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Mohammed V, Arockiaraj J. Unveiling the trifecta of cyanobacterial quorum sensing: LuxI, LuxR and LuxS as the intricate machinery for harmful algal bloom formation in freshwater ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171644. [PMID: 38471587 DOI: 10.1016/j.scitotenv.2024.171644] [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: 06/28/2023] [Revised: 02/22/2024] [Accepted: 03/09/2024] [Indexed: 03/14/2024]
Abstract
Harmful algal blooms (HABs) are causing significant disruptions in freshwater ecosystems, primarily due to the proliferation of cyanobacteria. These blooms have a widespread impact on various lakes globally, leading to profound environmental and health consequences. Cyanobacteria, with their ability to produce diverse toxins, pose a particular concern as they negatively affect the well-being of humans and animals, exacerbating the situation. Notably, cyanobacteria utilize quorum sensing (QS) as a complex communication mechanism that facilitates coordinated growth and toxin production. QS plays a critical role in regulating the dynamics of HABs. However, recent advances in control and mitigation strategies have shown promising results in effectively managing and reducing the occurrence of HABs. This comprehensive review explores the intricate aspects of cyanobacteria development in freshwater ecosystems, explicitly focusing on deciphering the signaling molecules associated with QS and their corresponding genes. Furthermore, a concise overview of diverse measures implemented to efficiently control and mitigate the spread of these bacteria will be provided, shedding light on the ongoing global efforts to address this urgent environmental issue. By deepening our understanding of the mechanisms driving cyanobacteria growth and developing targeted control strategies, we hope to safeguard freshwater ecosystems and protect the health of humans and animals from the detrimental impacts of HABs.
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Affiliation(s)
- Vajagathali Mohammed
- Department of Forensic Science, Yenepoya Institute of Arts, Science, Commerce, and Management, Yenepoya (Deemed to be University), Mangaluru 575013, Karnataka, India
| | - Jesu Arockiaraj
- Toxicology and Pharmacology Laboratory, Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur 603203, Chengalpattu District, Tamil Nadu, India.
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2
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Beurel E. Stress in the microbiome-immune crosstalk. Gut Microbes 2024; 16:2327409. [PMID: 38488630 PMCID: PMC10950285 DOI: 10.1080/19490976.2024.2327409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/04/2024] [Indexed: 03/19/2024] Open
Abstract
The gut microbiota exerts a mutualistic interaction with the host in a fragile ecosystem and the host intestinal, neural, and immune cells. Perturbations of the gastrointestinal track composition after stress have profound consequences on the central nervous system and the immune system. Reciprocally, brain signals after stress affect the gut microbiota highlighting the bidirectional communication between the brain and the gut. Here, we focus on the potential role of inflammation in mediating stress-induced gut-brain changes and discuss the impact of several immune cells and inflammatory molecules of the gut-brain dialogue after stress. Understanding the impact of microbial changes on the immune system after stress might provide new avenues for therapy.
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Affiliation(s)
- Eléonore Beurel
- Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami, Miami, FL, USA
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL, USA
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3
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Aggarwal S, Huang E, Do H, Makthal N, Li Y, Bapteste E, Lopez P, Bernard C, Kumaraswami M. The leaderless communication peptide (LCP) class of quorum-sensing peptides is broadly distributed among Firmicutes. Nat Commun 2023; 14:5947. [PMID: 37741855 PMCID: PMC10518010 DOI: 10.1038/s41467-023-41719-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 09/14/2023] [Indexed: 09/25/2023] Open
Abstract
The human pathogen Streptococcus pyogenes secretes a short peptide (leaderless communication peptide, LCP) that mediates intercellular communication and controls bacterial virulence through interaction with its receptor, RopB. Here, we show that LCP and RopB homologues are present in other Firmicutes. We experimentally validate that LCPs with distinct peptide communication codes act as bacterial intercellular signals and regulate gene expression in Streptococcus salivarius, Streptococcus porcinus, Enterococcus malodoratus and Limosilactobacillus reuteri. Our results indicate that LCPs are more widespread than previously thought, and their characterization may uncover new signaling mechanisms and roles in coordinating diverse bacterial traits.
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Affiliation(s)
- Shifu Aggarwal
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Elaine Huang
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Hackwon Do
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA
- Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon, 21990, South Korea
| | - Nishanth Makthal
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA
| | - Yanyan Li
- Communication Molecules and Adaptation of Microorganisms (MCAM), CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Eric Bapteste
- Institut de Systématique, Evolution et Biodiversité (ISYEB), Sorbonne Université, CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Philippe Lopez
- Institut de Systématique, Evolution et Biodiversité (ISYEB), Sorbonne Université, CNRS, Muséum National d'Histoire Naturelle, Paris, France
| | - Charles Bernard
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland.
| | - Muthiah Kumaraswami
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, 77030, USA.
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, 77030, USA.
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4
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Golob JL. Human Microbiomes and Disease for the Biomedical Data Scientist. Annu Rev Biomed Data Sci 2023; 6:259-273. [PMID: 37159872 DOI: 10.1146/annurev-biodatasci-020722-043017] [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: 05/11/2023]
Abstract
The human microbiome is complex, variable from person to person, essential for health, and related to both the risk for disease and the efficacy of our treatments. There are robust techniques to describe microbiota with high-throughput sequencing, and there are hundreds of thousands of already-sequenced specimens in public archives. The promise remains to use the microbiome both as a prognostic factor and as a target for precision medicine. However, when used as an input in biomedical data science modeling, the microbiome presents unique challenges. Here, we review the most common techniques used to describe microbial communities, explore these unique challenges, and discuss the more successful approaches for biomedical data scientists seeking to use the microbiome as an input in their studies.
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Affiliation(s)
- Jonathan L Golob
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; ,
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5
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Hu D, Laczkovich I, Federle MJ, Morrison DA. Identification and Characterization of Negative Regulators of Rgg1518 Quorum Sensing in Streptococcus pneumoniae. J Bacteriol 2023; 205:e0008723. [PMID: 37341600 PMCID: PMC10367586 DOI: 10.1128/jb.00087-23] [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: 03/21/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023] Open
Abstract
Streptococcus pneumoniae is an agent of otitis media, septicemia, and meningitis and remains the leading cause of community-acquired pneumonia regardless of vaccine use. Of the various strategies that S. pneumoniae takes to enhance its potential to colonize the human host, quorum sensing (QS) is an intercellular communication process that provides coordination of gene expression at a community level. Numerous putative QS systems are identifiable in the S. pneumoniae genome, but their gene-regulatory activities and contributions to fitness have yet to be fully evaluated. To contribute to assessing regulatory activities of rgg paralogs present in the D39 genome, we conducted transcriptomic analysis of mutants of six QS regulators. Our results find evidence that at least four QS regulators impact the expression of a polycistronic operon (encompassing genes spd_1517 to spd_1513) that is directly controlled by the Rgg/SHP1518 QS system. As an approach to unravel the convergent regulation placed on the spd_1513-1517 operon, we deployed transposon mutagenesis screening in search of upstream regulators of the Rgg/SHP1518 QS system. The screen identified two types of insertion mutants that result in increased activity of Rgg1518-dependent transcription, one type being where the transposon inserted into pepO, an annotated endopeptidase, and the other type being insertions in spxB, a pyruvate oxidase. We demonstrate that pneumococcal PepO degrades SHP1518 to prevent activation of Rgg/SHP1518 QS. Moreover, the glutamic acid residue in the conserved "HExxH" domain is indispensable for the catalytic function of PepO. Finally, we confirmed the metalloendopeptidase property of PepO, which requires zinc ions, but not other ions, to facilitate peptidyl hydrolysis. IMPORTANCE Streptococcus pneumoniae uses quorum sensing to communicate and regulate virulence. In our study, we focused on one Rgg quorum sensing system (Rgg/SHP1518) and found that multiple other Rgg regulators also control it. We further identified two enzymes that inhibit Rgg/SHP1518 signaling and revealed and validated one enzyme's mechanisms for breaking down quorum sensing signaling molecules. Our findings shed light on the complex regulatory network of quorum sensing in Streptococcus pneumoniae.
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Affiliation(s)
- Duoyi Hu
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Irina Laczkovich
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Michael J. Federle
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
- Center for Biomolecular Science, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Donald A. Morrison
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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Chiang-Ni C, Chen YW, Chen KL, Jiang JX, Shi YA, Hsu CY, Chen YYM, Lai CH, Chiu CH. RopB represses the transcription of speB in the absence of SIP in group A Streptococcus. Life Sci Alliance 2023; 6:e202201809. [PMID: 37001914 PMCID: PMC10071013 DOI: 10.26508/lsa.202201809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023] Open
Abstract
RopB is a quorum-sensing regulator that binds to the SpeB-inducing peptide (SIP) under acidic conditions. SIP is known to be degraded by the endopeptidase PepO, whose transcription is repressed by the CovR/CovS two-component regulatory system. Both SIP-bound RopB (RopB-SIP) and SIP-free RopB (apo-RopB) can bind to the speB promoter; however, only RopB-SIP activates speB transcription. In this study, we found that the SpeB expression was higher in the ropB mutant than in the SIP-inactivated (SIP*) mutant. Furthermore, the deletion of ropB in the SIP* mutant derepressed speB expression, suggesting that apo-RopB is a transcriptional repressor of speB Up-regulation of PepO in the covS mutant degraded SIP, resulting in the down-regulation of speB We demonstrate that deleting ropB in the covS mutant derepressed the speB expression, suggesting that the speB repression in this mutant was mediated not only by PepO-dependent SIP degradation but also by apo-RopB. These findings reveal a crosstalk between the CovR/CovS and RopB-SIP systems and redefine the role of RopB in regulating speB expression in group A Streptococcus.
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Affiliation(s)
- Chuan Chiang-Ni
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Yan-Wen Chen
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Kai-Lin Chen
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Jian-Xian Jiang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yong-An Shi
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Yun Hsu
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Ywan M Chen
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Chih-Ho Lai
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Cheng-Hsun Chiu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
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7
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Milly TA, Tal-Gan Y. Targeting Peptide-Based Quorum Sensing Systems for the Treatment of Gram-Positive Bacterial Infections. Pept Sci (Hoboken) 2023; 115:e24298. [PMID: 37397504 PMCID: PMC10312355 DOI: 10.1002/pep2.24298] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/27/2022] [Indexed: 08/27/2023]
Abstract
Bacteria utilize a cell density-dependent communication system called quorum sensing (QS) to coordinate group behaviors. In Gram-positive bacteria, QS involves the production of and response to auto-inducing peptide (AIP) signaling molecules to modulate group phenotypes, including pathogenicity. As such, this bacterial communication system has been identified as a potential therapeutic target against bacterial infections. More specifically, developing synthetic modulators derived from the native peptide signal paves a new way to selectively block the pathogenic behaviors associated with this signaling system. Moreover, rational design and development of potent synthetic peptide modulators allows in depth understanding of the molecular mechanisms that drive QS circuits in diverse bacterial species. Overall, studies aimed at understanding the role of QS in microbial social behavior could result in the accumulation of significant knowledge of microbial interactions, and consequently lead to the development of alternative therapeutic agents to treat bacterial infectivity. In this review, we discuss recent advances in the development of peptide-based modulators to target QS systems in Gram-positive pathogens, with a focus on evaluating the therapeutic potential associated with these bacterial signaling pathways.
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Affiliation(s)
- Tahmina A. Milly
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada, 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada, 89557, United States
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8
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Wang J, Li P, Wang N, Wang J, Xing D. Antibacterial features of material surface: strong enough to serve as antibiotics? J Mater Chem B 2023; 11:280-302. [PMID: 36533438 DOI: 10.1039/d2tb02139k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacteria are small but need big efforts to control. The use of antibiotics not only produces superbugs that are increasingly difficult to inactivate, but also raises environmental concerns with the growing consumption. It is now believed that the antibacterial task can count on some physiochemical features of material surfaces, which can be anti-adhesive or bactericidal without releasing toxicants. It is necessary to evaluate to what extent can we rely on the surface design since the actual application scenarios will need the antibacterial performance to be sharp, robust, environmentally friendly, and long-lasting. Herein, we review the recent laboratory advances that have been classified based on the specific surface features, including hydrophobicity, charge potential, micromorphology, stiffness and viscosity, and photoactivity, and the antibacterial mechanisms of each feature are included to provide a basic rationale for future design. The significance of anti-biofilms is also introduced, given the big role of biofilms in bacteria-caused damage. A perspective on the potential wide application of antibacterial surface features as a substitute or supplement to antibiotics is then discussed. Surface design is no doubt a solution worthy to explore, and future success will be a result of further progress in multiple directions, including mechanism study and material preparation.
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Affiliation(s)
- Jie Wang
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266071, China. .,CAS Key Laboratory of Marine Environmental Corrosion and Bio-Fouling, Institute of Oceanology, China Academy of Sciences, Qingdao 266071, China.
| | - Ping Li
- School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao 266071, China
| | - Ning Wang
- CAS Key Laboratory of Marine Environmental Corrosion and Bio-Fouling, Institute of Oceanology, China Academy of Sciences, Qingdao 266071, China.
| | - Jing Wang
- CAS Key Laboratory of Marine Environmental Corrosion and Bio-Fouling, Institute of Oceanology, China Academy of Sciences, Qingdao 266071, China.
| | - Dongming Xing
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266071, China.
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9
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Segawa T, Manias DA, Dunny GM. Structural Differences in Complexes between the Master Regulator PrgX, Peptide Pheromones, and Operator Binding Sites Determine the Induction State for Conjugative Transfer of pCF10. J Bacteriol 2022; 204:e0029822. [PMID: 36354318 PMCID: PMC9764970 DOI: 10.1128/jb.00298-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/13/2022] [Indexed: 11/12/2022] Open
Abstract
Pheromone-inducible conjugation in the Enterococcus faecalis pCF10 system is regulated by the PrgX transcription factor through binding interactions at two operator binding sites (XBS1 and XBS2) upstream of the transcription start site of the prgQ operon encoding the conjugation machinery. Repression of transcription requires the interaction of a PrgX tetramer with both XBSs via formation of a DNA loop. The ability of PrgX to regulate prgQ transcription is modulated by its interaction with two antagonistic regulatory peptides, ICF10 (I) and cCF10 (C); the former peptide inhibits prgQ transcription, while the latter peptide enhances prgQ transcription. In this report, we used electrophoretic mobility shift assays (EMSAs) and DNase footprinting to examine binding interactions between the XBS operator sites and various forms of PrgX (Apo-X, PrgX/I, and PrgX/C). Whereas a previous model based on high-resolution structures of PrgX proposed that the functional differences between PrgX/C and PrgX/I resulted from differences in PrgX oligomerization state, the current results show that specific differences in XBS2 occupancy by bound tetramers account for the differential regulatory properties of the two peptide/PrgX complexes and for the effects of XBS mutations on regulation. The results also confirmed a DNA looping model of PrgX function. IMPORTANCE Peptide pheromones regulate antibiotic resistance transfer in Enterococcus faecalis. Here, we present new data showing that pheromone-dependent regulation of transfer genes is mediated via effects on the structures of complexes between peptides, the intracellular peptide receptor, and operator sites on the target DNA.
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Affiliation(s)
- Takaya Segawa
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Dawn A. Manias
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Gary M. Dunny
- Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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10
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Host–Bacterial Interactions: Outcomes of Antimicrobial Peptide Applications. MEMBRANES 2022; 12:membranes12070715. [PMID: 35877918 PMCID: PMC9317001 DOI: 10.3390/membranes12070715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 02/04/2023]
Abstract
The bacterial membrane is part of a secretion system which plays an integral role to secrete proteins responsible for cell viability and pathogenicity; pathogenic bacteria, for example, secrete virulence factors and other membrane-associated proteins to invade the host cells through various types of secretion systems (Type I to Type IX). The bacterial membrane can also mediate microbial communities’ communication through quorum sensing (QS), by secreting auto-stimulants to coordinate gene expression. QS plays an important role in regulating various physiological processes, including bacterial biofilm formation while providing increased virulence, subsequently leading to antimicrobial resistance. Multi-drug resistant (MDR) bacteria have emerged as a threat to global health, and various strategies targeting QS and biofilm formation have been explored by researchers worldwide. Since the bacterial secretion systems play such a crucial role in host–bacterial interactions, this review intends to outline current understanding of bacterial membrane systems, which may provide new insights for designing approaches aimed at antimicrobials discovery. Various mechanisms pertaining interaction of the bacterial membrane with host cells and antimicrobial agents will be highlighted, as well as the evolution of bacterial membranes in evasion of antimicrobial agents. Finally, the use of antimicrobial peptides (AMPs) as a cellular device for bacterial secretion systems will be discussed as emerging potential candidates for the treatment of multidrug resistance infections.
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11
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Abdullah IT, Ulijasz AT, Girija UV, Tam S, Andrew P, Hiller NL, Wallis R, Yesilkaya H. Structure‐function analysis for development of peptide inhibitors for a Gram positive quorum sensing system. Mol Microbiol 2022; 117:1464-1478. [PMID: 35575437 PMCID: PMC9233744 DOI: 10.1111/mmi.14921] [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: 02/03/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/27/2022]
Abstract
The Streptococcus pneumoniae Rgg144/SHP144 regulator‐peptide quorum sensing (QS) system is critical for nutrient utilization, oxidative stress response, and virulence. Here, we characterized this system by assessing the importance of each residue within the active short hydrophobic peptide (SHP) by alanine‐scanning mutagenesis and testing the resulting peptides for receptor binding and activation of the receptor. Interestingly, several of the mutations had little effect on binding to Rgg144 but reduced transcriptional activation appreciably. In particular, a proline substitution (P21A) reduced transcriptional activation by 29‐fold but bound with a 3‐fold higher affinity than the wild‐type SHP. Consistent with the function of Rgg144, the mutant peptide led to decreased utilization of mannose and increased susceptibility to superoxide generator paraquat. Pangenome comparison showed full conservation of P21 across SHP144 allelic variants. Crystallization of Rgg144 in the absence of peptide revealed a comparable structure to the DNA bound and free forms of its homologs suggesting similar mechanisms of activation. Together, these analyses identify key interactions in a critical pneumococcal QS system. Further manipulation of the SHP has the potential to facilitate the development of inhibitors that are functional across strains. The approach described here is likely to be effective across QS systems in multiple species.
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Affiliation(s)
- Iman Tajer Abdullah
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
- Department of Biology, College of Science University of Kirkuk Iraq
| | - Andrew T. Ulijasz
- Department of Microbiology and Immunology Loyola University Chicago Maywood IL USA
| | | | - Sien Tam
- Department of Biological Sciences Carnegie Mellon University Pittsburgh, PA 15213
| | - Peter Andrew
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
| | - N. Luisa Hiller
- Department of Biological Sciences Carnegie Mellon University Pittsburgh, PA 15213
| | - Russell Wallis
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
| | - Hasan Yesilkaya
- Department of Respiratory Sciences University of Leicester Leicester United Kingdom
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12
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Martínez OF, Duque HM, Franco OL. Peptidomimetics as Potential Anti-Virulence Drugs Against Resistant Bacterial Pathogens. Front Microbiol 2022; 13:831037. [PMID: 35516442 PMCID: PMC9062693 DOI: 10.3389/fmicb.2022.831037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/28/2022] [Indexed: 12/11/2022] Open
Abstract
The uncontrollable spread of superbugs calls for new approaches in dealing with microbial-antibiotic resistance. Accordingly, the anti-virulence approach has arisen as an attractive unconventional strategy to face multidrug-resistant pathogens. As an emergent strategy, there is an imperative demand for discovery, design, and development of anti-virulence drugs. In this regard, peptidomimetic compounds could be a valuable source of anti-virulence drugs, since these molecules circumvent several shortcomings of natural peptide-based drugs like proteolytic instability, immunogenicity, toxicity, and low bioavailability. Some emerging evidence points to the feasibility of peptidomimetics to impair pathogen virulence. Consequently, in this review, we shed some light on the potential of peptidomimetics as anti-virulence drugs to overcome antibiotic resistance. Specifically, we address the anti-virulence activity of peptidomimetics against pathogens' secretion systems, biofilms, and quorum-sensing systems.
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Affiliation(s)
- Osmel Fleitas Martínez
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Biotecnologia, S-Inova Biotech, Universidade Católica Dom Bosco, Campo Grande, Brazil
| | - Harry Morales Duque
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil
| | - Octávio Luiz Franco
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Biotecnologia, S-Inova Biotech, Universidade Católica Dom Bosco, Campo Grande, Brazil
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13
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Rebuffat S. Ribosomally synthesized peptides, foreground players in microbial interactions: recent developments and unanswered questions. Nat Prod Rep 2021; 39:273-310. [PMID: 34755755 DOI: 10.1039/d1np00052g] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
It is currently well established that multicellular organisms live in tight association with complex communities of microorganisms including a large number of bacteria. These are immersed in complex interaction networks reflecting the relationships established between them and with host organisms; yet, little is known about the molecules and mechanisms involved in these mutual interactions. Ribosomally synthesized peptides, among which bacterial antimicrobial peptides called bacteriocins and microcins have been identified as contributing to host-microbe interplays, are either unmodified or post-translationally modified peptides. This review will unveil current knowledge on these ribosomal peptide-based natural products, their interplay with the host immune system, and their roles in microbial interactions and symbioses. It will include their major structural characteristics and post-translational modifications, the main rules of their maturation pathways, and the principal ecological functions they ensure (communication, signalization, competition), especially in symbiosis, taking select examples in various organisms. Finally, we address unanswered questions and provide a framework for deciphering big issues inspiring future directions in the field.
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Affiliation(s)
- Sylvie Rebuffat
- Laboratory Molecules of Communication and Adaptation of Microorganisms (MCAM, UMR 7245 CNRS-MNHN), National Museum of Natural History (MNHN), National Centre of Scientific Research (CNRS), CP 54, 57 rue Cuvier 75005, Paris, France.
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Abstract
Bacteriophages are the most diverse and abundant biological entities on the Earth and require host bacteria to replicate. Because of this obligate relationship, in addition to the challenging conditions of surrounding environments, phages must integrate information about extrinsic and intrinsic factors when infecting their host. This integration helps to determine whether the infection becomes lytic or lysogenic, which likely influences phage spreading and long-term survival. Although a variety of environmental and physiological clues are known to modulate lysis-lysogeny decisions, the social interplay among phages and host populations has been overlooked until recently. A growing body of evidence indicates that cell-cell communication in bacteria and, more recently, peptide-based communication among phage-phage populations, affect phage-host interactions by controlling phage lysis-lysogeny decisions and phage counter-defensive strategies in bacteria. Here, we explore and discuss the role of signal molecules as well as quorum sensing and quenching factors that mediate phage-host interactions. Our aim is to provide an overview of population-dependent mechanisms that influence phage replication, and how social communication may affect the dynamics and evolution of microbial communities, including their implications in phage therapy.
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15
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Quorum Sensing in Streptococcus mutans Regulates Production of Tryglysin, a Novel RaS-RiPP Antimicrobial Compound. mBio 2021; 12:mBio.02688-20. [PMID: 33727351 PMCID: PMC8092268 DOI: 10.1128/mbio.02688-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacteria interact and compete with a large community of organisms in their natural environment. Streptococcus mutans is one such organism, and it is an important member of the oral microbiota. We found that S. mutans uses a quorum-sensing system to regulate production of a novel posttranslationally modified peptide capable of inhibiting growth of several streptococcal species. The genus Streptococcus encompasses a large bacterial taxon that commonly colonizes mucosal surfaces of vertebrates and is capable of disease etiologies originating from diverse body sites, including the respiratory, digestive, and reproductive tracts. Identifying new modes of treating infections is of increasing importance, as antibiotic resistance has escalated. Streptococcus mutans is an important opportunistic pathogen that is an agent of dental caries and is capable of systemic diseases such as endocarditis. As such, understanding how it regulates virulence and competes in the oral niche is a priority in developing strategies to defend from these pathogens. We determined that S. mutans UA159 possesses a bona fide short hydrophobic peptide (SHP)/Rgg quorum-sensing system that regulates a specialized biosynthetic operon featuring a radical-SAM (S-adenosyl-l-methionine) (RaS) enzyme and produces a ribosomally synthesized and posttranslationally modified peptide (RiPP). The pairing of SHP/Rgg regulatory systems with RaS biosynthetic operons is conserved across streptococci, and a locus similar to that in S. mutans is found in Streptococcus ferus, an oral streptococcus isolated from wild rats. We identified the RaS-RiPP product from this operon and solved its structure using a combination of analytical methods; we term these RiPPs tryglysin A and B for the unusual Trp-Gly-Lys linkage. We report that tryglysins specifically inhibit the growth of other streptococci, but not other Gram-positive bacteria such as Enterococcus faecalis or Lactococcus lactis. We predict that tryglysin is produced by S. mutans in its oral niche, thus inhibiting the growth of competing species, including several medically relevant streptococci.
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16
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Fu L, Li Q, Chen C, Zhang Y, Liu Y, Xu L, Zhou Y, Li C, Zhou D, Rittmann BE. Benzoic and salicylic acid are the signaling molecules of Chlorella cells for improving cell growth. CHEMOSPHERE 2021; 265:129084. [PMID: 33261837 DOI: 10.1016/j.chemosphere.2020.129084] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/11/2020] [Accepted: 11/19/2020] [Indexed: 05/28/2023]
Abstract
Cell-to-cell communication regulates microalgae production via signaling molecules (SMs), but few microalgal SM species are known. Here, we document two new microalgae SMs, benzoic acid (BA) and salicylic acid (SA). Initially, crude SMs were extracted from a microalgae culture in which microalgae grew on heterotrophic-enriched phosphorus nutrition. The extracted SMs enhanced Chlorella growth by ∼72%, promoted nutrient uptake, and up-regulated the mitogen-activated protein-kinase signaling cascade. Fourier transform infrared and nuclear magnetic resonance analyses identified the putative SMs was aromatic carboxylic acids. BA and SA were identified using high-resolution mass spectrometry. BA and SA addition increased cell growth by ∼75% and ∼25%; and improved ATP production by ∼35% and ∼20%. Transcriptomic analysis showed that BA and SA were biosynthesized via CoA-dependent, non-oxidative pathway. The SMs upregulated TCA-cycle enzymes, which promoted carbon assimilation and activated DNA-replicating enzyme, so that accelerated cell division. This study identified two new SMs for microalgae cell communication and provides means to identify other SMs.
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Affiliation(s)
- Liang Fu
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Qingcheng Li
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Congli Chen
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China; National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| | - Yueju Zhang
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Yinglu Liu
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Liang Xu
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China
| | - Yihan Zhou
- National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| | - Chengbin Li
- Changchun Water Group Co. Ltd, Changchun, 130021, China
| | - Dandan Zhou
- Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China.
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, 85287, USA
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17
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Crespo I, Bernardo N, Miguel-Arribas A, Singh PK, Luque-Ortega JR, Alfonso C, Malfois M, Meijer WJJ, Boer DR. Inactivation of the dimeric RappLS20 anti-repressor of the conjugation operon is mediated by peptide-induced tetramerization. Nucleic Acids Res 2020; 48:8113-8127. [PMID: 32658272 PMCID: PMC7430634 DOI: 10.1093/nar/gkaa540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 06/08/2020] [Accepted: 06/15/2020] [Indexed: 12/21/2022] Open
Abstract
Quorum sensing allows bacterial cells to communicate through the release of soluble signaling molecules into the surrounding medium. It plays a pivotal role in controlling bacterial conjugation in Gram-positive cells, a process that has tremendous impact on health. Intracellular regulatory proteins of the RRNPP family are common targets of these signaling molecules. The RRNPP family of gene regulators bind signaling molecules at their C-terminal domain (CTD), but have highly divergent functionalities at their N-terminal effector domains (NTD). This divergence is also reflected in the functional states of the proteins, and is highly interesting from an evolutionary perspective. RappLS20 is an RRNPP encoded on the Bacillus subtilis plasmid pLS20. It relieves the gene repression effectuated by RcopLS20 in the absence of the mature pLS20 signaling peptide Phr*pLS20. We report here an in-depth structural study of apo and Phr*pLS20-bound states of RappLS20 at various levels of atomic detail. We show that apo-RappLS20 is dimeric and that Phr*pLS20-bound Rap forms NTD-mediated tetramers. In addition, we show that RappLS20 binds RcopLS20 directly in the absence of Phr*pLS20 and that addition of Phr*pLS20 releases RcopLS20 from RappLS20. This allows RcopLS20 to bind the promotor region of crucial conjugation genes blocking their expression.
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Affiliation(s)
- Isidro Crespo
- ALBA Synchrotron Light Source, C. de la Llum 2-26, Cerdanyola del Vallès, 08290 Barcelona, Spain
| | - Nerea Bernardo
- ALBA Synchrotron Light Source, C. de la Llum 2-26, Cerdanyola del Vallès, 08290 Barcelona, Spain
| | - Andrés Miguel-Arribas
- Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), C. Nicolás Cabrera 1, Universidad Autónoma, Canto Blanco, 28049 Madrid, Spain
| | - Praveen K Singh
- Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), C. Nicolás Cabrera 1, Universidad Autónoma, Canto Blanco, 28049 Madrid, Spain
| | - Juan R Luque-Ortega
- Molecular Interactions Facility, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C. Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Carlos Alfonso
- Systems Biochemistry of Bacterial Division Lab, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C. Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Marc Malfois
- ALBA Synchrotron Light Source, C. de la Llum 2-26, Cerdanyola del Vallès, 08290 Barcelona, Spain
| | - Wilfried J J Meijer
- Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM), C. Nicolás Cabrera 1, Universidad Autónoma, Canto Blanco, 28049 Madrid, Spain
| | - Dirk Roeland Boer
- ALBA Synchrotron Light Source, C. de la Llum 2-26, Cerdanyola del Vallès, 08290 Barcelona, Spain
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18
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Multi-omics Approach Reveals How Yeast Extract Peptides Shape Streptococcus thermophilus Metabolism. Appl Environ Microbiol 2020; 86:AEM.01446-20. [PMID: 32769193 DOI: 10.1128/aem.01446-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/04/2020] [Indexed: 12/28/2022] Open
Abstract
Peptides present in growth media are essential for nitrogen nutrition and optimal growth of lactic acid bacteria. In addition, according to their amino acid composition, they can also directly or indirectly play regulatory roles and influence global metabolism. This is especially relevant during the propagation phase to produce high cell counts of active lactic acid bacteria used as starters in the dairy industry. In the present work, we aimed at investigating how the respective compositions of two different yeast extracts, with a specific focus on peptide content, influenced Streptococcus thermophilus metabolism during growth under pH-controlled conditions. In addition to free amino acid quantification, we used a multi-omics approach (peptidomics, proteomics, and transcriptomics) to identify peptides initially present in the two culture media and to follow S. thermophilus gene expression and bacterial protein production during growth. The free amino acid and peptide compositions of the two yeast extracts differed qualitatively and quantitatively. Nevertheless, the two yeast extracts sustained similar levels of growth of S. thermophilus and led to equivalent final biomasses. However, transcriptomics and proteomics showed differential gene expression and protein production in several S. thermophilus metabolic pathways, especially amino acid, citrate, urease, purine, and pyrimidine metabolisms. The probable role of the regulator CodY is discussed in this context. Moreover, we observed significant differences in the production of regulators and of a quorum sensing regulatory system. The possible roles of yeast extract peptides on the modulation of the quorum sensing system expression are evaluated.IMPORTANCE Improving the performance and industrial robustness of bacteria used in fermentations and food industry remains a challenge. We showed here that two Streptococcus thermophilus fermentations, performed with the same strain in media that differ only by their yeast extract compositions and, more especially, their peptide contents, led to similar growth kinetics and final biomasses, but several genes and proteins were differentially expressed/produced. In other words, subtle variations in peptide composition of the growth medium can finely tune the metabolism status of the starter. Our work, therefore, suggests that acting on growth medium components and especially on their peptide content, we could modulate bacterial metabolism and produce bacteria differently programmed for further purposes. This might have applications for preparing active starter cultures.
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19
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Shastry RP, Rekha PD. Bacterial cross talk with gut microbiome and its implications: a short review. Folia Microbiol (Praha) 2020; 66:15-24. [PMID: 32949007 DOI: 10.1007/s12223-020-00821-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/09/2020] [Indexed: 12/14/2022]
Abstract
Human gut microbiota exists in a complicated symbiotic relationship which postulates to impact health and disease conditions on the host. Interestingly, the gut microbiome shows different mechanisms to regulate host physiology and metabolism including cell-to-cell communications. But microbiota imbalance is characterized to change in the host normal functioning and lead to the development and progression of major human diseases. Therefore, the direct cross talk through the microbial metabolites or peptides suggests the evidence of host health and disease. Recent reports highlight the adaptation signals/small molecules promoting microbial colonization which allows modulating immunity of host and leads to pathogen colonization. Moreover, quorum sensing peptides are also evident in the involvement of host disease conditions. Here, we review the current understanding of the gut microbiota cross talk with mammalian cells through metabolites and peptides. These studies are providing insight into the prediction of signature molecules which significantly provide information for the understanding of the interaction for precision medicine applications.
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Affiliation(s)
- Rajesh P Shastry
- Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangalore, 575018, India.
| | - P D Rekha
- Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangalore, 575018, India
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20
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Bushin LB, Covington BC, Rued BE, Federle MJ, Seyedsayamdost MR. Discovery and Biosynthesis of Streptosactin, a Sactipeptide with an Alternative Topology Encoded by Commensal Bacteria in the Human Microbiome. J Am Chem Soc 2020; 142:16265-16275. [DOI: 10.1021/jacs.0c05546] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Leah B. Bushin
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Brett C. Covington
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Britta E. Rued
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Michael J. Federle
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Mohammad R. Seyedsayamdost
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
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21
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Involvement of Chromosomally Encoded Homologs of the RRNPP Protein Family in Enterococcus faecalis Biofilm Formation and Urinary Tract Infection Pathogenesis. J Bacteriol 2020; 202:JB.00063-20. [PMID: 32540933 DOI: 10.1128/jb.00063-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/02/2020] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecalis is an opportunistic pathogen capable of causing infections, including endocarditis and urinary tract infections (UTI). One of the well-characterized quorum-sensing pathways in E. faecalis involves coordination of the conjugal transfer of pheromone-responsive plasmids by PrgX, a member of the RRNPP protein family. Members of this protein family in various Firmicutes have also been shown to contribute to numerous cellular processes, including sporulation, competence, conjugation, nutrient sensing, biofilm formation, and virulence. As PrgX is a plasmid-encoded RRNPP family member, we surveyed the genome of the multidrug-resistant strain V583 for additional RRNPP homologs using computational searches and refined those identified hits for predicted structural similarities to known RRNPP family members. This led us to investigate the contribution of the chromosomally encoded RRNPP homologs to biofilm processes and pathogenesis in a catheter-associated urinary tract infection (CAUTI) model. In this study, we identified five such homologs and report that 3 of the 5 homologs, EF0073, EF1599, and EF1316, affect biofilm formation as well as outcomes in the CAUTI model.IMPORTANCE Enterococcus faecalis causes health care-associated infections and displays resistance to a variety of broad-spectrum antibiotics by acquisition of resistance traits as well as the ability to form biofilms. Even though a growing number of factors related to biofilm formation have been identified, mechanisms that contribute to biofilm formation are still largely unknown. Members of the RRNPP protein family regulate a diverse set of biological reactions in low-G+C Gram-positive bacteria (Firmicutes). Here, we identify three predicted structural homologs of the RRNPP family, EF0073, EF1599, and EF1316, which affect biofilm formation and CAUTI pathogenesis.
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22
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Kotte AK, Severn O, Bean Z, Schwarz K, Minton NP, Winzer K. RRNPP-type quorum sensing affects solvent formation and sporulation in Clostridium acetobutylicum. MICROBIOLOGY (READING, ENGLAND) 2020; 166:579-592. [PMID: 32375981 PMCID: PMC7376267 DOI: 10.1099/mic.0.000916] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/27/2020] [Indexed: 12/14/2022]
Abstract
The strictly anaerobic bacterium Clostridium acetobutylicum is well known for its ability to convert sugars into organic acids and solvents, most notably the potential biofuel butanol. However, the regulation of its fermentation metabolism, in particular the shift from acid to solvent production, remains poorly understood. The aim of this study was to investigate whether cell-cell communication plays a role in controlling the timing of this shift or the extent of solvent formation. Analysis of the available C. acetobutylicum genome sequences revealed the presence of eight putative RRNPP-type quorum-sensing systems, here designated qssA to qssH, each consisting of an RRNPP-type regulator gene followed by a small open reading frame encoding a putative signalling peptide precursor. The identified regulator and signal peptide precursor genes were designated qsrA to qsrH and qspA to qspH, respectively. Triplicate regulator mutants were generated in strain ATCC 824 for each of the eight systems and screened for phenotypic changes. The qsrB mutants showed increased solvent formation during early solventogenesis and hence the QssB system was selected for further characterization. Overexpression of qsrB severely reduced solvent and endospore formation and this effect could be overcome by adding short synthetic peptides to the culture medium representing a specific region of the QspB signalling peptide precursor. In addition, overexpression of qspB increased the production of acetone and butanol and the initial (48 h) titre of heat-resistant endospores. Together, these findings establish a role for QssB quorum sensing in the regulation of early solventogenesis and sporulation in C. acetobutylicum.
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Affiliation(s)
- Ann-Kathrin Kotte
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham, UK
- Present address: Independent Commodity Intelligence Service, Bishopsgate, London, UK
| | - Oliver Severn
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham, UK
- Present address: Singer Instruments, Roadwater, Watchet, UK
| | - Zak Bean
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham, UK
- Present address: CHAIN Biotechnology Ltd, MediCity, Nottingham, UK
| | - Katrin Schwarz
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham, UK
- Present address: Azotic Technologies Ltd, BioCity, Nottingham, UK
| | - Nigel P. Minton
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham, UK
| | - Klaus Winzer
- BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, The University of Nottingham, Nottingham, UK
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23
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Feng J, Zong W, Wang P, Zhang ZT, Gu Y, Dougherty M, Borovok I, Wang Y. RRNPP-type quorum-sensing systems regulate solvent formation, sporulation and cell motility in Clostridium saccharoperbutylacetonicum. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:84. [PMID: 32411297 PMCID: PMC7206700 DOI: 10.1186/s13068-020-01723-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/30/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Clostridium saccharoperbutylacetonicum N1-4 (HMT) is a strictly anaerobic, spore-forming Gram-positive bacterium capable of hyper-butanol production through the well-known acetone-butanol-ethanol fermentation process. Recently, five putative RRNPP-type QSSs (here designated as QSS1 to QSS5) were predicted in this bacterial strain, each of which comprises a putative RRNPP-type regulator (QssR1 to QssR5) and a cognate signaling peptide precursor (QssP1 to QssP5). In addition, both proteins are encoded by the same operon. The functions of these multiple RRNPP-type QSSs are unknown. RESULTS To elucidate the function of multiple RRNPP-type QSSs as related to cell metabolism and solvent production in N1-4 (HMT), we constructed qssR-deficient mutants ΔR1, ΔR2, ΔR3 and ΔR5 through gene deletion using CRISPR-Cas9 and N1-4-dcas9-R4 (with the QssR4 expression suppressed using CRISPR-dCas9). We also constructed complementation strains by overexpressing the corresponding regulator gene. Based on systematic characterization, results indicate that QSS1, QSS2, QSS3, and QSS5 positively regulate the sol operon expression and thus solvent production, but they likely negatively regulate cell motility. Consequently, QSS4 might not directly regulate solvent production, but positively affect cell migration. In addition, QSS3 and QSS5 appear to positively regulate sporulation efficiency. CONCLUSIONS Our study provides the first insights into the roles of multiple RRNPP-type QSSs of C. saccharoperbutylacetonicum for the regulation of solvent production, cell motility, and sporulation. Results of this study expand our knowledge of how multiple paralogous QSSs are involved in the regulation of essential bacterial metabolism pathways.
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Affiliation(s)
- Jun Feng
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Wenming Zong
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
- School of Engineering, Anhui Agricultural University, Hefei, 230036 China
| | - Pixiang Wang
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Zhong-Tian Zhang
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Yanyan Gu
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Mark Dougherty
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
| | - Ilya Borovok
- School of Molecular Cell Biology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, 6997801 Tel Aviv, Israel
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, 350 Mell Street, Auburn, AL 36849 USA
- Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849 USA
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24
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Multiple and Overlapping Functions of Quorum Sensing Proteins for Cell Specialization in Bacillus Species. J Bacteriol 2020; 202:JB.00721-19. [PMID: 32071096 DOI: 10.1128/jb.00721-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In bacterial populations, quorum sensing (QS) systems participate in the regulation of specialization processes and regulate collective behaviors that mediate interactions and allow survival of the species. In Gram-positive bacteria, QS systems of the RRNPP family (Rgg, Rap, NprR, PlcR, and PrgX) consist of intracellular receptors and their cognate signaling peptides. Two of these receptors, Rap and NprR, have regained attention in Bacillus subtilis and the Bacillus cereus group. Some Rap proteins, such as RapH and Rap60, are multifunctional and/or redundant in function, linking the specialization processes of sporulation and competence, as well as global expression changes in the transition phase in B. subtilis NprR, an evolutionary intermediate between Rap and RRNPP transcriptional activators, is a bifunctional regulator that modulates sporulation initiation and activates nutrient scavenging genes. In this review, we discuss how these receptors switch between functions and connect distinct signaling pathways. Based on structural evidence, we propose that RapH and Rap60 should be considered moonlighting proteins. Additionally, we analyze an evolutionary and ecological perspective to understand the multifunctionality and functional redundancy of these regulators in both Bacillus spp. and non-Bacillus Firmicutes Understanding the mechanistic, structural, ecological, and evolutionary basis for the multifunctionality and redundancy of these QS systems is a key step for achieving the development of innovative technologies for health and agriculture.
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25
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Babel H, Naranjo-Meneses P, Trauth S, Schulmeister S, Malengo G, Sourjik V, Bischofs IB. Ratiometric population sensing by a pump-probe signaling system in Bacillus subtilis. Nat Commun 2020; 11:1176. [PMID: 32132526 PMCID: PMC7055314 DOI: 10.1038/s41467-020-14840-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 02/04/2020] [Indexed: 12/20/2022] Open
Abstract
Communication by means of diffusible signaling molecules facilitates higher-level organization of cellular populations. Gram-positive bacteria frequently use signaling peptides, which are either detected at the cell surface or ‘probed’ by intracellular receptors after being pumped into the cytoplasm. While the former type is used to monitor cell density, the functions of pump-probe networks are less clear. Here we show that pump-probe networks can, in principle, perform different tasks and mediate quorum-sensing, chronometric and ratiometric control. We characterize the properties of the prototypical PhrA-RapA system in Bacillus subtilis using FRET. We find that changes in extracellular PhrA concentrations are tracked rather poorly; instead, cells accumulate and strongly amplify the signal in a dose-dependent manner. This suggests that the PhrA-RapA system, and others like it, have evolved to sense changes in the composition of heterogeneous populations and infer the fraction of signal-producing cells in a mixed population to coordinate cellular behaviors. Gram-positive bacteria can release signaling peptides that are ‘probed’ by intracellular receptors after being pumped into the cytoplasm. Here, Babel et al. show that these pump-probe networks can infer the fraction of signal-producing cells in a mixed population, and do not necessarily mediate typical quorum-sensing control.
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Affiliation(s)
- Heiko Babel
- BioQuant Center of the University of Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Pablo Naranjo-Meneses
- BioQuant Center of the University of Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Stephanie Trauth
- BioQuant Center of the University of Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Sonja Schulmeister
- BioQuant Center of the University of Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany
| | - Gabriele Malengo
- Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany.,LOEWE Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Str. 16, 35043, Marburg, Germany
| | - Victor Sourjik
- Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany.,LOEWE Center for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Str. 16, 35043, Marburg, Germany
| | - Ilka B Bischofs
- BioQuant Center of the University of Heidelberg, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany. .,Center for Molecular Biology (ZMBH), University of Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany. .,Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany.
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26
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Guan Z, Pei K, Wang J, Cui Y, Zhu X, Su X, Zhou Y, Zhang D, Tang C, Yin P, Liu Z, Zou T. Structural insights into DNA recognition by AimR of the arbitrium communication system in the SPbeta phage. Cell Discov 2019; 5:29. [PMID: 31149347 PMCID: PMC6536502 DOI: 10.1038/s41421-019-0101-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/28/2019] [Accepted: 05/05/2019] [Indexed: 12/11/2022] Open
Abstract
A newly identified arbitrium communication system regulates the lysis-to-lysogeny decision in a Bacillus bacteriophage. This system contains an arbitrium hexapeptide as a signal, the cellular receptor AimR, and the lysogenic negative regulator AimX. AimR specifically targets the downstream DNA to activate aimX gene expression. The arbitrium peptide binds to AimR, inhibiting its DNA-binding to promote phage lysogeny. Recently, we and other groups have elucidated how arbitrium peptide sensed by AimR. However, the molecular mechanisms of DNA recognition by AimR and the regulation of its DNA-binding activity by the peptide remain largely unknown. Here, we report the crystal structure of the AimR–DNA complex at 2.1 Å resolution. The N-terminal HTH motif recognizes the palindromic DNA sequence, buttressed by interactions between positively charged residues and the DNA phosphate groups. The DNA-bound AimR assembles a more closed dimer than the peptide-bound form. Single-molecule FRET and crosslinking assays revealed that the AimR protein samples both open and closed conformations in solution. Arbitrium peptide binding induces a closed-to-open conformational change of AimR, eliminating DNA targeting. Our structural and functional analysis provides new insights into the DNA recognition mechanism of AimR and its regulation by the arbitrium peptide in the context of phage lysis-lysogeny decisions.
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Affiliation(s)
- Zeyuan Guan
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Kai Pei
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Jing Wang
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Yongqing Cui
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Xiang Zhu
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Xiang Su
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Yuanbao Zhou
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Delin Zhang
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Chun Tang
- 2CAS Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, and National Center for Magnetic Resonance at Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071 Hubei Province China
| | - Ping Yin
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Zhu Liu
- 1National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan, 430070 Hubei China
| | - Tingting Zou
- 3College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070 Hubei China
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27
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Kohler V, Keller W, Grohmann E. Regulation of Gram-Positive Conjugation. Front Microbiol 2019; 10:1134. [PMID: 31191478 PMCID: PMC6540685 DOI: 10.3389/fmicb.2019.01134] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/03/2019] [Indexed: 12/20/2022] Open
Abstract
Type IV Secretion Systems (T4SSs) are membrane-spanning multiprotein complexes dedicated to protein secretion or conjugative DNA transport (conjugation systems) in bacteria. The prototype and best-characterized T4SS is that of the Gram-negative soil bacterium Agrobacterium tumefaciens. For Gram-positive bacteria, only conjugative T4SSs have been characterized in some biochemical, structural, and mechanistic details. These conjugation systems are predominantly encoded by self-transmissible plasmids but are also increasingly detected on integrative and conjugative elements (ICEs) and transposons. Here, we report regulatory details of conjugation systems from Enterococcus model plasmids pIP501 and pCF10, Bacillus plasmid pLS1, Clostridium plasmid pCW3, and staphylococcal plasmid pSK41. In addition, regulation of conjugative processes of ICEs (ICEBs1, ICESt1, ICESt3) by master regulators belonging to diverse repressor families will be discussed. A special focus of this review lies on the comparison of regulatory mechanisms executed by proteins belonging to the RRNPP family. These regulators share a common fold and govern several essential bacterial processes, including conjugative transfer.
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Affiliation(s)
- Verena Kohler
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - Walter Keller
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - Elisabeth Grohmann
- Life Sciences and Technology, Beuth University of Applied Sciences Berlin, Berlin, Germany
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28
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Characterization of a Signaling System in Streptococcus mitis That Mediates Interspecies Communication with Streptococcus pneumoniae. Appl Environ Microbiol 2019; 85:AEM.02297-18. [PMID: 30389765 DOI: 10.1128/aem.02297-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022] Open
Abstract
Streptococcus mitis is found in the oral cavity and nasopharynx and forms a significant portion of the human microbiome. In this study, in silico analyses indicated the presence of an Rgg regulator and short hydrophobic peptide (Rgg/SHP) cell-to-cell communication system in S. mitis Although Rgg presented greater similarity to a repressor in Streptococcus pyogenes, autoinducing assays and genetic mutation analysis revealed that in S. mitis Rgg acts as an activator. Transcriptome analysis showed that in addition to shp, the system regulates two other downstream genes, comprising a segment of a putative lantibiotic gene cluster that is in a conjugative element locus in different members of the mitis group. Close comparison to a similar lantibiotic gene cluster in Streptococcus pneumoniae indicated that S. mitis lacked the full set of genes. Despite the potential of SHP to trigger a futile cycle of autoinduction, growth was not significantly affected for the rgg mutant under normal or antibiotic stress conditions. The S. mitis SHP was, however, fully functional in promoting cross-species communication and increasing S. pneumoniae surface polysaccharide production, which in this species is regulated by Rgg/SHP. The activity of SHPs produced by both species was detected in cocultures using a S. mitis reporter strain. In competitive assays, a slight advantage was observed for the rgg mutants. We conclude that the Rgg/SHP system in S. mitis regulates the expression of its own shp and activates an Rgg/SHP system in S. pneumoniae that regulates surface polysaccharide synthesis. Fundamentally, cross-communication of such systems may have a role during multispecies interactions.IMPORTANCE Bacteria secrete signal molecules into the environment which are sensed by other cells when the density reaches a certain threshold. In this study, we describe a communication system in Streptococcus mitis, a commensal species from the oral cavity, which we also found in several species and strains of streptococci from the mitis group. Further, we show that this system can promote cross-communication with S. pneumoniae, a closely related major human pathogen. Importantly, we show that this cross-communication can take place during coculture. While the genes regulated in S. mitis are likely part of a futile cycle of activation, the target genes in S. pneumoniae are potentially involved in virulence. The understanding of such complex communication networks can provide important insights into the dynamics of bacterial communities.
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29
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Structural basis of the arbitrium peptide–AimR communication system in the phage lysis–lysogeny decision. Nat Microbiol 2018; 3:1266-1273. [DOI: 10.1038/s41564-018-0239-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 08/06/2018] [Indexed: 11/08/2022]
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30
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Rezaei Javan R, van Tonder AJ, King JP, Harrold CL, Brueggemann AB. Genome Sequencing Reveals a Large and Diverse Repertoire of Antimicrobial Peptides. Front Microbiol 2018; 9:2012. [PMID: 30210481 PMCID: PMC6120550 DOI: 10.3389/fmicb.2018.02012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 08/09/2018] [Indexed: 12/14/2022] Open
Abstract
Competition among bacterial members of the same ecological niche is mediated by bacteriocins: antimicrobial peptides produced by bacterial species to kill other bacteria. Bacteriocins are also promising candidates for novel antimicrobials. Streptococcus pneumoniae (the “pneumococcus”) is a leading cause of morbidity and mortality worldwide and a frequent colonizer of the human nasopharynx. Here, 14 newly discovered bacteriocin gene clusters were identified among >6,200 pneumococcal genomes. The molecular epidemiology of the bacteriocin clusters was investigated using a large global and historical pneumococcal dataset dating from 1916. These analyses revealed extraordinary bacteriocin diversity among pneumococci and the majority of bacteriocin clusters were also found in other streptococcal species. Genomic hotspots for the integration of different bacteriocin gene clusters were discovered. Experimentally, bacteriocin genes were transcriptionally active when the pneumococcus was under stress and when two strains were co-cultured in broth. These findings reveal much more diversity among bacterial defense mechanisms than previously appreciated, which fundamentally broaden our understanding of bacteriocins relative to intraspecies and interspecies nasopharyngeal competition and bacterial population structure.
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Affiliation(s)
- Reza Rezaei Javan
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - James P King
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Caroline L Harrold
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Angela B Brueggemann
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Department of Medicine, Imperial College London, London, United Kingdom
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31
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Zhi X, Abdullah IT, Gazioglu O, Manzoor I, Shafeeq S, Kuipers OP, Hiller NL, Andrew PW, Yesilkaya H. Rgg-Shp regulators are important for pneumococcal colonization and invasion through their effect on mannose utilization and capsule synthesis. Sci Rep 2018; 8:6369. [PMID: 29686372 PMCID: PMC5913232 DOI: 10.1038/s41598-018-24910-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/05/2018] [Indexed: 01/18/2023] Open
Abstract
Microbes communicate with each other by using quorum sensing (QS) systems and modulate their collective 'behavior' for in-host colonization and virulence, biofilm formation, and environmental adaptation. The recent increase in genome data availability reveals the presence of several putative QS sensing circuits in microbial pathogens, but many of these have not been functionally characterized yet, despite their possible utility as drug targets. To increase the repertoire of functionally characterized QS systems in bacteria, we studied Rgg144/Shp144 and Rgg939/Shp939, two putative QS systems in the important human pathogen Streptococcus pneumoniae. We find that both of these QS circuits are induced by short hydrophobic peptides (Shp) upon sensing sugars found in the respiratory tract, such as galactose and mannose. Microarray analyses using cultures grown on mannose and galactose revealed that the expression of a large number of genes is controlled by these QS systems, especially those encoding for essential physiological functions and virulence-related genes such as the capsular locus. Moreover, the array data revealed evidence for cross-talk between these systems. Finally, these Rgg systems play a key role in colonization and virulence, as deletion mutants of these QS systems are attenuated in the mouse models of colonization and pneumonia.
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Affiliation(s)
- Xiangyun Zhi
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, LE1 9HN, UK
| | - Iman Tajer Abdullah
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, LE1 9HN, UK
- Department of Biology, College of Science, University of Kirkuk, Kirkuk, Iraq
| | - Ozcan Gazioglu
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, LE1 9HN, UK
| | - Irfan Manzoor
- Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Sulman Shafeeq
- Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Oscar P Kuipers
- Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - N Luisa Hiller
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213, USA
| | - Peter W Andrew
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, LE1 9HN, UK
| | - Hasan Yesilkaya
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, LE1 9HN, UK.
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32
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Endopeptidase PepO Regulates the SpeB Cysteine Protease and Is Essential for the Virulence of Invasive M1T1 Streptococcus pyogenes. J Bacteriol 2018; 200:JB.00654-17. [PMID: 29378883 DOI: 10.1128/jb.00654-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/18/2018] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pyogenes (group A Streptococcus [GAS]) causes a wide range of human infections. The pathogenesis of GAS infections is dependent on the temporal expression of numerous secreted and surface-associated virulence factors that interact with host proteins. Streptococcal pyrogenic exotoxin B (SpeB) is one of the most extensively studied toxins produced by GAS, and the coordinate growth phase-dependent regulation of speB expression is linked to disease severity phenotypes. Here, we identified the endopeptidase PepO as a novel growth phase-dependent regulator of SpeB in the invasive GAS M1 serotype strain 5448. By using transcriptomics followed by quantitative reverse transcriptase PCR and Western blot analyses, we demonstrate through targeted mutagenesis that PepO influences growth phase-dependent induction of speB gene expression. Compared to wild-type and complemented mutant strains, we demonstrate that the 5448ΔpepO mutant strain is more susceptible to killing by human neutrophils and is attenuated in virulence in a murine model of invasive GAS infection. Our results expand the complex regulatory network that is operating in GAS to control SpeB production and suggest that PepO is a virulence requirement during GAS M1T1 strain 5448 infections.IMPORTANCE Despite the continuing susceptibility of S. pyogenes to penicillin, this bacterial pathogen remains a leading infectious cause of global morbidity and mortality. A particular subclone of the M1 serotype (M1T1) has persisted globally for decades as the most frequently isolated serotype from patients with invasive and noninvasive diseases in Western countries. One of the key GAS pathogenicity factors is the potent broad-spectrum cysteine protease SpeB. Although there has been extensive research interest on the regulatory mechanisms that control speB gene expression, its genetic regulation is not fully understood. Here, we identify the endopeptidase PepO as a new regulator of speB gene expression in the globally disseminated M1T1 clone and as being essential for virulence.
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33
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Shenoy AT, Brissac T, Gilley RP, Kumar N, Wang Y, Gonzalez-Juarbe N, Hinkle WS, Daugherty SC, Shetty AC, Ott S, Tallon LJ, Deshane J, Tettelin H, Orihuela CJ. Streptococcus pneumoniae in the heart subvert the host response through biofilm-mediated resident macrophage killing. PLoS Pathog 2017; 13:e1006582. [PMID: 28841717 PMCID: PMC5589263 DOI: 10.1371/journal.ppat.1006582] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 09/07/2017] [Accepted: 08/15/2017] [Indexed: 11/18/2022] Open
Abstract
For over 130 years, invasive pneumococcal disease has been associated with the presence of extracellular planktonic pneumococci, i.e. diplococci or short chains in affected tissues. Herein, we show that Streptococcus pneumoniae that invade the myocardium instead replicate within cellular vesicles and transition into non-purulent biofilms. Pneumococci within mature cardiac microlesions exhibited salient biofilm features including intrinsic resistance to antibiotic killing and the presence of an extracellular matrix. Dual RNA-seq and subsequent principal component analyses of heart- and blood-isolated pneumococci confirmed the biofilm phenotype in vivo and revealed stark anatomical site-specific differences in virulence gene expression; the latter having major implications on future vaccine antigen selection. Our RNA-seq approach also identified three genomic islands as exclusively expressed in vivo. Deletion of one such island, Region of Diversity 12, resulted in a biofilm-deficient and highly inflammogenic phenotype within the heart; indicating a possible link between the biofilm phenotype and a dampened host-response. We subsequently determined that biofilm pneumococci released greater amounts of the toxin pneumolysin than did planktonic or RD12 deficient pneumococci. This allowed heart-invaded wildtype pneumococci to kill resident cardiac macrophages and subsequently subvert cytokine/chemokine production and neutrophil infiltration into the myocardium. This is the first report for pneumococcal biofilm formation in an invasive disease setting. We show that biofilm pneumococci actively suppress the host response through pneumolysin-mediated immune cell killing. As such, our findings contradict the emerging notion that biofilm pneumococci are passively immunoquiescent.
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Affiliation(s)
- Anukul T. Shenoy
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, The University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Terry Brissac
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Ryan P. Gilley
- Department of Microbiology, Immunology, and Molecular Genetics, The University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Nikhil Kumar
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Yong Wang
- Division of Pulmonary, Allergy & Critical Care Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Norberto Gonzalez-Juarbe
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Whitney S. Hinkle
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Sean C. Daugherty
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Amol C. Shetty
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sandra Ott
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Luke J. Tallon
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Jessy Deshane
- Division of Pulmonary, Allergy & Critical Care Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Carlos J. Orihuela
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, The University of Texas Health San Antonio, San Antonio, TX, United States of America
- * E-mail:
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34
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Communication between viruses guides lysis-lysogeny decisions. Nature 2017; 541:488-493. [PMID: 28099413 PMCID: PMC5378303 DOI: 10.1038/nature21049] [Citation(s) in RCA: 338] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 12/13/2016] [Indexed: 01/24/2023]
Abstract
Temperate viruses can become dormant in their host cells, a process called lysogeny. In every infection, such viruses decide between the lytic and the lysogenic cycles, that is, whether to replicate and lyse their host or to lysogenize and keep the host viable. Here we show that viruses (phages) of the SPbeta group use a small-molecule communication system to coordinate lysis-lysogeny decisions. During infection of its Bacillus host cell, the phage produces a six amino-acids-long communication peptide that is released into the medium. In subsequent infections, progeny phages measure the concentration of this peptide and lysogenize if the concentration is sufficiently high. We found that different phages encode different versions of the communication peptide, demonstrating a phage-specific peptide communication code for lysogeny decisions. We term this communication system the 'arbitrium' system, and further show that it is encoded by three phage genes: aimP, which produces the peptide; aimR, the intracellular peptide receptor; and aimX, a negative regulator of lysogeny. The arbitrium system enables a descendant phage to 'communicate' with its predecessors, that is, to estimate the amount of recent previous infections and hence decide whether to employ the lytic or lysogenic cycle.
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35
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Quorum Sensing Regulation of Competence and Bacteriocins in Streptococcus pneumoniae and mutans. Genes (Basel) 2017; 8:genes8010015. [PMID: 28067778 PMCID: PMC5295010 DOI: 10.3390/genes8010015] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/25/2016] [Accepted: 12/27/2016] [Indexed: 11/17/2022] Open
Abstract
The human pathogens Streptococcus pneumoniae and Streptococcus mutans have both evolved complex quorum sensing (QS) systems that regulate the production of bacteriocins and the entry into the competent state, a requirement for natural transformation. Natural transformation provides bacteria with a mechanism to repair damaged genes or as a source of new advantageous traits. In S. pneumoniae, the competence pathway is controlled by the two-component signal transduction pathway ComCDE, which directly regulates SigX, the alternative sigma factor required for the initiation into competence. Over the past two decades, effectors of cellular killing (i.e., fratricides) have been recognized as important targets of the pneumococcal competence QS pathway. Recently, direct interactions between the ComCDE and the paralogous BlpRH pathway, regulating bacteriocin production, were identified, further strengthening the interconnections between these two QS systems. Interestingly, a similar theme is being revealed in S. mutans, the primary etiological agent of dental caries. This review compares the relationship between the bacteriocin and the competence QS pathways in both S. pneumoniae and S. mutans, and hopes to provide clues to regulatory pathways across the genus Streptococcus as a potential tool to efficiently investigate putative competence pathways in nontransformable streptococci.
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