-lactams.
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Affiliation(s)
- Henri Voedts
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université Paris Cité, Paris, France
| | - Constantin Anoyatis-Pelé
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université Paris Cité, Paris, France
| | - Olivier Langella
- GQE-Le Moulon/PAPPSO, Université Paris-Saclay, INRAE, CNRS, AgroParisTech, IDEEV, Gif-sur-Yvette, France
| | - Filippo Rusconi
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université Paris Cité, Paris, France
- GQE-Le Moulon/PAPPSO, Université Paris-Saclay, INRAE, CNRS, AgroParisTech, IDEEV, Gif-sur-Yvette, France
| | - Jean-Emmanuel Hugonnet
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université Paris Cité, Paris, France.
| | - Michel Arthur
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université Paris Cité, Paris, France.
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22
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Qi W, Jonker MJ, Katsavelis D, de Leeuw W, Wortel M, Ter Kuile BH. The Effect of the Stringent Response and Oxidative Stress Response on Fitness Costs of De Novo Acquisition of Antibiotic Resistance. Int J Mol Sci 2024; 25:2582. [PMID: 38473832 DOI: 10.3390/ijms25052582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/12/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Resistance evolution during exposure to non-lethal levels of antibiotics is influenced by various stress responses of bacteria which are known to affect growth rate. Here, we aim to disentangle how the interplay between resistance development and associated fitness costs is affected by stress responses. We performed de novo resistance evolution of wild-type strains and single-gene knockout strains in stress response pathways using four different antibiotics. Throughout resistance development, the increase in minimum inhibitory concentration (MIC) is accompanied by a gradual decrease in growth rate, most pronounced in amoxicillin or kanamycin. By measuring biomass yield on glucose and whole-genome sequences at intermediate and final time points, we identified two patterns of how the stress responses affect the correlation between MIC and growth rate. First, single-gene knockout E. coli strains associated with reactive oxygen species (ROS) acquire resistance faster, and mutations related to antibiotic permeability and pumping out occur earlier. This increases the metabolic burden of resistant bacteria. Second, the ΔrelA knockout strain, which has reduced (p)ppGpp synthesis, is restricted in its stringent response, leading to diminished growth rates. The ROS-related mutagenesis and the stringent response increase metabolic burdens during resistance development, causing lower growth rates and higher fitness costs.
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Affiliation(s)
- Wenxi Qi
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Martijs J Jonker
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Drosos Katsavelis
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Wim de Leeuw
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Meike Wortel
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Benno H Ter Kuile
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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23
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Van Loon JC, Whitfield GB, Wong N, O'Neal L, Henrickson A, Demeler B, O'Toole GA, Parsek MR, Howell PL. Binding of GTP to BifA is required for the production of Pel-dependent biofilms in Pseudomonas aeruginosa. J Bacteriol 2024; 206:e0033123. [PMID: 38197635 PMCID: PMC10882990 DOI: 10.1128/jb.00331-23] [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: 10/06/2023] [Accepted: 12/13/2023] [Indexed: 01/11/2024] Open
Abstract
The Pel exopolysaccharide is one of the most mechanistically conserved and phylogenetically diverse bacterial biofilm matrix determinants. Pel is a major contributor to the structural integrity of Pseudomonas aeruginosa biofilms, and its biosynthesis is regulated by the binding of cyclic-3',5'-dimeric guanosine monophosphate (c-di-GMP) to the PelD receptor. c-di-GMP is synthesized from two molecules of guanosine triphosphate (GTP) by diguanylate cyclases with GGDEF domains and degraded by phosphodiesterases with EAL or HD-GYP domains. As the P. aeruginosa genome encodes 43 c-di-GMP metabolic enzymes, one way signaling specificity can be achieved is through direct interaction between specific enzyme-receptor pairs. Here, we show that the inner membrane hybrid GGDEF-EAL enzyme, BifA, directly interacts with PelD via its cytoplasmic HAMP, GGDEF, and EAL domains. Despite having no catalytic function, the degenerate active site motif of the BifA GGDEF domain (GGDQF) has retained the ability to bind GTP with micromolar affinity. Mutations that abolish GTP binding result in increased biofilm formation but stable global c-di-GMP levels. Our data suggest that BifA forms a dimer in solution and that GTP binding induces conformational changes in dimeric BifA that enhance the BifA-PelD interaction and stimulate its phosphodiesterase activity, thus reducing c-di-GMP levels and downregulating Pel biosynthesis. Structural comparisons between the dimeric AlphaFold2 model of BifA and the structures of other hybrid GGDEF-EAL proteins suggest that the regulation of BifA by GTP may occur through a novel mechanism.IMPORTANCEc-di-GMP is the most common cyclic dinucleotide used by bacteria to regulate phenotypes such as motility, biofilm formation, virulence factor production, cell cycle progression, and cell differentiation. While the identification and initial characterization of c-di-GMP metabolic enzymes are well established, our understanding of how these enzymes are regulated to provide signaling specificity remains understudied. Here we demonstrate that the inactive GGDEF domain of BifA binds GTP and regulates the adjacent phosphodiesterase EAL domain, ultimately downregulating Pel-dependent P. aeruginosa biofilm formation through an interaction with PelD. This discovery adds to the growing body of literature regarding how hybrid GGDEF-EAL enzymes are regulated and provides additional precedence for studying how direct interactions between c-di-GMP metabolic enzymes and effectors result in signaling specificity.
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Affiliation(s)
- Jaime C. Van Loon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Gregory B. Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Nicole Wong
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Lindsey O'Neal
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - Amy Henrickson
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada
| | - G. A. O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Matthew R. Parsek
- Department of Microbiology, University of Washington, Seattle, Washington, USA
| | - P. Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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24
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Zhu M, Mu H, Dai X. Integrated control of bacterial growth and stress response by (p)ppGpp in Escherichia coli: A seesaw fashion. iScience 2024; 27:108818. [PMID: 38299113 PMCID: PMC10828813 DOI: 10.1016/j.isci.2024.108818] [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: 07/13/2023] [Revised: 12/02/2023] [Accepted: 01/02/2024] [Indexed: 02/02/2024] Open
Abstract
To thrive in nature, bacteria have to reproduce efficiently under favorable conditions and persist during stress. The global strategy that integrates the growth control and stress response remains to be explored. Here, we find that a moderate induction of (p)ppGpp reduces growth rate but significantly enhances the stress tolerance of E. coli, resulting from a global resource re-allocation from ribosome synthesis to the synthesis of stress-responsive proteins. Strikingly, the activation of stress response by (p)ppGpp is still largely retained in the absence of RpoS. In addition, (p)ppGpp induction could activate the catabolism of alanine and arginine, facilitating the adaption of bacteria to nutrient downshift. Our work demonstrates that the activation of stress response by (p)ppGpp could occur in an RpoS-independent manner and (p)ppGpp enables bacteria to integrate the control of growth and stress response in a seesaw fashion, thus acting as an important global regulator of the bacterial fitness landscape.
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Affiliation(s)
- Manlu Zhu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences & National Key Laboratory of Green Pesticides, Central China Normal University, Wuhan, China
| | - Haoyan Mu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences & National Key Laboratory of Green Pesticides, Central China Normal University, Wuhan, China
| | - Xiongfeng Dai
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences & National Key Laboratory of Green Pesticides, Central China Normal University, Wuhan, China
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25
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Malik A, Oludiran A, Poudel A, Alvarez OB, Woodward C, Purcell EB. RelQ-mediated alarmone signaling regulates growth, sporulation, and stress-induced biofilm formation in Clostridioides difficile. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580318. [PMID: 38405794 PMCID: PMC10888890 DOI: 10.1101/2024.02.14.580318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signaling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors, and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm formation in the presence of sub-lethal stress, the ΔrelQ strain cannot upregulate biofilm production in response to stress. Deletion of relQ slows spore accumulation in planktonic cultures but accelerates it in biofilms. This work establishes biofilm formation and sporulation as alarmone-mediated processes in C. difficile and reveals the importance of RelQ in stress-induced biofilm regulation.
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Affiliation(s)
- Areej Malik
- Biomedical Sciences Program, Old Dominion University, Norfolk, Virginia, 23529, USA
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Adenrele Oludiran
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Asia Poudel
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Orlando Berumen Alvarez
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Charles Woodward
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
| | - Erin B. Purcell
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia, 23529, USA
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26
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Lo CC, Yeh TH, Jao YH, Wang TH, Lo HR. Efficacy of outer membrane permeabilization in promoting aromatic isothiocyanates-mediated eradication of multidrug resistant Gram-negative bacteria and bacterial persisters. Folia Microbiol (Praha) 2024:10.1007/s12223-024-01143-6. [PMID: 38319459 DOI: 10.1007/s12223-024-01143-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 01/27/2024] [Indexed: 02/07/2024]
Abstract
Multidrug resistant (MDR) bacteria are recognized to be one of the most important problems in public health. The outer membrane permeability is a critical intrinsic mechanism of bacterial resistance. In addition, bacteria produce a small number of dormant persister cells causing multidrug tolerance that reduces antimicrobial efficacy. This study aimed to evaluate the inhibitory effects of the combination of aromatic isothiocyanates (ITCs) with membrane-active agents on bacterial persisters and MDR Gram-negative bacteria. Our study demonstrated that membrane-active agents, particularly ethylenediaminetetraacetic acid (EDTA) synergistically enhanced the inhibitory activity of aromatic benzyl ITC and phenethyl ITC against most Gram-negative bacteria strains with fractional inhibitory concentration index values ranging from 0.18 to 0.5 and 0.16 to 0.5, respectively, and contributed to an 8- to 64-fold minimal inhibitory concentration reduction compared with those of aromatic ITCs alone. The EDTA-aromatic ITCs combination effectively reduced the survival rates of tested bacteria and significantly eradicated bacterial persisters (p = 0.033 and 0.037, respectively). The growth kinetics analysis also supported the enhanced inhibitory effect of EDTA-aromatic ITCs combination against tested bacteria. Our results suggested an alternate treatment strategy against Gram-negative bacteria, promoting the entry of aromatic ITCs into bacterial cytoplasm to facilitate bacterial clearance and thus preventing the development of bacterial resistance.
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Affiliation(s)
- Chung-Cheng Lo
- Department of Internal Medicine, Pingtung Veterans General Hospital Longquan Branch, Pingtung, 912012, Taiwan
| | - Tzu-Hui Yeh
- Department of Pathology and Laboratory Medicine, Pingtung Veterans General Hospital, Pingtung, 900053, Taiwan
| | - Ya-Hsuan Jao
- Department of Clinical Laboratory, Kaohsiung Municipal Min-Sheng Hospital, Kaohsiung, 802511, Taiwan
| | - Tzu-Hui Wang
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, 813414, Taiwan
| | - Horng-Ren Lo
- Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung, 831301, Taiwan.
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27
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Kashevarova NM, Khaova EA, Tkachenko AG. The regulatory effects of (p)ppGpp and indole on cAMP synthesis in Escherichia coli cells. Vavilovskii Zhurnal Genet Selektsii 2024; 28:15-23. [PMID: 38465243 PMCID: PMC10917672 DOI: 10.18699/vjgb-24-03] [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: 07/14/2023] [Revised: 10/13/2023] [Accepted: 10/15/2023] [Indexed: 03/12/2024] Open
Abstract
Bacterial stress adaptive response is formed due to changes in the cell gene expression profile in response to alterations in environmental conditions through the functioning of regulatory networks. The mutual influence of network signaling molecules represented by cells' natural metabolites, including indole and second messengers (p) ppGpp and cAMP, is hitherto not well understood, being the aim of this study. E. coli parent strain BW25141 ((p) ppGpp+) and deletion knockout BW25141ΔrelAΔspoT which is unable to synthesize (p)ppGpp ((p)ppGpp0) were cultivated in M9 medium supplemented with different glucose concentrations (5.6 and 22.2 mM) in the presence of tryptophan as a substrate for indole synthesis and in its absence. The glucose content was determined with the glucose oxidase method; the indole content, by means of HPLC; and the cAMP concentration, by ELISA. The onset of an increase in initially low intracellular cAMP content coincided with the depletion of glucose in the medium. Maximum cAMP accumulation in the cells was proportional to the concentration of initially added glucose. At the same time, the (p) ppGpp0 mutant showed a decrease in maximum cAMP levels compared to the (p)ppGpp+ parent, which was the most pronounced in the medium with 22.2 mM glucose. So, (p)ppGpp was able to positively regulate cAMP formation. The promoter of the tryptophanase operon responsible for indole biosynthesis is known to be under the positive control of catabolic repression. Therefore, in the cells of the (p)ppGpp+ strain grown in the tryptophan-free medium that were characterized by a low rate of spontaneous indole formation, its synthesis significantly increased in response to the rising cAMP level just after glucose depletion. However, this was not observed in the (p)ppGpp0 mutant cells with reduced cAMP accumulation. When tryptophan was added to the medium, both of these strains demonstrated high indole production, which was accompanied by a decrease in cAMP accumulation compared to the tryptophan-free control. Thus, under glucose depletion, (p)ppGpp can positively regulate the accumulation of both cAMP and indole, while the latter, in its turn, has a negative effect on cAMP formation.
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Affiliation(s)
- N M Kashevarova
- Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Perm, Russia
| | - E A Khaova
- Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Perm, Russia
| | - A G Tkachenko
- Institute of Ecology and Genetics of Microorganisms of the Ural Branch of the Russian Academy of Sciences, Perm, Russia
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28
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Chrenková A, Bisiak F, Brodersen DE. Breaking bad nucleotides: understanding the regulatory mechanisms of bacterial small alarmone hydrolases. Trends Microbiol 2024:S0966-842X(23)00363-3. [PMID: 38262803 DOI: 10.1016/j.tim.2023.12.011] [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: 11/11/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/25/2024]
Abstract
Guanosine tetra- and pentaphosphate nucleotides, (p)ppGpp, function as central secondary messengers and alarmones in bacterial cell biology, signalling a range of stress conditions, including nutrient starvation and exposure to cell-wall-targeting antibiotics, and are critical for survival. While activation of the stringent response and alarmone synthesis on starved ribosomes by members of the RSH (Rel) class of proteins is well understood, much less is known about how single-domain small alarmone synthetases (SASs) and their corresponding alarmone hydrolases, the small alarmone hydrolases (SAHs), are regulated and contribute to (p)ppGpp homeostasis. The substrate spectrum of these enzymes has recently been expanded to include hyperphosphorylated adenosine nucleotides, suggesting that they take part in a highly complex and interconnected signalling network. In this review, we provide an overview of our understanding of the SAHs and discuss their structure, function, regulation, and phylogeny.
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Affiliation(s)
- Adriana Chrenková
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000 Aarhus C, Denmark
| | - Francesco Bisiak
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000 Aarhus C, Denmark
| | - Ditlev E Brodersen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, DK-8000 Aarhus C, Denmark.
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29
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Zhou RW, Gordon IJ, Hei Y, Wang B. Synthetase and Hydrolase Specificity Collectively Excludes 2'-Deoxyguanosine from Bacterial Alarmone. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.06.574488. [PMID: 38260349 PMCID: PMC10802352 DOI: 10.1101/2024.01.06.574488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
In response to starvation, virtually all bacteria pyrophosphorylate the 3'-hydroxy group of GTP or GDP to produce two messenger nucleotides collectively denoted as (p)ppGpp. Also known as alarmones, (p)ppGpp reprograms bacterial physiology to arrest growth and promote survival. Intriguingly, although cellular concentration of dGTP is two orders of magnitude lower than that of GTP, alarmone synthetases are highly selective against using 2'-deoxyguanosine (2dG) nucleotides as substrates. We thus hypothesize that production of 2dG alarmone, (p)pp(dG)pp, is highly deleterious, which drives a strong negative selection to exclude 2dG nucleotides from alarmone signaling. In this work, we show that the B. subtilis SasB synthetase prefers GDP over dGDP with 65,000-fold higher kcat/Km, a specificity stricter than RNA polymerase selecting against 2'-deoxynucleotides. Using comparative chemical proteomics, we found that although most known alarmone-binding proteins in Escherichia coli cannot distinguish ppGpp from pp(dG)pp, hydrolysis of pp(dG)pp by the essential hydrolase, SpoT, is 1,000-fold slower. This inability to degrade 2'-deoxy-3'-pyrophosphorylated substrate is a common feature of the alarmone hydrolase family. We further show that SpoT is a binuclear metallopyrophoshohydrolase and that hydrolysis of ppGpp and pp(dG)pp shares the same metal dependence. Our results support a model in which 2'-OH directly coordinates the Mn2+ at SpoT active center to stabilize the hydrolysis-productive conformation of ppGpp. Taken together, our study reveals a vital role of 2'-OH in alarmone degradation, provides new insight on the catalytic mechanism of alarmone hydrolases, and leads to the conclusion that 2dG nucleotides must be strictly excluded from alarmone synthesis because bacteria lack the key machinery to down-regulate such products.
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Affiliation(s)
- Rich W Zhou
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Isis J Gordon
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yuanyuan Hei
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Boyuan Wang
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
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30
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Maffei E, Woischnig AK, Burkolter MR, Heyer Y, Humolli D, Thürkauf N, Bock T, Schmidt A, Manfredi P, Egli A, Khanna N, Jenal U, Harms A. Phage Paride can kill dormant, antibiotic-tolerant cells of Pseudomonas aeruginosa by direct lytic replication. Nat Commun 2024; 15:175. [PMID: 38168031 PMCID: PMC10761892 DOI: 10.1038/s41467-023-44157-3] [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: 10/17/2023] [Accepted: 12/01/2023] [Indexed: 01/05/2024] Open
Abstract
Bacteriophages are ubiquitous viral predators that have primarily been studied using fast-growing laboratory cultures of their bacterial hosts. However, microbial life in nature is mostly in a slow- or non-growing, dormant state. Here, we show that diverse phages can infect deep-dormant bacteria and suspend their replication until the host resuscitates ("hibernation"). However, a newly isolated Pseudomonas aeruginosa phage, named Paride, can directly replicate and induce the lysis of deep-dormant hosts. While non-growing bacteria are notoriously tolerant to antibiotic drugs, the combination with Paride enables the carbapenem meropenem to eradicate deep-dormant cultures in vitro and to reduce a resilient bacterial infection of a tissue cage implant in mice. Our work might inspire new treatments for persistent bacterial infections and, more broadly, highlights two viral strategies to infect dormant bacteria (hibernation and direct replication) that will guide future studies on phage-host interactions.
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Affiliation(s)
- Enea Maffei
- Biozentrum, University of Basel, Basel, Switzerland
- Institute of Food, Nutrition and Health, D-HEST, ETH Zurich, Zurich, Switzerland
| | - Anne-Kathrin Woischnig
- Laboratory of Infection Biology, Department of Biomedicine, University and University Hospital Basel, Basel, Switzerland
| | - Marco R Burkolter
- Biozentrum, University of Basel, Basel, Switzerland
- Institute of Food, Nutrition and Health, D-HEST, ETH Zurich, Zurich, Switzerland
| | - Yannik Heyer
- Biozentrum, University of Basel, Basel, Switzerland
| | - Dorentina Humolli
- Institute of Food, Nutrition and Health, D-HEST, ETH Zurich, Zurich, Switzerland
| | | | - Thomas Bock
- Biozentrum, University of Basel, Basel, Switzerland
| | | | | | - Adrian Egli
- Division of Clinical Bacteriology and Mycology, University Hospital Basel, Basel, Switzerland
- Applied Microbiology Research, Department of Biomedicine, University of Basel, Basel, Switzerland
- Division of Infectious Diseases and Hospital Epidemiology, University and University Hospital of Basel, Basel, Switzerland
| | - Nina Khanna
- Institute of Food, Nutrition and Health, D-HEST, ETH Zurich, Zurich, Switzerland
- Laboratory of Infection Biology, Department of Biomedicine, University and University Hospital Basel, Basel, Switzerland
| | - Urs Jenal
- Biozentrum, University of Basel, Basel, Switzerland
| | - Alexander Harms
- Biozentrum, University of Basel, Basel, Switzerland.
- Institute of Food, Nutrition and Health, D-HEST, ETH Zurich, Zurich, Switzerland.
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Hidese R, Ohbayashi R, Kato Y, Matsuda M, Tanaka K, Imamura S, Ashida H, Kondo A, Hasunuma T. ppGpp accumulation reduces the expression of the global nitrogen homeostasis-modulating NtcA regulon by affecting 2-oxoglutarate levels. Commun Biol 2023; 6:1285. [PMID: 38145988 PMCID: PMC10749895 DOI: 10.1038/s42003-023-05632-1] [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: 03/06/2023] [Accepted: 11/23/2023] [Indexed: 12/27/2023] Open
Abstract
The cyanobacterium Synechococcus elongatus PCC 7942 accumulates alarmone guanosine tetraphosphate (ppGpp) under stress conditions, such as darkness. A previous study observed that artificial ppGpp accumulation under photosynthetic conditions led to the downregulation of genes involved in the nitrogen assimilation system, which is activated by the global nitrogen regulator NtcA, suggesting that ppGpp regulates NtcA activity. However, the details of this mechanism have not been elucidated. Here, we investigate the metabolic responses associated with ppGpp accumulation by heterologous expression of the ppGpp synthetase RelQ. The pool size of 2-oxoglutarate (2-OG), which activates NtcA, is significantly decreased upon ppGpp accumulation. De novo 13C-labeled CO2 assimilation into the Calvin-Benson-Bassham cycle and glycolytic intermediates continues irrespective of ppGpp accumulation, whereas the labeling of 2-OG is significantly decreased under ppGpp accumulation. The low 2-OG levels in the RelQ overexpression cells could be because of the inhibition of metabolic enzymes, including aconitase, which are responsible for 2-OG biosynthesis. We propose a metabolic rearrangement by ppGpp accumulation, which negatively regulates 2-OG levels to maintain carbon and nitrogen balance.
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Affiliation(s)
- Ryota Hidese
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Ryudo Ohbayashi
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
- Department of Biological Sciences, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Yuichi Kato
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Mami Matsuda
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
- NTT Space Environment and Enegy Laboratories, Nippon Telegraph and Telephone Corporation, 3-9-11 Midori-cho, Musashino-shi, Tokyo, 180-8585, Japan
| | - Hiroki Ashida
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-Ku, Kobe, 657-8501, Japan
| | - Akihiko Kondo
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Research Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Research Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan.
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32
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Giengkam S, Kullapanich C, Wongsantichon J, Adcox HE, Gillespie JJ, Salje J. Orientia tsutsugamushi: comprehensive analysis of the mobilome of a highly fragmented and repetitive genome reveals the capacity for ongoing lateral gene transfer in an obligate intracellular bacterium. mSphere 2023; 8:e0026823. [PMID: 37850800 PMCID: PMC10732058 DOI: 10.1128/msphere.00268-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/22/2023] [Indexed: 10/19/2023] Open
Abstract
IMPORTANCE Obligate intracellular bacteria, or those only capable of growth inside other living cells, have limited opportunities for horizontal gene transfer with other microbes due to their isolated replicative niche. The human pathogen Ot, an obligate intracellular bacterium causing scrub typhus, encodes an unusually high copy number of a ~40 gene mobile genetic element that typically facilitates genetic transfer across microbes. This proliferated element is heavily degraded in Ot and previously assumed to be inactive. Here, we conducted a detailed analysis of this element in eight Ot strains and discovered two strains with at least one intact copy. This implies that the element is still capable of moving across Ot populations and suggests that the genome of this bacterium may be even more dynamic than previously appreciated. Our work raises questions about intracellular microbial evolution and sounds an alarm for gene-based efforts focused on diagnosing and combatting scrub typhus.
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Affiliation(s)
- Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chitrasak Kullapanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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33
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Margarita V, Carboni G, Diaz N, Rappelli P, Fiori PL. Patterns of antibiotic resistance of Mycoplasma hominis endosymbiont of Trichomonas vaginalis and the influence of bacterial intracellular location on drug susceptibility. J Glob Antimicrob Resist 2023; 35:210-215. [PMID: 37816433 DOI: 10.1016/j.jgar.2023.09.021] [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: 07/05/2023] [Revised: 09/29/2023] [Accepted: 09/30/2023] [Indexed: 10/12/2023] Open
Abstract
OBJECTIVES Mycoplasma hominis, an opportunistic pathogen of the human lower urogenital tract, can survive and replicate within the protozoan Trichomonas vaginalis, establishing an endosymbiotic relationship. The intracellular location may provide a means for the bacteria to evade the immune system and protection from antimicrobial activities. Our aim was to investigate the influence of the endosymbiotic association of M. hominis with trichomonad cells on bacterial antibiotic susceptibility. METHODS We evaluated antibiotic resistance patterns in a group of M. hominis isolated from T. vaginalis clinical specimens as well as in M. hominis isolated from patients without trichomoniasis. Using an experimental model system, we compared the minimum inhibitory concentration (MIC) and lethal concentration (MLC) of tetracycline on M. hominis endosymbionts of T. vaginalis and extracellular bacteria. RESULTS The incidence rate of M. hominis strains resistant to C14 and C15 macrolide antibiotics was higher in intracellular strains associated with T. vaginalis compared with extracellular bacteria isolated from women not affected by trichomoniasis. However, sensitivity to tetracycline and quinolones was similar in both groups. In vitro experiments demonstrated that M. hominis strains, when isolated as endosymbionts from T. vaginalis, exhibited reduced sensitivity to tetracycline when cultured extracellularly for at least eight weeks. CONCLUSION The intracellular localization of bacteria within trichomonad cells may affect antibiotic susceptibility.
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Affiliation(s)
- Valentina Margarita
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro, Sassari, Italy
| | - Gavino Carboni
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro, Sassari, Italy
| | - Nicia Diaz
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro, Sassari, Italy
| | - Paola Rappelli
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro, Sassari, Italy; Azienda Universitaria Ospedaliera (AOU) Sassari, Sassari, Italy
| | - Pier Luigi Fiori
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro, Sassari, Italy; Azienda Universitaria Ospedaliera (AOU) Sassari, Sassari, Italy.
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Fung DK, Trinquier AE, Wang JD. Crosstalk between (p)ppGpp and other nucleotide second messengers. Curr Opin Microbiol 2023; 76:102398. [PMID: 37866203 PMCID: PMC10842992 DOI: 10.1016/j.mib.2023.102398] [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: 08/07/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/24/2023]
Abstract
In response to environmental cues, bacteria produce intracellular nucleotide messengers to regulate a wide variety of cellular processes and physiology. Studies on individual nucleotide messengers, such as (p)ppGpp or cyclic (di)nucleotides, have established their respective regulatory themes. As research on nucleotide signaling networks expands, recent studies have begun to uncover various crosstalk mechanisms between (p)ppGpp and other nucleotide messengers, including signal conversion, allosteric regulation, and target competition. The multiple layers of crosstalk implicate that (p)ppGpp is intricately linked to different nucleotide signaling pathways. From a physiological perspective, (p)ppGpp crosstalk enables fine-tuning and feedback regulation with other nucleotide messengers to achieve optimal adaptation.
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Affiliation(s)
- Danny K Fung
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Aude E Trinquier
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jue D Wang
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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35
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Guiraud P, Germain E, Byrne D, Maisonneuve E. The YmgB-SpoT interaction triggers the stringent response in Escherichia coli. J Biol Chem 2023; 299:105429. [PMID: 37926282 PMCID: PMC10704370 DOI: 10.1016/j.jbc.2023.105429] [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: 07/17/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023] Open
Abstract
Virtually all bacterial species synthesize (p)ppGpp (guanosine penta- or tetraphosphate), a pleiotropic regulator of the so-called stringent response, which controls many aspects of cellular physiology and metabolism. In Escherichia coli, (p)ppGpp levels are controlled by two homologous enzymes: the (p)ppGpp synthetase RelA and the bifunctional synthetase/hydrolase SpoT. We recently identified several protein candidates that can modulate (p)ppGpp levels in E. coli. In this work, we show that the putative two-component system connector protein YmgB can promote SpoT-dependent accumulation of ppGpp in E. coli. Importantly, we determined that the control of SpoT activities by YmgB is independent of its proposed role in the two-component Rcs system, and these two functions can be uncoupled. Using genetic and structure-function analysis, we show that the regulation of SpoT activities by YmgB occurs by functional and direct binding in vivo and in vitro to the TGS and Helical domains of SpoT. These results further support the role of these domains in controlling the reciprocal enzymatic states.
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Affiliation(s)
- Paul Guiraud
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS-Aix Marseille Univ (UMR7283), Marseille, France
| | - Elsa Germain
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS-Aix Marseille Univ (UMR7283), Marseille, France
| | - Deborah Byrne
- Protein Expression Facility, Institut de Microbiologie de la Méditerranée, CNRS-Aix Marseille Univ, Marseille, France
| | - Etienne Maisonneuve
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS-Aix Marseille Univ (UMR7283), Marseille, France.
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36
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Grucela PK, Zhang YE. Basal level of ppGpp coordinates Escherichia coli cell heterogeneity and ampicillin resistance and persistence. MICROBIAL CELL (GRAZ, AUSTRIA) 2023; 10:248-260. [PMID: 37933276 PMCID: PMC10625690 DOI: 10.15698/mic2023.11.808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/20/2023] [Accepted: 10/18/2023] [Indexed: 11/08/2023]
Abstract
The universal stringent response alarmone ppGpp (guanosine penta and tetra phosphates) plays a crucial role in various aspects of fundamental cell physiology (e.g., cell growth rate, cell size) and thus bacterial tolerance to and survival of external stresses, including antibiotics. Besides transient antibiotic tolerance (persistence), ppGpp was recently found to contribute to E. coli resistance to ampicillin. How ppGpp regulates both the persistence and resistance to antibiotics remains incompletely understood. In this study, we first clarified that the absence of ppGpp in E. coli (ppGpp0 strain) resulted in a decreased minimal inhibition concentration (MIC) value of ampicillin but, surprisingly, a higher persistence level to ampicillin during exponential growth in MOPS rich medium. High basal ppGpp levels, thus lower growth rate, did not produce high ampicillin persistence. Importantly, we found that the high ampicillin persistence of the ppGpp0 strain is not due to dormant overnight carry-over cells. Instead, the absence of ppGpp produced higher cell heterogeneity, propagating during the regrowth and the killing phases, leading to higher ampicillin persistence. Consistently, we isolated a suppressor mutation of the ppGpp0 strain that restored the standard MIC value of ampicillin and reduced its cell heterogeneity and the ampicillin persistence level concomitantly. Altogether, we discussed the fundamental role of basal level of ppGpp in regulating cell homogeneity and ampicillin persistence.
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Affiliation(s)
| | - Yong Everett Zhang
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark
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37
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Shearer HL, Pace PE, Smith LM, Fineran PC, Matthews AJ, Camilli A, Dickerhof N, Hampton MB. Identification of Streptococcus pneumoniae genes associated with hypothiocyanous acid tolerance through genome-wide screening. J Bacteriol 2023; 205:e0020823. [PMID: 37791755 PMCID: PMC10601753 DOI: 10.1128/jb.00208-23] [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: 07/05/2023] [Accepted: 09/01/2023] [Indexed: 10/05/2023] Open
Abstract
Streptococcus pneumoniae is a commensal bacterium and invasive pathogen that causes millions of deaths worldwide. The pneumococcal vaccine offers limited protection, and the rise of antimicrobial resistance will make treatment increasingly challenging, emphasizing the need for new antipneumococcal strategies. One possibility is to target antioxidant defenses to render S. pneumoniae more susceptible to oxidants produced by the immune system. Human peroxidase enzymes will convert bacterial-derived hydrogen peroxide to hypothiocyanous acid (HOSCN) at sites of colonization and infection. Here, we used saturation transposon mutagenesis and deep sequencing to identify genes that enable S. pneumoniae to tolerate HOSCN. We identified 37 genes associated with S. pneumoniae HOSCN tolerance, including genes involved in metabolism, membrane transport, DNA repair, and oxidant detoxification. Single-gene deletion mutants of the identified antioxidant defense genes sodA, spxB, trxA, and ahpD were generated and their ability to survive HOSCN was assessed. With the exception of ΔahpD, all deletion mutants showed significantly greater sensitivity to HOSCN, validating the result of the genome-wide screen. The activity of hypothiocyanous acid reductase or glutathione reductase, known to be important for S. pneumoniae tolerance of HOSCN, was increased in three of the mutants, highlighting the compensatory potential of antioxidant systems. Double deletion of the gene encoding glutathione reductase and sodA sensitized the bacteria significantly more than single deletion. The HOSCN defense systems identified in this study may be viable targets for novel therapeutics against this deadly pathogen. IMPORTANCE Streptococcus pneumoniae is a human pathogen that causes pneumonia, bacteremia, and meningitis. Vaccination provides protection only against a quarter of the known S. pneumoniae serotypes, and the bacterium is rapidly becoming resistant to antibiotics. As such, new treatments are required. One strategy is to sensitize the bacteria to killing by the immune system. In this study, we performed a genome-wide screen to identify genes that help this bacterium resist oxidative stress exerted by the host at sites of colonization and infection. By identifying a number of critical pneumococcal defense mechanisms, our work provides novel targets for antimicrobial therapy.
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Affiliation(s)
- Heather L. Shearer
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
| | - Paul E. Pace
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Leah M. Smith
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Peter C. Fineran
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand
| | - Allison J. Matthews
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Nina Dickerhof
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
| | - Mark B. Hampton
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
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Herzberg C, Meißner J, Warneke R, Stülke J. The many roles of cyclic di-AMP to control the physiology of Bacillus subtilis. MICROLIFE 2023; 4:uqad043. [PMID: 37954098 PMCID: PMC10636490 DOI: 10.1093/femsml/uqad043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/21/2023] [Accepted: 10/19/2023] [Indexed: 11/14/2023]
Abstract
The dinucleotide cyclic di-AMP (c-di-AMP) is synthesized as a second messenger in the Gram-positive model bacterium Bacillus subtilis as well as in many bacteria and archaea. Bacillus subtilis possesses three diadenylate cyclases and two phosphodiesterases that synthesize and degrade the molecule, respectively. Among the second messengers, c-di-AMP is unique since it is essential for B. subtilis on the one hand but toxic upon accumulation on the other. This role as an "essential poison" is related to the function of c-di-AMP in the control of potassium homeostasis. C-di-AMP inhibits the expression and activity of potassium uptake systems by binding to riboswitches and transporters and activates the activity of potassium exporters. In this way, c-di-AMP allows the adjustment of uptake and export systems to achieve a balanced intracellular potassium concentration. C-di-AMP also binds to two dedicated signal transduction proteins, DarA and DarB. Both proteins seem to interact with other proteins in their apo state, i.e. in the absence of c-di-AMP. For DarB, the (p)ppGpp synthetase/hydrolase Rel and the pyruvate carboxylase PycA have been identified as targets. The interactions trigger the synthesis of the alarmone (p)ppGpp and of the acceptor molecule for the citric acid cycle, oxaloacetate, respectively. In the absence of c-di-AMP, many amino acids inhibit the growth of B. subtilis. This feature can be used to identify novel players in amino acid homeostasis. In this review, we discuss the different functions of c-di-AMP and their physiological relevance.
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Affiliation(s)
- Christina Herzberg
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Janek Meißner
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Robert Warneke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
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Shea J, Davis L, Quaye B, Gedeon T. Ribosome Abundance Control in Prokaryotes. Bull Math Biol 2023; 85:119. [PMID: 37861893 DOI: 10.1007/s11538-023-01212-w] [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: 05/01/2023] [Accepted: 09/06/2023] [Indexed: 10/21/2023]
Abstract
Cell growth is an essential phenotype of any unicellular organism and it crucially depends on precise control of protein synthesis. We construct a model of the feedback mechanisms that regulate abundance of ribosomes in E. coli, a prototypical prokaryotic organism. Since ribosomes are needed to produce more ribosomes, the model includes a positive feedback loop central to the control of cell growth. Our analysis of the model shows that there can be only two coexisting equilibrium states across all 23 parameters. This precludes the existence of hysteresis, suggesting that the ribosome abundance changes continuously with parameters. These states are related by a transcritical bifurcation, and we provide an analytic formula for parameters that admit either state.
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Affiliation(s)
- Jacob Shea
- Department of Mathematical Sciences, Montana State University, Bozeman, MT, 59717, USA
| | - Lisa Davis
- Department of Mathematical Sciences, Montana State University, Bozeman, MT, 59717, USA
| | - Bright Quaye
- Department of Economics, Washington University, St. Louis, MO, USA
| | - Tomas Gedeon
- Department of Mathematical Sciences, Montana State University, Bozeman, MT, 59717, USA.
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40
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Huang S, Zhang X, Song Z, Rahman MU, Fan B. Transcriptional Profiling and Transposon Mutagenesis Study of the Endophyte Pantoea eucalypti FBS135 Adapting to Nitrogen Starvation. Int J Mol Sci 2023; 24:14282. [PMID: 37762583 PMCID: PMC10532344 DOI: 10.3390/ijms241814282] [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: 08/17/2023] [Revised: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
The research on plant endophytes has been drawing a lot of attention in recent years. Pantoea belongs to a group of endophytes with plant growth-promoting activity and has been widely used in agricultural fields. In our earlier studies, Pantoea eucalypti FBS135 was isolated from healthy-growing Pinus massoniana and was able to promote pine growth. P. eucalypti FBS135 can grow under extremely low nitrogen conditions. To understand the mechanism of the low-nitrogen tolerance of this bacterium, the transcriptome of FBS135 in the absence of nitrogen was examined in this study. We found that FBS135 actively regulates its gene expression in response to nitrogen deficiency. Nearly half of the number (4475) of genes in FBS135 were differentially expressed under this condition, mostly downregulated, while it significantly upregulated many transportation-associated genes and some nitrogen metabolism-related genes. In the downregulated genes, the ribosome pathway-related ones were significantly enriched. Meanwhile, we constructed a Tn5 transposon library of FBS135, from which four genes involved in low-nitrogen tolerance were screened out, including the gene for the host-specific protein J, RNA polymerase σ factor RpoS, phosphoribosamine-glycine ligase, and serine acetyltransferase. Functional analysis of the genes revealed their potential roles in the adaptation to nitrogen limitation. The results obtained in this work shed light on the mechanism of endophytes represented by P. eucalypti FBS135, at the overall transcriptional level, to an environmentally limited nitrogen supply and provided a basis for further investigation on this topic.
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Affiliation(s)
- Shengquan Huang
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
| | - Xiuyu Zhang
- Department of Biology and Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Zongwen Song
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
| | - Mati Ur Rahman
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
| | - Ben Fan
- Department of Forestry, Nanjing Forestry University, Nanjing 210037, China (M.U.R.)
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Sinha S, RS N, Devarakonda Y, Rathi A, Reddy Regatti P, Batra S, Syal K. Tale of Twin Bifunctional Second Messenger (p)ppGpp Synthetases and Their Function in Mycobacteria. ACS OMEGA 2023; 8:32258-32270. [PMID: 37720788 PMCID: PMC10500699 DOI: 10.1021/acsomega.3c03557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 08/16/2023] [Indexed: 09/19/2023]
Abstract
M. tuberculosis, an etiological agent of tuberculosis, requires a long treatment regimen due to its ability to respond to stress and persist inside the host. The second messenger (p)ppGpp-mediated stress response plays a critical role in such long-term survival, persistence, and antibiotic tolerance which may also lead to the emergence of multiple drug resistance. In mycobacteria, (pp)pGpp molecules are synthesized predominantly by two bifunctional enzymes-long RSH-Rel and short SAS-RelZ. The long RSH-Rel is a major (p)ppGpp synthetase and hydrolase. How it switches its activity from synthesis to hydrolysis remains unclear. RelMtb mutant has been reported to be defective in biofilm formation, cell wall function, and persister cell formation. The survival of such mutants has also been observed to be compromised in infection models. In M. smegmatis, short SAS-RelZ has RNase HII activity in addition to (pp)Gpp synthesis activity. The RNase HII function of RelZ has been implicated in resolving replication-transcription conflicts by degrading R-loops. However, the mechanism and regulatory aspects of such a regulation remain elusive. In this article, we have discussed (p)ppGpp metabolism and its role in managing the stress response network of mycobacteria, which is responsible for long-term survival inside the host, making it an important therapeutic target.
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Affiliation(s)
- Shubham
Kumar Sinha
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
| | - Neethu RS
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
| | - Yogeshwar Devarakonda
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
| | - Ajita Rathi
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
| | - Pavan Reddy Regatti
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
| | - Sakshi Batra
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
| | - Kirtimaan Syal
- Genetics and Molecular Microbiology
Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India, 500078
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Njenga R, Boele J, Öztürk Y, Koch HG. Coping with stress: How bacteria fine-tune protein synthesis and protein transport. J Biol Chem 2023; 299:105163. [PMID: 37586589 PMCID: PMC10502375 DOI: 10.1016/j.jbc.2023.105163] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/18/2023] Open
Abstract
Maintaining a functional proteome under different environmental conditions is challenging for every organism, in particular for unicellular organisms, such as bacteria. In order to cope with changing environments and stress conditions, bacteria depend on strictly coordinated proteostasis networks that control protein production, folding, trafficking, and degradation. Regulation of ribosome biogenesis and protein synthesis are cornerstones of this cellular adaptation in all domains of life, which is rationalized by the high energy demand of both processes and the increased resistance of translationally silent cells against internal or external poisons. Reduced protein synthesis ultimately also reduces the substrate load for protein transport systems, which are required for maintaining the periplasmic, inner, and outer membrane subproteomes. Consequences of impaired protein transport have been analyzed in several studies and generally induce a multifaceted response that includes the upregulation of chaperones and proteases and the simultaneous downregulation of protein synthesis. In contrast, generally less is known on how bacteria adjust the protein targeting and transport machineries to reduced protein synthesis, e.g., when cells encounter stress conditions or face nutrient deprivation. In the current review, which is mainly focused on studies using Escherichia coli as a model organism, we summarize basic concepts on how ribosome biogenesis and activity are regulated under stress conditions. In addition, we highlight some recent developments on how stress conditions directly impair protein targeting to the bacterial membrane. Finally, we describe mechanisms that allow bacteria to maintain the transport of stress-responsive proteins under conditions when the canonical protein targeting pathways are impaired.
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Affiliation(s)
- Robert Njenga
- Faculty of Medicine, Institute for Biochemistry and Molecular Biology, ZBMZ, Albert-Ludwigs University Freiburg, Freiburg, Germany; Faculty of Biology, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Julian Boele
- Faculty of Medicine, Institute for Biochemistry and Molecular Biology, ZBMZ, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Yavuz Öztürk
- Faculty of Medicine, Institute for Biochemistry and Molecular Biology, ZBMZ, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Hans-Georg Koch
- Faculty of Medicine, Institute for Biochemistry and Molecular Biology, ZBMZ, Albert-Ludwigs University Freiburg, Freiburg, Germany.
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He L, Groom JD, Wilson EH, Fernandez J, Konopka MC, Beck DAC, Lidstrom ME. A methanotrophic bacterium to enable methane removal for climate mitigation. Proc Natl Acad Sci U S A 2023; 120:e2310046120. [PMID: 37603746 PMCID: PMC10466089 DOI: 10.1073/pnas.2310046120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 07/19/2023] [Indexed: 08/23/2023] Open
Abstract
The rapid increase of the potent greenhouse gas methane in the atmosphere creates great urgency to develop and deploy technologies for methane mitigation. One approach to removing methane is to use bacteria for which methane is their carbon and energy source (methanotrophs). Such bacteria naturally convert methane to CO2 and biomass, a value-added product and a cobenefit of methane removal. Typically, methanotrophs grow best at around 5,000 to 10,000 ppm methane, but methane in the atmosphere is 1.9 ppm. Air above emission sites such as landfills, anaerobic digestor effluents, rice paddy effluents, and oil and gas wells contains elevated methane in the 500 ppm range. If such sites are targeted for methane removal, technology harnessing aerobic methanotroph metabolism has the potential to become economically and environmentally viable. The first step in developing such methane removal technology is to identify methanotrophs with enhanced ability to grow and consume methane at 500 ppm and lower. We report here that some existing methanotrophic strains grow well at 500 ppm methane, and one of them, Methylotuvimicrobium buryatense 5GB1C, consumes such low methane at enhanced rates compared to previously published values. Analyses of bioreactor-based performance and RNAseq-based transcriptomics suggest that this ability to utilize low methane is based at least in part on extremely low non-growth-associated maintenance energy and on high methane specific affinity. This bacterium is a candidate to develop technology for methane removal at emission sites. If appropriately scaled, such technology has the potential to slow global warming by 2050.
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Affiliation(s)
- Lian He
- Department of Chemical Engineering, University of Washington, Seattle, WA98195
| | - Joseph D. Groom
- Department of Chemical Engineering, University of Washington, Seattle, WA98195
| | - Erin H. Wilson
- School of Computer Science & Engineering, University of Washington, Seattle, WA98195
| | | | | | - David A. C. Beck
- Department of Chemical Engineering, University of Washington, Seattle, WA98195
- eScience Institute, University of Washington, Seattle, WA98195
| | - Mary E. Lidstrom
- Department of Chemical Engineering, University of Washington, Seattle, WA98195
- Department of Microbiology, University of Washington, Seattle, WA98195
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Hengge R. The symbolic power of nucleotide second messengers - or how prokaryotes link sensing and responding to their outside world. MICROLIFE 2023; 4:uqad036. [PMID: 37635902 PMCID: PMC10449370 DOI: 10.1093/femsml/uqad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 08/04/2023] [Indexed: 08/29/2023]
Affiliation(s)
- Regine Hengge
- Institut für Biologie / Mikrobiologie and Excellence Cluster Matters of Activity, Humboldt-Universität zu Berlin, Philippstr. 13 – Haus 22, 10115 Berlin, Germany
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45
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Wan X, Chou WK, Brynildsen MP. Amino acids can deplete ATP and impair nitric oxide detoxification by Escherichia coli. Free Radic Biol Med 2023; 205:90-99. [PMID: 37253411 DOI: 10.1016/j.freeradbiomed.2023.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/18/2023] [Accepted: 05/15/2023] [Indexed: 06/01/2023]
Abstract
Nitric oxide (·NO) is a prevalent antimicrobial that is known to damage iron-containing enzymes in amino acid (AA) biosynthesis pathways. With Escherichia coli, ·NO is detoxified in aerobic environments by Hmp, which is an enzyme that is synthesized de novo in response to ·NO. With this knowledgebase, it is expected that the availability of AAs in the extracellular environment would enhance ·NO detoxification, because AAs would foster translation of Hmp. However, we observed that ·NO detoxification by E. coli was far slower in populations grown and treated in the presence of AAs (AA+) in comparison to those grown and stressed in the absence of AAs (AA-). Further experiments revealed that AA+ populations had difficulty translating proteins under ·NO stress, and that ·NO activated the stringent response in AA+ populations. Additional work revealed significant ATP depletion in ·NO-stressed AA+ cultures that far exceeded that of ·NO-stressed AA- populations. Transcription, translation, and RelA were not found to be significant contributors to the ATP depletion observed, whereas AA import was implicated as a significant ATP consumption pathway. Alleviating ATP depletion while maintaining access to AAs partially restored ·NO detoxification, which suggested that ATP depletion contributed to the translational difficulties observed in ·NO-stressed AA+ populations. These data reveal an unexpected interaction within the ·NO response network of E. coli that stimulates a stringent response by RelA in conditions where AAs are plentiful.
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Affiliation(s)
- Xuanqing Wan
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Wen Kang Chou
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
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46
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Wang M, Tang NY, Xie S, Watt RM. Functional Characterization of Small Alarmone Synthetase and Small Alarmone Hydrolase Proteins from Treponema denticola. Microbiol Spectr 2023; 11:e0510022. [PMID: 37289081 PMCID: PMC10434055 DOI: 10.1128/spectrum.05100-22] [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: 12/11/2022] [Accepted: 05/18/2023] [Indexed: 06/09/2023] Open
Abstract
The stringent response enables bacteria to survive nutrient starvation, antibiotic challenge, and other threats to cellular survival. Two alarmone (magic spot) second messengers, guanosine pentaphosphate (pppGpp) and guanosine tetraphosphate (ppGpp), which are synthesized by RelA/SpoT homologue (RSH) proteins, play central roles in the stringent response. The pathogenic oral spirochete bacterium Treponema denticola lacks a long-RSH homologue but encodes putative small alarmone synthetase (Tde-SAS, TDE1711) and small alarmone hydrolase (Tde-SAH, TDE1690) proteins. Here, we characterize the respective in vitro and in vivo activities of Tde-SAS and Tde-SAH, which respectively belong to the previously uncharacterized RSH families DsRel and ActSpo2. The tetrameric 410-amino acid (aa) Tde-SAS protein preferentially synthesizes ppGpp over pppGpp and a third alarmone, pGpp. Unlike RelQ homologues, alarmones do not allosterically stimulate the synthetic activities of Tde-SAS. The ~180 aa C-terminal tetratricopeptide repeat (TPR) domain of Tde-SAS acts as a brake on the alarmone synthesis activities of the ~220-aa N-terminal catalytic domain. Tde-SAS also synthesizes "alarmone-like" nucleotides such as adenosine tetraphosphate (ppApp), albeit at considerably lower rates. The 210-aa Tde-SAH protein efficiently hydrolyzes all guanosine and adenosine-based alarmones in a Mn(II) ion-dependent manner. Using a growth assays with a ΔrelAΔspoT strain of Escherichia coli that is deficient in pppGpp/ppGpp synthesis, we demonstrate that Tde-SAS can synthesize alarmones in vivo to restore growth in minimal media. Taken together, our results add to our holistic understanding of alarmone metabolism across diverse bacterial species. IMPORTANCE The spirochete bacterium Treponema denticola is a common component of the oral microbiota. However, it may play important pathological roles in multispecies oral infectious diseases such as periodontitis: a severe and destructive form of gum disease, which is a major cause of tooth loss in adults. The operation of the stringent response, a highly conserved survival mechanism, is known to help many bacterial species cause persistent or virulent infections. By characterizing the biochemical functions of the proteins putatively responsible for the stringent response in T. denticola, we may gain molecular insight into how this bacterium can survive within harsh oral environments and promote infection. Our results also expand our general understanding of proteins that synthesize nucleotide-based intracellular signaling molecules in bacteria.
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Affiliation(s)
- Miao Wang
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Nga-Yeung Tang
- Department of Pathology and Laboratory Medicine, Beaumont Health, Royal Oak, Michigan, USA
- Department of Pathology and Laboratory Medicine, Oakland University William Beaumont School of Medicine, Auburn Hills, Michigan, USA
| | - Shujie Xie
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Rory M. Watt
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
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47
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Zhou Y, Liao H, Pei L, Pu Y. Combatting persister cells: The daunting task in post-antibiotics era. CELL INSIGHT 2023; 2:100104. [PMID: 37304393 PMCID: PMC10250163 DOI: 10.1016/j.cellin.2023.100104] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/25/2023] [Accepted: 04/21/2023] [Indexed: 06/13/2023]
Abstract
Over the years, much attention has been drawn to antibiotic resistance bacteria, but drug inefficacy caused by a subgroup of special phenotypic variants - persisters - has been largely neglected in both scientific and clinical field. Interestingly, this subgroup of phenotypic variants displayed their power of withstanding sufficient antibiotics exposure in a mechanism different from antibiotic resistance. In this review, we summarized the clinical importance of bacterial persisters, the evolutionary link between resistance, tolerance, and persistence, redundant mechanisms of persister formation as well as methods of studying persister cells. In the light of our recent findings of membrane-less organelle aggresome and its important roles in regulating bacterial dormancy depth, we propose an alternative approach for anti-persister therapy. That is, to force a persister into a deeper dormancy state to become a VBNC (viable but non-culturable) cell that is incapable of regrowth. We hope to provide the latest insights on persister studies and call upon more research interest into this field.
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Affiliation(s)
- Yidan Zhou
- Department of Clinical Laboratory, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
| | - Hebin Liao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
| | - Linsen Pei
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
| | - Yingying Pu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei- MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China
- Medical Research Institute, School of Medicine, Wuhan University, Wuhan, 430079, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan, 430079, China
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48
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Huang C, Li W, Chen J. Stringent Response Factor DksA Contributes to Fatty Acid Degradation Function to Influence Cell Membrane Stability and Polymyxin B Resistance of Yersinia enterocolitica. Int J Mol Sci 2023; 24:11951. [PMID: 37569327 PMCID: PMC10418728 DOI: 10.3390/ijms241511951] [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: 06/26/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 08/13/2023] Open
Abstract
DksA is a proteobacterial regulator that binds directly to the secondary channel of RNA polymerase with (p)ppGpp and is responsible for various bacterial physiological activities. While (p)ppGpp is known to be involved in the regulation and response of fatty acid metabolism pathways in many foodborne pathogens, the role of DksA in this process has yet to be clarified. This study aimed to characterize the function of DksA on fatty acid metabolism and cell membrane structure in Yersinia enterocolitica. Therefore, comparison analysis of gene expression, growth conditions, and membrane permeabilization among the wide-type (WT), DksA-deficient mutant (YEND), and the complemented strain was carried out. It confirmed that deletion of DksA led to a more than four-fold decrease in the expression of fatty acid degradation genes, including fadADEIJ. Additionally, YEND exhibited a smaller growth gap compared to the WT strain at low temperatures, indicating that DksA is not required for the growth of Y. enterocolitica in cold environments. Given that polymyxin B is a cationic antimicrobial peptide that targets the cell membrane, the roles of DksA under polymyxin B exposure were also characterized. It was found that DksA positively regulates the integrity of the inner and outer membranes of Y. enterocolitica under polymyxin B, preventing the leakage of intracellular nucleic acids and proteins and ultimately reducing the sensitivity of Y. enterocolitica to polymyxin B. Taken together, this study provides insights into the functions of DksA and paves the way for novel fungicide development.
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Affiliation(s)
| | | | - Jingyu Chen
- Beijing Laboratory for Food Quality and Safety, College of Food Science & Nutritional Engineering, China Agricultural University, 17 Qinghua East Rd., Beijing 100083, China
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49
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Grucela PK, Fuhrer T, Sauer U, Chao Y, Zhang YE. Ribose 5-phosphate: the key metabolite bridging the metabolisms of nucleotides and amino acids during stringent response in Escherichia coli? MICROBIAL CELL (GRAZ, AUSTRIA) 2023; 10:141-144. [PMID: 37395996 PMCID: PMC10311079 DOI: 10.15698/mic2023.07.799] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 07/04/2023]
Abstract
The bacterial stringent response and its effector alarmone guanosine penta- or tetra - phosphates (p)ppGpp are vital for bacterial tolerance and survival of various stresses in environments (including antibiotics) and host cells (virulence). (p)ppGpp does so by binding to its numerous target proteins and reprograming bacterial transcriptome to tune down the synthesis of nucleotides and rRNA/tRNA, and up-regulate amino acid biosynthesis genes. Recent identification of more novel (p)ppGpp direct binding proteins in Escherichia coli and their deep studies have unveiled unprecedented details of how (p)ppGpp coordinates the nucleotide and amino acid metabolic pathways upon stringent response; however, the mechanistic link between nucleotide and amino acid metabolisms remains still incompletely understood. Here we propose the metabolite ribose 5'-phosphate as the key link between nucleotide and amino acid metabolisms and a working model integrating both the transcriptional and metabolic effects of (p)ppGpp on E. coli physiological adaptation during the stringent response.
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Affiliation(s)
| | - Tobias Fuhrer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Yanjie Chao
- The Center for Microbes, Development and Health (CMDH), Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yong Everett Zhang
- Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark
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50
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Riffaud CM, Rucks EA, Ouellette SP. Persistence of obligate intracellular pathogens: alternative strategies to overcome host-specific stresses. Front Cell Infect Microbiol 2023; 13:1185571. [PMID: 37284502 PMCID: PMC10239878 DOI: 10.3389/fcimb.2023.1185571] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/05/2023] [Indexed: 06/08/2023] Open
Abstract
In adapting to the intracellular niche, obligate intracellular bacteria usually undergo a reduction of genome size by eliminating genes not needed for intracellular survival. These losses can include, for example, genes involved in nutrient anabolic pathways or in stress response. Living inside a host cell offers a stable environment where intracellular bacteria can limit their exposure to extracellular effectors of the immune system and modulate or outright inhibit intracellular defense mechanisms. However, highlighting an area of vulnerability, these pathogens are dependent on the host cell for nutrients and are very sensitive to conditions that limit nutrient availability. Persistence is a common response shared by evolutionarily divergent bacteria to survive adverse conditions like nutrient deprivation. Development of persistence usually compromises successful antibiotic therapy of bacterial infections and is associated with chronic infections and long-term sequelae for the patients. During persistence, obligate intracellular pathogens are viable but not growing inside their host cell. They can survive for a long period of time such that, when the inducing stress is removed, reactivation of their growth cycles resumes. Given their reduced coding capacity, intracellular bacteria have adapted different response mechanisms. This review gives an overview of the strategies used by the obligate intracellular bacteria, where known, which, unlike model organisms such as E. coli, often lack toxin-antitoxin systems and the stringent response that have been linked to a persister phenotype and amino acid starvation states, respectively.
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