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Isenberg RY, Holschbach CS, Gao J, Mandel MJ. Functional analysis of cyclic diguanylate-modulating proteins in Vibrio fischeri. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.24.550417. [PMID: 37546929 PMCID: PMC10402110 DOI: 10.1101/2023.07.24.550417] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
As bacterial symbionts transition from a motile free-living state to a sessile biofilm state, they must coordinate behavior changes suitable to each lifestyle. Cyclic diguanylate (c-di-GMP) is an intracellular signaling molecule that can regulate this transition, and it is synthesized by diguanylate cyclase (DGC) enzymes and degraded by phosphodiesterase (PDE) enzymes. Generally, c-di-GMP inhibits motility and promotes biofilm formation. While c-di-GMP and the enzymes that contribute to its metabolism have been well-studied in pathogens, considerably less focus has been placed on c-di-GMP regulation in beneficial symbionts. Vibrio fischeri is the sole beneficial symbiont of the Hawaiian bobtail squid ( Euprymna scolopes ) light organ, and the bacterium requires both motility and biofilm formation to efficiently colonize. C-di-GMP regulates swimming motility and cellulose exopolysaccharide production in V. fischeri . The genome encodes 50 DGCs and PDEs, and while a few of these proteins have been characterized, the majority have not undergone comprehensive characterization. In this study, we use protein overexpression to systematically characterize the functional potential of all 50 V. fischeri proteins. All 28 predicted DGCs and 14 predicted PDEs displayed at least one phenotype consistent with their predicted function, and a majority of each displayed multiple phenotypes. Finally, active site mutant analysis of proteins with the potential for both DGC and PDE activities revealed potential activities for these proteins. This work presents a systems-level functional analysis of a family of signaling proteins in a tractable animal symbiont and will inform future efforts to characterize the roles of individual proteins during lifestyle transitions.
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Affiliation(s)
- Ruth Y. Isenberg
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI USA
- Current address: Department of Microbiology and Immunology, University of Minnesota Medical School, Minneapolis, MN USA
| | - Chandler S. Holschbach
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI USA
| | - Jing Gao
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL USA
| | - Mark J. Mandel
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI USA
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2
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Moulding PB, El-Halfawy OM. Chemical-mediated virulence: the effects of host chemicals on microbial virulence and potential new antivirulence strategies. Can J Microbiol 2024. [PMID: 38905704 DOI: 10.1139/cjm-2024-0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/23/2024]
Abstract
The rising antimicrobial resistance rates and declining antimicrobial discovery necessitate alternative strategies to combat multidrug-resistant pathogens. Targeting microbial virulence is an emerging area of interest. Traditionally, virulence factors were largely restricted to bacteria-derived toxins, adhesins, capsules, quorum sensing systems, secretion systems, factors required to sense, respond to, acquire, or synthesize, and utilize trace elements (such as iron and other metals) and micronutrients (such as vitamins), and other factors bacteria use to establish infection, form biofilms, or damage the host tissues and regulatory elements thereof. However, this traditional definition overlooks bacterial virulence that may be induced or influenced by host-produced metabolites or other chemicals that bacteria may encounter at the infection site. This review will discuss virulence from a non-traditional perspective, shedding light on chemical-mediated host-pathogen interactions and outlining currently available mechanistic insight into increased bacterial virulence in response to host factors. This review aims to define a possibly underestimated theme of chemically mediated host-pathogen interactions and encourage future validation and characterization of the contribution of host chemicals to microbial virulence in vivo. From this perspective, we discuss proposed antivirulence compounds and suggest new potential targets for antimicrobials that prevent chemical-mediated virulence. We also explore proposed host-targeting therapeutics reducing the level of host chemicals that induce microbial virulence, serving as virulence attenuators. Understanding the host chemical-mediated virulence may enable new antimicrobial solutions to fight multidrug-resistant pathogens.
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Affiliation(s)
- Peri B Moulding
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
| | - Omar M El-Halfawy
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK S4S 0A2, Canada
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Alexandria, 21521, Egypt
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3
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Barber MF, Fitzgerald JR. Mechanisms of host adaptation by bacterial pathogens. FEMS Microbiol Rev 2024; 48:fuae019. [PMID: 39003250 PMCID: PMC11308195 DOI: 10.1093/femsre/fuae019] [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: 04/15/2024] [Revised: 07/02/2024] [Accepted: 07/24/2024] [Indexed: 07/15/2024] Open
Abstract
The emergence of new infectious diseases poses a major threat to humans, animals, and broader ecosystems. Defining factors that govern the ability of pathogens to adapt to new host species is therefore a crucial research imperative. Pathogenic bacteria are of particular concern, given dwindling treatment options amid the continued expansion of antimicrobial resistance. In this review, we summarize recent advancements in the understanding of bacterial host species adaptation, with an emphasis on pathogens of humans and related mammals. We focus particularly on molecular mechanisms underlying key steps of bacterial host adaptation including colonization, nutrient acquisition, and immune evasion, as well as suggest key areas for future investigation. By developing a greater understanding of the mechanisms of host adaptation in pathogenic bacteria, we may uncover new strategies to target these microbes for the treatment and prevention of infectious diseases in humans, animals, and the broader environment.
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Affiliation(s)
- Matthew F Barber
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, United States
- Department of Biology, University of Oregon, Eugene, OR 97403, United States
| | - J Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
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4
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Meng Y, Zhang X, Zhai Y, Li Y, Shao Z, Liu S, Zhang C, Xing XH, Zheng H. Identification of the mutual gliding locus as a factor for gut colonization in non-native bee hosts using the ARTP mutagenesis. MICROBIOME 2024; 12:93. [PMID: 38778376 PMCID: PMC11112851 DOI: 10.1186/s40168-024-01813-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 04/09/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND The gut microbiota and their hosts profoundly affect each other's physiology and evolution. Identifying host-selected traits is crucial to understanding the processes that govern the evolving interactions between animals and symbiotic microbes. Current experimental approaches mainly focus on the model bacteria, like hypermutating Escherichia coli or the evolutionary changes of wild stains by host transmissions. A method called atmospheric and room temperature plasma (ARTP) may overcome the bottleneck of low spontaneous mutation rates while maintaining mild conditions for the gut bacteria. RESULTS We established an experimental symbiotic system with gnotobiotic bee models to unravel the molecular mechanisms promoting host colonization. By in vivo serial passage, we tracked the genetic changes of ARTP-treated Snodgrassella strains from Bombus terrestris in the non-native honeybee host. We observed that passaged isolates showing genetic changes in the mutual gliding locus have a competitive advantage in the non-native host. Specifically, alleles in the orphan mglB, the GTPase activating protein, promoted colonization potentially by altering the type IV pili-dependent motility of the cells. Finally, competition assays confirmed that the mutations out-competed the ancestral strain in the non-native honeybee gut but not in the native host. CONCLUSIONS Using the ARTP mutagenesis to generate a mutation library of gut symbionts, we explored the potential genetic mechanisms for improved gut colonization in non-native hosts. Our findings demonstrate the implication of the cell mutual-gliding motility in host association and provide an experimental system for future study on host-microbe interactions. Video Abstract.
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Affiliation(s)
- Yujie Meng
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China
- MGI Tech, Qingdao, 266426, China
| | - Xue Zhang
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing, 100083, China
| | - Yifan Zhai
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, 250100, China
| | - Yuan Li
- MGI Tech, Qingdao, 266426, China
| | | | | | - Chong Zhang
- Department of Chemical Engineering, Institute of Biochemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Xin-Hui Xing
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Hao Zheng
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
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5
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Glenn SJ, Gentry-Lear Z, Shavlik M, Harms MJ, Asaki TJ, Baylink A. Bacterial vampirism mediated through taxis to serum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.07.548164. [PMID: 37461633 PMCID: PMC10350070 DOI: 10.1101/2023.07.07.548164] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Bacteria of the family Enterobacteriaceae are associated with gastrointestinal (GI) bleeding and bacteremia and are a leading cause of death, from sepsis, for individuals with inflammatory bowel diseases. The bacterial behaviors and mechanisms underlying why these bacteria are prone to bloodstream entry remains poorly understood. Herein, we report that clinical isolates of non-typhoidal Salmonella enterica serovars, Escherichia coli, and Citrobacter koseri are rapidly attracted toward sources of human serum. To simulate GI bleeding, we utilized a custom injection-based microfluidics device and found that femtoliter volumes of human serum are sufficient to induce the bacterial population to swim toward and aggregate at the serum source. This response is orchestrated through chemotaxis, and a major chemical cue driving chemoattraction is L-serine, an amino acid abundant in serum that is recognized through direct binding by the chemoreceptor Tsr. We report the first crystal structures of Salmonella Typhimurium Tsr in complex with L-serine and identify a conserved amino acid recognition motif for L-serine shared among Tsr orthologues. By mapping the phylogenetic distribution of this chemoreceptor we found Tsr to be widely conserved among Enterobacteriaceae and numerous World Health Organization priority pathogens associated with bloodstream infections. Lastly, we find that Enterobacteriaceae use human serum as a source of nutrients for growth and that chemotaxis and the chemoreceptor Tsr provides a competitive advantage for migration into enterohaemorrhagic lesions. We term this bacterial behavior of taxis toward serum, colonization of hemorrhagic lesions, and the consumption of serum nutrients, as 'bacterial vampirism' which may relate to the proclivity of Enterobacteriaceae for bloodstream infections.
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Stevick RJ, Audrain B, Bedu S, Dray N, Ghigo JM, Pérez-Pascual D. Anti-diarrheal drug loperamide induces dysbiosis in zebrafish microbiota via bacterial inhibition. MICROBIOME 2023; 11:252. [PMID: 37951983 PMCID: PMC10638762 DOI: 10.1186/s40168-023-01690-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 10/04/2023] [Indexed: 11/14/2023]
Abstract
BACKGROUND Perturbations of animal-associated microbiomes from chemical stress can affect host physiology and health. While dysbiosis induced by antibiotic treatments and disease is well known, chemical, nonantibiotic drugs have recently been shown to induce changes in microbiome composition, warranting further exploration. Loperamide is an opioid-receptor agonist widely prescribed for treating acute diarrhea in humans. Loperamide is also used as a tool to study the impact of bowel dysfunction in animal models by inducing constipation, but its effect on host-associated microbiota is poorly characterized. RESULTS We used conventional and gnotobiotic larval zebrafish models to show that in addition to host-specific effects, loperamide also has anti-bacterial activities that directly induce changes in microbiota diversity. This dysbiosis is due to changes in bacterial colonization, since gnotobiotic zebrafish mono-colonized with bacterial strains sensitive to loperamide are colonized up to 100-fold lower when treated with loperamide. Consistently, the bacterial diversity of gnotobiotic zebrafish colonized by a mix of 5 representative bacterial strains is affected by loperamide treatment. CONCLUSION Our results demonstrate that loperamide, in addition to host effects, also induces dysbiosis in a vertebrate model, highlighting that established treatments can have underlooked secondary effects on microbiota structure and function. This study further provides insights for future studies exploring how common medications directly induce changes in host-associated microbiota. Video Abstract.
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Affiliation(s)
- Rebecca J Stevick
- Genetics of Biofilms Laboratory, UMR 6047, Institut Pasteur Université Paris Cité, CNRS, Paris, France
| | - Bianca Audrain
- Genetics of Biofilms Laboratory, UMR 6047, Institut Pasteur Université Paris Cité, CNRS, Paris, France
| | - Sébastien Bedu
- Zebrafish Neurogenetics Laboratory, UMR 3738, Institut Pasteur Université Paris Cité, CNRS, Paris, France
| | - Nicolas Dray
- Zebrafish Neurogenetics Laboratory, UMR 3738, Institut Pasteur Université Paris Cité, CNRS, Paris, France
| | - Jean-Marc Ghigo
- Genetics of Biofilms Laboratory, UMR 6047, Institut Pasteur Université Paris Cité, CNRS, Paris, France.
| | - David Pérez-Pascual
- Genetics of Biofilms Laboratory, UMR 6047, Institut Pasteur Université Paris Cité, CNRS, Paris, France.
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7
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Römling U. Cyclic di-GMP signaling-Where did you come from and where will you go? Mol Microbiol 2023; 120:564-574. [PMID: 37427497 DOI: 10.1111/mmi.15119] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/17/2023] [Accepted: 06/22/2023] [Indexed: 07/11/2023]
Abstract
Microbes including bacteria are required to respond to their often continuously changing ecological niches in order to survive. While many signaling molecules are produced as seemingly circumstantial byproducts of common biochemical reactions, there are a few second messenger signaling systems such as the ubiquitous cyclic di-GMP second messenger system that arise through the synthesis of dedicated multidomain enzymes triggered by multiple diverse external and internal signals. Being one of the most numerous and widespread signaling system in bacteria, cyclic di-GMP signaling contributes to adjust physiological and metabolic responses in all available ecological niches. Those niches range from deep-sea and hydrothermal springs to the intracellular environment in human immune cells such as macrophages. This outmost adaptability is possible by the modularity of the cyclic di-GMP turnover proteins which enables coupling of enzymatic activity to the diversity of sensory domains and the flexibility in cyclic di-GMP binding sites. Nevertheless, commonly regulated fundamental microbial behavior include biofilm formation, motility, and acute and chronic virulence. The dedicated domains carrying out the enzymatic activity indicate an early evolutionary origin and diversification of "bona fide" second messengers such as cyclic di-GMP which is estimated to have been present in the last universal common ancestor of archaea and bacteria and maintained in the bacterial kingdom until today. This perspective article addresses aspects of our current view on the cyclic di-GMP signaling system and points to knowledge gaps that still await answers.
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Affiliation(s)
- Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
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8
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Obeng N, Czerwinski A, Schütz D, Michels J, Leipert J, Bansept F, García García MJ, Schultheiß T, Kemlein M, Fuß J, Tholey A, Traulsen A, Sondermann H, Schulenburg H. Bacterial c-di-GMP has a key role in establishing host-microbe symbiosis. Nat Microbiol 2023; 8:1809-1819. [PMID: 37653009 PMCID: PMC10522488 DOI: 10.1038/s41564-023-01468-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 08/10/2023] [Indexed: 09/02/2023]
Abstract
Most microbes evolve faster than their hosts and should therefore drive evolution of host-microbe interactions. However, relatively little is known about the characteristics that define the adaptive path of microbes to host association. Here we identified microbial traits that mediate adaptation to hosts by experimentally evolving the free-living bacterium Pseudomonas lurida with the nematode Caenorhabditis elegans as its host. After ten passages, we repeatedly observed the evolution of beneficial host-specialist bacteria, with improved persistence in the nematode being associated with increased biofilm formation. Whole-genome sequencing revealed mutations that uniformly upregulate the bacterial second messenger, cyclic diguanylate (c-di-GMP). We subsequently generated mutants with upregulated c-di-GMP in different Pseudomonas strains and species, which consistently increased host association. Comparison of pseudomonad genomes from various environments revealed that c-di-GMP underlies adaptation to a variety of hosts, from plants to humans. This study indicates that c-di-GMP is fundamental for establishing host association.
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Affiliation(s)
- Nancy Obeng
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| | - Anna Czerwinski
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| | - Daniel Schütz
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| | - Jan Michels
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| | - Jan Leipert
- Department of Systematic Proteome Research and Bioanalytics, University of Kiel, Kiel, Germany
| | | | - María J García García
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Thekla Schultheiß
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
- Institute of Toxicology and Pharmacology, University of Kiel, Kiel, Germany
| | - Melinda Kemlein
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany
| | - Janina Fuß
- Institute of Clinical Molecular Biology, University of Kiel, Kiel, Germany
| | - Andreas Tholey
- Department of Systematic Proteome Research and Bioanalytics, University of Kiel, Kiel, Germany
| | - Arne Traulsen
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Holger Sondermann
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- Section of Biology, University of Kiel, Kiel, Germany
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, University of Kiel, Kiel, Germany.
- Max Planck Institute for Evolutionary Biology, Plön, Germany.
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9
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McCann JR, Rawls JF. Essential Amino Acid Metabolites as Chemical Mediators of Host-Microbe Interaction in the Gut. Annu Rev Microbiol 2023; 77:479-497. [PMID: 37339735 PMCID: PMC11188676 DOI: 10.1146/annurev-micro-032421-111819] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Amino acids are indispensable substrates for protein synthesis in all organisms and incorporated into diverse aspects of metabolic physiology and signaling. However, animals lack the ability to synthesize several of them and must acquire these essential amino acids from their diet or perhaps their associated microbial communities. The essential amino acids therefore occupy a unique position in the health of animals and their relationships with microbes. Here we review recent work connecting microbial production and metabolism of essential amino acids to host biology, and the reciprocal impacts of host metabolism of essential amino acids on their associated microbes. We focus on the roles of the branched-chain amino acids (valine, leucine, and isoleucine) and tryptophan on host-microbe communication in the intestine of humans and other vertebrates. We then conclude by highlighting research questions surrounding the less-understood aspects of microbial essential amino acid synthesis in animal hosts.
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Affiliation(s)
- Jessica R McCann
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, North Carolina, USA; ,
| | - John F Rawls
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, North Carolina, USA; ,
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10
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Smith TJ, Sundarraman D, Melancon E, Desban L, Parthasarathy R, Guillemin K. A mucin-regulated adhesin determines the spatial organization and inflammatory character of a bacterial symbiont in the vertebrate gut. Cell Host Microbe 2023; 31:1371-1385.e6. [PMID: 37516109 PMCID: PMC10492631 DOI: 10.1016/j.chom.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 05/11/2023] [Accepted: 07/06/2023] [Indexed: 07/31/2023]
Abstract
In a healthy gut, microbes are often aggregated with host mucus, yet the molecular basis for this organization and its impact on intestinal health are unclear. Mucus is a viscous physical barrier separating resident microbes from epithelia, but it also provides glycan cues that regulate microbial behaviors. Here, we describe a mucin-sensing pathway in an Aeromonas symbiont of zebrafish, Aer01. In response to the mucin-associated glycan N-acetylglucosamine, a sensor kinase regulates the expression of an aggregation-promoting adhesin we named MbpA. Upon MbpA disruption, Aer01 colonizes to normal levels but is largely planktonic and more pro-inflammatory. Increasing cell surface MbpA rescues these traits. MbpA-like adhesins are common in human-associated bacteria, and the expression of an Akkermansia muciniphila MbpA-like adhesin in MbpA-deficient Aer01 restores lumenal aggregation and reverses its pro-inflammatory character. Our work demonstrates how resident bacteria use mucin glycans to modulate behaviors congruent with host health.
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Affiliation(s)
- T Jarrod Smith
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Deepika Sundarraman
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, OR, USA
| | - Ellie Melancon
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | - Laura Desban
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | - Raghuveer Parthasarathy
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, OR, USA
| | - Karen Guillemin
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA; Institute of Neuroscience, University of Oregon, Eugene, OR, USA; Humans and the Microbiome Program, Canadian Institute for Advanced Research, Toronto, ON, Canada.
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11
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Wang T, Shen P, He Y, Zhang Y, Liu J. Spatial transcriptome uncovers rich coordination of metabolism in E. coli K12 biofilm. Nat Chem Biol 2023:10.1038/s41589-023-01282-w. [PMID: 37055614 DOI: 10.1038/s41589-023-01282-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 02/02/2023] [Indexed: 04/15/2023]
Abstract
Microbial communities often display region-specific properties, which give rise to complex interactions and emergent behaviors that are critical to the homeostasis and stress response of the communities. However, systems-level understanding of these properties still remains elusive. In this study, we established RAINBOW-seq and profiled the transcriptome of Escherichia coli biofilm communities with high spatial resolution and high gene coverage. We uncovered three modes of community-level coordination, including cross-regional resource allocation, local cycling and feedback signaling, which were mediated by strengthened transmembrane transport and spatially specific activation of metabolism. As a consequence of such coordination, the nutrient-limited region of the community maintained an unexpectedly high level of metabolism, enabling it to express many signaling genes and functionally unknown genes with potential sociality functions. Our work provides an extended understanding of the metabolic interplay in biofilms and presents a new approach of investigating complex interactions in bacterial communities on the systems level.
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Affiliation(s)
- Tianmin Wang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Ping Shen
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Yihui He
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Yuzhen Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Jintao Liu
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China.
- Tsinghua-Peking Center for Life Sciences, Beijing, China.
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12
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Scarinci G, Sourjik V. Impact of direct physical association and motility on fitness of a synthetic interkingdom microbial community. THE ISME JOURNAL 2023; 17:371-381. [PMID: 36566339 PMCID: PMC9938286 DOI: 10.1038/s41396-022-01352-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022]
Abstract
Mutualistic exchange of metabolites can play an important role in microbial communities. Under natural environmental conditions, such exchange may be compromised by the dispersal of metabolites and by the presence of non-cooperating microorganisms. Spatial proximity between members during sessile growth on solid surfaces has been shown to promote stabilization of cross-feeding communities against these challenges. Nonetheless, many natural cross-feeding communities are not sessile but rather pelagic and exist in turbulent aquatic environments, where partner proximity is often achieved via direct cell-cell adhesion, and cooperation occurs between physically associated cells. Partner association in aquatic environments could be further enhanced by motility of individual planktonic microorganisms. In this work, we establish a model bipartite cross-feeding community between bacteria and yeast auxotrophs to investigate the impact of direct adhesion between prokaryotic and eukaryotic partners and of bacterial motility in a stirred mutualistic co-culture. We demonstrate that adhesion can provide fitness benefit to the bacterial partner, likely by enabling local metabolite exchange within co-aggregates, and that it counteracts invasion of the community by a non-cooperating cheater strain. In a turbulent environment and at low cell densities, fitness of the bacterial partner and its competitiveness against a non-cooperating strain are further increased by motility that likely facilitates partner encounters and adhesion. These results suggest that, despite their potential fitness costs, direct adhesion between partners and its enhancement by motility may play key roles as stabilization factors for metabolic communities in turbulent aquatic environments.
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Affiliation(s)
- Giovanni Scarinci
- grid.419554.80000 0004 0491 8361Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany.
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13
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Wisnoski NI, Lennon JT. Scaling up and down: movement ecology for microorganisms. Trends Microbiol 2023; 31:242-253. [PMID: 36280521 DOI: 10.1016/j.tim.2022.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022]
Abstract
Movement is critical for the fitness of organisms, both large and small. It dictates how individuals acquire resources, evade predators, exchange genetic material, and respond to stressful environments. Movement also influences ecological and evolutionary dynamics at higher organizational levels, such as populations and communities. However, the links between individual motility and the processes that generate and maintain microbial diversity are poorly understood. Movement ecology is a framework linking the physiological and behavioral properties of individuals to movement patterns across scales of space, time, and biological organization. By synthesizing insights from cell biology, ecology, and evolution, we expand theory from movement ecology to predict the causes and consequences of microbial movements.
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Affiliation(s)
- Nathan I Wisnoski
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, WY 82071, USA; Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
| | - Jay T Lennon
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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Abstract
During colonization of the Hawaiian bobtail squid (Euprymna scolopes), Vibrio fischeri bacteria undergo a lifestyle transition from a planktonic motile state in the environment to a biofilm state in host mucus. Cyclic diguanylate (c-di-GMP) is a cytoplasmic signaling molecule that is important for regulating motility-biofilm transitions in many bacterial species. V. fischeri encodes 50 proteins predicted to synthesize and/or degrade c-di-GMP, but a role for c-di-GMP regulation during host colonization has not been investigated. We examined strains exhibiting either low or high levels of c-di-GMP during squid colonization and found that while a low-c-di-GMP strain had no colonization defect, a high c-di-GMP strain was severely impaired. Expression of a heterologous c-di-GMP phosphodiesterase restored colonization, demonstrating that the effect is due to high c-di-GMP levels. In the constitutive high-c-di-GMP state, colonizing V. fischeri exhibited reduced motility, altered biofilm aggregate morphology, and a regulatory interaction where transcription of one polysaccharide locus is inhibited by the presence of the other polysaccharide. Our results highlight the importance of proper c-di-GMP regulation during beneficial animal colonization, illustrate multiple pathways regulated by c-di-GMP in the host, and uncover an interplay of multiple exopolysaccharide systems in host-associated aggregates.
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15
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Zhong X, Li J, Lu F, Zhang J, Guo L. Application of zebrafish in the study of the gut microbiome. Animal Model Exp Med 2022; 5:323-336. [PMID: 35415967 PMCID: PMC9434591 DOI: 10.1002/ame2.12227] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/15/2022] [Accepted: 03/24/2022] [Indexed: 12/18/2022] Open
Abstract
Zebrafish (Danio rerio) have attracted much attention over the past decade as a reliable model for gut microbiome research. Owing to their low cost, strong genetic and development coherence, efficient preparation of germ-free (GF) larvae, availability in high-throughput chemical screening, and fitness for intravital imaging in vivo, zebrafish have been extensively used to investigate microbiome-host interactions and evaluate the toxicity of environmental pollutants. In this review, the advantages and disadvantages of zebrafish for studying the role of the gut microbiome compared with warm-blooded animal models are first summarized. Then, the roles of zebrafish gut microbiome on host development, metabolic pathways, gut-brain axis, and immune disorders and responses are addressed. Furthermore, their applications for the toxicological assessment of aquatic environmental pollutants and exploration of the molecular mechanism of pathogen infections are reviewed. We highlight the great potential of the zebrafish model for developing probiotics for xenobiotic detoxification, resistance against bacterial infection, and disease prevention and cure. Overall, the zebrafish model promises a brighter future for gut microbiome research.
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Affiliation(s)
- Xiaoting Zhong
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China.,Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease, Guangdong Medical University, Zhanjiang, China
| | - Jinglin Li
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Furong Lu
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Jingjing Zhang
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease, Guangdong Medical University, Zhanjiang, China.,The Marine Biomedical Research Institute of Guangdong Zhanjiang, Zhanjiang, China
| | - Lianxian Guo
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, China.,Dongguan Innovation Institute, Guangdong Medical University, Dongguan, China
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16
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Akahoshi DT, Bevins CL. Flagella at the Host-Microbe Interface: Key Functions Intersect With Redundant Responses. Front Immunol 2022; 13:828758. [PMID: 35401545 PMCID: PMC8987104 DOI: 10.3389/fimmu.2022.828758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/21/2022] [Indexed: 12/15/2022] Open
Abstract
Many bacteria and other microbes achieve locomotion via flagella, which are organelles that function as a swimming motor. Depending on the environment, flagellar motility can serve a variety of beneficial functions and confer a fitness advantage. For example, within a mammalian host, flagellar motility can provide bacteria the ability to resist clearance by flow, facilitate access to host epithelial cells, and enable travel to nutrient niches. From the host’s perspective, the mobility that flagella impart to bacteria can be associated with harmful activities that can disrupt homeostasis, such as invasion of epithelial cells, translocation across epithelial barriers, and biofilm formation, which ultimately can decrease a host’s reproductive fitness from a perspective of natural selection. Thus, over an evolutionary timescale, the host developed a repertoire of innate and adaptive immune countermeasures that target and mitigate this microbial threat. These countermeasures are wide-ranging and include structural components of the mucosa that maintain spatial segregation of bacteria from the epithelium, mechanisms of molecular recognition and inducible responses to flagellin, and secreted effector molecules of the innate and adaptive immune systems that directly inhibit flagellar motility. While much of our understanding of the dynamics of host-microbe interaction regarding flagella is derived from studies of enteric bacterial pathogens where flagella are a recognized virulence factor, newer studies have delved into host interaction with flagellated members of the commensal microbiota during homeostasis. Even though many aspects of flagellar motility may seem innocuous, the host’s redundant efforts to stop bacteria in their tracks highlights the importance of this host-microbe interaction.
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17
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Abstract
Cyclic diguanylate (c-di-GMP) signal transduction systems provide bacteria with the ability to sense changing cell status or environmental conditions and then execute suitable physiological and social behaviors in response. In this review, we provide a comprehensive census of the stimuli and receptors that are linked to the modulation of intracellular c-di-GMP. Emerging evidence indicates that c-di-GMP networks sense light, surfaces, energy, redox potential, respiratory electron acceptors, temperature, and structurally diverse biotic and abiotic chemicals. Bioinformatic analysis of sensory domains in diguanylate cyclases and c-di-GMP-specific phosphodiesterases as well as the receptor complexes associated with them reveals that these functions are linked to a diverse repertoire of protein domain families. We describe the principles of stimulus perception learned from studying these modular sensory devices, illustrate how they are assembled in varied combinations with output domains, and summarize a system for classifying these sensor proteins based on their complexity. Biological information processing via c-di-GMP signal transduction not only is fundamental to bacterial survival in dynamic environments but also is being used to engineer gene expression circuitry and synthetic proteins with à la carte biochemical functionalities.
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Colin R, Sourjik V. Running after your host: Stimulation of bacterial motility promotes colonization. Cell Host Microbe 2021; 29:1211-1213. [PMID: 34384522 DOI: 10.1016/j.chom.2021.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In this issue of Cell Host and Microbe, Robinson et al. (2021) make elegant use of experimental evolution to demonstrate that increased motility promotes migration toward and colonization of zebrafish larvae by a commensal bacterium. Stimulation of motility depends on bacterial second messenger and on signals released by resident host microbiota.
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Affiliation(s)
- Remy Colin
- Max Planck Institute for Terrestrial Microbiology, Marburg, D-35043, Germany; Center for Synthetic Microbiology (SYNMIKRO), Marburg, D-35043, Germany
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology, Marburg, D-35043, Germany; Center for Synthetic Microbiology (SYNMIKRO), Marburg, D-35043, Germany.
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19
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York A. Sensing when to colonize. Nat Rev Microbiol 2021; 19:550. [PMID: 34272519 DOI: 10.1038/s41579-021-00609-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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