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Pani S, Mohapatra SS. Phenotypic heterogeneity in bacteria: the rise of antibiotic persistence, clinical implications, and therapeutic opportunities. Arch Microbiol 2024; 206:446. [PMID: 39460765 DOI: 10.1007/s00203-024-04173-3] [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: 09/05/2024] [Revised: 09/27/2024] [Accepted: 10/16/2024] [Indexed: 10/28/2024]
Abstract
The rising incidence of antimicrobial resistance (AMR) and the diminishing antibiotics discovery pipeline have created an unprecedented scenario where minor infections could become untreatable. AMR phenomenon is genetically encoded, and various genetic determinants have been implicated in their emergence and spread. Nevertheless, several non-genetic phenomena are also involved in antibiotic treatment failure which requires a systematic investigation. It has been observed that in an isogenic population of bacteria, not all cells behave or respond the same way to an antibiotic, because of the inherent heterogeneity among them. This heterogeneity is not always heritable but rather phenotypic. Three distinct types of phenotypic heterogeneity, namely tolerance, persistence, and heteroresistance have been observed in bacteria having significant clinical implications influencing the treatment outcome. While tolerance is when a population can survive high doses of antibiotics without changing the minimum inhibitory concentration (MIC) of the drug, persistence occurs in a subpopulation of bacteria that can survive exposure to high antibiotic doses. In contrast, when a subpopulation shows a very high MIC in comparison to the rest of the population, the phenomenon is called heteroresistance. In this article, we have highlighted bacterial persistence with a focus on their emergence and the underlying molecular mechanisms. Moreover, we have tried to associate the genome-wide methylation status with that of the heterogeneity at a single-cell level that may explain the role of epigenetic mechanisms in the development of persistence.
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Affiliation(s)
- Srimayee Pani
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur, Odisha, 760007, India
| | - Saswat S Mohapatra
- Molecular Microbiology Lab, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur, Odisha, 760007, India.
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2
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Jandl B, Dighe S, Gasche C, Makristathis A, Muttenthaler M. Intestinal biofilms: pathophysiological relevance, host defense, and therapeutic opportunities. Clin Microbiol Rev 2024; 37:e0013323. [PMID: 38995034 PMCID: PMC11391705 DOI: 10.1128/cmr.00133-23] [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] [Indexed: 07/13/2024] Open
Abstract
SUMMARYThe human intestinal tract harbors a profound variety of microorganisms that live in symbiosis with the host and each other. It is a complex and highly dynamic environment whose homeostasis directly relates to human health. Dysbiosis of the gut microbiota and polymicrobial biofilms have been associated with gastrointestinal diseases, including irritable bowel syndrome, inflammatory bowel diseases, and colorectal cancers. This review covers the molecular composition and organization of intestinal biofilms, mechanistic aspects of biofilm signaling networks for bacterial communication and behavior, and synergistic effects in polymicrobial biofilms. It further describes the clinical relevance and diseases associated with gut biofilms, the role of biofilms in antimicrobial resistance, and the intestinal host defense system and therapeutic strategies counteracting biofilms. Taken together, this review summarizes the latest knowledge and research on intestinal biofilms and their role in gut disorders and provides directions toward the development of biofilm-specific treatments.
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Affiliation(s)
- Bernhard Jandl
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Vienna, Austria
- Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, Vienna, Austria
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Satish Dighe
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Christoph Gasche
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Vienna, Vienna, Austria
- Loha for Life, Center for Gastroenterology and Iron Deficiency, Vienna, Austria
| | - Athanasios Makristathis
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Markus Muttenthaler
- Faculty of Chemistry, Institute of Biological Chemistry, University of Vienna, Vienna, Austria
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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3
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Geraldes C, Tavares L, Gil S, Oliveira M. Antibiotic heteroresistance and persistence: an additional aid in hospital acquired infections by Enterococcus spp.? Future Microbiol 2024; 19:1407-1418. [PMID: 39229839 DOI: 10.1080/17460913.2024.2393003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 08/13/2024] [Indexed: 09/05/2024] Open
Abstract
Enterococcus, particularly E. faecium and E. faecalis, are responsible for many hospital-acquired infections. With their intrinsic antibiotic resistance and ability to form biofilms, enterococcal infections are already challenging to manage. However, when heterogenous populations are present, such as those exhibiting heteroresistance and persistence, the complexity of these infections increases exponentially not only due to their treatment but also due to their difficult diagnosis. In this study, we provide a summary of the current understanding of both heteroresistance and persistence in terms of mechanisms, diagnosis and treatment and subsequently review recent literature pertaining to these susceptibility types specifically in enterococci.
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Affiliation(s)
- Catarina Geraldes
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- AL4AnimalS - Associate Laboratory for Animal & Veterinary Sciences, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Luís Tavares
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- AL4AnimalS - Associate Laboratory for Animal & Veterinary Sciences, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Solange Gil
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- AL4AnimalS - Associate Laboratory for Animal & Veterinary Sciences, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- BICU - Biological Isolation & Containment Unit, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Manuela Oliveira
- CIISA - Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- AL4AnimalS - Associate Laboratory for Animal & Veterinary Sciences, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- cE3c - Centre for Ecology, Evolution & Environmental Changes & CHANGE-Global Change & Sustainability Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
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Sett A, Dubey V, Bhowmik S, Pathania R. Decoding Bacterial Persistence: Mechanisms and Strategies for Effective Eradication. ACS Infect Dis 2024; 10:2525-2539. [PMID: 38940498 DOI: 10.1021/acsinfecdis.4c00270] [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] [Indexed: 06/29/2024]
Abstract
The ability of pathogenic bacteria to evade antibiotic treatment is an intricate and multifaceted phenomenon. Over the years, treatment failure among patients due to determinants of antimicrobial resistance (AMR) has been the focal point for the research and development of new therapeutic agents. However, the survival of bacteria by persisting under antibiotic stress has largely been overlooked. Bacterial persisters are a subpopulation of sensitive bacterial cells exhibiting a noninheritable drug-tolerant phenotype. They are linked to the recalcitrance of infections in healthcare settings, in turn giving rise to AMR variants. The importance of bacterial persistence in recurring infections has been firmly recognized. Fundamental work over the past decade has highlighted numerous unique tolerance factors contributing to the persister phenotype in many clinically relevant pathogens. This review summarizes contributing factors that could aid in developing new strategies against bacterial antibiotic persisters.
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Affiliation(s)
- Abhiroop Sett
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand 247667, India
| | - Vineet Dubey
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand 247667, India
| | - Somok Bhowmik
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand 247667, India
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Roorkee, Uttarakhand 247667, India
- Centre of Excellence in Disaster Mitigation and Management, Indian Institute of Technology, Roorkee, Uttarakhand 247667, India
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Kunnath AP, Suodha Suoodh M, Chellappan DK, Chellian J, Palaniveloo K. Bacterial Persister Cells and Development of Antibiotic Resistance in Chronic Infections: An Update. Br J Biomed Sci 2024; 81:12958. [PMID: 39170669 PMCID: PMC11335562 DOI: 10.3389/bjbs.2024.12958] [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: 03/06/2024] [Accepted: 07/25/2024] [Indexed: 08/23/2024]
Abstract
The global issue of antimicrobial resistance poses significant challenges to public health. The World Health Organization (WHO) has highlighted it as a major global health threat, causing an estimated 700,000 deaths worldwide. Understanding the multifaceted nature of antibiotic resistance is crucial for developing effective strategies. Several physiological and biochemical mechanisms are involved in the development of antibiotic resistance. Bacterial cells may escape the bactericidal actions of the drugs by entering a physiologically dormant state known as bacterial persistence. Recent findings in this field suggest that bacterial persistence can be one of the main sources of chronic infections. The antibiotic tolerance developed by the persister cells could tolerate high levels of antibiotics and may give rise to persister offspring. These persister offspring could be attributed to antibiotic resistance mechanisms, especially in chronic infections. This review attempts to shed light on persister-induced antibiotic resistance and the current therapeutic strategies.
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Affiliation(s)
- Anil Philip Kunnath
- Division of Applied Biomedical Science and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Mohamed Suodha Suoodh
- Division of Applied Biomedical Science and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Dinesh Kumar Chellappan
- Department of Life Sciences, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Jestin Chellian
- Department of Life Sciences, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Kishneth Palaniveloo
- Institute of Ocean and Earth Sciences, Institute for Advanced Studies Building, Universiti Malaya, Kuala Lumpur, Malaysia
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Schicketanz M, Petrová M, Rejman D, Sosio M, Donadio S, Zhang YE. Direct detection of stringent alarmones (pp)pGpp using malachite green. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:312-320. [PMID: 39119257 PMCID: PMC11307201 DOI: 10.15698/mic2024.08.834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 08/10/2024]
Abstract
The alarmone (p)ppGpp serves as the signalling molecule for the bacterial universal stringent response and plays a crucial role in bacterial virulence, persistence, and stress adaptation. Consequently, there is a significant focus on developing new drugs that target and modulate the levels of (p)ppGpp as a potential strategy for controlling bacterial infections. However, despite the availability of various methods for detecting (p)ppGpp, a simple and straightforward detection method is needed. In this study, we demonstrated that malachite green, a well-established compound used for phosphate detection, can directly detect (p)ppGpp and its analogues esp., pGpp. By utilizing malachite green, we identified three new inhibitors of the hydrolase activity of SpoT, one of the two RelA-SpoT homolog (RSH) proteins responsible for making and hydrolyzing (p)ppGpp in Escherichia coli. These findings highlight the convenience and practicality of malachite green, which can be widely employed in high-throughput studies to investigate (pp)pGpp in vitro and discover novel regulators of RSH proteins.
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Affiliation(s)
- Muriel Schicketanz
- Department of Biology, University of CopenhagenCopenhagen, DK-2200Denmark
| | - Magdalena Petrová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.iPragueCzech Republic
| | - Dominik Rejman
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences v.v.iPragueCzech Republic
| | | | | | - Yong Everett Zhang
- Department of Biology, University of CopenhagenCopenhagen, DK-2200Denmark
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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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8
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Ralhan K, Iyer KA, Diaz LL, Bird R, Maind A, Zhou QA. Navigating Antibacterial Frontiers: A Panoramic Exploration of Antibacterial Landscapes, Resistance Mechanisms, and Emerging Therapeutic Strategies. ACS Infect Dis 2024; 10:1483-1519. [PMID: 38691668 PMCID: PMC11091902 DOI: 10.1021/acsinfecdis.4c00115] [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: 02/10/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 05/03/2024]
Abstract
The development of effective antibacterial solutions has become paramount in maintaining global health in this era of increasing bacterial threats and rampant antibiotic resistance. Traditional antibiotics have played a significant role in combating bacterial infections throughout history. However, the emergence of novel resistant strains necessitates constant innovation in antibacterial research. We have analyzed the data on antibacterials from the CAS Content Collection, the largest human-curated collection of published scientific knowledge, which has proven valuable for quantitative analysis of global scientific knowledge. Our analysis focuses on mining the CAS Content Collection data for recent publications (since 2012). This article aims to explore the intricate landscape of antibacterial research while reviewing the advancement from traditional antibiotics to novel and emerging antibacterial strategies. By delving into the resistance mechanisms, this paper highlights the need to find alternate strategies to address the growing concern.
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Affiliation(s)
| | | | - Leilani Lotti Diaz
- CAS,
A Division of the American Chemical Society, Columbus, Ohio 43210, United States
| | - Robert Bird
- CAS,
A Division of the American Chemical Society, Columbus, Ohio 43210, United States
| | - Ankush Maind
- ACS
International India Pvt. Ltd., Pune 411044, India
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9
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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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Phan MD, Schirra HJ, Nhu NTK, Peters KM, Sarkar S, Allsopp LP, Achard MES, Kappler U, Schembri MA. Combined functional genomic and metabolomic approaches identify new genes required for growth in human urine by multidrug-resistant Escherichia coli ST131. mBio 2024; 15:e0338823. [PMID: 38353545 PMCID: PMC10936160 DOI: 10.1128/mbio.03388-23] [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: 12/15/2023] [Accepted: 01/02/2024] [Indexed: 03/14/2024] Open
Abstract
Urinary tract infections (UTIs) are one of the most common bacterial infections in humans, with ~400 million cases across the globe each year. Uropathogenic Escherichia coli (UPEC) is the major cause of UTI and increasingly associated with antibiotic resistance. This scenario has been worsened by the emergence and spread of pandemic UPEC sequence type 131 (ST131), a multidrug-resistant clone associated with extraordinarily high rates of infection. Here, we employed transposon-directed insertion site sequencing in combination with metabolomic profiling to identify genes and biochemical pathways required for growth and survival of the UPEC ST131 reference strain EC958 in human urine (HU). We identified 24 genes required for growth in HU, which mapped to diverse pathways involving small peptide, amino acid and nucleotide metabolism, the stringent response pathway, and lipopolysaccharide biosynthesis. We also discovered a role for UPEC resistance to fluoride during growth in HU, most likely associated with fluoridation of drinking water. Complementary nuclear magnetic resonance (NMR)-based metabolomics identified changes in a range of HU metabolites following UPEC growth, the most pronounced being L-lactate, which was utilized as a carbon source via the L-lactate dehydrogenase LldD. Using a mouse UTI model with mixed competitive infection experiments, we demonstrated a role for nucleotide metabolism and the stringent response in UPEC colonization of the mouse bladder. Together, our application of two omics technologies combined with different infection-relevant settings has uncovered new factors required for UPEC growth in HU, thus enhancing our understanding of this pivotal step in the UPEC infection pathway. IMPORTANCE Uropathogenic Escherichia coli (UPEC) cause ~80% of all urinary tract infections (UTIs), with increasing rates of antibiotic resistance presenting an urgent threat to effective treatment. To cause infection, UPEC must grow efficiently in human urine (HU), necessitating a need to understand mechanisms that promote its adaptation and survival in this nutrient-limited environment. Here, we used a combination of functional genomic and metabolomic techniques and identified roles for the metabolism of small peptides, amino acids, nucleotides, and L-lactate, as well as the stringent response pathway, lipopolysaccharide biosynthesis, and fluoride resistance, for UPEC growth in HU. We further demonstrated that pathways involving nucleotide metabolism and the stringent response are required for UPEC colonization of the mouse bladder. The UPEC genes and metabolic pathways identified in this study represent targets for the development of innovative therapeutics to prevent UPEC growth during human UTI, an urgent need given the rapidly rising rates of global antibiotic resistance.
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Affiliation(s)
- Minh-Duy Phan
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Horst Joachim Schirra
- School of Environment and Science, Griffith University, Nathan, Queensland, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Nguyen Thi Khanh Nhu
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Kate M. Peters
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Sohinee Sarkar
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Luke P. Allsopp
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Maud E. S. Achard
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Ulrike Kappler
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark A. Schembri
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, Queensland, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
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11
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Sidorov RY, Tkachenko AG. The Mechanism of Inhibition of Mycobacterial (p)ppGpp Synthetases by a Synthetic Analog of Erogorgiaene. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:407-416. [PMID: 38648761 DOI: 10.1134/s0006297924030027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 01/09/2024] [Accepted: 01/09/2024] [Indexed: 04/25/2024]
Abstract
The synthesis of (p)ppGpp alarmones plays a vital role in the regulation of metabolism suppression, growth rate control, virulence, bacterial persistence, and biofilm formation. The (p)ppGpp alarmones are synthesized by proteins of the RelA/SpoT homolog (RSH) superfamily, including long bifunctional RSH proteins and small alarmone synthetases. Here, we investigated enzyme kinetics and dose-dependent enzyme inhibition to elucidate the mechanism of 4-(4,7-dimethyl-1,2,3,4-tetrahydronaphthalen-1-yl)pentanoic acid (DMNP) action on the (p)ppGpp synthetases RelMsm and RelZ from Mycolicibacterium smegmatis and RelMtb from Mycobacterium tuberculosis. DMNP was found to inhibit the activity of RelMtb. According to the enzyme kinetics analysis, DMNP acts as a noncompetitive inhibitor of RelMsm and RelZ. Based on the results of molecular docking, the DMNP-binding site is located in the proximity of the synthetase domain active site. This study might help in the development of alarmone synthetase inhibitors, which includes relacin and its derivatives, as well as DMNP - a synthetic analog of the marine coral metabolite erogorgiaene. Unlike conventional antibiotics, alarmone synthetase inhibitors target metabolic pathways linked to the bacterial stringent response. Although these pathways are not essential for bacteria, they regulate the development of adaptation mechanisms. Combining conventional antibiotics that target actively growing cells with compounds that impede bacterial adaptation may address challenges associated with antimicrobial resistance and bacterial persistence.
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Affiliation(s)
- Roman Y Sidorov
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Ural Branch of Russian Academy of Sciences, Perm, 614000, Russia.
- Perm State University, Perm, 614990, Russia
| | - Alexander G Tkachenko
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Ural Branch of Russian Academy of Sciences, Perm, 614000, Russia
- Perm State University, Perm, 614990, Russia
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12
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Mendogralo EY, Nesterova LY, Nasibullina ER, Shcherbakov RO, Myasnikov DA, Tkachenko AG, Sidorov RY, Uchuskin MG. Synthesis, Antimicrobial and Antibiofilm Activities, and Molecular Docking Investigations of 2-(1 H-Indol-3-yl)-1 H-benzo[ d]imidazole Derivatives. Molecules 2023; 28:7095. [PMID: 37894573 PMCID: PMC10609029 DOI: 10.3390/molecules28207095] [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: 09/25/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/29/2023] Open
Abstract
The treatment of many bacterial and fungal infections remains a problem due to increasing antibiotic resistance and biofilm formation by pathogens. In the present article, a methodology for the chemoselective synthesis of 2-(1H-indol-3-yl)-1H-benzo[d]imidazole derivatives is presented. We report on the antimicrobial activity of synthesized 2-(1H-indol-3-yl)-1H-benzo[d]imidazoles with significant activity against Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 43300 (MRSA), Mycobacterium smegmatis (mc(2)155/ATCC 700084), and Candida albicans ATCC 10231. High activity against staphylococci was shown by indolylbenzo[d]imidazoles 3ao and 3aq (minimum inhibitory concentration (MIC) < 1 µg/mL) and 3aa and 3ad (MIC 3.9-7.8 µg/mL). A low MIC was demonstrated by 2-(1H-indol-3-yl)-1-methyl-1H-benzo[d]imidazole (3ag) against M. smegmatis and against C. albicans (3.9 µg/mL and 3.9 µg/mL, respectively). 2-(5-Bromo-1H-indol-3-yl)-6,7-dimethyl-1H-benzo[d]imidazole (3aq) showed a low MIC of 3.9 µg/mL against C. albicans. Compounds 3aa, 3ad, 3ao, and 3aq exhibited excellent antibiofilm activity, inhibiting biofilm formation and killing cells in mature biofilms. Molecular docking analysis identified three potential interaction models for the investigated compounds, implicating (p)ppGpp synthetases/hydrolases, FtsZ proteins, or pyruvate kinases in their antibacterial action mechanism.
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Affiliation(s)
- Elena Y. Mendogralo
- Department of Chemistry, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (E.R.N.); (R.O.S.); (D.A.M.); (R.Y.S.); (M.G.U.)
| | - Larisa Y. Nesterova
- Department of Biology, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (L.Y.N.); (A.G.T.)
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, The Ural Branch of Russian Academy of Sciences, Goleva St. 13, 614081 Perm, Russia
| | - Ekaterina R. Nasibullina
- Department of Chemistry, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (E.R.N.); (R.O.S.); (D.A.M.); (R.Y.S.); (M.G.U.)
| | - Roman O. Shcherbakov
- Department of Chemistry, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (E.R.N.); (R.O.S.); (D.A.M.); (R.Y.S.); (M.G.U.)
| | - Danil A. Myasnikov
- Department of Chemistry, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (E.R.N.); (R.O.S.); (D.A.M.); (R.Y.S.); (M.G.U.)
| | - Alexander G. Tkachenko
- Department of Biology, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (L.Y.N.); (A.G.T.)
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, The Ural Branch of Russian Academy of Sciences, Goleva St. 13, 614081 Perm, Russia
| | - Roman Y. Sidorov
- Department of Chemistry, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (E.R.N.); (R.O.S.); (D.A.M.); (R.Y.S.); (M.G.U.)
- Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, The Ural Branch of Russian Academy of Sciences, Goleva St. 13, 614081 Perm, Russia
| | - Maxim G. Uchuskin
- Department of Chemistry, Perm State University, Bukireva St. 15, 614990 Perm, Russia; (E.R.N.); (R.O.S.); (D.A.M.); (R.Y.S.); (M.G.U.)
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13
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Pan X, Liu W, Du Q, Zhang H, Han D. Recent Advances in Bacterial Persistence Mechanisms. Int J Mol Sci 2023; 24:14311. [PMID: 37762613 PMCID: PMC10531727 DOI: 10.3390/ijms241814311] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
The recurrence of bacterial infectious diseases is closely associated with bacterial persisters. This subpopulation of bacteria can escape antibiotic treatment by entering a metabolic status of low activity through various mechanisms, for example, biofilm, toxin-antitoxin modules, the stringent response, and the SOS response. Correspondingly, multiple new treatments are being developed. However, due to their spontaneous low abundance in populations and the lack of research on in vivo interactions between persisters and the host's immune system, microfluidics, high-throughput sequencing, and microscopy techniques are combined innovatively to explore the mechanisms of persister formation and maintenance at the single-cell level. Here, we outline the main mechanisms of persister formation, and describe the cutting-edge technology for further research. Despite the significant progress regarding study techniques, some challenges remain to be tackled.
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Affiliation(s)
- Xiaozhou Pan
- Department of Clinical Laboratory, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Wenxin Liu
- Department of Clinical Laboratory, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Qingqing Du
- Department of Clinical Laboratory, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Hong Zhang
- Department of Clinical Laboratory, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
| | - Dingding Han
- Department of Clinical Laboratory, Shanghai Children’s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
- Institute of Pediatric Infection, Immunity, and Critical Care Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai 200062, China
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14
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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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15
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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: 11] [Impact Index Per Article: 11.0] [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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16
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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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17
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Zhai Y, Pribis JP, Dooling SW, Garcia-Villada L, Minnick P, Xia J, Liu J, Mei Q, Fitzgerald DM, Herman C, Hastings P, Costa-Mattioli M, Rosenberg SM. Drugging evolution of antibiotic resistance at a regulatory network hub. SCIENCE ADVANCES 2023; 9:eadg0188. [PMID: 37352342 PMCID: PMC10289659 DOI: 10.1126/sciadv.adg0188] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 05/22/2023] [Indexed: 06/25/2023]
Abstract
Evolution of antibiotic resistance is a world health crisis, fueled by new mutations. Drugs to slow mutagenesis could, as cotherapies, prolong the shelf-life of antibiotics, yet evolution-slowing drugs and drug targets have been underexplored and ineffective. Here, we used a network-based strategy to identify drugs that block hubs of fluoroquinolone antibiotic-induced mutagenesis. We identify a U.S. Food and Drug Administration- and European Medicines Agency-approved drug, dequalinium chloride (DEQ), that inhibits activation of the Escherichia coli general stress response, which promotes ciprofloxacin-induced (stress-induced) mutagenic DNA break repair. We uncover the step in the pathway inhibited: activation of the upstream "stringent" starvation stress response, and find that DEQ slows evolution without favoring proliferation of DEQ-resistant mutants. Furthermore, we demonstrate stress-induced mutagenesis during mouse infections and its inhibition by DEQ. Our work provides a proof-of-concept strategy for drugs to slow evolution in bacteria and generally.
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Affiliation(s)
- Yin Zhai
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - John P. Pribis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sean W. Dooling
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Libertad Garcia-Villada
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - P.J. Minnick
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jun Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jingjing Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qian Mei
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
- Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX 77030, USA
| | - Devon M. Fitzgerald
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christophe Herman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - P.J. Hastings
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mauro Costa-Mattioli
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Susan M. Rosenberg
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Graduate Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA
- The Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
- Systems, Synthetic, and Physical Biology Program, Rice University, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
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18
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Termination factor Rho mediates transcriptional reprogramming of Bacillus subtilis stationary phase. PLoS Genet 2023; 19:e1010618. [PMID: 36735730 PMCID: PMC9931155 DOI: 10.1371/journal.pgen.1010618] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/15/2023] [Accepted: 01/14/2023] [Indexed: 02/04/2023] Open
Abstract
Transcription termination factor Rho is known for its ubiquitous role in suppression of pervasive, mostly antisense, transcription. In the model Gram-positive bacterium Bacillus subtilis, de-repression of pervasive transcription by inactivation of rho revealed the role of Rho in the regulation of post-exponential differentiation programs. To identify other aspects of the regulatory role of Rho during adaptation to starvation, we have constructed a B. subtilis strain (Rho+) that expresses rho at a relatively stable high level in order to compensate for its decrease in the wild-type cells entering stationary phase. The RNAseq analysis of Rho+, WT and Δrho strains (expression profiles can be visualized at http://genoscapist.migale.inrae.fr/seb_rho/) shows that Rho over-production enhances the termination efficiency of Rho-sensitive terminators, thus reducing transcriptional read-through and antisense transcription genome-wide. Moreover, the Rho+ strain exhibits global alterations of sense transcription with the most significant changes observed for the AbrB, CodY, and stringent response regulons, forming the pathways governing the transition to stationary phase. Subsequent physiological analyses demonstrated that maintaining rho expression at a stable elevated level modifies stationary phase-specific physiology of B. subtilis cells, weakens stringent response, and thereby negatively affects the cellular adaptation to nutrient limitations and other stresses, and blocks the development of genetic competence and sporulation. These results highlight the Rho-specific termination of transcription as a novel element controlling stationary phase. The release of this control by decreasing Rho levels during the transition to stationary phase appears crucial for the functionality of complex gene networks ensuring B. subtilis survival in stationary phase.
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19
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Ju Y, Zhang F, Yu P, Zhang Y, Zhao P, Xu P, Sun L, Bao Y, Long H. A Bibliometric Analysis of Research on Bacterial Persisters. BIOMED RESEARCH INTERNATIONAL 2023; 2023:4302914. [PMID: 36644164 PMCID: PMC9839416 DOI: 10.1155/2023/4302914] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/30/2022] [Accepted: 12/20/2022] [Indexed: 01/09/2023]
Abstract
BACKGROUND In the past two decades, the surge of research on bacterial persisters has been inspired as increasingly concerning about the frequent failure of antibiotics treatment. This study was aimed at presenting a bibliometric and visualized analysis of relative publications on bacterial persisters, which offered insights into the development and research trends of this field. METHODS The Web of Science Core Collection and Ovid MEDLINE databases were utilized to retrieve relevant publications on bacterial persisters from 2001 to 2021. After manual selection, data including titles, authors, journals, author keywords, addresses, the number of citations, and publication years were subsequently extracted. The data analysis and visual mapping were conducted with Excel, SPSS, R studio, and VOSviewer. RESULTS In this study, 1,903 relevant publications on bacterial persisters were included. During 2001-2021, there was an exponential growth in the quantity of publications. It was found that these studies were conducted by 7,182 authors from 74 different countries. The USA led the scientific production with the highest total number of publications (859) and citation frequency (52,022). The Antimicrobial Agents and Chemotherapy was the most influential journal with 113 relevant publications. The cooccurrence analysis revealed that studies on bacterial persisters focused on four aspects: "the role of persisters in biofilms," "clinical persistent infection," "anti-persister treatment," and "mechanism of persister formation." CONCLUSION In the past two decades, the global field of bacterial persisters has significantly increased. The USA was the leading country in this field. Mechanistic studies continued to be the future hotspots, which may be helpful to adopt new strategies against persisters and solve the problem of chronic infection in the clinic.
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Affiliation(s)
- Yuan Ju
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Fang Zhang
- Department of Pharmacy, The Air Force Hospital of Western Theater Command, Chengdu, China
| | - Pingjing Yu
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Yu Zhang
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Ping Zhao
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Ping Xu
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Luwei Sun
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Yongqing Bao
- Sichuan University Library, Sichuan University, Chengdu, China
| | - Haiyue Long
- Sichuan University Library, Sichuan University, Chengdu, China
- Department of Pharmacy, The Air Force Hospital of Western Theater Command, Chengdu, China
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20
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Sidorov RY, Tkachenko AG. DMNP, a Synthetic Analog of Erogorgiaene, Inhibits the ppGpp Synthetase Activity of the Small Alarmone Synthetase RelZ. BIO WEB OF CONFERENCES 2023. [DOI: 10.1051/bioconf/20235708002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Suppression of the stringent response is a promising strategy for the treatment of persistent bacterial infections. A novel class of compounds having a mechanism of action based on alarmone synthetase inhibition and suppressing the synthesis of (p)ppGpp alarmones in bacteria may provide a more effective treatment for latent infections and resolve problems associated with bacterial persistence. Conventional antibiotics primarily act on actively growing bacteria, but they are inactive against persister cells with a slowed metabolism. Alarmone synthetase inhibitors have antipersister properties that may enhance conventional antibiotics’ antibacterial action. Two groups of RSH proteins are responsible for the synthesis of alarmones: long RelA/SpoT homologs and small alarmone synthetases. Many species of bacteria possess both types of enzymes. Despite the fact that a number of inhibitors of bifunctional long synthetases/hydrolases have been described to date, their properties with respect to monofunctional small alarmone synthetases have been studied poorly. This study investigated the effect of the alarmone synthetase inhibitor DMNP on the purified RelZ small alarmone synthetase protein from Mycolicibacterium smegmatis.
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21
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Chen Y, Zhang Z, Chen Y, Zhou S, Deng Q, Wang S. Enhancement of inhibition rate of antibiotic against bacteria by molecularly imprinted nanoparticles targeting alarmone nucleotides as antibiotic adjuvants. J Mater Chem B 2022; 10:9438-9445. [PMID: 36321529 DOI: 10.1039/d2tb00641c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Antibiotic tolerance and resistance in bacteria have caused a great threat to humankind. Bacteria can rapidly accumulate alarmone nucleotides (guanosine tetra- and pentaphosphate, usually denoted as (p)ppGpp) to repair damaged DNA under adverse conditions. The inhibition synthetase enzyme activity of (p)ppGpp, indirectly preventing synthesis, or promoting degradation, has been reported; however, transferring these strategies to practical applications is still a challenging task due to the lack of highly effective molecules for these purposes. Here, an approach based on molecularly imprinted polymer nanoparticles (MIP-NPs) as antibiotic adjuvants was proposed, where MIP-NPs with specific recognition sites were used to capture alarmone nucleotides released by bacteria during stringent response activation. Enhanced inhibition rates of 40-80% were achieved in the presence of the MIP-NPs. The dose of antibiotic could be greatly reduced by utilizing the MIP-NPs as adjuvants for a similar deactivation effectiveness. Good biocompatibility (no obvious hemolysis or cytotoxic effects) and apparent antimicrobial efficiency for resisting wound infection in vivo support the fact that well-designed MIP-NPs have a bright future in dealing with the growing threat of antibiotic tolerance and resistance.
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Affiliation(s)
- Yali Chen
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 1038 Dagu South Road, Tianjin, 300457, China.
| | - Zhen Zhang
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 1038 Dagu South Road, Tianjin, 300457, China.
| | - Yujie Chen
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 1038 Dagu South Road, Tianjin, 300457, China.
| | - Shufang Zhou
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 1038 Dagu South Road, Tianjin, 300457, China.
| | - Qiliang Deng
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 1038 Dagu South Road, Tianjin, 300457, China.
| | - Shuo Wang
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, 1038 Dagu South Road, Tianjin, 300457, China. .,Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, 94 Weijin Road, Tianjin, 300071, China.
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22
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Fernández-García L, Muthami JM, Tomas M, Wood TK. What are the options for treating infections by persister-forming pathogens? Environ Microbiol 2022; 24:4500-4504. [PMID: 35912818 DOI: 10.1111/1462-2920.16117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Laura Fernández-García
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA.,Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Joy M Muthami
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Maria Tomas
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA
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23
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Dawan J, Ahn J. Bacterial Stress Responses as Potential Targets in Overcoming Antibiotic Resistance. Microorganisms 2022; 10:microorganisms10071385. [PMID: 35889104 PMCID: PMC9322497 DOI: 10.3390/microorganisms10071385] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/03/2022] [Accepted: 07/08/2022] [Indexed: 12/23/2022] Open
Abstract
Bacteria can be adapted to adverse and detrimental conditions that induce general and specific responses to DNA damage as well as acid, heat, cold, starvation, oxidative, envelope, and osmotic stresses. The stress-triggered regulatory systems are involved in bacterial survival processes, such as adaptation, physiological changes, virulence potential, and antibiotic resistance. Antibiotic susceptibility to several antibiotics is reduced due to the activation of stress responses in cellular physiology by the stimulation of resistance mechanisms, the promotion of a resistant lifestyle (biofilm or persistence), and/or the induction of resistance mutations. Hence, the activation of bacterial stress responses poses a serious threat to the efficacy and clinical success of antibiotic therapy. Bacterial stress responses can be potential targets for therapeutic alternatives to antibiotics. An understanding of the regulation of stress response in association with antibiotic resistance provides useful information for the discovery of novel antimicrobial adjuvants and the development of effective therapeutic strategies to control antibiotic resistance in bacteria. Therefore, this review discusses bacterial stress responses linked to antibiotic resistance in Gram-negative bacteria and also provides information on novel therapies targeting bacterial stress responses that have been identified as potential candidates for the effective control of Gram-negative antibiotic-resistant bacteria.
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Affiliation(s)
- Jirapat Dawan
- Department of Biomedical Science, Kangwon National University, Chuncheon 24341, Gangwon, Korea;
| | - Juhee Ahn
- Department of Biomedical Science, Kangwon National University, Chuncheon 24341, Gangwon, Korea;
- Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Gangwon, Korea
- Correspondence: ; Tel.: +82-33-250-6564
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24
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Coppa C, Sorrentino L, Civera M, Minneci M, Vasile F, Sattin S. New Chemotypes for the Inhibition of (p)ppGpp Synthesis in the Quest for New Antimicrobial Compounds. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27103097. [PMID: 35630574 PMCID: PMC9143738 DOI: 10.3390/molecules27103097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/07/2022] [Accepted: 05/10/2022] [Indexed: 11/16/2022]
Abstract
Antimicrobial resistance (AMR) poses a serious threat to our society from both the medical and economic point of view, while the antibiotic discovery pipeline has been dwindling over the last decades. Targeting non-essential bacterial pathways, such as those leading to antibiotic persistence, a bacterial bet-hedging strategy, will lead to new molecular entities displaying low selective pressure, thereby reducing the insurgence of AMR. Here, we describe a way to target (p)ppGpp (guanosine tetra- or penta-phosphate) signaling, a non-essential pathway involved in the formation of persisters, with a structure-based approach. A superfamily of enzymes called RSH (RelA/SpoT Homolog) regulates the intracellular levels of this alarmone. We virtually screened several fragment libraries against the (p)ppGpp synthetase domain of our RSH chosen model RelSeq, selected three main chemotypes, and measured their interaction with RelSeq by thermal shift assay and STD-NMR. Most of the tested fragments are selective for the synthetase domain, allowing us to select the aminobenzoic acid scaffold as a hit for lead development.
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25
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Elgrail MM, Chen E, Shaffer MG, Srinivasa V, Griffith MP, Mustapha MM, Shields RK, Van Tyne D, Culyba MJ. Convergent Evolution of Antibiotic Tolerance in Patients with Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia. Infect Immun 2022; 90:e0000122. [PMID: 35285704 PMCID: PMC9022596 DOI: 10.1128/iai.00001-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/12/2022] [Indexed: 02/06/2023] Open
Abstract
Severe infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are often complicated by persistent bacteremia (PB) despite active antibiotic therapy. Antibiotic resistance rarely contributes to MRSA-PB, suggesting an important role for antibiotic tolerance pathways. To identify bacterial factors associated with PB, we sequenced the whole genomes of 206 MRSA isolates derived from 20 patients with PB and looked for genetic signatures of adaptive within-host evolution. We found that genes involved in the tricarboxylic acid cycle (citZ and odhA) and stringent response (rel) bore repeated, independent, protein-altering mutations across multiple infections, indicative of convergent evolution. Both pathways have been linked previously to antibiotic tolerance. Mutations in citZ were identified most frequently, and further study showed they caused antibiotic tolerance through the loss of citrate synthase activity. Isolates harboring mutant alleles (citZ, odhA, and rel) were sampled at a low frequency from each patient but were detected in 10 (50%) of the patients. These results suggest that subpopulations of antibiotic-tolerant mutants emerge commonly during MRSA-PB. Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of hospital-acquired infection. In severe cases, bacteria invade the bloodstream and cause bacteremia, a condition associated with high mortality. We analyzed the genomes of serial MRSA isolates derived from patients with bacteremia that persisted through active antibiotic therapy and found a frequent evolution of pathways leading to antibiotic tolerance. Antibiotic tolerance is distinct from antibiotic resistance, and the role of tolerance in clinical failure of antibiotic therapy is defined poorly. Our results show genetic evidence that perturbation of specific metabolic pathways plays an important role in the ability of MRSA to evade antibiotics during severe infection.
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Affiliation(s)
- Mitra M. Elgrail
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Edwin Chen
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Marla G. Shaffer
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Vatsala Srinivasa
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Marissa P. Griffith
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mustapha M. Mustapha
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Ryan K. Shields
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Daria Van Tyne
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Matthew J. Culyba
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Evolutionary Biology and Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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26
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Poudel A, Pokhrel A, Oludiran A, Coronado EJ, Alleyne K, Gilfus MM, Gurung RK, Adhikari SB, Purcell EB. Unique Features of Alarmone Metabolism in Clostridioides difficile. J Bacteriol 2022; 204:e0057521. [PMID: 35254095 PMCID: PMC9017329 DOI: 10.1128/jb.00575-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/01/2022] [Indexed: 11/20/2022] Open
Abstract
The "magic spot" alarmones (pp)pGpp, previously implicated in Clostridioides difficile antibiotic survival, are synthesized by the RelA-SpoT homolog (RSH) of C. difficile (RSHCd) and RelQCd. These enzymes are transcriptionally activated by diverse environmental stresses. RSHCd has previously been reported to synthesize ppGpp, but in this study, we found that both clostridial enzymes exclusively synthesize pGpp. While direct synthesis of pGpp from a GMP substrate, and (p)ppGpp hydrolysis into pGpp by NUDIX hydrolases, have previously been reported, there is no precedent for a bacterium synthesizing pGpp exclusively. Hydrolysis of the 5' phosphate or pyrophosphate from GDP or GTP substrates is necessary for activity by the clostridial enzymes, neither of which can utilize GMP as a substrate. Both enzymes are remarkably insensitive to the size of their metal ion cofactor, tolerating a broad array of metals that do not allow activity in (pp)pGpp synthetases from other organisms. It is clear that while C. difficile utilizes alarmone signaling, its mechanisms of alarmone synthesis are not directly homologous to those in more completely characterized organisms. IMPORTANCE Despite the role of the stringent response in antibiotic survival and recurrent infections, it has been a challenging target for antibacterial therapies because it is so ubiquitous. This is an especially relevant consideration for the treatment of Clostridioides difficile infection (CDI), as exposure to broad-spectrum antibiotics that harm commensal microbes is a major risk factor for CDI. Here, we report that both of the alarmone synthetase enzymes that mediate the stringent response in this organism employ a unique mechanism that requires the hydrolysis of two phosphate bonds and synthesize the triphosphate alarmone pGpp exclusively. Inhibitors targeted against these noncanonical synthetases have the potential to be highly specific and minimize detrimental effects to stringent response pathways in commensal microbes.
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Affiliation(s)
- Asia Poudel
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Astha Pokhrel
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Adenrele Oludiran
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Estevan J Coronado
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Kwincy Alleyne
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Marrett M Gilfus
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Raj K Gurung
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Surya B Adhikari
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
| | - Erin B Purcell
- Old Dominion Universitygrid.261368.8, Department of Chemistry and Biochemistry, Norfolk, Virginia, USA
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27
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Veetilvalappil VV, Aranjani JM, Mahammad FS, Joseph A. Awakening sleeper cells: a narrative review on bacterial magic spot synthetases as potential drug targets to overcome persistence. Curr Genet 2022; 68:49-60. [PMID: 34787710 PMCID: PMC8801413 DOI: 10.1007/s00294-021-01221-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 10/29/2022]
Abstract
Magic spot synthetases are emerging targets to overcome persistence caused by stringent response. The 'stringent response' is a bacterial stress survival mechanism, which results in the accumulation of alarmones (also called Magic spots) leading to the formation of dormant persister cells. These 'sleeper cells' evade antibiotic treatment and could result in relapse of infection. This review broadly investigates the phenomenon of stringent response and persistence, and specifically discusses the distribution, classification, and nomenclature of proteins such as Rel/SpoT homologs (RSH), responsible for alarmone synthesis. The authors further explain the relevance of RSH as potential drug targets to break the dormancy of persister cells commonly seen in biofilms. One of the significant factors that initiate alarmone synthesis is nutrient deficiency. In a starved condition, ribosome-associated RSH detects deacylated tRNA and initiates alarmone synthesis. Accumulation of alarmones has a considerable effect on bacterial physiology, virulence, biofilm formation, and persister cell formation. Preventing alarmone synthesis by inhibiting RSH responsible for alarmone synthesis will prevent or reduce persister cells' formation. Magic spot synthetases are thus potential targets that could be explored to overcome persistence seen in biofilms.
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Affiliation(s)
- Vimal Venu Veetilvalappil
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India
| | - Jesil Mathew Aranjani
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India.
| | - Fayaz Shaik Mahammad
- Department of Biotechnology, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India
| | - Alex Joseph
- Department of Pharmaceutical Chemistry, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, Udupi, Karnataka, 576104, India
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28
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Kaushik V, Sharma S, Tiwari M, Tiwari V. Anti-persister strategies against stress induced bacterial persistence. Microb Pathog 2022; 164:105423. [PMID: 35092834 DOI: 10.1016/j.micpath.2022.105423] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/17/2022] [Accepted: 01/24/2022] [Indexed: 01/22/2023]
Abstract
The increase in antibiotic non-responsive bacteria is the leading concern in current research-oriented to eliminate pathogens. Nowadays, the excess use of antibiotics without specifically understanding the potentiality of killing pathogens and bacterial survival patterns has helped bacteria emerge indefatigably. Bacteria use various mechanisms such as resistance, persistence, and tolerance to ensure survival. Among these, persistence is a mechanism by which bacteria reside in their dormant state, bypassing the effects of treatments, making it crucial for bacterial survival. Persistent bacterial cells arise from the normal bacterial population as a slow-growing subset of bacteria with no metabolic flux. This behavior renders it to survive for a longer duration and at higher concentrations of antibiotics. They are one of the underlying causes of recurrence of bacterial infections. The present article explains the detailed molecular mechanisms and strategies of bacterial persistence, including the toxin-antitoxin modules, DNA damage, the formation of inactive ribosomal complexes, (p)ppGpp network, antibiotic-induced persistence, which are triggered by drug-induced stress. The article also comprehensively covers the epigenetic memory of persistence in bacteria, and anti-persistent therapeutics like antimicrobial molecules, synthetic peptides, acyldepsipeptide antibiotics, and endolysin therapy to reduce persister cell formation and control their frequency. These strategies could be utilized in combating the pathogenic bacteria undergoing persistence.
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Affiliation(s)
- Vaishali Kaushik
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer, 305817, India
| | - Saroj Sharma
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer, 305817, India
| | - Monalisa Tiwari
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer, 305817, India
| | - Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer, 305817, India.
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29
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Joshi C, Kothari V. Bacterial Stress-response Machinery as a Target for Next-generation Antimicrobials. Infect Disord Drug Targets 2022; 22:e210322202493. [PMID: 35319398 DOI: 10.2174/1871526522666220321153332] [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: 10/16/2021] [Revised: 10/30/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Affiliation(s)
- Chinmayi Joshi
- Smt. S.S.Patel Nootan Science and Commerce College, Sankalchand Patel University, Visnagar 384315, India
| | - Vijay Kothari
- Institute of Science, Nirma University, Ahmedabad 382481, India
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30
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Lee JB, Kim SK, Yoon JW. Pathophysiology of enteropathogenic Escherichia coli during a host infection. J Vet Sci 2022; 23:e28. [PMID: 35187883 PMCID: PMC8977535 DOI: 10.4142/jvs.21160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 11/20/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is a major cause of infantile diarrhea in developing countries. However, sporadic outbreaks caused by this microorganism in developed countries are frequently reported recently. As an important zoonotic pathogen, EPEC is being monitored annually in several countries. Hallmark of EPEC infection is formation of attaching and effacing (A/E) lesions on the small intestine. To establish A/E lesions during a gastrointestinal tract (GIT) infeciton, EPEC must thrive in diverse GIT environments. A variety of stress responses by EPEC have been reported. These responses play significant roles in helping E. coli pass through GIT environments and establishing E. coli infection. Stringent response is one of those responses. It is mediated by guanosine tetraphosphate. Interestingly, previous studies have demonstrated that stringent response is a universal virulence regulatory mechanism present in many bacterial pathogens including EPEC. However, biological signficance of a bacterial stringent response in both EPEC and its interaction with the host during a GIT infection is unclear. It needs to be elucidated to broaden our insight to EPEC pathogenesis. In this review, diverse responses, including stringent response, of EPEC during a GIT infection are discussed to provide a new insight into EPEC pathophysiology in the GIT.
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Affiliation(s)
- Jun Bong Lee
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Se Kye Kim
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
| | - Jang Won Yoon
- College of Veterinary Medicine & Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, Korea
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31
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In Mycobacterium abscessus, the stringent factor Rel regulates metabolism, but is not the only (p)ppGpp synthase. J Bacteriol 2021; 204:e0043421. [PMID: 34898264 DOI: 10.1128/jb.00434-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The stringent response is a broadly conserved stress response system that exhibits functional variability across bacterial clades. Here, we characterize the role of the stringent factor Rel in the non-tuberculous mycobacterial pathogen, Mycobacterium abscessus (Mab). We found that deletion of rel does not ablate (p)ppGpp synthesis, and that rel does not provide a survival advantage in several stress conditions, or in antibiotic treatment. Transcriptional data show that RelMab is involved in regulating expression of anabolism and growth genes in stationary phase. However, it does not activate transcription of stress response or antibiotic resistance genes, and actually represses transcription of many antibiotic resistance genes. This work shows that there is an unannotated (p)ppGpp synthetase in Mab. Importance In this study, we examined the functional roles of the stringent factor Rel in Mycobacterium abscessus (Mab). In most species, stringent factors synthesize the alarmone (p)ppGpp, which globally alters transcription to promote growth arrest and survival under stress and in antibiotic treatment. Our work shows that in Mab, an emerging pathogen which is resistant to many antibiotics, the stringent factor Rel is not solely responsible for synthesizing (p)ppGpp. We find that RelMab downregulates many metabolic genes under stress, but does not upregulate stress response genes and does not promote antibiotic tolerance. This study implies that there is another critical but unannotated (p)ppGpp synthetase in Mab, and suggests that RelMab inhibitors are unlikely to sensitize Mab infections to antibiotic treatment.
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32
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Syal K, Rs N, Reddy MVNJ. The extended (p)ppGpp family: New dimensions in Stress response. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 2:100052. [PMID: 34841343 PMCID: PMC8610335 DOI: 10.1016/j.crmicr.2021.100052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/21/2021] [Accepted: 07/25/2021] [Indexed: 11/30/2022] Open
Abstract
Second messenger (p)ppGpp mediated stress response plays a crucial role in bacterial persistence and multiple drug resistance. In E. coli, (p)ppGpp binds to RNA polymerase and upregulates the transcription of genes essential for stress response while concurrently downregulating the expression of genes critical for growth and metabolism. Recently, the family of alarmone molecules has expanded to pppGpp, ppGpp, pGpp & (pp)pApp as distinct members. These molecules may help in fine-tuning stress responses in different hostile conditions. Do all of these molecules bind to RNA polymerase? Do they compete with each other or complement each other's functions is still not clear. Earlier, others and we have synthesized artificial analogs of (p)ppGpp that inhibited (p)ppGpp synthesis and long-term survival in M. smegmatis and in B. subtilis suggesting that analogs could compete with each other. Understanding the interplay of these molecules will allow deciphering novel pathways that can be potentially subjected to the therapeutic intervention. In this article, we have reviewed newly characterized second messengers and discussed their mode of action. We have also documented the progress made to-date in understanding the molecular basis of regulation of transcription by second messenger ppGpp, pppGpp, and pGpp.
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Affiliation(s)
- Kirtimaan Syal
- Department of Biological Sciences, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India
| | - Neethu Rs
- Department of Biological Sciences, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India
| | - M V N Janardhan Reddy
- Department of Biological Sciences, Birla Institute of Technology and Sciences-Pilani, Hyderabad campus, Hyderabad, Telangana, India
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33
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Wan X, Brynildsen MP. Robustness of nitric oxide detoxification to nitrogen starvation in Escherichia coli requires RelA. Free Radic Biol Med 2021; 176:286-297. [PMID: 34624482 DOI: 10.1016/j.freeradbiomed.2021.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/04/2021] [Indexed: 01/18/2023]
Abstract
Reactive nitrogen species and nutrient deprivation are two elements of the immune response used to eliminate pathogens within phagosomes. Concomitantly, pathogenic bacteria have evolved defense systems to cope with phagosomal stressors, which include enzymes that detoxify nitric oxide (•NO) and respond to nutrient scarcity. A deeper understanding of how those defense systems are deployed under adverse conditions that contain key elements of phagosomes will facilitate targeting of those systems for therapeutic purposes. Here we investigated how Escherichia coli detoxifies •NO in the absence of useable nitrogen, because nitrogen availability is limited in phagosomes due to the removal of nitrogenous compounds (e.g., amino acids). We hypothesized that nitrogen starvation would impair •NO detoxification by E. coli because it depresses translation rates and the main E. coli defense enzyme, Hmp, is synthesized in response to •NO. However, we found that E. coli detoxifies •NO at the same rate regardless of whether useable nitrogen was present. We confirmed that the nitrogen in •NO and its autoxidation products could not be used by E. coli under our experimental conditions, and discovered that •NO eliminated differences in carbon and oxygen consumption between nitrogen-replete and nitrogen-starved cultures. Interestingly, E. coli does not consume measurable extracellular nitrogen during •NO stress despite the need to translate defense enzymes. Further, we found that RelA, which responds to uncharged tRNA, was required to observe the robustness of •NO detoxification to nitrogen starvation. These data demonstrate that E. coli is well poised to detoxify •NO in the absence of useable nitrogen and suggest that the stringent response could be a useful target to potentiate the antibacterial activity of •NO.
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Affiliation(s)
- Xuanqing Wan
- 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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34
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Pulschen AA, Fernandes AZN, Cunha AF, Sastre DE, Matsuguma BE, Gueiros-Filho FJ. Many birds with one stone: targeting the (p)ppGpp signaling pathway of bacteria to improve antimicrobial therapy. Biophys Rev 2021; 13:1039-1051. [DOI: 10.1007/s12551-021-00895-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 10/25/2021] [Indexed: 12/19/2022] Open
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35
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Gupta KR, Arora G, Mattoo A, Sajid A. Stringent Response in Mycobacteria: From Biology to Therapeutic Potential. Pathogens 2021; 10:pathogens10111417. [PMID: 34832573 PMCID: PMC8622095 DOI: 10.3390/pathogens10111417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 01/16/2023] Open
Abstract
Mycobacterium tuberculosis is a human pathogen that can thrive inside the host immune cells for several years and cause tuberculosis. This is due to the propensity of M. tuberculosis to synthesize a sturdy cell wall, shift metabolism and growth, secrete virulence factors to manipulate host immunity, and exhibit stringent response. These attributes help M. tuberculosis to manage the host response, and successfully establish and maintain an infection even under nutrient-deprived stress conditions for years. In this review, we will discuss the importance of mycobacterial stringent response under different stress conditions. The stringent response is mediated through small signaling molecules called alarmones “(pp)pGpp”. The synthesis and degradation of these alarmones in mycobacteria are mediated by Rel protein, which is both (p)ppGpp synthetase and hydrolase. Rel is important for all central dogma processes—DNA replication, transcription, and translation—in addition to regulating virulence, drug resistance, and biofilm formation. Rel also plays an important role in the latent infection of M. tuberculosis. Here, we have discussed the literature on alarmones and Rel proteins in mycobacteria and highlight that (p)ppGpp-analogs and Rel inhibitors could be designed and used as antimycobacterial compounds against M. tuberculosis and non-tuberculous mycobacterial infections.
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Affiliation(s)
| | - Gunjan Arora
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA;
| | - Abid Mattoo
- Pharmaceutical Development, Ultragenyx Gene Therapy, Woburn, MA 01801, USA;
| | - Andaleeb Sajid
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA;
- Correspondence: or
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36
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Danchik C, Wang S, Karakousis PC. Targeting the Mycobacterium tuberculosis Stringent Response as a Strategy for Shortening Tuberculosis Treatment. Front Microbiol 2021; 12:744167. [PMID: 34690990 PMCID: PMC8529327 DOI: 10.3389/fmicb.2021.744167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/14/2021] [Indexed: 11/13/2022] Open
Abstract
The stringent response is well conserved across bacterial species and is a key pathway involved both in bacterial survival and virulence and in the induction of antibiotic tolerance in Mycobacteria. It is mediated by the alarmone (p)ppGpp and the regulatory molecule inorganic polyphosphate in response to stress conditions such as nutrient starvation. Efforts to pharmacologically target various components of the stringent response have shown promise in modulating mycobacterial virulence and antibiotic tolerance. In this review, we summarize the current understanding of the stringent response and its role in virulence and tolerance in Mycobacteria, including evidence that targeting this pathway could have therapeutic benefit.
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Affiliation(s)
| | | | - Petros C. Karakousis
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States
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37
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Léger L, Byrne D, Guiraud P, Germain E, Maisonneuve E. NirD curtails the stringent response by inhibiting RelA activity in Escherichia coli. eLife 2021; 10:64092. [PMID: 34323689 PMCID: PMC8321558 DOI: 10.7554/elife.64092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 07/08/2021] [Indexed: 11/19/2022] Open
Abstract
Bacteria regulate their metabolism to adapt and survive adverse conditions, in particular to stressful downshifts in nutrient availability. These shifts trigger the so-called stringent response, coordinated by the signaling molecules guanosine tetra and pentaphosphate collectively referred to as (p)ppGpp. In Escherichia coli, accumulation of theses alarmones depends on the (p)ppGpp synthetase RelA and the bifunctional (p)ppGpp synthetase/hydrolase SpoT. A tight regulation of these intracellular activities is therefore crucial to rapidly adjust the (p)ppGpp levels in response to environmental stresses but also to avoid toxic consequences of (p)ppGpp over-accumulation. In this study, we show that the small protein NirD restrains RelA-dependent accumulation of (p)ppGpp and can inhibit the stringent response in E. coli. Mechanistically, our in vivo and in vitro studies reveal that NirD directly binds the catalytic domains of RelA to balance (p)ppGpp accumulation. Finally, we show that NirD can control RelA activity by directly inhibiting the rate of (p)ppGpp synthesis.
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Affiliation(s)
- Loïc Léger
- 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
| | - 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
| | - Etienne Maisonneuve
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS-Aix Marseille Univ (UMR7283), Marseille, France
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Chau NYE, Ahmad S, Whitney JC, Coombes BK. Emerging and divergent roles of pyrophosphorylated nucleotides in bacterial physiology and pathogenesis. PLoS Pathog 2021; 17:e1009532. [PMID: 33984072 PMCID: PMC8118318 DOI: 10.1371/journal.ppat.1009532] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Bacteria inhabit diverse environmental niches and consequently must modulate their metabolism to adapt to stress. The nucleotide second messengers guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp) (collectively referred to as (p)ppGpp) are essential for survival during nutrient starvation. (p)ppGpp is synthesized by the RelA-SpoT homologue (RSH) protein family and coordinates the control of cellular metabolism through its combined effect on over 50 proteins. While the role of (p)ppGpp has largely been associated with nutrient limitation, recent studies have shown that (p)ppGpp and related nucleotides have a previously underappreciated effect on different aspects of bacterial physiology, such as maintaining cellular homeostasis and regulating bacterial interactions with a host, other bacteria, or phages. (p)ppGpp produced by pathogenic bacteria facilitates the evasion of host defenses such as reactive nitrogen intermediates, acidic pH, and the complement system. Additionally, (p)ppGpp and pyrophosphorylated derivatives of canonical adenosine nucleotides called (p)ppApp are emerging as effectors of bacterial toxin proteins. Here, we review the RSH protein family with a focus on its unconventional roles during host infection and bacterial competition.
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Affiliation(s)
- N. Y Elizabeth Chau
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Shehryar Ahmad
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - John C. Whitney
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
| | - Brian K. Coombes
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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Srinivasan R, Santhakumari S, Poonguzhali P, Geetha M, Dyavaiah M, Xiangmin L. Bacterial Biofilm Inhibition: A Focused Review on Recent Therapeutic Strategies for Combating the Biofilm Mediated Infections. Front Microbiol 2021; 12:676458. [PMID: 34054785 PMCID: PMC8149761 DOI: 10.3389/fmicb.2021.676458] [Citation(s) in RCA: 121] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/14/2021] [Indexed: 12/31/2022] Open
Abstract
Biofilm formation is a major concern in various sectors and cause severe problems to public health, medicine, and industry. Bacterial biofilm formation is a major persistent threat, as it increases morbidity and mortality, thereby imposing heavy economic pressure on the healthcare sector. Bacterial biofilms also strengthen biofouling, affecting shipping functions, and the offshore industries in their natural environment. Besides, they accomplish harsh roles in the corrosion of pipelines in industries. At biofilm state, bacterial pathogens are significantly resistant to external attack like antibiotics, chemicals, disinfectants, etc. Within a cell, they are insensitive to drugs and host immune responses. The development of intact biofilms is very critical for the spreading and persistence of bacterial infections in the host. Further, bacteria form biofilms on every probable substratum, and their infections have been found in plants, livestock, and humans. The advent of novel strategies for treating and preventing biofilm formation has gained a great deal of attention. To prevent the development of resistant mutants, a feasible technique that may target adhesive properties without affecting the bacterial vitality is needed. This stimulated research is a rapidly growing field for applicable control measures to prevent biofilm formation. Therefore, this review discusses the current understanding of antibiotic resistance mechanisms in bacterial biofilm and intensely emphasized the novel therapeutic strategies for combating biofilm mediated infections. The forthcoming experimental studies will focus on these recent therapeutic strategies that may lead to the development of effective biofilm inhibitors than conventional treatments.
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Affiliation(s)
- Ramanathan Srinivasan
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, School of Life Sciences, Fujian Agriculture and Forestry University, Fujian, China.,Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fujian, China
| | - Sivasubramanian Santhakumari
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry, India
| | | | - Mani Geetha
- PG Research and Department of Microbiology, St. Joseph's College of Arts and Science (Autonomous), Tamil Nadu, India
| | - Madhu Dyavaiah
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Lin Xiangmin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, School of Life Sciences, Fujian Agriculture and Forestry University, Fujian, China.,Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fujian, China.,Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fujian, China
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An AY, Choi KYG, Baghela AS, Hancock REW. An Overview of Biological and Computational Methods for Designing Mechanism-Informed Anti-biofilm Agents. Front Microbiol 2021; 12:640787. [PMID: 33927701 PMCID: PMC8076610 DOI: 10.3389/fmicb.2021.640787] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 03/23/2021] [Indexed: 12/29/2022] Open
Abstract
Bacterial biofilms are complex and highly antibiotic-resistant aggregates of microbes that form on surfaces in the environment and body including medical devices. They are key contributors to the growing antibiotic resistance crisis and account for two-thirds of all infections. Thus, there is a critical need to develop anti-biofilm specific therapeutics. Here we discuss mechanisms of biofilm formation, current anti-biofilm agents, and strategies for developing, discovering, and testing new anti-biofilm agents. Biofilm formation involves many factors and is broadly regulated by the stringent response, quorum sensing, and c-di-GMP signaling, processes that have been targeted by anti-biofilm agents. Developing new anti-biofilm agents requires a comprehensive systems-level understanding of these mechanisms, as well as the discovery of new mechanisms. This can be accomplished through omics approaches such as transcriptomics, metabolomics, and proteomics, which can also be integrated to better understand biofilm biology. Guided by mechanistic understanding, in silico techniques such as virtual screening and machine learning can discover small molecules that can inhibit key biofilm regulators. To increase the likelihood that these candidate agents selected from in silico approaches are efficacious in humans, they must be tested in biologically relevant biofilm models. We discuss the benefits and drawbacks of in vitro and in vivo biofilm models and highlight organoids as a new biofilm model. This review offers a comprehensive guide of current and future biological and computational approaches of anti-biofilm therapeutic discovery for investigators to utilize to combat the antibiotic resistance crisis.
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Affiliation(s)
| | | | | | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
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Nowicki D, Krause K, Szamborska P, Żukowska A, Cech GM, Szalewska-Pałasz A. Induction of the Stringent Response Underlies the Antimicrobial Action of Aliphatic Isothiocyanates. Front Microbiol 2021; 11:591802. [PMID: 33584562 PMCID: PMC7874123 DOI: 10.3389/fmicb.2020.591802] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/15/2020] [Indexed: 11/24/2022] Open
Abstract
Bacterial resistance to known antibiotics comprises a serious threat to public health. Propagation of multidrug-resistant pathogenic strains is a reason for undertaking a search for new therapeutic strategies, based on newly developed chemical compounds and the agents present in nature. Moreover, antibiotic treatment of infections caused by enterotoxin toxin-bearing strain—enterohemorrhagic Escherichia coli (EHEC) is considered hazardous and controversial due to the possibility of induction of bacteriophage-encoded toxin production by the antibiotic-mediated stress. The important source of potentially beneficial compounds are secondary plant metabolites, isothiocyanates (ITC), and phytoncides from the Brassicaceae family. We reported previously that sulforaphane and phenethyl isothiocyanate, already known for their chemopreventive and anticancer features, exhibit significant antibacterial effects against various pathogenic bacteria. The mechanism of their action is based on the induction of the stringent response and accumulation of its alarmones, the guanosine penta- and tetraphosphate. In this process, the amino acid starvation path is employed via the RelA protein, however, the precise mechanism of amino acid limitation in the presence of ITCs is yet unknown. In this work, we asked whether ITCs could act synergistically with each other to increase the antibacterial effect. A set of aliphatic ITCs, such as iberin, iberverin, alyssin, erucin, sulforaphen, erysolin, and cheirolin was tested in combination with sulforaphane against E. coli. Our experiments show that all tested ITCs exhibit strong antimicrobial effect individually, and this effect involves the stringent response caused by induction of the amino acid starvation. Interestingly, excess of specific amino acids reversed the antimicrobial effects of ITCs, where the common amino acid for all tested compounds was glycine. The synergistic action observed for iberin, iberverin, and alyssin also led to accumulation of (p)ppGpp, and the minimal inhibitory concentration necessary for the antibacterial effect was four- to eightfold lower than for individual ITCs. Moreover, the unique mode of ITC action is responsible for inhibition of prophage induction and toxin production, in addition to growth inhibition of EHEC strains. Thus, the antimicrobial effect of plant secondary metabolites by the stringent response induction could be employed in potential therapeutic strategies.
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Affiliation(s)
- Dariusz Nowicki
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Klaudyna Krause
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Patrycja Szamborska
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Adrianna Żukowska
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Grzegorz M Cech
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
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Leonard TE, Siratan E, Hartiadi LY, Crystalia AA. Insights into antimicrobial peptides in fighting anthrax: A review. Drug Dev Res 2021; 82:754-766. [PMID: 33580543 DOI: 10.1002/ddr.21803] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/31/2020] [Accepted: 01/27/2021] [Indexed: 12/12/2022]
Abstract
Anthrax is an infectious disease occurring worldwide and is a threat to global society due to its possible misuse as a biological weapon. Bacillus anthracis is the etiologic agent of this disease which can be transmitted via inhalation, ingestion, and skin contact. Globally, it is estimated around 2000 anthrax cases occur per year. Upon infection, the organism can cause cytolysis of macrophage and produce exotoxin capable of inducing edema and lymphatic blockage. Another challenge posed by the organism is the ability to form spores in harsh conditions. Various antibiotics have been used to fight the disease. However, like many other microbes, B. anthracis may develop resistance, thus the discovery of new therapeutics is urgently required. Antimicrobial peptides (AMPs) have been discovered since 1980s and attracted researchers in the antimicrobial field. In this review, the work and studies on the attempts to discover potent AMPs to treat anthrax together with the brief overview of the synthesis and modification pathways of several AMPs have been presented.
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Affiliation(s)
- Theodore Ebenezer Leonard
- Department of Pharmacy, Indonesia International Institute for Life Sciences (i3L), Jakarta, Indonesia
| | - Elsabda Siratan
- Department of Pharmacy, Indonesia International Institute for Life Sciences (i3L), Jakarta, Indonesia
| | - Leonny Yulita Hartiadi
- Department of Pharmacy, Indonesia International Institute for Life Sciences (i3L), Jakarta, Indonesia
| | - Audrey Amira Crystalia
- Department of Pharmacy, Indonesia International Institute for Life Sciences (i3L), Jakarta, Indonesia
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Tkachenko AG, Kashevarova NM, Sidorov RY, Nesterova LY, Akhova AV, Tsyganov IV, Vaganov VY, Shipilovskikh SA, Rubtsov AE, Malkov AV. A synthetic diterpene analogue inhibits mycobacterial persistence and biofilm formation by targeting (p)ppGpp synthetases. Cell Chem Biol 2021; 28:1420-1432.e9. [PMID: 33621482 DOI: 10.1016/j.chembiol.2021.01.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/14/2020] [Accepted: 01/25/2021] [Indexed: 01/23/2023]
Abstract
Bacterial persistence coupled with biofilm formation is directly associated with failure of antibiotic treatment of tuberculosis. We have now identified 4-(4,7-DiMethyl-1,2,3,4-tetrahydroNaphthalene-1-yl)Pentanoic acid (DMNP), a synthetic diterpene analogue, as a lead compound that was capable of suppressing persistence and eradicating biofilms in Mycobacterium smegmatis. By using two reciprocal experimental approaches - ΔrelMsm and ΔrelZ gene knockout mutations versus relMsm and relZ overexpression technique - we showed that both RelMsm and RelZ (p)ppGpp synthetases are plausible candidates for serving as targets for DMNP. In vitro, DMNP inhibited (p)ppGpp-synthesizing activity of purified RelMsm in a concentration-dependent manner. These findings, supplemented by molecular docking simulation, suggest that DMNP targets the structural sites shared by RelMsm, RelZ, and presumably by a few others as yet unidentified (p)ppGpp producers, thereby inhibiting persister cell formation and eradicating biofilms. Therefore, DMNP may serve as a promising lead for development of antimycobacterial drugs.
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Affiliation(s)
- Alexander G Tkachenko
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Ural Branch, Goleva 13, Perm, 614081, Perm Krai, Russia; Perm State University, Bukireva 15, Perm, 614990, Perm Krai, Russia.
| | - Natalya M Kashevarova
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Ural Branch, Goleva 13, Perm, 614081, Perm Krai, Russia
| | - Roman Yu Sidorov
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Ural Branch, Goleva 13, Perm, 614081, Perm Krai, Russia; Perm State University, Bukireva 15, Perm, 614990, Perm Krai, Russia
| | - Larisa Yu Nesterova
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Ural Branch, Goleva 13, Perm, 614081, Perm Krai, Russia; Perm State University, Bukireva 15, Perm, 614990, Perm Krai, Russia
| | - Anna V Akhova
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Ural Branch, Goleva 13, Perm, 614081, Perm Krai, Russia; Perm State University, Bukireva 15, Perm, 614990, Perm Krai, Russia
| | - Ivan V Tsyganov
- Laboratory of Microbial Adaptation, Institute of Ecology and Genetics of Microorganisms, Perm Federal Research Center, Russian Academy of Sciences, Ural Branch, Goleva 13, Perm, 614081, Perm Krai, Russia; Perm State University, Bukireva 15, Perm, 614990, Perm Krai, Russia
| | | | | | | | - Andrei V Malkov
- Department of Chemistry, Loughborough University Address: University Road, Loughborough, Leicestershire LE11 3TU, UK.
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Mosselhy DA, Assad M, Sironen T, Elbahri M. Nanotheranostics: A Possible Solution for Drug-Resistant Staphylococcus aureus and their Biofilms? NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:E82. [PMID: 33401760 PMCID: PMC7824312 DOI: 10.3390/nano11010082] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/24/2020] [Accepted: 12/30/2020] [Indexed: 12/14/2022]
Abstract
Staphylococcus aureus is a notorious pathogen that colonizes implants (orthopedic and breast implants) and wounds with a vicious resistance to antibiotic therapy. Methicillin-resistant S. aureus (MRSA) is a catastrophe mainly restricted to hospitals and emerged to community reservoirs, acquiring resistance and forming biofilms. Treating biofilms is problematic except via implant removal or wound debridement. Nanoparticles (NPs) and nanofibers could combat superbugs and biofilms and rapidly diagnose MRSA. Nanotheranostics combine diagnostics and therapeutics into a single agent. This comprehensive review is interpretative, utilizing mainly recent literature (since 2016) besides the older remarkable studies sourced via Google Scholar and PubMed. We unravel the molecular S. aureus resistance and complex biofilm. The diagnostic properties and detailed antibacterial and antibiofilm NP mechanisms are elucidated in exciting stories. We highlight the challenges of bacterial infections nanotheranostics. Finally, we discuss the literature and provide "three action appraisals". (i) The first appraisal consists of preventive actions (two wings), avoiding unnecessary hospital visits, hand hygiene, and legislations against over-the-counter antibiotics as the general preventive wing. Our second recommended preventive wing includes preventing the adverse side effects of the NPs from resistance and toxicity by establishing standard testing procedures. These standard procedures should provide breakpoints of bacteria's susceptibility to NPs and a thorough toxicological examination of every single batch of synthesized NPs. (ii) The second appraisal includes theranostic actions, using nanotheranostics to diagnose and treat MRSA, such as what we call "multifunctional theranostic nanofibers. (iii) The third action appraisal consists of collaborative actions.
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Affiliation(s)
- Dina A. Mosselhy
- Nanochemistry and Nanoengineering, Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, 02150 Espoo, Finland;
- Microbiological Unit, Fish Diseases Department, Animal Health Research Institute, Dokki, Giza 12618, Egypt
- Department of Virology, Faculty of Medicine, University of Helsinki, P.O. Box 21, 00014 Helsinki, Finland;
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland
| | - Mhd Assad
- Nanochemistry and Nanoengineering, Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, 02150 Espoo, Finland;
| | - Tarja Sironen
- Department of Virology, Faculty of Medicine, University of Helsinki, P.O. Box 21, 00014 Helsinki, Finland;
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland
| | - Mady Elbahri
- Nanochemistry and Nanoengineering, Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, 02150 Espoo, Finland;
- Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Kiel University, 24143 Kiel, Germany
- Center for Nanotechnology, Zewail City of Science and Technology, Sheikh Zayed District, Giza 12588, Egypt
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Kundra S, Colomer-Winter C, Lemos JA. Survival of the Fittest: The Relationship of (p)ppGpp With Bacterial Virulence. Front Microbiol 2020; 11:601417. [PMID: 33343543 PMCID: PMC7744563 DOI: 10.3389/fmicb.2020.601417] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/16/2020] [Indexed: 12/11/2022] Open
Abstract
The signaling nucleotide (p)ppGpp has been the subject of intense research in the past two decades. Initially discovered as the effector molecule of the stringent response, a bacterial stress response that reprograms cell physiology during amino acid starvation, follow-up studies indicated that many effects of (p)ppGpp on cell physiology occur at levels that are lower than those needed to fully activate the stringent response, and that the repertoire of enzymes involved in (p)ppGpp metabolism is more diverse than initially thought. Of particular interest, (p)ppGpp regulation has been consistently linked to bacterial persistence and virulence, such that the scientific pursuit to discover molecules that interfere with (p)ppGpp signaling as a way to develop new antimicrobials has grown substantially in recent years. Here, we highlight contemporary studies that have further supported the intimate relationship of (p)ppGpp with bacterial virulence and studies that provided new insights into the different mechanisms by which (p)ppGpp modulates bacterial virulence.
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Affiliation(s)
- Shivani Kundra
- Department of Oral Biology, UF College of Dentistry, Gainesville, FL, United States
| | | | - José A Lemos
- Department of Oral Biology, UF College of Dentistry, Gainesville, FL, United States
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Huemer M, Mairpady Shambat S, Brugger SD, Zinkernagel AS. Antibiotic resistance and persistence-Implications for human health and treatment perspectives. EMBO Rep 2020; 21:e51034. [PMID: 33400359 PMCID: PMC7726816 DOI: 10.15252/embr.202051034] [Citation(s) in RCA: 255] [Impact Index Per Article: 63.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/13/2020] [Accepted: 11/02/2020] [Indexed: 12/24/2022] Open
Abstract
Antimicrobial resistance (AMR) and persistence are associated with an elevated risk of treatment failure and relapsing infections. They are thus important drivers of increased morbidity and mortality rates resulting in growing healthcare costs. Antibiotic resistance is readily identifiable with standard microbiological assays, and the threat imposed by antibiotic resistance has been well recognized. Measures aiming to reduce resistance development and spreading of resistant bacteria are being enforced. However, the phenomenon of bacteria surviving antibiotic exposure despite being fully susceptible, so-called antibiotic persistence, is still largely underestimated. In contrast to antibiotic resistance, antibiotic persistence is difficult to measure and therefore often missed, potentially leading to treatment failures. In this review, we focus on bacterial mechanisms allowing evasion of antibiotic killing and discuss their implications on human health. We describe the relationship between antibiotic persistence and bacterial heterogeneity and discuss recent studies that link bacterial persistence and tolerance with the evolution of antibiotic resistance. Finally, we review persister detection methods, novel strategies aiming at eradicating bacterial persisters and the latest advances in the development of new antibiotics.
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Affiliation(s)
- Markus Huemer
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Srikanth Mairpady Shambat
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Silvio D Brugger
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Annelies S Zinkernagel
- Department of Infectious Diseases and Hospital EpidemiologyUniversity Hospital ZurichUniversity of ZurichZurichSwitzerland
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Fernández-Coll L, Cashel M. Possible Roles for Basal Levels of (p)ppGpp: Growth Efficiency Vs. Surviving Stress. Front Microbiol 2020; 11:592718. [PMID: 33162969 PMCID: PMC7581894 DOI: 10.3389/fmicb.2020.592718] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/16/2020] [Indexed: 11/18/2022] Open
Abstract
Two (p)ppGpp nucleotide analogs, sometimes abbreviated simply as ppGpp, are widespread in bacteria and plants. Their name alarmone reflects a view of their function as intracellular hormone-like protective alarms that can increase a 100-fold when sensing any of an array of physical or nutritional dangers, such as abrupt starvation, that trigger lifesaving adjustments of global gene expression and physiology. The diversity of mechanisms for stress-specific adjustments of this sort is large and further compounded by almost infinite microbial diversity. The central question raised by this review is whether the small basal levels of (p)ppGpp functioning during balanced growth serve very different roles than alarmone-like functions. Recent discoveries that abrupt amino acid starvation of Escherichia coli, accompanied by very high levels of ppGpp, occasion surprising instabilities of transfer RNA (tRNA), ribosomal RNA (rRNA), and ribosomes raises new questions. Is this destabilization, a mode of regulation linearly related to (p)ppGpp over the entire continuum of (p)ppGpp levels, including balanced growth? Are regulatory mechanisms exerted by basal (p)ppGpp levels fundamentally different than for high levels? There is evidence from studies of other organisms suggesting special regulatory features of basal levels compared to burst of (p)ppGpp. Those differences seem to be important even during bacterial infection, suggesting that unbalancing the basal levels of (p)ppGpp may become a future antibacterial treatment. A simile for this possible functional duality is that (p)ppGpp acts like a car’s brake, able to stop to avoid crashes as well as to slow down to drive safely.
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Affiliation(s)
- Llorenç Fernández-Coll
- Intramural Research Program, Eunice Kennedy Shriver NICHD, NIH, Bethesda, MD, United States
| | - Michael Cashel
- Intramural Research Program, Eunice Kennedy Shriver NICHD, NIH, Bethesda, MD, United States
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Das B, Bhadra RK. (p)ppGpp Metabolism and Antimicrobial Resistance in Bacterial Pathogens. Front Microbiol 2020; 11:563944. [PMID: 33162948 PMCID: PMC7581866 DOI: 10.3389/fmicb.2020.563944] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/09/2020] [Indexed: 12/13/2022] Open
Abstract
Single cell microorganisms including pathogens relentlessly face myriads of physicochemical stresses in their living environment. In order to survive and multiply under such unfavorable conditions, microbes have evolved with complex genetic networks, which allow them to sense and respond against these stresses. Stringent response is one such adaptive mechanism where bacteria can survive under nutrient starvation and other related stresses. The effector molecules for the stringent response are guanosine-5'-triphosphate 3'-diphosphate (pppGpp) and guanosine-3', 5'-bis(diphosphate) (ppGpp), together called (p)ppGpp. These effector molecules are now emerging as master regulators for several physiological processes of bacteria including virulence, persistence, and antimicrobial resistance. (p)ppGpp may work independently or along with its cofactor DksA to modulate the activities of its prime target RNA polymerase and other metabolic enzymes, which are involved in different biosynthetic pathways. Enzymes involved in (p)ppGpp metabolisms are ubiquitously present in bacteria and categorized them into three classes, i.e., canonical (p)ppGpp synthetase (RelA), (p)ppGpp hydrolase/synthetase (SpoT/Rel/RSH), and small alarmone synthetases (SAS). While RelA gets activated in response to amino acid starvation, enzymes belonging to SpoT/Rel/RSH and SAS family can synthesize (p)ppGpp in response to glucose starvation and several other stress conditions. In this review, we will discuss about the current status of the following aspects: (i) diversity of (p)ppGpp biosynthetic enzymes among different bacterial species including enteropathogens, (ii) signals that modulate the activity of (p)ppGpp synthetase and hydrolase, (iii) effect of (p)ppGpp in the production of antibiotics, and (iv) role of (p)ppGpp in the emergence of antibiotic resistant pathogens. Emphasis has been given to the cholera pathogen Vibrio cholerae due to its sophisticated and complex (p)ppGpp metabolic pathways, rapid mutational rate, and acquisition of antimicrobial resistance determinants through horizontal gene transfer. Finally, we discuss the prospect of (p)ppGpp metabolic enzymes as potential targets for developing antibiotic adjuvants and tackling persistence of infections.
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Affiliation(s)
- Bhabatosh Das
- Infection and Immunology Division, Translational Health Science and Technology Institute (THSTI), Faridabad, India
| | - Rupak K Bhadra
- Infectious Diseases and Immunology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB), Kolkata, India
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Hegde V, Raman AS, Patil PR, Prakash B. Purification and preliminary characterization of four Rel homologues from pathogenic bacteria: Implications for species-specific inhibitor design. Protein Expr Purif 2020; 177:105760. [PMID: 33002609 DOI: 10.1016/j.pep.2020.105760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 11/27/2022]
Abstract
Resistance to antibiotics is a serious concern to treat infectious diseases and also, for food preservation. Existing antibiotics generally inhibit enzymes participating in key bacterial processes, such as formation of cell wall, replication, transcription and translation. However, bacteria have rapidly evolved new mechanisms to combat these antibiotics and it hence becomes indispensable to identify newer targets and identify/design inhibitors against them. Another concern is that most antibiotics are broad spectrum; they largely bind and inhibit the active site of the target enzyme. Rel proteins, which synthesize (and hydrolyze) (p)ppGpp in response to a variety of stress encountered by bacteria, is a profitable target owing to its distinct absence in humans and an intricate regulation of the catalytic activities. Inactivation of (p)ppGpp synthesis by Rel, disables bacterial survival in Mycobacterium tuberculosis and Staphylococcus aureus, while inactivating the hydrolysis activity was lethal. The poor MIC values of the currently known Rel inhibitors present a distinct opportunity to develop better inhibitors and warrants a detailed structural characterization and understanding of the complex regulation in Rel proteins. It will open new avenues for the design of effective, species-specific inhibitors. In an attempt to identify unique sites for inhibitor design using structure-based approaches, we initiate a study of Rel homologues from four different pathogenic bacteria, in order to compare their attributes with well characterized Rel homologues. Here, we present cloning, over-expression, purification and preliminary characterization of these four homologues; and suggest similarities and differences that can be exploited for inhibitor design.
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Affiliation(s)
- Vinayak Hegde
- Department of Molecular Nutrition, CSIR-CFTRI, Mysore, 570020, India; Academy of Scientific and Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Apoorva S Raman
- Department of Molecular Nutrition, CSIR-CFTRI, Mysore, 570020, India
| | - Pratik Rajendra Patil
- Biological Sciences and Bio -Engineering Department, Indian Institute of Technology, Kanpur, 208016, India.
| | - Balaji Prakash
- Department of Molecular Nutrition, CSIR-CFTRI, Mysore, 570020, India.
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Zhang T, Zhu J, Xu J, Shao H, Zhou R. Regulation of (p)ppGpp and Its Homologs on Environmental Adaptation, Survival, and Pathogenicity of Streptococci. Front Microbiol 2020; 11:1842. [PMID: 33101217 PMCID: PMC7545056 DOI: 10.3389/fmicb.2020.01842] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/14/2020] [Indexed: 11/13/2022] Open
Abstract
Most streptococci are commensals, pathogens, or opportunistic pathogens for humans and animals. Therefore, it is important for streptococci to adapt to the various challenging environments of the host during the processes of infection or colonization, as well as to in vitro conditions for transmission. Stringent response (SR) is a special class of adaptive response induced by the signal molecules (p)ppGpp, which regulate several physiological aspects, such as long-term persistence, virulence, biofilm formation, and quorum sensing in bacteria. To understand the roles of SR in streptococci, the current mini-review gives a general overview on: (1) (p)ppGpp synthetases in the genus of Streptococcus, (2) the effects of (p)ppGpp on the physiological phenotypes, persistence, and pathogenicity of streptococci, (3) the transcriptional regulation induced by (p)ppGpp in streptococci, and (4) the link between (p)ppGpp and another nutrient regulatory protein CodY in streptococci.
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Affiliation(s)
- Tengfei Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Jiawen Zhu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Institute of Animal Sciences, Chengdu Academy of Agricultural and Forestry Sciences, Chengdu, China
| | - Jiajia Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Huabin Shao
- Key Laboratory of Prevention and Control Agents for Animal Bacteriosis (Ministry of Agriculture and Rural Affairs), Institute of Animal and Veterinary Science, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,International Research Center for Animal Disease (Ministry of Science & Technology of China), Wuhan, China.,Cooperative Innovation Center of Sustainable Pig Production, Wuhan, China
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