scholarly journals Identification of signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

2020 ◽  
Author(s):  
Andrew A. Bridges ◽  
Chenyi Fei ◽  
Bonnie L. Bassler
Keyword(s):  
Signal Transduction ◽  
Vibrio Cholerae ◽  
Disease Transmission ◽  
Biofilm Formation ◽  
Cell Attachment ◽  
Sensory System ◽  
Matrix Degradation ◽  
Free Swimming ◽  
Molecular Events ◽  
Biofilm Dispersal

AbstractBacteria alternate between being free-swimming and existing as members of sessile multicellular communities called biofilms. The biofilm lifecycle occurs in three stages: cell attachment, biofilm maturation, and biofilm dispersal. Vibrio cholerae biofilms are hyper-infectious and biofilm formation and dispersal are considered central to disease transmission. While biofilm formation is well-studied, almost nothing is known about biofilm dispersal. Here, we conduct an imaging screen for V. cholerae mutants that fail to disperse, revealing three classes of dispersal components: signal transduction proteins, matrix-degradation enzymes, and motility factors. Signaling proteins dominated the screen and among them, we focused on an uncharacterized two-component sensory system that we name DbfS/DbfR for Dispersal of Biofilm Sensor/Regulator. Phospho-DbfR represses biofilm dispersal. DbfS dephosphorylates and thereby inactivates DbfR, which permits dispersal. Matrix degradation requires two enzymes: LapG, which cleaves adhesins, and RbmB, which digests matrix polysaccharide. Reorientations in swimming direction, mediated by CheY3, are necessary for cells to escape from the porous biofilm matrix. We suggest that these components act sequentially: signaling launches dispersal by terminating matrix production and triggering matrix digestion and, subsequently, cell motility permits escape from biofilms. This study lays the groundwork for interventions that modulate V. cholerae biofilm dispersal to ameliorate disease.Significance statementThe pathogen Vibrio cholerae alternates between the free-swimming state and existing in sessile multicellular communities known as biofilms. Transitioning between these lifestyles is key for disease transmission. V. cholerae biofilm formation is well studied, however, almost nothing is known about how V. cholerae cells disperse from biofilms, precluding understanding of a central pathogenicity step. Here, we conducted a high-content imaging screen for V. cholerae mutants that failed to disperse. Our screen revealed three classes of components required for dispersal: signal transduction, matrix degradation, and motility factors. We characterized these components to reveal the sequence of molecular events that choreograph V. cholerae biofilm dispersal. Our report provides a framework for developing strategies to modulate biofilm dispersal to prevent or treat disease.

scholarly journals Identification and analysis of the signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal

2020 ◽  
Author(s):  
Andrew Bridges ◽  
Chenyi Fei ◽  
Bonnie Bassler
Keyword(s):  
Vibrio Cholerae ◽  
Disease Transmission ◽  
Biofilm Formation ◽  
Cell Attachment ◽  
Sensory System ◽  
Signaling Proteins ◽  
Matrix Degradation ◽  
Three Stages ◽  
Biofilm Dispersal ◽  
Signal Transduction Proteins

Abstract Bacteria alternate between being free-swimming and existing as members of sessile multicellular communities called biofilms. The biofilm lifecycle occurs in three stages: cell attachment, biofilm maturation, and biofilm dispersal. Vibrio cholerae biofilms are hyper-infectious and biofilm formation and dispersal are considered central to disease transmission. While biofilm formation is well-studied, almost nothing is known about biofilm dispersal. Here, we conduct an imaging screen for V. cholerae mutants that fail to disperse, revealing three classes of dispersal components: signal transduction proteins, matrix-degradation enzymes, and motility factors. Signaling proteins dominated the screen and among them, we focused on an uncharacterized two-component sensory system that we name DbfS/DbfR for Dispersal of Biofilm Sensor/Regulator. Phospho-DbfR represses biofilm dispersal. DbfS dephosphorylates and thereby inactivates DbfR, which permits dispersal. Matrix degradation requires two enzymes: LapG, which cleaves adhesins, and RbmB, which digests matrix polysaccharide. Reorientations in swimming direction, mediated by CheY3, are necessary for cells to escape from the porous biofilm matrix. We suggest that these components act sequentially: signaling launches dispersal by terminating matrix production and triggering matrix digestion and, subsequently, cell motility permits escape from biofilms. This study lays the groundwork for interventions that modulate V. cholerae biofilm dispersal to ameliorate disease.

scholarly journals Identification of signaling pathways, matrix-digestion enzymes, and motility components controllingVibrio choleraebiofilm dispersal

2020 ◽  
Vol 117 (51) ◽  
pp. 32639-32647
Author(s):  
Andrew A. Bridges ◽  
Chenyi Fei ◽  
Bonnie L. Bassler
Keyword(s):  
Disease Transmission ◽  
Biofilm Formation ◽  
Cell Attachment ◽  
Sensory System ◽  
Signaling Proteins ◽  
Matrix Degradation ◽  
Three Stages ◽  
Matrix Production ◽  
Biofilm Dispersal ◽  
Signal Transduction Proteins

Bacteria alternate between being free-swimming and existing as members of sessile multicellular communities called biofilms. The biofilm lifecycle occurs in three stages: cell attachment, biofilm maturation, and biofilm dispersal.Vibrio choleraebiofilms are hyperinfectious, and biofilm formation and dispersal are considered central to disease transmission. While biofilm formation is well studied, almost nothing is known about biofilm dispersal. Here, we conducted an imaging screen forV. choleraemutants that fail to disperse, revealing three classes of dispersal components: signal transduction proteins, matrix-degradation enzymes, and motility factors. Signaling proteins dominated the screen and among them, we focused on an uncharacterized two-component sensory system that we term DbfS/DbfR for dispersal of biofilm sensor/regulator. Phospho-DbfR represses biofilm dispersal. DbfS dephosphorylates and thereby inactivates DbfR, which permits dispersal. Matrix degradation requires two enzymes: LapG, which cleaves adhesins, and RbmB, which digests matrix polysaccharides. Reorientation in swimming direction, mediated by CheY3, is necessary for cells to escape from the porous biofilm matrix. We suggest that these components act sequentially: signaling launches dispersal by terminating matrix production and triggering matrix digestion, and subsequent cell motility permits escape from biofilms. This study lays the groundwork for interventions aimed at modulatingV. choleraebiofilm dispersal to ameliorate disease.

scholarly journals Toxin-Antitoxin Systems in Escherichia coli Influence Biofilm Formation through YjgK (TabA) and Fimbriae

2008 ◽  
Vol 191 (4) ◽  
pp. 1258-1267 ◽  
Author(s):  
Younghoon Kim ◽  
Xiaoxue Wang ◽  
Qun Ma ◽  
Xue-Song Zhang ◽  
Thomas K. Wood
Keyword(s):  
Biofilm Formation ◽  
Cell Attachment ◽  
Single Gene ◽  
Transcriptome Profiling ◽  
Uncharacterized Protein ◽  
Qrt Pcr ◽  
Biofilm Dispersal ◽  
Biofilm Development ◽  
Whole Transcriptome

ABSTRACT The roles of toxin-antitoxin (TA) systems in bacteria have been debated. Here, the role of five TA systems in regard to biofilm development was investigated (listed as toxin/antitoxin: MazF/MazE, RelE/RelB, ChpB, YoeB/YefM, and YafQ/DinJ). Although these multiple TA systems were reported previously to not impact bacterial fitness, we found that deletion of the five TA systems decreased biofilm formation initially (8 h) on three different surfaces and then increased biofilm formation (24 h) by decreasing biofilm dispersal. Whole-transcriptome profiling revealed that the deletion of the five TA systems induced expression of a single gene, yjgK, which encodes an uncharacterized protein; quantitative real-time PCR (qRT-PCR) confirmed consistent induction of this gene (at 8, 15, and 24 h). Corroborating the complex phenotype seen upon deleting the TA systems, overexpression of YjgK decreased biofilm formation at 8 h and increased biofilm formation at 24 h; deletion of yjgK also affected biofilm formation in the expected manner by increasing biofilm formation after 8 h and decreasing biofilm formation after 24 h. In addition, YjgK significantly reduced biofilm dispersal. Whole-transcriptome profiling revealed YjgK represses fimbria genes at 8 h (corroborated by qRT-PCR and a yeast agglutination assay), which agrees with the decrease in biofilm formation upon deleting the five TA systems at 8 h, as well as that seen upon overexpressing YjgK. Sand column assays confirmed that deleting the five TA systems reduced cell attachment. Furthermore, deletion of each of the five toxins increased biofilm formation at 8 h, and overexpression of the five toxins repressed biofilm formation at 8 h, a result that is opposite that of deleting all five TA systems; this suggests that complex regulation occurs involving the antitoxins. Also, the ability of the global regulator Hha to reduce biofilm formation was dependent on the presence of these TA systems. Hence, we suggest that one role of TA systems is to influence biofilm formation.

scholarly journals The Two-Component Signal Transduction System VxrAB Positively Regulates Vibrio cholerae Biofilm Formation

2017 ◽  
Vol 199 (18) ◽  
Author(s):  
Jennifer K. Teschler ◽  
Andrew T. Cheng ◽  
Fitnat H. Yildiz
Keyword(s):  
Signal Transduction ◽  
Vibrio Cholerae ◽  
Histidine Kinase ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Response Regulator ◽  
Systematic Analysis ◽  
Content Type ◽  
Two Component ◽  
Two Component Signal Transduction

ABSTRACT Two-component signal transduction systems (TCSs), typically composed of a sensor histidine kinase (HK) and a response regulator (RR), are the primary mechanism by which pathogenic bacteria sense and respond to extracellular signals. The pathogenic bacterium Vibrio cholerae is no exception and harbors 52 RR genes. Using in-frame deletion mutants of each RR gene, we performed a systematic analysis of their role in V. cholerae biofilm formation. We determined that 7 RRs impacted the expression of an essential biofilm gene and found that the recently characterized RR, VxrB, regulates the expression of key structural and regulatory biofilm genes in V. cholerae. vxrB is part of a 5-gene operon, which contains the cognate HK vxrA and three genes of unknown function. Strains carrying ΔvxrA and ΔvxrB mutations are deficient in biofilm formation, while the ΔvxrC mutation enhances biofilm formation. The overexpression of VxrB led to a decrease in motility. We also observed a small but reproducible effect of the absence of VxrB on the levels of cyclic di-GMP (c-di-GMP). Our work reveals a new function for the Vxr TCS as a regulator of biofilm formation and suggests that this regulation may act through key biofilm regulators and the modulation of cellular c-di-GMP levels. IMPORTANCE Biofilms play an important role in the Vibrio cholerae life cycle, providing protection from environmental stresses and contributing to the transmission of V. cholerae to the human host. V. cholerae can utilize two-component systems (TCS), composed of a histidine kinase (HK) and a response regulator (RR), to regulate biofilm formation in response to external cues. We performed a systematic analysis of V. cholerae RRs and identified a new regulator of biofilm formation, VxrB. We demonstrated that the VxrAB TCS is essential for robust biofilm formation and that this system may regulate biofilm formation via its regulation of key biofilm regulators and cyclic di-GMP levels. This research furthers our understanding of the role that TCSs play in the regulation of V. cholerae biofilm formation.

scholarly journals A Conserved Regulatory Circuit Controls Large Adhesins in Vibrio cholerae

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Giordan Kitts ◽  
Krista M. Giglio ◽  
David Zamorano-Sánchez ◽  
Jin Hwan Park ◽  
Loni Townsley ◽  
...  
Keyword(s):  
Cell Surface ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Diarrheal Disease ◽  
Cell Attachment ◽  
Surface Display ◽  
Second Messenger ◽  
Bacterial Biofilm ◽  
Content Type ◽  
Regulatory Circuit

ABSTRACT The dinucleotide second messenger c-di-GMP has emerged as a central regulator of reversible cell attachment during bacterial biofilm formation. A prominent cell adhesion mechanism first identified in pseudomonads combines two c-di-GMP-mediated processes: transcription of a large adhesin and its cell surface display via posttranslational proteolytic control. Here, we characterize an orthologous c-di-GMP effector system and show that it is operational in Vibrio cholerae, where it regulates two distinct classes of adhesins. Through structural analyses, we reveal a conserved autoinhibition mechanism of the c-di-GMP receptor that controls adhesin proteolysis and present a structure of a c-di-GMP-bound receptor module. We further establish functionality of the periplasmic protease controlled by the receptor against the two adhesins. Finally, transcription and functional assays identify physiological roles of both c-di-GMP-regulated adhesins in surface attachment and biofilm formation. Together, our studies highlight the conservation of a highly efficient signaling effector circuit for the control of cell surface adhesin expression and its versatility by revealing strain-specific variations. IMPORTANCE Vibrio cholerae, the causative agent of the diarrheal disease cholera, benefits from a sessile biofilm lifestyle that enhances survival outside the host but also contributes to host colonization and infectivity. The bacterial second messenger c-di-GMP has been identified as a central regulator of biofilm formation, including in V. cholerae; however, our understanding of the pathways that contribute to this process is incomplete. Here, we define a conserved signaling system that controls the stability of large adhesion proteins at the cell surface of V. cholerae, which are important for cell attachment and biofilm formation. Insight into the regulatory circuit underlying biofilm formation may inform targeted strategies to interfere with a process that renders this bacterium remarkably adaptable to changing environments.

scholarly journals A mutagenic screen reveals NspS residues important for regulation of Vibrio cholerae biofilm formation

Microbiology ◽  
2021 ◽  
Author(s):  
Erin C. Young ◽  
Jackson T. Baumgartner ◽  
Ece Karatan ◽  
Misty L. Kuhn
Keyword(s):  
Signal Transduction ◽  
Ligand Binding ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Type Species ◽  
Binding Proteins ◽  
Signal Transduction Pathway ◽  
Signalling Pathway ◽  
Content Type ◽  
Link Type

Biofilm formation in the human intestinal pathogen Vibrio cholerae is in part regulated by norspermidine, spermidine and spermine. V. cholerae senses these polyamines through a signalling pathway consisting of the periplasmic protein, NspS, and the integral membrane c-di-GMP phosphodiesterase MbaA. NspS and MbaA belong to a proposed class of novel signalling systems composed of periplasmic ligand-binding proteins and membrane-bound c-di-GMP phosphodiesterases containing both GGDEF and EAL domains. In this signal transduction pathway, NspS is hypothesized to interact with MbaA in the periplasm to regulate its phosphodiesterase activity. Polyamine binding to NspS likely alters this interaction, leading to the activation or inhibition of biofilm formation depending on the polyamine. The purpose of this study was to determine the amino acids important for NspS function. We performed random mutagenesis of the nspS gene, identified mutant clones deficient in biofilm formation, determined their responsiveness to norspermidine and mapped the location of these residues onto NspS homology models. Single mutants clustered on two lobes of the NspS model, but the majority were found on a single lobe that appeared to be more mobile upon norspermidine binding. We also identified residues in the putative ligand-binding site that may be important for norspermidine binding and interactions with MbaA. Ultimately, our results provide new insights into this novel signalling pathway in V. cholerae and highlight differences between periplasmic binding proteins involved in transport versus signal transduction.

scholarly journals Inverse regulation of Vibrio cholerae biofilm dispersal by polyamine signals

2020 ◽  
Author(s):  
Andrew A. Bridges ◽  
Bonnie L. Bassler
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Self And Other ◽  
Human Host ◽  
Signal Relay ◽  
Biofilm Dispersal ◽  
Methylene Group

AbstractThe global pathogen Vibrio cholerae undergoes cycles of biofilm formation and dispersal in the environment and the human host. Little is understood about biofilm dispersal. Here, we show that MbaA, a periplasmic polyamine sensor, and PotD1, a polyamine importer, regulate V. cholerae biofilm dispersal. Spermidine, a commonly produced polyamine, drives V. cholerae dispersal, whereas norspermidine, an uncommon polyamine produced by vibrios, inhibits dispersal. Spermidine and norspermidine differ by one methylene group. Both polyamines function to control dispersal via periplasmic detection by MbaA and subsequent signal relay. Biofilm dispersal fails in the absence of PotD1 because reuptake of endogenously produced norspermidine does not occur, so it accumulates in the periplasm where it stimulates MbaA. These results suggest that V. cholerae uses MbaA to monitor environmental polyamines, blends of which potentially provide information about numbers of ‘self’ and ‘other’. This information is used to dictate whether or not to disperse from biofilms.

scholarly journals Inverse regulation of Vibrio cholerae biofilm dispersal by polyamine signals

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Andrew A Bridges ◽  
Bonnie L Bassler
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Self And Other ◽  
Human Host ◽  
Signal Relay ◽  
Biofilm Dispersal ◽  
Methylene Group

The global pathogen Vibrio cholerae undergoes cycles of biofilm formation and dispersal in the environment and the human host. Little is understood about biofilm dispersal. Here, we show that MbaA, a periplasmic polyamine sensor, and PotD1, a polyamine importer, regulate V. cholerae biofilm dispersal. Spermidine, a commonly produced polyamine, drives V. cholerae dispersal, whereas norspermidine, an uncommon polyamine produced by vibrios, inhibits dispersal. Spermidine and norspermidine differ by one methylene group. Both polyamines control dispersal via MbaA detection in the periplasm and subsequent signal relay. Our results suggest that dispersal fails in the absence of PotD1 because endogenously produced norspermidine is not reimported, periplasmic norspermidine accumulates, and it stimulates MbaA signaling. These results suggest that V. cholerae uses MbaA to monitor environmental polyamines, blends of which potentially provide information about numbers of ‘self’ and ‘other’. This information is used to dictate whether or not to disperse from biofilms.

scholarly journals Vibrio cholerae NspS, a homologue of ABC-type periplasmic solute binding proteins, facilitates transduction of polyamine signals independent of their transport

Microbiology ◽  
2014 ◽  
Vol 160 (5) ◽  
pp. 832-843 ◽  
Author(s):  
Steven R. Cockerell ◽  
Alex C. Rutkovsky ◽  
Josiah P. Zayner ◽  
Rebecca E. Cooper ◽  
Lindsay R. Porter ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Comparative Genomics ◽  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Binding Proteins ◽  
Potential Role ◽  
Sensory Transduction ◽  
Environmental Signals ◽  
Almost All ◽  
Current Annotation

The polyamines norspermidine and spermidine are among the environmental signals that regulate Vibrio cholerae biofilm formation. The effects of these polyamines are mediated by NspS, a member of the bacterial periplasmic solute binding protein superfamily. Almost all members of this superfamily characterized to date are components of ATP-binding cassette-type transporters involved in nutrient uptake. Consequently, in the current annotation of the V. cholerae genome, NspS has been assigned a function in transport. The objective of this study was to further characterize NspS and investigate its potential role in transport. Our results support a role for NspS in signal transduction in response to norspermidine and spermidine, but not their transport. In addition, we provide evidence that these polyamine signals are processed by c-di-GMP signalling networks in the cell. Furthermore, we present comparative genomics analyses which reveal the presence of NspS-like proteins in a variety of bacteria, suggesting that periplasmic ligand binding proteins may be widely utilized for sensory transduction.

scholarly journals Optimized quinoline amino alcohols as disruptors and dispersal agents of Vibrio cholerae biofilms

2015 ◽  
Vol 13 (31) ◽  
pp. 8495-8499 ◽  
Author(s):  
Brian León ◽  
F. P. Jake Haeckl ◽  
Roger G. Linington
Keyword(s):  
Vibrio Cholerae ◽  
Amino Alcohol ◽  
Biofilm Formation ◽  
Bacterial Pathogens ◽  
Amino Alcohols ◽  
Human Pathogen ◽  
Biofilm Dispersal ◽  
Dispersal Agents

The biofilm state is an integral part of the lifecycle of many bacterial pathogens, but no treatments currently exist that directly impact biofilm formation or persistence. Here we report the development of a quinoline amino alcohol scaffold with both biofilm inhibitory and biofilm dispersal activities against the human pathogen Vibrio cholerae.

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