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Zhu B, Cen Z, Chen Y, Shang K, Zhai J, Han M, Wang J, Chen Z, Wei T, Han Z. α-Pyrone mediates quorum sensing through the conservon system in Nocardiopsis sp. Microbiol Res 2024; 285:127767. [PMID: 38776619 DOI: 10.1016/j.micres.2024.127767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024]
Abstract
Actinobacteria produce a plethora of bioactive secondary metabolites that are often regulated by quorum-sensing signaling molecules via specific binding to their cognate TetR-type receptors. Here, we identified monocyclic α-pyrone as a new class of actinobacterial signaling molecules influencing quorum sensing process in Nocardiopsis sp. LDBS0036, primarily evidenced by a significant reduction in the production of phenazines in the pyrone-null mutant compared to the wild-type strain. Exogenous addition of the α-pyrone can partially restore the expression of some pathways to the wild strain level. Moreover, a unique multicomponent system referred to as a conservon, which is widespread in actinobacteria and generally contains four or five functionally conserved proteins, may play an important role in detecting and transmitting α-pyrone signals in LDBS0036. We found the biosynthetic gene clusters of α-pyrone and their associated conservon genes are highly conserved in Nocardiopsis, indicating the widespread prevalence and significant function of this regulate mechanism within Nocardiopsis genus. Furthermore, homologous α-pyrones from different actinobacterial species were also found to mediate interspecies communication. Our results thus provide insights into a novel quorum-sensing signaling system and imply that various modes of bacterial communication remain undiscovered.
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Affiliation(s)
- Boyu Zhu
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ziyun Cen
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiqiu Chen
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; Hainan University, Haikou, Hainan 570100, China
| | - Kun Shang
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China
| | - Ji'an Zhai
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meigui Han
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiawei Wang
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; Hainan University, Haikou, Hainan 570100, China
| | - Zhiyong Chen
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China
| | - Taoshu Wei
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuang Han
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan 572000, China.
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Li C, Zhou H, Gou H, Fan Z, Zhang Y, Tang P, Huang J, Xu Y, Li L. Autoinducer-2 produced by oral microbial flora and alveolar bone loss in periodontitis. J Periodontal Res 2024; 59:576-588. [PMID: 38411269 DOI: 10.1111/jre.13247] [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: 03/07/2023] [Revised: 12/21/2023] [Accepted: 02/06/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVE The aim of this study was to investigate the association between autoinducer-2 (AI-2) of oral microbial flora and the alveolar bone destruction in periodontitis to determine if AI-2 may have the potential that monitor periodontitis and predict bone loss. BACKGROUND Plaque biofilm was the initiating factor of periodontitis and the essential factor of periodontal tissue destruction. The formation of biofilms depended on the complex regulation of the quorum sensing (QS) system, in which bacteria could sense changes in surrounding bacterial density by secreting the autoinducer (AI) to regulate the corresponding physiological function. Most oral bacteria also communicated with each other to form biofilms administrating the QS system, which implied that the QS system of periodontal pathogens was related to periodontitis, but the specific relationship was unknown. METHOD We collected the gingival crevicular fluid (GCF) samples and measured the concentration of AI-2 in samples using the Vibrio harveyi BB180 bioluminescent-reporter system. To explore the interaction between AI-2 and bone metabolism, we utilized AI-2 purified from Fusobacterium nucleatum to investigate the impact of F. nucleatum AI-2 on osteoclast differentiation. Moreover, we constructed murine periodontitis models and multi-species biofilm models to study the association between AI-2 and periodontal disease progression. RESULTS The AI-2 concentration in GCF samples increased along with periodontal disease progression (p < .0001). F. nucleatum AI-2 promoted osteoclast differentiation in a dose-dependent manner. In the periodontitis mice model, the CEJ-ABC distance in the F. nucleatum AI-2 treatment group was higher than that in the simple ligation group (p < .01), and the maxilla of the mice in the group exhibited significantly lower BMD and BV/TV values (p < .05). CONCLUSIONS We demonstrated that the AI-2 concentration varied with the alveolar bone destruction in periodontitis, and it may have the potential for screening periodontitis. F. nucleatum AI-2 promoted osteoclast differentiation in a dose-dependent manner and aggravated bone loss.
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Affiliation(s)
- Cheng Li
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Hancheng Zhou
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Huiqing Gou
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Zixin Fan
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Yifei Zhang
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Pengzhou Tang
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Jiaxin Huang
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Yan Xu
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
| | - Lu Li
- Department of Periodontics, Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, China
- Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, China
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Siemers M, Lippegaus A, Papenfort K. ChimericFragments: computation, analysis and visualization of global RNA networks. NAR Genom Bioinform 2024; 6:lqae035. [PMID: 38633425 PMCID: PMC11023125 DOI: 10.1093/nargab/lqae035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/08/2024] [Accepted: 03/28/2024] [Indexed: 04/19/2024] Open
Abstract
RNA-RNA interactions are a key feature of post-transcriptional gene regulation in all domains of life. While ever more experimental protocols are being developed to study RNA duplex formation on a genome-wide scale, computational methods for the analysis and interpretation of the underlying data are lagging behind. Here, we present ChimericFragments, an analysis framework for RNA-seq experiments that produce chimeric RNA molecules. ChimericFragments implements a novel statistical method based on the complementarity of the base-pairing RNAs around their ligation site and provides an interactive graph-based visualization for data exploration and interpretation. ChimericFragments detects true RNA-RNA interactions with high precision and is compatible with several widely used experimental procedures such as RIL-seq, LIGR-seq or CLASH. We further demonstrate that ChimericFragments enables the systematic detection of novel RNA regulators and RNA-target pairs with crucial roles in microbial physiology and virulence. ChimericFragments is written in Julia and available at: https://github.com/maltesie/ChimericFragments.
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Affiliation(s)
- Malte Siemers
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany
- Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Anne Lippegaus
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany
| | - Kai Papenfort
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany
- Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany
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4
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Sprenger M, Siemers M, Krautwurst S, Papenfort K. Small RNAs direct attack and defense mechanisms in a quorum sensing phage and its host. Cell Host Microbe 2024; 32:727-738.e6. [PMID: 38579715 DOI: 10.1016/j.chom.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/02/2024] [Accepted: 03/13/2024] [Indexed: 04/07/2024]
Abstract
Many, if not all, bacteria use quorum sensing (QS) to control collective behaviors, and more recently, QS has also been discovered in bacteriophages (phages). Phages can produce communication molecules of their own, or "listen in" on the host's communication processes, to switch between lytic and lysogenic modes of infection. Here, we study the interaction of Vibrio cholerae with the lysogenic phage VP882, which is activated by the QS molecule DPO. We discover that induction of VP882 results in the binding of phage transcripts to the major RNA chaperone Hfq, which in turn outcompetes and downregulates host-encoded small RNAs (sRNAs). VP882 itself also encodes Hfq-binding sRNAs, and we demonstrate that one of these sRNAs, named VpdS, promotes phage replication by regulating host and phage mRNA levels. We further show that host-encoded sRNAs can antagonize phage replication by downregulating phage mRNA expression and thus might be part of the host's phage defense arsenal.
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Affiliation(s)
- Marcel Sprenger
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany
| | - Malte Siemers
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany; Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany
| | | | - Kai Papenfort
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany; Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany.
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5
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Grant NA, Donkor GY, Sontz JT, Soto W, Waters CM. Deployment of a Vibrio cholerae ordered transposon mutant library in a quorum-competent genetic background. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.31.564941. [PMID: 37961142 PMCID: PMC10634969 DOI: 10.1101/2023.10.31.564941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Vibrio cholerae, the causative agent of cholera, has sparked seven pandemics in recent centuries, with the current one being the most prolonged. V. cholerae's pathogenesis hinges on its ability to switch between low and high cell density gene regulatory states, enabling transmission between host and the environment. Previously, a transposon mutant library for V. cholerae was created to support investigations aimed toward uncovering the genetic determinants of its pathogenesis. However, subsequent sequencing uncovered a mutation in the gene luxO of the parent strain, rendering mutants unable to exhibit high cell density behaviors. In this study, we used chitin-independent natural transformation to move transposon insertions from these low cell density mutants into a wildtype genomic background. Library transfer was aided by a novel gDNA extraction we developed using thymol, which also showed high lysis-specificity for Vibrio. The resulting Grant Library comprises 3,102 unique transposon mutants, covering 79.8% of V. cholerae's open reading frames. Whole genome sequencing of randomly selected mutants demonstrates 100% precision in transposon transfer to cognate genomic positions of the recipient strain. Notably, in no instance did the luxO mutation transfer into the wildtype background. Our research uncovered density-dependent epistasis in growth on inosine, an immunomodulatory metabolite secreted by gut bacteria that is implicated in enhancing gut barrier functions. Additionally, Grant Library mutants retain the plasmid that enables rapid, scarless genomic editing. In summary, the Grant Library reintroduces organismal relevant genetic contexts absent in the low cell density locked library equivalent.
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Affiliation(s)
- Nkrumah A. Grant
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, IL
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing MI
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI
| | | | - Jordan T. Sontz
- MSU College of Osteopathic Medicine, Michigan State University, East Lansing, MI
| | - William Soto
- Department of Biology, College of William and Mary, Williamsburg, VA
| | - Christopher M. Waters
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing MI
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, MI
- MSU College of Osteopathic Medicine, Michigan State University, East Lansing, MI
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Abstract
Small regulatory RNA (sRNAs) are key mediators of posttranscriptional gene control in bacteria. Assisted by RNA-binding proteins, a single sRNA often modulates the expression of dozens of genes, and thus sRNAs frequently adopt central roles in regulatory networks. Posttranscriptional regulation by sRNAs comes with several unique features that cannot be achieved by transcriptional regulators. However, for optimal network performance, transcriptional and posttranscriptional control mechanisms typically go hand-in-hand. This view is reflected by the ever-growing class of mixed network motifs involving sRNAs and transcription factors, which are ubiquitous in biology and whose regulatory properties we are beginning to understand. In addition, sRNA activity can be antagonized by base-pairing with sponge RNAs, adding yet another layer of complexity to these networks. In this article, we summarize the regulatory concepts underlying sRNA-mediated gene control in bacteria and discuss how sRNAs shape the output of a network, focusing on several key examples.
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Affiliation(s)
- Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany;
- Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
| | - Sahar Melamed
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel;
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7
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Skliros D, Droubogiannis S, Kalloniati C, Katharios P, Flemetakis E. Perturbation of Quorum Sensing after the Acquisition of Bacteriophage Resistance Could Contribute to Novel Traits in Vibrio alginolyticus. Microorganisms 2023; 11:2273. [PMID: 37764117 PMCID: PMC10535087 DOI: 10.3390/microorganisms11092273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Bacteria employ a wide range of molecular mechanisms to confer resistance to bacteriophages, and these mechanisms are continuously being discovered and characterized. However, there are instances where certain bacterial species, despite lacking these known mechanisms, can still develop bacteriophage resistance through intricate metabolic adaptation strategies, potentially involving mutations in transcriptional regulators or phage receptors. Vibrio species have been particularly useful for studying the orchestrated metabolic responses of Gram-negative marine bacteria in various challenges. In a previous study, we demonstrated that Vibrio alginolyticus downregulates the expression of specific receptors and transporters in its membrane, which may enable the bacterium to evade infection by lytic bacteriophages. In our current study, our objective was to explore how the development of bacteriophage resistance in Vibrio species disrupts the quorum-sensing cascade, subsequently affecting bacterial physiology and metabolic capacity. Using a real-time quantitative PCR (rt-QPCR) platform, we examined the expression pattern of quorum-sensing genes, auto-inducer biosynthesis genes, and cell density regulatory proteins in phage-resistant strains. Our results revealed that bacteriophage-resistant bacteria downregulate the expression of quorum-sensing regulatory proteins, such as LuxM, LuxN, and LuxP. This downregulation attenuates the normal perception of quorum-sensing peptides and subsequently diminishes the expression of cell density regulatory proteins, including LuxU, aphA, and LuxR. These findings align with the diverse phenotypic traits observed in the phage-resistant strains, such as altered biofilm formation, reduced planktonic growth, and reduced virulence. Moreover, the transcriptional depletion of aphA, the master regulator associated with low cell density, was linked to the downregulation of genes related to virulence. This phenomenon appears to be phage-specific, suggesting a finely tuned metabolic adaptation driven by phage-host interaction. These findings contribute to our understanding of the role of Vibrio species in microbial marine ecology and highlight the complex interplay between phage resistance, quorum sensing, and bacterial physiology.
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Affiliation(s)
- Dimitrios Skliros
- Laboratory of Molecular Biology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece; (D.S.); (C.K.)
| | - Stavros Droubogiannis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, 71500 Heraklion, Greece; (S.D.); (P.K.)
| | - Chrysanthi Kalloniati
- Laboratory of Molecular Biology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece; (D.S.); (C.K.)
- Department of Marine Sciences, University of the Aegean, 81100 Mytilene, Greece
| | - Pantelis Katharios
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, 71500 Heraklion, Greece; (S.D.); (P.K.)
| | - Emmanouil Flemetakis
- Laboratory of Molecular Biology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece; (D.S.); (C.K.)
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8
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Duddy OP, Silpe JE, Fei C, Bassler BL. Natural silencing of quorum-sensing activity protects Vibrio parahaemolyticus from lysis by an autoinducer-detecting phage. PLoS Genet 2023; 19:e1010809. [PMID: 37523407 PMCID: PMC10426928 DOI: 10.1371/journal.pgen.1010809] [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: 06/02/2023] [Revised: 08/15/2023] [Accepted: 07/15/2023] [Indexed: 08/02/2023] Open
Abstract
Quorum sensing (QS) is a chemical communication process that bacteria use to track population density and orchestrate collective behaviors. QS relies on the production, accumulation, and group-wide detection of extracellular signal molecules called autoinducers. Vibriophage 882 (phage VP882), a bacterial virus, encodes a homolog of the Vibrio QS receptor-transcription factor, called VqmA, that monitors the Vibrio QS autoinducer DPO. Phage VqmA binds DPO at high host-cell density and activates transcription of the phage gene qtip. Qtip, an antirepressor, launches the phage lysis program. Phage-encoded VqmA when bound to DPO also manipulates host QS by activating transcription of the host gene vqmR. VqmR is a small RNA that controls downstream QS target genes. Here, we sequence Vibrio parahaemolyticus strain O3:K6 882, the strain from which phage VP882 was initially isolated. The chromosomal region normally encoding vqmR and vqmA harbors a deletion encompassing vqmR and a portion of the vqmA promoter, inactivating that QS system. We discover that V. parahaemolyticus strain O3:K6 882 is also defective in its other QS systems, due to a mutation in luxO, encoding the central QS transcriptional regulator LuxO. Both the vqmR-vqmA and luxO mutations lock V. parahaemolyticus strain O3:K6 882 into the low-cell density QS state. Reparation of the QS defects in V. parahaemolyticus strain O3:K6 882 promotes activation of phage VP882 lytic gene expression and LuxO is primarily responsible for this effect. Phage VP882-infected QS-competent V. parahaemolyticus strain O3:K6 882 cells lyse more rapidly and produce more viral particles than the QS-deficient parent strain. We propose that, in V. parahaemolyticus strain O3:K6 882, constitutive maintenance of the low-cell density QS state suppresses the launch of the phage VP882 lytic cascade, thereby protecting the bacterial host from phage-mediated lysis.
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Affiliation(s)
- Olivia P. Duddy
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Justin E. Silpe
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Chenyi Fei
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Bonnie L. Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
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9
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Ghandour R, Papenfort K. Small regulatory RNAs in Vibrio cholerae. MICROLIFE 2023; 4:uqad030. [PMID: 37441523 PMCID: PMC10335731 DOI: 10.1093/femsml/uqad030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023]
Abstract
Vibrio cholerae is a major human pathogen causing the diarrheal disease, cholera. Regulation of virulence in V. cholerae is a multifaceted process involving gene expression changes at the transcriptional and post-transcriptional level. Whereas various transcription factors have been reported to modulate virulence in V. cholerae, small regulatory RNAs (sRNAs) have now been established to also participate in virulence control and the regulation of virulence-associated processes, such as biofilm formation, quorum sensing, stress response, and metabolism. In most cases, these sRNAs act by base-pairing with multiple target transcripts and this process typically requires the aid of an RNA-binding protein, such as the widely conserved Hfq protein. This review article summarizes the functional roles of sRNAs in V. cholerae, their underlying mechanisms of gene expression control, and how sRNAs partner with transcription factors to modulate complex regulatory programs. In addition, we will discuss regulatory principles discovered in V. cholerae that not only apply to other Vibrio species, but further extend into the large field of RNA-mediated gene expression control in bacteria.
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Affiliation(s)
- Rabea Ghandour
- Friedrich Schiller University Jena, Institute of Microbiology, 07745 Jena, Germany
| | - Kai Papenfort
- Corresponding author. Institute of Microbiology, General Microbiology, Friedrich Schiller University Jena, Winzerlaer Straße 2, 07745 Jena, Germany. Tel: +49-3641-949-311; E-mail:
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10
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Duddy OP, Silpe JE, Fei C, Bassler BL. Natural Silencing of Quorum-Sensing Activity Protects Vibrio parahaemolyticus from Lysis by an Autoinducer-Detecting Phage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543668. [PMID: 37333398 PMCID: PMC10274711 DOI: 10.1101/2023.06.05.543668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Quorum sensing (QS) is a chemical communication process that bacteria use to track population density and orchestrate collective behaviors. QS relies on the production, accumulation, and group-wide detection of extracellular signal molecules called autoinducers. Vibriophage 882 (phage VP882), a bacterial virus, encodes a homolog of the Vibrio QS receptor-transcription factor, called VqmA, that monitors the Vibrio QS autoinducer DPO. Phage VqmA binds DPO at high host-cell density and activates transcription of the phage gene qtip . Qtip, an antirepressor, launches the phage lysis program. Phage-encoded VqmA when bound to DPO also manipulates host QS by activating transcription of the host gene vqmR . VqmR is a small RNA that controls downstream QS target genes. Here, we sequence Vibrio parahaemolyticus strain O3:K6 882, the strain from which phage VP882 was initially isolated. The chromosomal region normally encoding vqmR and vqmA harbors a deletion encompassing vqmR and a portion of the vqmA promoter, inactivating that QS system. We discover that V. parahaemolyticus strain O3:K6 882 is also defective in its other QS systems, due to a mutation in luxO , encoding the central QS transcriptional regulator LuxO. Both the vqmR-vqmA and luxO mutations lock V. parahaemolyticus strain O3:K6 882 into the low-cell density QS state. Reparation of the QS defects in V. parahaemolyticus strain O3:K6 882 promotes activation of phage VP882 lytic gene expression and LuxO is primarily responsible for this effect. Phage VP882-infected QS-competent V. parahaemolyticus strain O3:K6 882 cells lyse more rapidly and produce more viral particles than the QS-deficient parent strain. We propose that, in V. parahaemolyticus strain O3:K6 882, constitutive maintenance of the low-cell density QS state suppresses the launch of the phage VP882 lytic cascade, thereby protecting the bacterial host from phage-mediated lysis.
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Affiliation(s)
- Olivia P. Duddy
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Justin E. Silpe
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Chenyi Fei
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Bonnie L. Bassler
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
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11
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Miller Conrad LC, Perez LJ. A Geneticist Transcribing the Chemical Language of Bacteria. Isr J Chem 2023; 63:e202200079. [PMID: 37469628 PMCID: PMC10353724 DOI: 10.1002/ijch.202200079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Indexed: 12/05/2022]
Abstract
The study of quorum sensing, bacterial cell-to-cell communication mediated by the production and detection of small molecule signals, has skyrocketed since its discovery in the last third of the 20th century. Building from early investigations of bacterial bioluminescence, the process has been characterized to control a numerous and growing number of group behaviors, including virulence and biofilm formation. Bonnie Bassler has made key contributions to the understanding of quorum sensing, leading interdisciplinary efforts to characterize key signaling pathway components and their respective signaling molecules across a range of gram-negative bacteria. This review highlights her work in the field, with a particular emphasis on the chemical contributions of her work.
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Affiliation(s)
- Laura C. Miller Conrad
- Department of Chemistry, San José State University, 1 Washington Sq, San Jose, CA 95192, USA
| | - Lark J. Perez
- Department of Chemistry & Biochemistry, Rowan University, 201 Mullica Hill Rd, Glassboro, NJ 08028, USA
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12
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Walton MG, Cubillejo I, Nag D, Withey JH. Advances in cholera research: from molecular biology to public health initiatives. Front Microbiol 2023; 14:1178538. [PMID: 37283925 PMCID: PMC10239892 DOI: 10.3389/fmicb.2023.1178538] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 04/14/2023] [Indexed: 06/08/2023] Open
Abstract
The aquatic bacterium Vibrio cholerae is the etiological agent of the diarrheal disease cholera, which has plagued the world for centuries. This pathogen has been the subject of studies in a vast array of fields, from molecular biology to animal models for virulence activity to epidemiological disease transmission modeling. V. cholerae genetics and the activity of virulence genes determine the pathogenic potential of different strains, as well as provide a model for genomic evolution in the natural environment. While animal models for V. cholerae infection have been used for decades, recent advances in this area provide a well-rounded picture of nearly all aspects of V. cholerae interaction with both mammalian and non-mammalian hosts, encompassing colonization dynamics, pathogenesis, immunological responses, and transmission to naïve populations. Microbiome studies have become increasingly common as access and affordability of sequencing has improved, and these studies have revealed key factors in V. cholerae communication and competition with members of the gut microbiota. Despite a wealth of knowledge surrounding V. cholerae, the pathogen remains endemic in numerous countries and causes sporadic outbreaks elsewhere. Public health initiatives aim to prevent cholera outbreaks and provide prompt, effective relief in cases where prevention is not feasible. In this review, we describe recent advancements in cholera research in these areas to provide a more complete illustration of V. cholerae evolution as a microbe and significant global health threat, as well as how researchers are working to improve understanding and minimize impact of this pathogen on vulnerable populations.
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Affiliation(s)
| | | | | | - Jeffrey H. Withey
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MI, United States
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13
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Lallement C, Goldring WPD, Jelsbak L. Global transcriptomic response of the AI-3 isomers 3,5-DPO and 3,6-DPO in Salmonella Typhimurium. Arch Microbiol 2023; 205:117. [PMID: 36929450 DOI: 10.1007/s00203-023-03450-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/14/2023] [Accepted: 02/23/2023] [Indexed: 03/18/2023]
Abstract
Bacterial intercellular signaling mediated by small molecules, also called autoinducers (AIs), enables synchronized behavior in response to environmental conditions, and in many bacterial pathogens, intercellular signaling controls virulence gene expression. However, in the intestinal pathogen Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium), although three signals, named AI-1, AI-2 and AI-3, have been described, their roles in virulence remain elusive. AI-3 is the 3,6- isomer of a previously described Vibrio cholerae signaling molecule; 3,5-dimethylpyrazin-2-ol (3,5-DPO). To elucidate the role of AI-3/DPO in S. Typhimurium, we have mapped the global transcriptomic responses to 3,5- and 3,6-DPO isomers in S. Typhimurium. Our studies showed that DPO affects expression of almost 8% of all genes. Specifically, expression of several genes involved in gut-colonization respond to DPO. Interestingly, most of the affected genes are similarly regulated by 3,5-DPO and 3,6-DPO, respectively, indicating that the two isomers have overlapping roles in S. Typhimurium.
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Affiliation(s)
- Claire Lallement
- Department of Sciences and Environment, Roskilde University, Roskilde, Denmark
| | | | - Lotte Jelsbak
- Department of Sciences and Environment, Roskilde University, Roskilde, Denmark.
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14
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Sun X, Li Y, Yang Q, Zhang H, Xu N, Tang Z, Wu S, Jiang Y, Mohamed HF, Ou D, Zheng X. Identification of quorum sensing-regulated Vibrio fortis as potential pathogenic bacteria for coral bleaching and the effects on the microbial shift. Front Microbiol 2023; 14:1116737. [PMID: 36819038 PMCID: PMC9935839 DOI: 10.3389/fmicb.2023.1116737] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/09/2023] [Indexed: 02/05/2023] Open
Abstract
Coastal pollution, global warming, ocean acidification, and other reasons lead to the imbalance of the coral reef ecosystem, resulting in the increasingly serious problem of coral degradation. Coral bleaching is often accompanied by structural abnormalities of coral symbiotic microbiota, among which Vibrio is highly concerned. In this study, Vibrio fortis S10-1 (MCCC 1H00104), isolated from sea cucumber, was used for the bacterial infection on coral Seriatopora guttatus and Pocillopora damicornis. The infection of S10-1 led to coral bleaching and a significant reduction of photosynthetic function in coral holobiont, and the pathogenicity of V. fortis was regulated by quorum sensing. Meanwhile, Vibrio infection also caused a shift of coral symbiotic microbial community, with significantly increased abundant Proteobacteria and Actinobacteria and significantly reduced abundant Firmicutes; on genus level, the abundance of Bacillus decreased significantly and the abundance of Rhodococcus, Ralstonia, and Burkholderia-Caballeronia-Paraburkholderia increased significantly; S10-1 infection also significantly impacted the water quality in the micro-ecosystem. In contrast, S10-1 infection showed less effect on the microbial community of the live stone, which reflected that the microbes in the epiphytic environment of the live stone might have a stronger ability of self-regulation; the algal symbionts mainly consisted of Cladocopium sp. and showed no significant effect by the Vibrio infection. This study verified that V. fortis is the primary pathogenic bacterium causing coral bleaching, revealed changes in the microbial community caused by its infection, provided strong evidence for the "bacterial bleaching" hypothesis, and provided an experimental experience for the exploration of the interaction mechanism among microbial communities, especially coral-associated Vibrio in the coral ecosystem, and potential probiotic strategy or QS regulation on further coral disease control.
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Affiliation(s)
- Xiaohui Sun
- College of Chemical Engineering, Huaqiao University, Xiamen, China,*Correspondence: Xiaohui Sun,
| | - Yan Li
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Qian Yang
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Han Zhang
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
| | - Nuo Xu
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Zheng Tang
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Shishi Wu
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Yusheng Jiang
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Hala F. Mohamed
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China,Botany and Microbiology Department (Girls Branch), Faculty of Science, Al-Azhar University, Cairo, Egypt
| | - Danyun Ou
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China,Key Laboratory of Marine Ecological Conservation and Restoration, Ministry of Natural Resources, Xiamen, China,Danyun Ou,
| | - Xinqing Zheng
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China,Key Laboratory of Marine Ecological Conservation and Restoration, Ministry of Natural Resources, Xiamen, China,Observation and Research Station of Coastal Wetland Ecosystem in Beibu Gulf, Ministry of Natural Resources, Xiamen, China,Xinqing Zheng,
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15
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Muhammad AY, Amonov M, Murugaiah C, Baig AA, Yusoff M. Intestinal colonization against Vibrio cholerae: host and microbial resistance mechanisms. AIMS Microbiol 2023; 9:346-374. [PMID: 37091815 PMCID: PMC10113163 DOI: 10.3934/microbiol.2023019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
Vibrio cholerae is a non-invasive enteric pathogen known to cause a major public health problem called cholera. The pathogen inhabits the aquatic environment while outside the human host, it is transmitted into the host easily through ingesting contaminated food and water containing the vibrios, thus causing diarrhoea and vomiting. V. cholerae must resist several layers of colonization resistance mechanisms derived from the host or the gut commensals to successfully survive, grow, and colonize the distal intestinal epithelium, thus causing an infection. The colonization resistance mechanisms derived from the host are not specific to V. cholerae but to all invading pathogens. However, some of the gut commensal-derived colonization resistance may be more specific to the pathogen, making it more challenging to overcome. Consequently, the pathogen has evolved well-coordinated mechanisms that sense and utilize the anti-colonization factors to modulate events that promote its survival and colonization in the gut. This review is aimed at discussing how V. cholerae interacts and resists both host- and microbe-specific colonization resistance mechanisms to cause infection.
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Affiliation(s)
| | - Malik Amonov
- Faculty of Medicine, Universiti Sultan Zainal Abidin, Malaysia
- * Correspondence: ; Tel: +60189164478
| | | | - Atif Amin Baig
- University Institute of Public Health, Faculty of Allied Health Sciences, The University of Lahore, Pakistan
| | - Marina Yusoff
- Faculty of Medicine, Universiti Sultan Zainal Abidin, Malaysia
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16
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An RNA sponge controls quorum sensing dynamics and biofilm formation in Vibrio cholerae. Nat Commun 2022; 13:7585. [PMID: 36482060 PMCID: PMC9732341 DOI: 10.1038/s41467-022-35261-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 11/24/2022] [Indexed: 12/13/2022] Open
Abstract
Small regulatory RNAs (sRNAs) acting in concert with the RNA chaperone Hfq are prevalent in many bacteria and typically act by base-pairing with multiple target transcripts. In the human pathogen Vibrio cholerae, sRNAs play roles in various processes including antibiotic tolerance, competence, and quorum sensing (QS). Here, we use RIL-seq (RNA-interaction-by-ligation-and-sequencing) to identify Hfq-interacting sRNAs and their targets in V. cholerae. We find hundreds of sRNA-mRNA interactions, as well as RNA duplexes formed between two sRNA regulators. Further analysis of these duplexes identifies an RNA sponge, termed QrrX, that base-pairs with and inactivates the Qrr1-4 sRNAs, which are known to modulate the QS pathway. Transcription of qrrX is activated by QrrT, a previously uncharacterized LysR-type transcriptional regulator. Our results indicate that QrrX and QrrT are required for rapid conversion from individual to community behaviours in V. cholerae.
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17
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Silpe JE, Duddy OP, Papenfort K. Microbial Communication via Pyrazine Signaling: a New Class of Signaling Molecules Identified in
Vibrio cholerae. Isr J Chem 2022. [DOI: 10.1002/ijch.202200063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Justin E. Silpe
- Department of Molecular Biology Princeton University Princeton New Jersey USA
| | - Olivia P. Duddy
- Department of Molecular Biology Princeton University Princeton New Jersey USA
| | - Kai Papenfort
- Friedrich Schiller University Jena Institute of Microbiology, General Microbiology Winzerlaer Straße 2 07745 Jena Germany
- Microverse Cluster Friedrich Schiller University Jena Jena Germany
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18
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Synergy between c-di-GMP and Quorum-Sensing Signaling in Vibrio cholerae Biofilm Morphogenesis. J Bacteriol 2022; 204:e0024922. [PMID: 36154360 PMCID: PMC9578409 DOI: 10.1128/jb.00249-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Transitions between individual and communal lifestyles allow bacteria to adapt to changing environments. Bacteria must integrate information encoded in multiple sensory cues to appropriately undertake these transitions. Here, we investigate how two prevalent sensory inputs converge on biofilm morphogenesis: quorum sensing, which endows bacteria with the ability to communicate and coordinate group behaviors, and second messenger c-di-GMP signaling, which allows bacteria to detect and respond to environmental stimuli. We use Vibrio cholerae as our model system, the autoinducer AI-2 to modulate quorum sensing, and the polyamine norspermidine to modulate NspS-MbaA-mediated c-di-GMP production. Individually, AI-2 and norspermidine drive opposing biofilm phenotypes, with AI-2 repressing and norspermidine inducing biofilm formation. Surprisingly, however, when AI-2 and norspermidine are simultaneously detected, they act synergistically to increase biofilm biomass and biofilm cell density. We show that this effect is caused by quorum-sensing-mediated activation of nspS-mbaA expression, which increases the levels of NspS and MbaA, and in turn, c-di-GMP biosynthesis, in response to norspermidine. Increased MbaA-synthesized c-di-GMP activates the VpsR transcription factor, driving elevated expression of genes encoding key biofilm matrix components. Thus, in the context of biofilm morphogenesis in V. cholerae, quorum-sensing regulation of c-di-GMP-metabolizing receptor levels connects changes in cell population density to detection of environmental stimuli. IMPORTANCE The development of multicellular communities, known as biofilms, facilitates beneficial functions of gut microbiome bacteria and makes bacterial pathogens recalcitrant to treatment. Understanding how bacteria regulate the biofilm life cycle is fundamental to biofilm control in industrial processes and in medicine. Here, we demonstrate how two major sensory inputs—quorum-sensing communication and second messenger c-di-GMP signaling—jointly regulate biofilm morphogenesis in the global pathogen Vibrio cholerae. We characterize the mechanism underlying a surprising synergy between quorum-sensing and c-di-GMP signaling in controlling biofilm development. Thus, the work connects changes in cell population density to detection of environmental stimuli in a pathogen of clinical significance.
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19
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Boron Derivatives Accelerate Biofilm Formation of Recombinant Escherichia coli via Increasing Quorum Sensing System Autoinducer-2 Activity. Int J Mol Sci 2022; 23:ijms23158059. [PMID: 35897636 PMCID: PMC9332218 DOI: 10.3390/ijms23158059] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/17/2022] Open
Abstract
Boron is an essential element for autoinducer-2 (AI-2) synthesis of quorum sensing (QS) system, which affects bacterial collective behavior. As a living biocatalyst, biofilms can stably catalyze the activity of intracellular enzymes. However, it is unclear how boron affects biofilm formation in E. coli, particularly recombinant E. coli with intracellular enzymes. This study screened different boron derivatives to explore their effect on biofilm formation. The stress response of biofilm formation to boron was illuminated by analyzing AI-2 activity, extracellular polymeric substances (EPS) composition, gene expression levels, etc. Results showed that boron derivatives promote AI-2 activity in QS system. After treatment with H3BO3 (0.6 mM), the AI-2 activity increased by 65.99%, while boron derivatives increased the biomass biofilms in the order H3BO3 > NaBO2 > Na2B4O7 > NaBO3. Moreover, treatment with H3BO3 (0.6 mM) increased biomass by 88.54%. Meanwhile, AI-2 activity had a linear correlation with polysaccharides and protein of EPS at 0−0.6 mM H3BO3 and NaBO2 (R2 > 0.8). Furthermore, H3BO3 upregulated the expression levels of biofilm formation genes, quorum sensing genes, and flagellar movement genes. These findings demonstrated that boron promoted biofilm formation by upregulating the expression levels of biofilm-related genes, improving the QS system AI-2 activity, and increasing EPS secretion in E. coli.
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20
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An insight into reactivity and bioactivity properties of quorum sensing peptides against PDE10A: a computational peptidology approach. J Mol Model 2022; 28:209. [PMID: 35789297 DOI: 10.1007/s00894-022-05176-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/30/2022] [Indexed: 12/21/2022]
Abstract
Peptides are currently the most promising lead molecules. Quorum sensing peptides have a variety of structural features and are regularly exposed to post-translational modifications. Antiparkinsonian drugs lose their efficacy after a long period of use, and patients develop motor problems such as drug-induced dyskinesia (DIDs). The interaction between PDE10A and cAMP is necessary for dopamine neurotransmission and may play a role in Parkinson's disease pathogenesis. cAMP and cGMP are cyclic nucleotides that act as secondary messengers in the signal transduction pathway, influencing a range of CNS activities. PDE enzymes hydrolyze phosphodiester bonds to break down cAMP and cGMP, allowing them to control intracellular levels of these second messengers effectively. PDE expression, and hence cyclic nucleotide levels and their downstream targets, may change with age and in numerous age-related illnesses, including Parkinson's disease, according to mounting evidence. At the peak of dyskinesias, cyclic nucleotide levels were lower, and using phosphodiesterase inhibitors before antiparkinsonian medicines reduced the severity of dyskinesias. In a recent study, PapRIV was found to have the ability to activate BV-2 microglia cells, indicating that this quorum sensing peptide may play a role in gut-brain contact. As a result of the current in silico work, mainly focused on QSPs as a lead molecule for inhibiting PDE10A, the SRNAT QSP sequence has been a potent molecule in molecular docking and molecular dynamics simulations. Furthermore, we can test the efficiency of therapeutic components in vitro and in vivo utilizing this computational approach against PDE10A.
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21
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Resistance Is Not Futile: The Role of Quorum Sensing Plasticity in Pseudomonas aeruginosa Infections and Its Link to Intrinsic Mechanisms of Antibiotic Resistance. Microorganisms 2022; 10:microorganisms10061247. [PMID: 35744765 PMCID: PMC9228389 DOI: 10.3390/microorganisms10061247] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/06/2022] [Accepted: 06/09/2022] [Indexed: 01/01/2023] Open
Abstract
Bacteria use a cell-cell communication process called quorum sensing (QS) to orchestrate collective behaviors. QS relies on the group-wide detection of extracellular signal molecules called autoinducers (AI). Quorum sensing is required for virulence and biofilm formation in the human pathogen Pseudomonas aeruginosa. In P. aeruginosa, LasR and RhlR are homologous LuxR-type soluble transcription factor receptors that bind their cognate AIs and activate the expression of genes encoding functions required for virulence and biofilm formation. While some bacterial signal transduction pathways follow a linear circuit, as phosphoryl groups are passed from one carrier protein to another ultimately resulting in up- or down-regulation of target genes, the QS system in P. aeruginosa is a dense network of receptors and regulators with interconnecting regulatory systems and outputs. Once activated, it is not understood how LasR and RhlR establish their signaling hierarchy, nor is it clear how these pathway connections are regulated, resulting in chronic infection. Here, we reviewed the mechanisms of QS progression as it relates to bacterial pathogenesis and antimicrobial resistance and tolerance.
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22
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Research Progress and Hopeful Strategies of Application of Quorum Sensing in Food, Agriculture and Nanomedicine. Microorganisms 2022; 10:microorganisms10061192. [PMID: 35744710 PMCID: PMC9229978 DOI: 10.3390/microorganisms10061192] [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: 05/13/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 02/06/2023] Open
Abstract
Quorum sensing (QS) regulates the expression of several genes including motility, biofilm development, virulence expression, population density detection and plasmid conjugation. It is based on “autoinducers”, small molecules that microorganisms produce and release in the extracellular milieu. The biochemistry of quorum sensing is widely discussed and numerous papers are available to scientists. The main purpose of this research is to understand how knowledge about this mechanism can be exploited for the benefit of humans and the environment. Here, we report the most promising studies on QS and their resulting applications in different fields of global interest: food, agriculture and nanomedicine.
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23
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Alviz-Gazitua P, González A, Lee MR, Aranda CP. Molecular Relationships in Biofilm Formation and the Biosynthesis of Exoproducts in Pseudoalteromonas spp. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:431-447. [PMID: 35486299 DOI: 10.1007/s10126-022-10097-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Most members of the Pseudoalteromonas genus have been isolated from living surfaces as members of epiphytic and epizooic microbiomes on marine macroorganisms. Commonly Pseudoalteromonas isolates are reported as a source of bioactive exoproducts, i.e., secondary metabolites, such as exopolymeric substances and extracellular enzymes. The experimental conditions for the production of these agents are commonly associated with sessile metabolic states such as biofilms or liquid cultures in the stationary growth phase. Despite this, the molecular mechanisms that connect biofilm formation and the biosynthesis of exoproducts in Pseudoalteromonas isolates have rarely been mentioned in the literature. This review compiles empirical evidence about exoproduct biosynthesis conditions and molecular mechanisms that regulate sessile metabolic states in Pseudoalteromonas species, to provide a comprehensive perspective on the regulatory convergences that generate the recurrent coexistence of both phenomena in this bacterial genus. This synthesis aims to provide perspectives on the extent of this phenomenon for the optimization of bioprospection studies and biotechnology processes based on these bacteria.
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Affiliation(s)
- P Alviz-Gazitua
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile
| | - A González
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile
| | - M R Lee
- Centro i~mar, Universidad de Los Lagos, Camino a Chinquihue km 6, P. Box 5480000, Puerto Montt, Chile
| | - C P Aranda
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile.
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24
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Yin WL, Xie ZY, Zeng YH, Zhang J, Long H, Ren W, Zhang X, Cai XN, Huang AY. Two (p)ppGpp Synthetase Genes, relA and spoT, Are Involved in Regulating Cell Motility, Exopolysaccharides Production, and Biofilm Formation of Vibrio alginolyticus. Front Microbiol 2022; 13:858559. [PMID: 35422789 PMCID: PMC9002329 DOI: 10.3389/fmicb.2022.858559] [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: 01/20/2022] [Accepted: 02/28/2022] [Indexed: 12/14/2022] Open
Abstract
The stringent response mediated by the signal molecule (p)ppGpp is involved in response to multiple environmental stresses and control of various physiological processes. Studies have revealed that (p)ppGpp strongly affects the formation and maintenance of several bacterial biofilms. However, the specific regulatory roles of (p)ppGpp in biofilms, especially in the expression of genes related to cell motility and exopolysaccharides (EPSs) production, remain poorly understood. We recently reported two (p)ppGpp synthetase genes relA and spoT from the epizootic pathogen Vibrio alginolyticus. Herein, we found that the (p)ppGpp synthetase genes of V. alginolyticus contributed to biofilm formation at low cell density and biofilm detachment at high cell density, respectively, in polystyrene microtiter plates. Quantitative reverse transcription PCR (qRT-PCR) analysis revealed that the expression levels of both EPSs and motility associated genes were consistent with the development of biofilms. Besides, the (p)ppGpp synthetase gene spoT was found to be closely involved in the regulation of flagellum, smooth/translucent colony morphology and spotty pellicle at the air-liquid interface. Interestingly, pleiotropic phenotypes of ΔrelAΔspoT were similar to that of the rpoN (σ54) deletion mutant. Meanwhile, the absence of (p)ppGpp synthetase genes significantly reduced the expression levels of rpoN at low cell density, suggesting that (p)ppGpp may mediate the formation via positively affecting the alternative sigma factor RpoN. These findings allow us to propose (p)ppGpp as a crucial regulator for biofilm development in V. alginolyticus, in view of the regulatory roles of relA and spoT in cell motility and EPSs production.
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Affiliation(s)
- Wen-Liang Yin
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China
| | - Zhen-Yu Xie
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Yan-Hua Zeng
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China
| | - Ju Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China
| | - Hao Long
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China
| | - Wei Ren
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Xiang Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Xiao-Ni Cai
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Ai-You Huang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
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25
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Kanungo S, Azman AS, Ramamurthy T, Deen J, Dutta S. Cholera. Lancet 2022; 399:1429-1440. [PMID: 35397865 DOI: 10.1016/s0140-6736(22)00330-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/14/2021] [Accepted: 02/07/2022] [Indexed: 12/11/2022]
Abstract
Cholera was first described in the areas around the Bay of Bengal and spread globally, resulting in seven pandemics during the past two centuries. It is caused by toxigenic Vibrio cholerae O1 or O139 bacteria. Cholera is characterised by mild to potentially fatal acute watery diarrhoeal disease. Prompt rehydration therapy is the cornerstone of management. We present an overview of cholera and its pathogenesis, natural history, bacteriology, and epidemiology, while highlighting advances over the past 10 years in molecular epidemiology, immunology, and vaccine development and deployment. Since 2014, the Global Task Force on Cholera Control, a WHO coordinated network of partners, has been working with several countries to develop national cholera control strategies. The global roadmap for cholera control focuses on stopping transmission in cholera hotspots through vaccination and improved water, sanitation, and hygiene, with the aim to reduce cholera deaths by 90% and eliminate local transmission in at least 20 countries by 2030.
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Affiliation(s)
- Suman Kanungo
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Andrew S Azman
- Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA; Institute of Global Health, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | | | - Jaqueline Deen
- Institute of Child Health and Human Development, National Institutes of Health, University of the Philippines-Manila, Manila, Philippines
| | - Shanta Dutta
- National Institute of Cholera and Enteric Diseases, Kolkata, India.
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26
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Yang L, Yuan TJ, Wan Y, Li WW, Liu C, Jiang S, Duan JA. Quorum sensing: a new perspective to reveal the interaction between gut microbiota and host. Future Microbiol 2022; 17:293-309. [PMID: 35164528 DOI: 10.2217/fmb-2021-0217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Quorum sensing (QS), a chemical communication process between bacteria, depends on the synthesis, secretion and detection of signal molecules. It can synchronize the gene expression of bacteria to promote cooperation within the population and improve competitiveness among populations. The preliminary exploration of bacterial QS has been completed under ideal and highly controllable conditions. There is an urgent need to investigate the QS of bacteria under natural conditions, especially the QS of intestinal flora, which is closely related to health. Excitingly, growing evidence has shown that QS also exists in the intestinal flora. The crosstalk of QS between gut microbiota and the host is systematically clarified in this review.
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Affiliation(s)
- Lei Yang
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
| | - Tian-Jie Yuan
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
| | - Yue Wan
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
| | - Wen-Wen Li
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
| | - Chen Liu
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
| | - Shu Jiang
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
| | - Jin-Ao Duan
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, 138 Xianlin Road, Nanjing, 210023, PR China
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Abstract
The COVID-19 pandemic has highlighted the need to identify additional antiviral small molecules to complement existing therapies. Although increasing evidence suggests that metabolites produced by the human microbiome have diverse biological activities, their antiviral properties remain poorly explored. Using a cell-based SARS-CoV-2 infection assay, we screened culture broth extracts from a collection of phylogenetically diverse human-associated bacteria for the production of small molecules with antiviral activity. Bioassay-guided fractionation uncovered three bacterial metabolites capable of inhibiting SARS-CoV-2 infection. This included the nucleoside analogue N6-(Δ2-isopentenyl)adenosine, the 5-hydroxytryptamine receptor agonist tryptamine, and the pyrazine 2,5-bis(3-indolylmethyl)pyrazine. The most potent of these, N6-(Δ2-isopentenyl)adenosine, had a 50% inhibitory concentration (IC50) of 2 μM. These natural antiviral compounds exhibit structural and functional similarities to synthetic drugs that have been clinically examined for use against COVID-19. Our discovery of structurally diverse metabolites with anti-SARS-CoV-2 activity from screening a small fraction of the bacteria reported to be associated with the human microbiome suggests that continued exploration of phylogenetically diverse human-associated bacteria is likely to uncover additional small molecules that inhibit SARS-CoV-2 as well as other viral infections. IMPORTANCE The continued prevalence of COVID-19 and the emergence of new variants has once again put the spotlight on the need for the identification of SARS-CoV-2 antivirals. The human microbiome produces an array of small molecules with bioactivities (e.g., host receptor ligands), but its ability to produce antiviral small molecules is relatively underexplored. Here, using a cell-based screening platform, we describe the isolation of three microbiome-derived metabolites that are able to prevent SARS-CoV-2 infection in vitro. These molecules display structural similarities to synthetic drugs that have been explored for the treatment of COVID-19, and these results suggest that the microbiome may be a fruitful source of the discovery of small molecules with antiviral activities.
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Interplay between Sublethal Aminoglycosides and Quorum Sensing: Consequences on Survival in V. cholerae. Cells 2021; 10:cells10113227. [PMID: 34831448 PMCID: PMC8621022 DOI: 10.3390/cells10113227] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 01/01/2023] Open
Abstract
Antibiotics are well known drugs which, when present above certain concentrations, are able to inhibit the growth of certain bacteria. However, a growing body of evidence shows that even when present at lower doses (subMIC, for sub-minimal inhibitory concentration), unable to inhibit or affect microbial growth, antibiotics work as signaling molecules, affect gene expression and trigger important bacterial stress responses. However, how subMIC antibiotic signaling interplays with other well-known signaling networks in bacteria (and the consequences of such interplay) is not well understood. In this work, through transcriptomic and genetic approaches, we have explored how quorum-sensing (QS) proficiency of V. cholerae affects this pathogen’s response to subMIC doses of the aminoglycoside tobramycin (TOB). We show that the transcriptomic signature of V. cholerae in response to subMIC TOB depends highly on the presence of QS master regulator HapR. In parallel, we show that subMIC doses of TOB are able to negatively interfere with the AI-2/LuxS QS network of V. cholerae, which seems critical for survival to aminoglycoside treatment and TOB-mediated induction of SOS response in this species. This interplay between QS and aminoglycosides suggests that targeting QS signaling may be a strategy to enhance aminoglycoside efficacy in V. cholerae.
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Pearl Mizrahi S, Elbaz N, Argaman L, Altuvia Y, Katsowich N, Socol Y, Bar A, Rosenshine I, Margalit H. The impact of Hfq-mediated sRNA-mRNA interactome on the virulence of enteropathogenic Escherichia coli. SCIENCE ADVANCES 2021; 7:eabi8228. [PMID: 34705501 PMCID: PMC8550237 DOI: 10.1126/sciadv.abi8228] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Small RNAs (sRNAs) exert their regulation posttranscriptionally by base pairing with their target mRNAs, often in association with the RNA chaperone protein Hfq. Here, integrating RNA-seq–based technologies and bioinformatics, we deciphered the Hfq-mediated sRNA-target interactome of enteropathogenic Escherichia coli (EPEC). The emerging network comprises hundreds of sRNA-mRNA pairs, including mRNAs of virulence-associated genes interacting with known sRNAs encoded within the core genome, as well as with newly found sRNAs encoded within pathogenicity islands. Some of the sRNAs affect multiple virulence genes, suggesting they function as hubs of virulence control. We further analyzed one such sRNA hub, MgrR, and one of its targets identified here, the major virulence-associated chaperon, cesT. We show that MgrR adjusts the level of EPEC cytotoxicity via regulation of CesT expression. Our results reveal an elaborate sRNA-mRNA interactome controlling the pathogenicity of EPEC and reinforce a role for sRNAs in the control of pathogen-host interaction.
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Affiliation(s)
- Sivan Pearl Mizrahi
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Netanel Elbaz
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Liron Argaman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Yael Altuvia
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Naama Katsowich
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Yaakov Socol
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Amir Bar
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
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Tahir Ul Qamar M, Ahmad S, Khan A, Mirza MU, Ahmad S, Abro A, Chen LL, Almatroudi A, Wei DQ. Structural probing of HapR to identify potent phytochemicals to control Vibrio cholera through integrated computational approaches. Comput Biol Med 2021; 138:104929. [PMID: 34655900 DOI: 10.1016/j.compbiomed.2021.104929] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/06/2021] [Accepted: 10/06/2021] [Indexed: 01/01/2023]
Abstract
Cholera is a severe small intestine bacterial disease caused by consumption of water and food contaminated with Vibrio cholera. The disease causes watery diarrhea leading to severe dehydration and even death if left untreated. In the past few decades, V. cholerae has emerged as multidrug-resistant enteric pathogen due to its rapid ability to adapt in detrimental environmental conditions. This research study aimed to design inhibitors of a master virulence gene expression regulator, HapR. HapR is critical in regulating the expression of several set of V. cholera virulence genes, quorum-sensing circuits and biofilm formation. A blind docking strategy was employed to infer the natural binding tendency of diverse phytochemicals extracted from medicinal plants by exposing the whole HapR structure to the screening library. Scoring function criteria was applied to prioritize molecules with strong binding affinity (binding energy < -11 kcal/mol) and as such two compounds: Strychnogucine A and Galluflavanone were filtered. Both the compounds were found favourably binding to the conserved dimerization interface of HapR. One rare binding conformation of Strychnogucine A was noticed docked at the elongated cavity formed by α1, α4 and α6 (binding energy of -12.5 kcal/mol). The binding stability of both top leads at dimer interface and elongated cavity was further estimated using long run of molecular dynamics simulations, followed by MMGB/PBSA binding free energy calculations to define the dominance of different binding energies. In a nutshell, this study presents computational evidence on antibacterial potential of phytochemicals capable of directly targeting bacterial virulence and highlight their great capacity to be utilized in the future experimental studies to stop the evolution of antibiotic resistance evolution.
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Affiliation(s)
| | - Sajjad Ahmad
- Department of Health and Biological Sciences, Abasyn University, Peshawar, Pakistan
| | - Abbas Khan
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China
| | - Muhammad Usman Mirza
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Canada
| | - Sarfraz Ahmad
- Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Asma Abro
- Department of Biotechnology, Faculty of Life Sciences and Informatics, Balochistan University of Information Technology Engineering and Management Sciences, Quetta, Pakistan
| | - Ling-Ling Chen
- College of Life Science and Technology, Guangxi University, Nanning, PR China.
| | - Ahmad Almatroudi
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah, Saudi Arabia
| | - Dong-Qing Wei
- Department of Bioinformatics and Biological Statistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China; Peng Cheng Laboratory, Vanke Cloud City Phase I Building 8, Xili Street, Nashan District, Shenzhen, Guangdong, PR China; State Key Laboratory of Microbial Metabolism, Shanghai-Islamabad-Belgrade Joint Innovation Center on Antibacterial Resistances, Joint Laboratory of International Cooperation in Metabolic and Developmental Sciences, Ministry of Education and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, PR China.
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31
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Venkat K, Hoyos M, Haycocks JR, Cassidy L, Engelmann B, Rolle-Kampczyk U, von Bergen M, Tholey A, Grainger DC, Papenfort K. A dual-function RNA balances carbon uptake and central metabolism in Vibrio cholerae. EMBO J 2021; 40:e108542. [PMID: 34612526 PMCID: PMC8672173 DOI: 10.15252/embj.2021108542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 11/22/2022] Open
Abstract
Bacterial small RNAs (sRNAs) are well known to modulate gene expression by base pairing with trans‐encoded transcripts and are typically non‐coding. However, several sRNAs have been reported to also contain an open reading frame and thus are considered dual‐function RNAs. In this study, we discovered a dual‐function RNA from Vibrio cholerae, called VcdRP, harboring a 29 amino acid small protein (VcdP), as well as a base‐pairing sequence. Using a forward genetic screen, we identified VcdRP as a repressor of cholera toxin production and link this phenotype to the inhibition of carbon transport by the base‐pairing segment of the regulator. By contrast, we demonstrate that the VcdP small protein acts downstream of carbon transport by binding to citrate synthase (GltA), the first enzyme of the citric acid cycle. Interaction of VcdP with GltA results in increased enzyme activity and together VcdR and VcdP reroute carbon metabolism. We further show that transcription of vcdRP is repressed by CRP allowing us to provide a model in which VcdRP employs two different molecular mechanisms to synchronize central metabolism in V. cholerae.
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Affiliation(s)
- Kavyaa Venkat
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Mona Hoyos
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - James Rj Haycocks
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Liam Cassidy
- Systematic Proteome Research & Bioanalytics, University of Kiel, Kiel, Germany
| | | | | | | | - Andreas Tholey
- Systematic Proteome Research & Bioanalytics, University of Kiel, Kiel, Germany
| | - David C Grainger
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany.,Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
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32
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Sun X, Ni Z, Tang J, Ding Y, Wang X, Li F. The abaI/ abaR Quorum Sensing System Effects on Pathogenicity in Acinetobacter baumannii. Front Microbiol 2021; 12:679241. [PMID: 34322102 PMCID: PMC8312687 DOI: 10.3389/fmicb.2021.679241] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 06/08/2021] [Indexed: 12/26/2022] Open
Abstract
Acinetobacter baumannii is a Gram-negative pathogen that has emerged as one of the most troublesome pathogens for healthcare institutions globally. Bacterial quorum sensing (QS) is a process of cell-to-cell communication that relies on the production, secretion, and detection of autoinducer (AI) signals to share information about cell density and regulate gene expression accordingly. The molecular and genetic bases of A. baumannii virulence remains poorly understood. Therefore, the contribution of the abaI/abaR QS system to growth characteristics, morphology, biofilm formation, resistance, motility, and virulence of A. baumannii was studied in detail. RNA sequencing (RNA-seq) analysis indicated that genes involved in various aspects of energy production and conversion; valine, leucine, and isoleucine degradation; and lipid transport and metabolism are associated with bacterial pathogenicity. Our work provides a new insight into the abaI/abaR QS system effects on pathogenicity in A. baumannii. We propose that targeting the acyl homoserine lactone (AHL) synthase enzyme abaI could provide an effective strategy for attenuating virulence. On the contrary, interdicting the AI synthase receptor abaR elicits unpredictable consequences, which may lead to enhanced bacterial virulence.
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Affiliation(s)
- Xiaoyu Sun
- Department of Pathogenobiology, The Key Laboratory of Zoonosis, Chinese Ministry of Education, College of Basic Medicine, Jilin University, Changchun, China
| | - Zhaohui Ni
- Department of Pathogenobiology, The Key Laboratory of Zoonosis, Chinese Ministry of Education, College of Basic Medicine, Jilin University, Changchun, China
| | - Jie Tang
- Department of Pathogenobiology, The Key Laboratory of Zoonosis, Chinese Ministry of Education, College of Basic Medicine, Jilin University, Changchun, China
| | - Yue Ding
- Department of Pathogenobiology, The Key Laboratory of Zoonosis, Chinese Ministry of Education, College of Basic Medicine, Jilin University, Changchun, China
| | - Xinlei Wang
- Department of Clinical Laboratory, The Second Hospital of Jilin University, Changchun, China
| | - Fan Li
- Department of Pathogenobiology, The Key Laboratory of Zoonosis, Chinese Ministry of Education, College of Basic Medicine, Jilin University, Changchun, China.,The Key Laboratory for Bionics Engineering, Ministry of Education, Jilin University, Changchun, China.,Engineering Research Center for Medical Biomaterials of Jilin Province, Jilin University, Changchun, China.,Key Laboratory for Biomedical Materials of Jilin Province, Jilin University, Changchun, China.,State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, Xinjiang, China
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33
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Duddy OP, Huang X, Silpe JE, Bassler BL. Mechanism underlying the DNA-binding preferences of the Vibrio cholerae and vibriophage VP882 VqmA quorum-sensing receptors. PLoS Genet 2021; 17:e1009550. [PMID: 34228715 PMCID: PMC8284805 DOI: 10.1371/journal.pgen.1009550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/16/2021] [Accepted: 06/16/2021] [Indexed: 11/19/2022] Open
Abstract
Quorum sensing is a chemical communication process that bacteria use to coordinate group behaviors. In the global pathogen Vibrio cholerae, one quorum-sensing receptor and transcription factor, called VqmA (VqmAVc), activates expression of the vqmR gene encoding the small regulatory RNA VqmR, which represses genes involved in virulence and biofilm formation. Vibriophage VP882 encodes a VqmA homolog called VqmAPhage that activates transcription of the phage gene qtip, and Qtip launches the phage lytic program. Curiously, VqmAPhage can activate vqmR expression but VqmAVc cannot activate expression of qtip. Here, we investigate the mechanism underlying this asymmetry. We find that promoter selectivity is driven by each VqmA DNA-binding domain and key DNA sequences in the vqmR and qtip promoters are required to maintain specificity. A protein sequence-guided mutagenesis approach revealed that the residue E194 of VqmAPhage and A192, the equivalent residue in VqmAVc, in the helix-turn-helix motifs contribute to promoter-binding specificity. A genetic screen to identify VqmAPhage mutants that are incapable of binding the qtip promoter but maintain binding to the vqmR promoter delivered additional VqmAPhage residues located immediately C-terminal to the helix-turn-helix motif as required for binding the qtip promoter. Surprisingly, these residues are conserved between VqmAPhage and VqmAVc. A second, targeted genetic screen revealed a region located in the VqmAVc DNA-binding domain that is necessary to prevent VqmAVc from binding the qtip promoter, thus restricting DNA binding to the vqmR promoter. We propose that the VqmAVc helix-turn-helix motif and the C-terminal flanking residues function together to prohibit VqmAVc from binding the qtip promoter. Bacteria use a chemical communication process called quorum sensing (QS) to orchestrate collective behaviors. Recent studies demonstrate that bacteria-infecting viruses, called phages, also employ chemical communication to regulate collective activities. Phages can encode virus-specific QS-like systems, or they can harbor genes encoding QS components resembling those of bacteria. The latter arrangement suggests the potential for chemical communication across domains, i.e., between bacteria and phages. Ramifications stemming from such cross-domain communication are not understood. Phage VP882 infects the global pathogen Vibrio cholerae, and “eavesdrops” on V. cholerae QS to optimize the timing of its transition from existing as a parasite to killing the host, and moreover, to manipulate V. cholerae biology. To accomplish these feats, phage VP882 relies on VqmAPhage, the phage-encoded homolog of the V. cholerae VqmAVc QS receptor and transcription factor. VqmAVc, by contrast, is constrained to the control of only V. cholerae genes and is incapable of regulating phage biology. Here, we discover the molecular mechanism underpinning the asymmetric transcriptional preferences of the phage-encoded and bacteria-encoded VqmA proteins. We demonstrate how VqmA transcriptional regulation is crucial to the survival and persistence of both the pathogen V. cholerae, and the phage that preys on it.
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Affiliation(s)
- Olivia P. Duddy
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Xiuliang Huang
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Justin E. Silpe
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Bonnie L. Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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34
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PapRIV, a BV-2 microglial cell activating quorum sensing peptide. Sci Rep 2021; 11:10723. [PMID: 34021199 PMCID: PMC8140105 DOI: 10.1038/s41598-021-90030-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/06/2021] [Indexed: 11/21/2022] Open
Abstract
Quorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.
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35
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Hsiao A, Zhu J. Pathogenicity and virulence regulation of Vibrio cholerae at the interface of host-gut microbiome interactions. Virulence 2020; 11:1582-1599. [PMID: 33172314 PMCID: PMC7671094 DOI: 10.1080/21505594.2020.1845039] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
The Gram-negative bacterium Vibrio cholerae is responsible for the severe diarrheal pandemic disease cholera, representing a major global public health concern. This pathogen transitions from aquatic reservoirs into epidemics in human populations, and has evolved numerous mechanisms to sense this transition in order to appropriately regulate its gene expression for infection. At the intersection of pathogen and host in the gastrointestinal tract lies the community of native gut microbes, the gut microbiome. It is increasingly clear that the diversity of species and biochemical activities within the gut microbiome represents a driver of infection outcome, through their ability to manipulate the signals used by V. cholerae to regulate virulence and fitness in vivo. A better mechanistic understanding of how commensal microbial action interacts with V. cholerae pathogenesis may lead to novel prophylactic and therapeutic interventions for cholera. Here, we review a subset of this burgeoning field of research.
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Affiliation(s)
- Ansel Hsiao
- Department of Microbiology & Plant Pathology, University of California Riverside, Riverside, CA, USA
| | - Jun Zhu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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36
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Peschek N, Herzog R, Singh PK, Sprenger M, Meyer F, Fröhlich KS, Schröger L, Bramkamp M, Drescher K, Papenfort K. RNA-mediated control of cell shape modulates antibiotic resistance in Vibrio cholerae. Nat Commun 2020; 11:6067. [PMID: 33247102 PMCID: PMC7695739 DOI: 10.1038/s41467-020-19890-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
Vibrio cholerae, the cause of cholera disease, exhibits a characteristic curved rod morphology, which promotes infectivity and motility in dense hydrogels. Periplasmic protein CrvA determines cell curvature in V. cholerae, yet the regulatory factors controlling CrvA are unknown. Here, we discover the VadR small RNA (sRNA) as a post-transcriptional inhibitor of the crvA mRNA. Mutation of vadR increases cell curvature, whereas overexpression has the inverse effect. We show that vadR transcription is activated by the VxrAB two-component system and triggered by cell-wall-targeting antibiotics. V. cholerae cells failing to repress crvA by VadR display decreased survival upon challenge with penicillin G indicating that cell shape maintenance by the sRNA is critical for antibiotic resistance. VadR also blocks the expression of various key biofilm genes and thereby inhibits biofilm formation in V. cholerae. Thus, VadR is an important regulator for synchronizing peptidoglycan integrity, cell shape, and biofilm formation in V. cholerae.
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Affiliation(s)
- Nikolai Peschek
- Institute of Microbiology, Friedrich Schiller University, 07745, Jena, Germany
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany
| | - Roman Herzog
- Institute of Microbiology, Friedrich Schiller University, 07745, Jena, Germany
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany
| | - Praveen K Singh
- Max Planck Institute for Terrestrial Microbiology, 35043, Marburg, Germany
| | - Marcel Sprenger
- Institute of Microbiology, Friedrich Schiller University, 07745, Jena, Germany
| | - Fabian Meyer
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany
- Institute for General Microbiology, Christian-Albrechts-University, Kiel, Germany
| | - Kathrin S Fröhlich
- Institute of Microbiology, Friedrich Schiller University, 07745, Jena, Germany
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany
- Microverse Cluster, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Luise Schröger
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany
| | - Marc Bramkamp
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany
- Institute for General Microbiology, Christian-Albrechts-University, Kiel, Germany
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, 35043, Marburg, Germany
- Department of Physics, Philipps-Universität Marburg, 35032, Marburg, Germany
| | - Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University, 07745, Jena, Germany.
- Faculty of Biology, Ludwig-Maximilians-University of Munich, 82152, Martinsried, Germany.
- Microverse Cluster, Friedrich Schiller University Jena, 07743, Jena, Germany.
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37
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Qin Z, Yang X, Chen G, Park C, Liu Z. Crosstalks Between Gut Microbiota and Vibrio Cholerae. Front Cell Infect Microbiol 2020; 10:582554. [PMID: 33194819 PMCID: PMC7644805 DOI: 10.3389/fcimb.2020.582554] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 09/17/2020] [Indexed: 12/11/2022] Open
Abstract
Vibrio cholerae, the causative agent of cholera, could proliferate in aquatic environment and infect humans through contaminated food and water. Enormous microorganisms residing in human gastrointestinal tract establish a special microecological system, which immediately responds to the invasion of V. cholerae, through “colonization resistance” mechanisms, such as antimicrobial peptide production, nutrients competition, and intestinal barrier maintenances. Meanwhile, V. cholerae could quickly sense those signals and modulate the expression of relevant genes to circumvent those stresses during infection, leading to successful colonization on the surface of small intestinal epithelial cells. In this review, we summarized the crosstalks profiles between gut microbiota and V. cholerae in the terms of Type VI Secretion System (T6SS), Quorum Sensing (QS), Reactive Oxygen Species (ROS)/pH stress, and Bioactive metabolites. These mechanisms can also be applied to molecular bacterial pathogenesis of other pathogens in host.
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Affiliation(s)
- Zixin Qin
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoman Yang
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Guozhong Chen
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Chaiwoo Park
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi Liu
- Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
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Kumar A, Das B, Kumar N. Vibrio Pathogenicity Island-1: The Master Determinant of Cholera Pathogenesis. Front Cell Infect Microbiol 2020; 10:561296. [PMID: 33123494 PMCID: PMC7574455 DOI: 10.3389/fcimb.2020.561296] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/11/2020] [Indexed: 11/13/2022] Open
Abstract
Cholera is an acute secretory diarrhoeal disease caused by the bacterium Vibrio cholerae. The key determinants of cholera pathogenicity, cholera toxin (CT), and toxin co-regulated pilus (TCP) are part of the genome of two horizontally acquired Mobile Genetic Elements (MGEs), CTXΦ, and Vibrio pathogenicity island 1 (VPI-1), respectively. Besides, V. cholerae genome harbors several others MGEs that provide antimicrobial resistance, metabolic functions, and other fitness traits. VPI-1, one of the most well characterized genomic island (GI), deserved a special attention, because (i) it encodes many of the virulence factors that facilitate development of cholera (ii) it is essential for the acquisition of CTXΦ and production of CT, and (iii) it is crucial for colonization of V. cholerae in the host intestine. Nevertheless, VPI-1 is ubiquitously present in all the epidemic V. cholerae strains. Therefore, to understand the role of MGEs in the evolution of cholera pathogen from a natural aquatic habitat, it is important to understand the VPI-1 encoded functions, their acquisition and possible mode of dissemination. In this review, we have therefore discussed our present understanding of the different functions of VPI-1 those are associated with virulence, important for toxin production and essential for the disease development.
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Affiliation(s)
- Ashok Kumar
- Translational Health Science and Technology Institute, Faridabad, India.,Centre for Doctoral Studies, Advanced Research Centre, Manipal Academy of Higher Education, Manipal, India
| | - Bhabatosh Das
- Translational Health Science and Technology Institute, Faridabad, India.,Centre for Doctoral Studies, Advanced Research Centre, Manipal Academy of Higher Education, Manipal, India
| | - Niraj Kumar
- Translational Health Science and Technology Institute, Faridabad, India.,Centre for Doctoral Studies, Advanced Research Centre, Manipal Academy of Higher Education, Manipal, India
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Ramamurthy T, Nandy RK, Mukhopadhyay AK, Dutta S, Mutreja A, Okamoto K, Miyoshi SI, Nair GB, Ghosh A. Virulence Regulation and Innate Host Response in the Pathogenicity of Vibrio cholerae. Front Cell Infect Microbiol 2020; 10:572096. [PMID: 33102256 PMCID: PMC7554612 DOI: 10.3389/fcimb.2020.572096] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
The human pathogen Vibrio cholerae is the causative agent of severe diarrheal disease known as cholera. Of the more than 200 "O" serogroups of this pathogen, O1 and O139 cause cholera outbreaks and epidemics. The rest of the serogroups, collectively known as non-O1/non-O139 cause sporadic moderate or mild diarrhea and also systemic infections. Pathogenic V. cholerae circulates between nutrient-rich human gut and nutrient-deprived aquatic environment. As an autochthonous bacterium in the environment and as a human pathogen, V. cholerae maintains its survival and proliferation in these two niches. Growth in the gastrointestinal tract involves expression of several genes that provide bacterial resistance against host factors. An intricate regulatory program involving extracellular signaling inputs is also controlling this function. On the other hand, the ability to store carbon as glycogen facilitates bacterial fitness in the aquatic environment. To initiate the infection, V. cholerae must colonize the small intestine after successfully passing through the acid barrier in the stomach and survive in the presence of bile and antimicrobial peptides in the intestinal lumen and mucus, respectively. In V. cholerae, virulence is a multilocus phenomenon with a large functionally associated network. More than 200 proteins have been identified that are functionally linked to the virulence-associated genes of the pathogen. Several of these genes have a role to play in virulence and/or in functions that have importance in the human host or the environment. A total of 524 genes are differentially expressed in classical and El Tor strains, the two biotypes of V. cholerae serogroup O1. Within the host, many immune and biological factors are able to induce genes that are responsible for survival, colonization, and virulence. The innate host immune response to V. cholerae infection includes activation of several immune protein complexes, receptor-mediated signaling pathways, and other bactericidal proteins. This article presents an overview of regulation of important virulence factors in V. cholerae and host response in the context of pathogenesis.
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Affiliation(s)
| | - Ranjan K Nandy
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asish K Mukhopadhyay
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Ankur Mutreja
- Global Health-Infectious Diseases, Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Keinosuke Okamoto
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.,Collaborative Research Center of Okayama University for Infectious Diseases in India, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shin-Ichi Miyoshi
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - G Balakrish Nair
- Microbiome Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
| | - Amit Ghosh
- Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India
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Spatiotemporal Regulation of Vibrio Exotoxins by HlyU and Other Transcriptional Regulators. Toxins (Basel) 2020; 12:toxins12090544. [PMID: 32842612 PMCID: PMC7551375 DOI: 10.3390/toxins12090544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
After invading a host, bacterial pathogens secrete diverse protein toxins to disrupt host defense systems. To ensure successful infection, however, pathogens must precisely regulate the expression of those exotoxins because uncontrolled toxin production squanders energy. Furthermore, inappropriate toxin secretion can trigger host immune responses that are detrimental to the invading pathogens. Therefore, bacterial pathogens use diverse transcriptional regulators to accurately regulate multiple exotoxin genes based on spatiotemporal conditions. This review covers three major exotoxins in pathogenic Vibrio species and their transcriptional regulation systems. When Vibrio encounters a host, genes encoding cytolysin/hemolysin, multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin, and secreted phospholipases are coordinately regulated by the transcriptional regulator HlyU. At the same time, however, they are distinctly controlled by a variety of other transcriptional regulators. How this coordinated but distinct regulation of exotoxins makes Vibrio species successful pathogens? In addition, anti-virulence strategies that target the coordinating master regulator HlyU and related future research directions are discussed.
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Abstract
Strigolactones are plant hormones with multiple roles that act as signaling molecules in many processes in the rhizosphere. In recent years, additional roles of strigolactones in nature have emerged, and here we report that strigolactones are able to modulate bacterial quorum sensing (QS) in the human pathogen Vibrio cholerae.
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Affiliation(s)
- Chen Mozes
- Department of Chemistry and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva, Israel
| | - Michael M. Meijler
- Department of Chemistry and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er Sheva, Israel
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42
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Hoyos M, Huber M, Förstner KU, Papenfort K. Gene autoregulation by 3' UTR-derived bacterial small RNAs. eLife 2020; 9:58836. [PMID: 32744240 PMCID: PMC7398697 DOI: 10.7554/elife.58836] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/23/2020] [Indexed: 01/01/2023] Open
Abstract
Negative feedback regulation, that is the ability of a gene to repress its own synthesis, is the most abundant regulatory motif known to biology. Frequently reported for transcriptional regulators, negative feedback control relies on binding of a transcription factor to its own promoter. Here, we report a novel mechanism for gene autoregulation in bacteria relying on small regulatory RNA (sRNA) and the major endoribonuclease, RNase E. TIER-seq analysis (transiently-inactivating-an-endoribonuclease-followed-by-RNA-seq) revealed ~25,000 RNase E-dependent cleavage sites in Vibrio cholerae, several of which resulted in the accumulation of stable sRNAs. Focusing on two examples, OppZ and CarZ, we discovered that these sRNAs are processed from the 3' untranslated region (3' UTR) of the oppABCDF and carAB operons, respectively, and base-pair with their own transcripts to inhibit translation. For OppZ, this process also triggers Rho-dependent transcription termination. Our data show that sRNAs from 3' UTRs serve as autoregulatory elements allowing negative feedback control at the post-transcriptional level.
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Affiliation(s)
- Mona Hoyos
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.,Faculty of Biology I, Ludwig-Maximilians-University of Munich, Martinsried, Germany
| | - Michaela Huber
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.,Faculty of Biology I, Ludwig-Maximilians-University of Munich, Martinsried, Germany
| | - Konrad U Förstner
- TH Köln - University of Applied Sciences, Institute of Information Science, Cologne, Germany.,ZB MED - Information Centre for Life Sciences, Cologne, Germany
| | - Kai Papenfort
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.,Faculty of Biology I, Ludwig-Maximilians-University of Munich, Martinsried, Germany.,Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
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43
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Abstract
Cholera is a devastating illness that kills tens of thousands of people annually. Vibrio cholerae, the causative agent of cholera, is an important model organism to investigate both bacterial pathogenesis and the impact of horizontal gene transfer on the emergence and dissemination of new virulent strains. Despite the importance of this pathogen, roughly one-third of V. cholerae genes are functionally unannotated, leaving large gaps in our understanding of this microbe. Through coexpression network analysis of existing RNA sequencing data, this work develops an approach to uncover novel gene-gene relationships and contextualize genes with no known function, which will advance our understanding of V. cholerae virulence and evolution. Research into the evolution and pathogenesis of Vibrio cholerae has benefited greatly from the generation of high-throughput sequencing data to drive molecular analyses. The steady accumulation of these data sets now provides a unique opportunity for in silico hypothesis generation via coexpression analysis. Here, we leverage all published V. cholerae RNA sequencing data, in combination with select data from other platforms, to generate a gene coexpression network that validates known gene interactions and identifies novel genetic partners across the entire V. cholerae genome. This network provides direct insights into genes influencing pathogenicity, metabolism, and transcriptional regulation, further clarifies results from previous sequencing experiments in V. cholerae (e.g., transposon insertion sequencing [Tn-seq] and chromatin immunoprecipitation sequencing [ChIP-seq]), and expands upon microarray-based findings in related Gram-negative bacteria. IMPORTANCE Cholera is a devastating illness that kills tens of thousands of people annually. Vibrio cholerae, the causative agent of cholera, is an important model organism to investigate both bacterial pathogenesis and the impact of horizontal gene transfer on the emergence and dissemination of new virulent strains. Despite the importance of this pathogen, roughly one-third of V. cholerae genes are functionally unannotated, leaving large gaps in our understanding of this microbe. Through coexpression network analysis of existing RNA sequencing data, this work develops an approach to uncover novel gene-gene relationships and contextualize genes with no known function, which will advance our understanding of V. cholerae virulence and evolution.
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44
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Tan D, Hansen MF, de Carvalho LN, Røder HL, Burmølle M, Middelboe M, Svenningsen SL. High cell densities favor lysogeny: induction of an H20 prophage is repressed by quorum sensing and enhances biofilm formation in Vibrio anguillarum. THE ISME JOURNAL 2020; 14:1731-1742. [PMID: 32269377 PMCID: PMC7305317 DOI: 10.1038/s41396-020-0641-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 11/09/2022]
Abstract
Temperate ϕH20-like phages are repeatedly identified at geographically distinct areas as free phage particles or as prophages of the fish pathogen Vibrio anguillarum. We studied mutants of a lysogenic isolate of V. anguillarum locked in the quorum-sensing regulatory modes of low (ΔvanT) and high (ΔvanO) cell densities by in-frame deletion of key regulators of the quorum-sensing pathway. Remarkably, we find that induction of the H20-like prophage is controlled by the quorum-sensing state of the host, with an eightfold increase in phage particles per cell in high-cell-density cultures of the quorum-sensing-deficient ΔvanT mutant. Comparative studies with prophage-free strains show that biofilm formation is promoted at low cell density and that the H20-like prophage stimulates this behavior. In contrast, the high-cell-density state is associated with reduced prophage induction, increased proteolytic activity, and repression of biofilm. The proteolytic activity may dually function to disperse the biofilm and as a quorum-sensing-mediated antiphage strategy. We demonstrate an intertwined regulation of phage-host interactions and biofilm formation, which is orchestrated by host quorum-sensing signaling, suggesting that increased lysogeny at high cell density is not solely a strategy for phages to piggy-back the successful bacterial hosts but is also a host strategy evolved to take control of the lysis-lysogeny switch to promote host fitness.
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Affiliation(s)
- Demeng Tan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- Dalian SEM Bio-Engineering Technology Co. Ltd, Dalian, China
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Mads Frederik Hansen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | | | - Mette Burmølle
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Mathias Middelboe
- Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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45
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Holoidovsky L, Meijler MM. Synthesis and Evaluation of Indole-Based Autoinducers on Quorum Sensing in Vibrio cholerae. ACS Infect Dis 2020; 6:572-576. [PMID: 32182033 DOI: 10.1021/acsinfecdis.9b00409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vibrio cholerae (V. cholerae) uses the autoinducer CAI-1 (cholera autoinducer 1) and several linked quorum sensing systems in order to efficiently sense its ever-changing environment and optimally coordinate population-wide gene expression. Indole has been reported as an important signal that is sensed by V. cholerae, and here, we report the synthesis and evaluation of a focused library of synthetic indole-CAI-1 derivatives as tools to probe quorum sensing (QS) in this human pathogen. Our results show interesting and diverging effects for several conjugates, as compared to CAI-1, on virulence factor production and biofilm formation.
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Affiliation(s)
- Lara Holoidovsky
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er-Sheva 8410501, Israel
| | - Michael M. Meijler
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be’er-Sheva 8410501, Israel
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46
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Abstract
Hfq (host factor for phage Q beta) is key for posttranscriptional gene regulation in many bacteria. Hfq's function is to stabilize sRNAs and to facilitate base-pairing with trans-encoded target mRNAs. Loss of Hfq typically results in pleiotropic phenotypes, and, in the major human pathogen Vibrio cholerae, Hfq inactivation has been linked to reduced virulence, failure to produce biofilms, and impaired intercellular communication. However, the RNA ligands of Hfq in V. cholerae are currently unknown. Here, we used RIP-seq (RNA immunoprecipitation followed by high-throughput sequencing) analysis to identify Hfq-bound RNAs in V. cholerae Our work revealed 603 coding and 85 noncoding transcripts associated with Hfq, including 44 sRNAs originating from the 3' end of mRNAs. Detailed investigation of one of these latter transcripts, named FarS (fatty acid regulated sRNA), showed that this sRNA is produced by RNase E-mediated maturation of the fabB 3'UTR, and, together with Hfq, inhibits the expression of two paralogous fadE mRNAs. The fabB and fadE genes are antagonistically regulated by the major fatty acid transcription factor, FadR, and we show that, together, FadR, FarS, and FadE constitute a mixed feed-forward loop regulating the transition between fatty acid biosynthesis and degradation in V. cholerae Our results provide the molecular basis for studies on Hfq in V. cholerae and highlight the importance of a previously unrecognized sRNA for fatty acid metabolism in this major human pathogen.
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47
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Tobias NJ, Brehm J, Kresovic D, Brameyer S, Bode HB, Heermann R. New Vocabulary for Bacterial Communication. Chembiochem 2020; 21:759-768. [PMID: 31709676 PMCID: PMC7154725 DOI: 10.1002/cbic.201900580] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Indexed: 12/21/2022]
Abstract
Quorum sensing (QS) is widely accepted as a procedure that bacteria use to converse. However, prevailing thinking places acyl homoserine lactones (AHLs) at the forefront of this communication pathway in Gram-negative bacteria. With the advent of high-throughput genomics and the subsequent influx of bacterial genomes, bioinformatics analysis has determined that the genes encoding AHL biosynthesis, originally discovered to be indispensable for QS (LuxI-like proteins and homologues), are often absent in QS-capable bacteria. Instead, the sensing protein (LuxR-like proteins) is present with an apparent inability to produce any outgoing AHL signal. Recently, several signals for these LuxR solos have been identified. Herein, advances in the field of QS are discussed, with a particular focus on recent research in the field of bacterial cell-cell communication.
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Affiliation(s)
- Nicholas J. Tobias
- Fachbereich BiowissenschaftenMerck-Stiftungsprofessur für Molekulare BiotechnologieGoethe-Universität FrankfurtMax-von-Laue-Strasse 960438Frankfurt am MainGermany
- LOEWE Center for Translational Biodiversity in Genomics (TBG)Frankfurt am MainGermany
| | - Jannis Brehm
- Institut für Molekulare PhysiologieMikrobiologie und WeinforschungJohannes-Gutenberg-Universität MainzJohann-Joachim-Becher-Weg 1355128MainzGermany
| | - Darko Kresovic
- Fachbereich BiowissenschaftenMerck-Stiftungsprofessur für Molekulare BiotechnologieGoethe-Universität FrankfurtMax-von-Laue-Strasse 960438Frankfurt am MainGermany
| | - Sophie Brameyer
- Biozentrum, Bereich MikrobiologieLudwig-Maximilians-Universität MünchenGroßhaderner Strasse 2–482152MartinsriedGermany
| | - Helge B. Bode
- Fachbereich BiowissenschaftenMerck-Stiftungsprofessur für Molekulare BiotechnologieGoethe-Universität FrankfurtMax-von-Laue-Strasse 960438Frankfurt am MainGermany
- LOEWE Center for Translational Biodiversity in Genomics (TBG)Frankfurt am MainGermany
- Buchmann Institute for Molecular Life Sciences (BMLS)Goethe-Universität FrankfurtMax-von-Laue-Strasse 1560438Frankfurt am MainGermany
| | - Ralf Heermann
- Institut für Molekulare PhysiologieMikrobiologie und WeinforschungJohannes-Gutenberg-Universität MainzJohann-Joachim-Becher-Weg 1355128MainzGermany
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48
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Silpe JE, Bridges AA, Huang X, Coronado DR, Duddy OP, Bassler BL. Separating Functions of the Phage-Encoded Quorum-Sensing-Activated Antirepressor Qtip. Cell Host Microbe 2020; 27:629-641.e4. [PMID: 32101705 DOI: 10.1016/j.chom.2020.01.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/21/2020] [Accepted: 01/28/2020] [Indexed: 01/21/2023]
Abstract
Quorum sensing is a process of chemical communication that bacteria use to track cell density and coordinate gene expression across a population. Bacteria-infecting viruses, called phages, can encode quorum-sensing components that enable them to integrate host cell density information into the lysis-lysogeny decision. Vibriophage VP882 is one such phage, and activation of its quorum-sensing pathway leads to the production of an antirepressor called Qtip. Qtip interferes with the prophage repressor (cIVP882), leading to host-cell lysis. Here, we show that Qtip interacts with the N terminus of cIVP882, inhibiting both cIVP882 DNA binding and cIVP882 autoproteolysis. Qtip also sequesters cIVP882, localizing it to the poles. Qtip can localize to the poles independently of cIVP882. Alanine-scanning mutagenesis of Qtip shows that its localization and interference with cIVP882 activities are separable. Comparison of Qtip to a canonical phage antirepressor reveals that despite both proteins interacting with their partner repressors, only Qtip drives polar localization.
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Affiliation(s)
- Justin E Silpe
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Andrew A Bridges
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Xiuliang Huang
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Daniela R Coronado
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Olivia P Duddy
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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49
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Huang X, Duddy OP, Silpe JE, Paczkowski JE, Cong J, Henke BR, Bassler BL. Mechanism underlying autoinducer recognition in the Vibrio cholerae DPO-VqmA quorum-sensing pathway. J Biol Chem 2020; 295:2916-2931. [PMID: 31964715 DOI: 10.1074/jbc.ra119.012104] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/15/2020] [Indexed: 11/06/2022] Open
Abstract
Quorum sensing is a bacterial communication process whereby bacteria produce, release, and detect extracellular signaling molecules called autoinducers to coordinate collective behaviors. In the pathogen Vibrio cholerae, the quorum-sensing autoinducer 3,5-dimethyl-pyrazin-2-ol (DPO) binds the receptor and transcription factor VqmA. The DPO-VqmA complex activates transcription of vqmR, encoding the VqmR small RNA, which represses genes required for biofilm formation and virulence factor production. Here, we show that VqmA is soluble and properly folded and activates basal-level transcription of its target vqmR in the absence of DPO. VqmA transcriptional activity is increased in response to increasing concentrations of DPO, allowing VqmA to drive the V. cholerae quorum-sensing transition at high cell densities. We solved the DPO-VqmA crystal structure to 2.0 Å resolution and compared it with existing structures to understand the conformational changes VqmA undergoes upon DNA binding. Analysis of DPO analogs showed that a hydroxyl or carbonyl group at the 2'-position is critical for binding to VqmA. The proposed DPO precursor, a linear molecule, N-alanyl-aminoacetone (Ala-AA), also bound and activated VqmA. Results from site-directed mutagenesis and competitive ligand-binding analyses revealed that DPO and Ala-AA occupy the same binding site. In summary, our structure-function analysis identifies key features required for VqmA activation and DNA binding and establishes that, whereas VqmA binds two different ligands, VqmA does not require a bound ligand for folding or basal transcriptional activity. However, bound ligand is required for maximal activity.
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Affiliation(s)
- Xiuliang Huang
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Olivia P Duddy
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
| | - Justin E Silpe
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
| | - Jon E Paczkowski
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544
| | - Jianping Cong
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
| | - Brad R Henke
- Opti-Mol Consulting, LLC, Cary, North Carolina 27513
| | - Bonnie L Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; Howard Hughes Medical Institute, Chevy Chase, Maryland 20815.
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Bridges AA, Bassler BL. The intragenus and interspecies quorum-sensing autoinducers exert distinct control over Vibrio cholerae biofilm formation and dispersal. PLoS Biol 2019; 17:e3000429. [PMID: 31710602 PMCID: PMC6872173 DOI: 10.1371/journal.pbio.3000429] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/21/2019] [Accepted: 10/24/2019] [Indexed: 12/19/2022] Open
Abstract
Vibrio cholerae possesses multiple quorum-sensing (QS) systems that control virulence and biofilm formation among other traits. At low cell densities, when QS autoinducers are absent, V. cholerae forms biofilms. At high cell densities, when autoinducers have accumulated, biofilm formation is repressed, and dispersal occurs. Here, we focus on the roles of two well-characterized QS autoinducers that function in parallel. One autoinducer, called cholerae autoinducer-1 (CAI-1), is used to measure Vibrio abundance, and the other autoinducer, called autoinducer-2 (AI-2), is widely produced by different bacterial species and presumed to enable V. cholerae to assess the total bacterial cell density of the vicinal community. The two V. cholerae autoinducers funnel information into a shared signal relay pathway. This feature of the QS system architecture has made it difficult to understand how specific information can be extracted from each autoinducer, how the autoinducers might drive distinct output behaviors, and, in turn, how the bacteria use QS to distinguish kin from nonkin in bacterial communities. We develop a live-cell biofilm formation and dispersal assay that allows examination of the individual and combined roles of the two autoinducers in controlling V. cholerae behavior. We show that the QS system works as a coincidence detector in which both autoinducers must be present simultaneously for repression of biofilm formation to occur. Within that context, the CAI-1 QS pathway is activated when only a few V. cholerae cells are present, whereas the AI-2 pathway is activated only at much higher cell density. The consequence of this asymmetry is that exogenous sources of AI-2, but not CAI-1, contribute to satisfying the coincidence detector to repress biofilm formation and promote dispersal. We propose that V. cholerae uses CAI-1 to verify that some of its kin are present before committing to the high-cell–density QS mode, but it is, in fact, the broadly made autoinducer AI-2 that sets the pace of the V. cholerae QS program. This first report of unique roles for the different V. cholerae autoinducers suggests that detection of kin fosters a distinct outcome from detection of nonkin. The pathogenic bacterium Vibrio cholerae uses both kin and nonkin quorum-sensing autoinducer molecules to control its biofilm life cycle; this study shows that each autoinducer plays a unique role in regulating biofilm formation and dispersal.
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Affiliation(s)
- Andrew A. Bridges
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Bonnie L. Bassler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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