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McCaughey C, Trebino MA, McAtamney A, Isenberg RY, Mandel MJ, Yildiz FH, Sanchez LM. A Label-Free Approach for Relative Spatial Quantitation of c-di-GMP in Microbial Biofilms. Anal Chem 2024; 96:8308-8316. [PMID: 38752543 PMCID: PMC11140670 DOI: 10.1021/acs.analchem.3c04687] [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: 10/17/2023] [Revised: 04/27/2024] [Accepted: 05/07/2024] [Indexed: 05/19/2024]
Abstract
Microbial biofilms represent an important lifestyle for bacteria and are dynamic three-dimensional structures. Cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous signaling molecule that is known to be tightly regulated with biofilm processes. While measurements of global levels of c-di-GMP have proven valuable toward understanding the genetic control of c-di-GMP production, there is a need for tools to observe the local changes of c-di-GMP production in biofilm processes. We have developed a label-free method for the direct detection of c-di-GMP in microbial colony biofilms using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). We applied this method to the enteric pathogen Vibrio cholerae, the marine symbiont V. fischeri, and the opportunistic pathogen Pseudomonas aeruginosa PA14 and detected spatial and temporal changes in c-di-GMP signal that accompanied genetic alterations in factors that synthesize and degrade the compound. We further demonstrated how this method can be simultaneously applied to detect additional metabolites of interest from a single sample.
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Affiliation(s)
- Catherine
S. McCaughey
- Department
of Chemistry and Biochemistry, University
of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Michael A. Trebino
- Department
of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Allyson McAtamney
- Department
of Chemistry and Biochemistry, University
of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Ruth Y. Isenberg
- Department
of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Microbiology
Doctoral Training Program, University of
Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Mark J. Mandel
- Department
of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Microbiology
Doctoral Training Program, University of
Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Fitnat H. Yildiz
- Department
of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Laura M. Sanchez
- Department
of Chemistry and Biochemistry, University
of California, Santa Cruz, Santa Cruz, California 95064, United States
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2
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Fung BL, Esin JJ, Visick KL. Vibrio fischeri: a model for host-associated biofilm formation. J Bacteriol 2024; 206:e0037023. [PMID: 38270381 PMCID: PMC10882983 DOI: 10.1128/jb.00370-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
Multicellular communities of adherent bacteria known as biofilms are often detrimental in the context of a human host, making it important to study their formation and dispersal, especially in animal models. One such model is the symbiosis between the squid Euprymna scolopes and the bacterium Vibrio fischeri. Juvenile squid hatch aposymbiotically and selectively acquire their symbiont from natural seawater containing diverse environmental microbes. Successful pairing is facilitated by ciliary movements that direct bacteria to quiet zones on the surface of the squid's symbiotic light organ where V. fischeri forms a small aggregate or biofilm. Subsequently, the bacteria disperse from that aggregate to enter the organ, ultimately reaching and colonizing deep crypt spaces. Although transient, aggregate formation is critical for optimal colonization and is tightly controlled. In vitro studies have identified a variety of polysaccharides and proteins that comprise the extracellular matrix. Some of the most well-characterized matrix factors include the symbiosis polysaccharide (SYP), cellulose polysaccharide, and LapV adhesin. In this review, we discuss these components, their regulation, and other less understood V. fischeri biofilm contributors. We also highlight what is currently known about dispersal from these aggregates and host cues that may promote it. Finally, we briefly describe discoveries gleaned from the study of other V. fischeri isolates. By unraveling the complexities involved in V. fischeri's control over matrix components, we may begin to understand how the host environment triggers transient biofilm formation and dispersal to promote this unique symbiotic relationship.
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Affiliation(s)
- Brittany L. Fung
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Jeremy J. Esin
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Karen L. Visick
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
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3
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Vander Griend JA, Isenberg RY, Kotla KR, Mandel MJ. Transcriptional pathways across colony biofilm models in the symbiont Vibrio fischeri. mSystems 2024; 9:e0081523. [PMID: 38126773 PMCID: PMC10804989 DOI: 10.1128/msystems.00815-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023] Open
Abstract
Beneficial microbial symbionts that are horizontally acquired by their animal hosts undergo a lifestyle transition from free-living in the environment to associating with host tissues. In the model symbiosis between the Hawaiian bobtail squid and its microbial symbiont Vibrio fischeri, one mechanism used to make this transition during host colonization is the formation of biofilm-like aggregates in host mucosa. Previous work identified factors that are sufficient to induce V. fischeri biofilm formation, yet much remains unknown regarding the breadth of target genes induced by these factors. Here, we probed two widely used in vitro models of biofilm formation to identify novel regulatory pathways in the squid symbiont V. fischeri ES114. We discovered a shared set of 232 genes that demonstrated similar patterns in expression in both models. These genes comprise multiple exopolysaccharide loci that are upregulated and flagellar motility genes that are downregulated, with a consistent decrease in measured swimming motility. Furthermore, we identified genes regulated downstream of the key sensor kinase RscS that are induced independent of the response regulator SypG. Our data suggest that transcriptional regulator VpsR plays a strong role in expression of at least a subset of these genes. Overall, this study adds to our understanding of the genes involved in V. fischeri biofilm regulation while revealing new regulatory pathways branching from previously characterized signaling networks.IMPORTANCEThe V. fischeri-squid system provides an opportunity to study biofilm development both in the animal host and in culture-based biofilm models that capture key aspects of in vivo signaling. In this work, we report the results of the transcriptomic profiling of two V. fischeri biofilm models followed by phenotypic validation and examination of novel signaling pathway architecture. Remarkable consistency between the models provides a strong basis for future studies using either approach or both. A subset of the factors identified by the approaches were validated in the work, and the body of transcriptomic data provides a number of leads for future studies in culture and during animal colonization.
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Affiliation(s)
- Jacob A. Vander Griend
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ruth Y. Isenberg
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ketan R. Kotla
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mark J. Mandel
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
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4
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Morot A, Delavat F, Bazire A, Paillard C, Dufour A, Rodrigues S. Genetic Insights into Biofilm Formation by a Pathogenic Strain of Vibrio harveyi. Microorganisms 2024; 12:186. [PMID: 38258011 PMCID: PMC10820411 DOI: 10.3390/microorganisms12010186] [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: 11/24/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
The Vibrio genus includes bacteria widely distributed in aquatic habitats and the infections caused by these bacteria can affect a wide range of hosts. They are able to adhere to numerous surfaces, which can result in biofilm formation that helps maintain them in the environment. The involvement of the biofilm lifestyle in the virulence of Vibrio pathogens of aquatic organisms remains to be investigated. Vibrio harveyi ORM4 is a pathogen responsible for an outbreak in European abalone Haliotis tuberculata populations. In the present study, we used a dynamic biofilm culture technique coupled with laser scanning microscopy to characterize the biofilm formed by V. harveyi ORM4. We furthermore used RNA-seq analysis to examine the global changes in gene expression in biofilm cells compared to planktonic bacteria, and to identify biofilm- and virulence-related genes showing altered expression. A total of 1565 genes were differentially expressed, including genes associated with motility, polysaccharide synthesis, and quorum sensing. The up-regulation of 18 genes associated with the synthesis of the type III secretion system suggests that this virulence factor is induced in V. harveyi ORM4 biofilms, providing indirect evidence of a relationship between biofilm and virulence.
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Affiliation(s)
- Amandine Morot
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France
| | | | - Alexis Bazire
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
| | | | - Alain Dufour
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
| | - Sophie Rodrigues
- Laboratoire de Biotechnologie et Chimie Marines, Université Bretagne Sud, EMR CNRS 6076, IUEM, 56100 Lorient, France
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5
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Donnelly AR, Giacobe EJ, Cook RA, Francis GM, Buddle GK, Beaubrun CL, Cecere AG, Miyashiro TI. Quantification of the capacity of vibrio fischeri to establish symbiosis with Euprymna scolopes. PLoS One 2023; 18:e0287519. [PMID: 37440554 PMCID: PMC10343157 DOI: 10.1371/journal.pone.0287519] [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: 03/21/2023] [Accepted: 06/01/2023] [Indexed: 07/15/2023] Open
Abstract
Most animals establish long-term symbiotic associations with bacteria that are critical for normal host physiology. The symbiosis that forms between the Hawaiian squid Euprymna scolopes and the bioluminescent bacterium Vibrio fischeri serves as an important model system for investigating the molecular mechanisms that promote animal-bacterial symbioses. E. scolopes hatch from their eggs uncolonized, which has led to the development of squid-colonization assays that are based on introducing culture-grown V. fischeri cells to freshly hatched juvenile squid. Recent studies have revealed that strains often exhibit large differences in how they establish symbiosis. Therefore, we sought to develop a simplified and reproducible protocol that permits researchers to determine appropriate inoculum levels and provides a platform to standardize the assay across different laboratories. In our protocol, we adapt a method commonly used for evaluating the infectivity of pathogens to quantify the symbiotic capacity of V. fischeri strains. The resulting metric, the symbiotic dose-50 (SD50), estimates the inoculum level that is necessary for a specific V. fischeri strain to establish a light-emitting symbiosis. Relative to other protocols, our method requires 2-5-fold fewer animals. Furthermore, the power analysis presented here suggests that the protocol can detect up to a 3-fold change in the SD50 between different strains.
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Affiliation(s)
- Aidan R. Donnelly
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Elizabeth J. Giacobe
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Rachel A. Cook
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Gareth M. Francis
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Grace K. Buddle
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Christina L. Beaubrun
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Andrew G. Cecere
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Tim I. Miyashiro
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
- The One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States of America
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6
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Surrett ED, Guckes KR, Cousins S, Ruskoski TB, Cecere AG, Ludvik DA, Okafor CD, Mandel MJ, Miyashiro TI. Two enhancer binding proteins activate σ 54-dependent transcription of a quorum regulatory RNA in a bacterial symbiont. eLife 2023; 12:e78544. [PMID: 37145113 PMCID: PMC10162802 DOI: 10.7554/elife.78544] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/20/2023] [Indexed: 05/06/2023] Open
Abstract
To colonize a host, bacteria depend on an ensemble of signaling systems to convert information about the various environments encountered within the host into specific cellular activities. How these signaling systems coordinate transitions between cellular states in vivo remains poorly understood. To address this knowledge gap, we investigated how the bacterial symbiont Vibrio fischeri initially colonizes the light organ of the Hawaiian bobtail squid Euprymna scolopes. Previous work has shown that the small RNA Qrr1, which is a regulatory component of the quorum-sensing system in V. fischeri, promotes host colonization. Here, we report that transcriptional activation of Qrr1 is inhibited by the sensor kinase BinK, which suppresses cellular aggregation by V. fischeri prior to light organ entry. We show that Qrr1 expression depends on the alternative sigma factor σ54 and the transcription factors LuxO and SypG, which function similar to an OR logic gate, thereby ensuring Qrr1 is expressed during colonization. Finally, we provide evidence that this regulatory mechanism is widespread throughout the Vibrionaceae family. Together, our work reveals how coordination between the signaling pathways underlying aggregation and quorum-sensing promotes host colonization, which provides insight into how integration among signaling systems facilitates complex processes in bacteria.
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Affiliation(s)
- Ericka D Surrett
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Kirsten R Guckes
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Shyan Cousins
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Terry B Ruskoski
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Andrew G Cecere
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Denise A Ludvik
- Department of Medical Microbiology and Immunology, University of Wisconsin-MadisonMadisonUnited States
| | - C Denise Okafor
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
- Department of Chemistry, Pennsylvania State UniversityUniversity ParkUnited States
| | - Mark J Mandel
- Department of Medical Microbiology and Immunology, University of Wisconsin-MadisonMadisonUnited States
| | - Tim I Miyashiro
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
- The Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State UniversityUniversity ParkUnited States
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7
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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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