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

ABSTRACTThe presence of the Lon protease in all three domains of life hints at its biological importance. The prokaryotic Lon protease is responsible not only for degrading abnormal proteins but also for carrying out the proteolytic regulation of specific protein targets. Posttranslational regulation by Lon is known to affect a variety of physiological traits in many bacteria, including biofilm formation, motility, and virulence. Here, we identify the regulatory roles of LonA in the human pathogenVibrio cholerae. We determined that the absence of LonA adversely affects biofilm formation, increases swimming motility, and influences intracellular levels of cyclic diguanylate. Whole-genome expression analysis revealed that the message abundance of genes involved in biofilm formation was decreased but that the message abundances of those involved in virulence and the type VI secretion system were increased in alonAmutant compared to the wild type. We further demonstrated that alonAmutant displays an increase in type VI secretion system activity and is markedly defective in colonization of the infant mouse. These findings suggest that LonA plays a critical role in the environmental survival and virulence ofV. cholerae.IMPORTANCEBacteria utilize intracellular proteases to degrade damaged proteins and adapt to changing environments. The Lon protease has been shown to be important for environmental adaptation and plays a crucial role in regulating the motility, biofilm formation, and virulence of numerous plant and animal pathogens. We find that LonA of the human pathogenV. choleraeis in line with this trend, as the deletion of LonA leads to hypermotility and defects in both biofilm formation and colonization of the infant mouse. In addition, we show that LonA regulates levels of cyclic diguanylate and the type VI secretion system. Our observations add to the known regulatory repertoire of the Lon protease and the current understanding ofV. choleraephysiology.

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Vibrio cholerae Strains Possess Multiple Strategies for Abiotic and Biotic Surface Colonization

Journal of Bacteriology ◽

10.1128/jb.01867-06 ◽

2007 ◽

Vol 189 (14) ◽

pp. 5348-5360 ◽

Cited By ~ 57

Author(s):

Ryan S. Mueller ◽

Diane McDougald ◽

Danielle Cusumano ◽

Nidhi Sodhi ◽

Staffan Kjelleberg ◽

...

Keyword(s):

Vibrio Cholerae ◽

Biofilm Formation ◽

Acid Metabolism ◽

Selective Advantage ◽

Human Pathogen ◽

Surface Colonization ◽

Multiple Strategies ◽

Lingulodinium Polyedrum ◽

Transposon Mutants

ABSTRACT Despite its notoriety as a human pathogen, Vibrio cholerae is an aquatic microbe suited to live in freshwater, estuarine, and marine environments where biofilm formation may provide a selective advantage. Here we report characterization of biofilms formed on abiotic and biotic surfaces by two non-O1/O139 V. cholerae strains, TP and SIO, and by the O1 V. cholerae strain N16961 in addition to the isolation of 44 transposon mutants of SIO and TP impaired in biofilm formation. During the course of characterizing the mutants, 30 loci which have not previously been associated with V. cholerae biofilms were identified. These loci code for proteins which perform a wide variety of functions, including amino acid metabolism, ion transport, and gene regulation. Also, when the plankton colonization abilities of strains N16961, SIO, and TP were examined, each strain showed increased colonization of dead plankton compared with colonization of live plankton (the dinoflagellate Lingulodinium polyedrum and the copepod Tigriopus californicus). Surprisingly, most of the biofilm mutants were not impaired in plankton colonization. Only mutants impaired in motility or chemotaxis showed reduced colonization. These results indicate the presence of both conserved and variable genes which influence the surface colonization properties of different V. cholerae subspecies.

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

10.21203/rs.3.rs-59007/v1 ◽

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.

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Role for Glycine Betaine Transport in Vibrio cholerae Osmoadaptation and Biofilm Formation within Microbial Communities

Applied and Environmental Microbiology ◽

10.1128/aem.71.7.3840-3847.2005 ◽

2005 ◽

Vol 71 (7) ◽

pp. 3840-3847 ◽

Cited By ~ 45

Author(s):

Dagmar Kapfhammer ◽

Ece Karatan ◽

Kathryn J. Pflughoeft ◽

Paula I. Watnick

Keyword(s):

Microbial Communities ◽

Vibrio Cholerae ◽

Glycine Betaine ◽

Biofilm Formation ◽

Bacterial Species ◽

Compatible Solutes ◽

Compatible Solute ◽

Human Pathogen ◽

Biofilm Development ◽

Solute Transporters

ABSTRACT Vibrio cholerae is a halophilic facultative human pathogen found in marine and estuarine environments. Accumulation of compatible solutes is important for growth of V. cholerae at NaCl concentrations greater than 250 mM. We have identified and characterized two compatible solute transporters, OpuD and PutP, that are involved in uptake of glycine betaine and proline by V. cholerae. V. cholerae does not, however, possess the bet genes, suggesting that it is unable to synthesize glycine betaine. In contrast, many Vibrio species are able to synthesize glycine betaine from choline. It has been shown that many bacteria not only synthesize but also secrete glycine betaine. We hypothesized that sharing of compatible solutes might be a mechanism for cooperativity in microbial communities. In fact, we have demonstrated that, in high-osmolarity medium, V. cholerae growth and biofilm development are enhanced by supplementation with either glycine betaine or spent media from other bacterial species. Thus, we propose that compatible solutes provided by other microorganisms may contribute to survival of V. cholerae in the marine environment through facilitation of osmoadaptation and biofilm development.

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Inverse regulation of Vibrio cholerae biofilm dispersal by polyamine signals

10.1101/2020.12.06.413526 ◽

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.

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

10.1101/2020.10.09.333351 ◽

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.

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Inverse regulation of Vibrio cholerae biofilm dispersal by polyamine signals

eLife ◽

10.7554/elife.65487 ◽

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.

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