scholarly journals Identification of Small Molecules That Antagonize Diguanylate Cyclase Enzymes To Inhibit Biofilm Formation

2012 ◽  
Vol 56 (10) ◽  
pp. 5202-5211 ◽  
Author(s):  
Karthik Sambanthamoorthy ◽  
Rudolph E. Sloup ◽  
Vijay Parashar ◽  
Joshua M. Smith ◽  
Eric E. Kim ◽  
...  
Keyword(s):  
Small Molecules ◽  
Biofilm Formation ◽  
Flow System ◽  
Total Concentration ◽  
Bacterial Biofilm ◽  
Diguanylate Cyclase ◽  
Signaling System ◽  
Chronic Infections ◽  
Content Type ◽  
New Strategies

ABSTRACTBacterial biofilm formation is responsible for numerous chronic infections, causing a severe health burden. Many of these infections cannot be resolved, as bacteria in biofilms are resistant to the host's immune defenses and antibiotic therapy. New strategies to treat biofilm-based infections are critically needed. Cyclic di-GMP (c-di-GMP) is a widely conserved second-messenger signal essential for biofilm formation. As this signaling system is found only in bacteria, it is an attractive target for the development of new antibiofilm interventions. Here, we describe the results of a high-throughput screen to identify small-molecule inhibitors of diguanylate cyclase (DGC) enzymes that synthesize c-di-GMP. We report seven small molecules that antagonize these enzymes and inhibit biofilm formation byVibrio cholerae. Moreover, two of these compounds significantly reduce the total concentration of c-di-GMP inV. cholerae, one of which also inhibits biofilm formation byPseudomonas aeruginosain a continuous-flow system. These molecules represent the first compounds described that are able to inhibit DGC activity to prevent biofilm formation.

scholarly journals Identification of Small Molecule Modulators of Diguanylate Cyclase by FRET-based High-Throughput-Screening

2018 ◽  
Author(s):  
Matthias Christen ◽  
Cassandra Kamischke ◽  
Hemantha D. Kulasekara ◽  
Kathleen C. Olivas ◽  
Bridget R. Kulasekara ◽  
...  
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
High Throughput ◽  
Biofilm Formation ◽  
High Throughput Screening ◽  
Diguanylate Cyclase ◽  
Chronic Infections ◽  
Structure Activity ◽  
Diguanylate Cyclases ◽  
Small Molecule Modulators

The bacterial second messenger cyclic diguanosine monophosphate (c-di-GMP) is a key regulator of cellular motility, the cell cycle, and biofilm formation with its resultant antibiotic tolerance, which may make chronic infections difficult to treat. Therefore, diguanylate cyclases, which regulate the spatiotemporal production of c-di-GMP, may be attractive drug targets to control biofilm formation that is part of chronic infections. In this paper, we present a FRET-based biochemical high-throughput screening approach coupled with detailed structure-activity studies to identify synthetic small molecule modulators of the diguanylate cyclase, DgcA, from Caulobacter crescentus. We identified a set of 7 small molecules that in the low µM range regulate DgcA enzymatic activity. Subsequent structure activity studies on selected scaffolds revealed a remarkable diversity of modulatory behaviors, including slight chemical substitutions that revert the effects from allosteric enzyme inhibition to activation. The compounds identified represent novel chemotypes and are potentially developable into chemical genetic tools for the dissection of c-di-GMP signaling networks and alteration of c-di-GMP associated phenotypes. In sum, our studies underline the importance for detailed mechanism of action studies for inhibitors of c-di-GMP signaling and demonstrate the complex interplay between synthetic small molecules and the regulatory mechanisms that control the activity of diguanylate cyclases.

scholarly journals Inhibition of Salmonella enterica Biofilm Formation Using Small-Molecule Adenosine Mimetics

2014 ◽  
Vol 59 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Jacob A. Koopman ◽  
Joanna M. Marshall ◽  
Aditi Bhatiya ◽  
Tadesse Eguale ◽  
Jesse J. Kwiek ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Mammalian Cells ◽  
Bacterial Species ◽  
Binding Pocket ◽  
Bacterial Biofilm ◽  
Chronic Infections ◽  
Content Type ◽  
Cellular Processes ◽  
Serovar Typhimurium

ABSTRACTBiofilms have been widely implicated in chronic infections and environmental persistence ofSalmonella enterica, facilitating enhanced colonization of surfaces and increasing the ability of the bacteria to be transmitted to new hosts.Salmonella entericaserovar Typhi biofilm formation on gallstones from humans and mice enhances gallbladder colonization and bacterial shedding, whileSalmonella entericaserovar Typhimurium biofilms facilitate long-term persistence in a number of environments important to food, medical, and farming industries.Salmonellaregulates expression of many virulence- and biofilm-related processes using kinase-driven pathways. Kinases play pivotal roles in phosphorylation and energy transfer in cellular processes and possess an ATP-binding pocket required for their functions. Many other cellular proteins also require ATP for their activity. Here we test the hypothesis that pharmacological interference with ATP-requiring enzymes utilizing adenosine mimetic compounds would decrease or inhibit bacterial biofilm formation. Through the screening of a 3,000-member ATP mimetic library, we identified a single compound (compound 7955004) capable of significantly reducing biofilm formation byS. Typhimurium andS. Typhi. The compound was not bactericidal or bacteriostatic towardS. Typhimurium or cytotoxic to mammalian cells. An ATP-Sepharose affinity matrix technique was used to discover potential protein-binding targets of the compound and identified GroEL and DeoD. Compound 7955004 was screened against other known biofilm-forming bacterial species and was found to potently inhibit biofilms ofAcinetobacter baumanniias well. The identification of a lead compound with biofilm-inhibiting capabilities towardSalmonellaprovides a potential new avenue of therapeutic intervention againstSalmonellabiofilm formation, with applicability to biofilms of other bacterial pathogens.

scholarly journals Lucilia sericata Chymotrypsin Disrupts Protein Adhesin-Mediated Staphylococcal Biofilm Formation

2012 ◽  
Vol 79 (4) ◽  
pp. 1393-1395 ◽  
Author(s):  
Llinos G. Harris ◽  
Yamni Nigam ◽  
James Sawyer ◽  
Dietrich Mack ◽  
David I. Pritchard
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Lucilia Sericata ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Formation Mechanisms ◽  
Chronic Infections ◽  
Content Type ◽  
Effective Activity

ABSTRACTStaphylococcus aureusandStaphylococcus epidermidisbiofilms cause chronic infections due to their ability to form biofilms. The excretions/secretions ofLucilia sericatalarvae (maggots) have effective activity for debridement and disruption of bacterial biofilms. In this paper, we demonstrate how chymotrypsin derived from maggot excretions/secretions disrupts protein-dependent bacterial biofilm formation mechanisms.

scholarly journals Thiol Starvation Induces Redox-Mediated Dysregulation of Escherichia coli Biofilm Components

2017 ◽  
Vol 200 (1) ◽  
Author(s):  
David A. Hufnagel ◽  
Janet E. Price ◽  
Rachel E. Stephenson ◽  
Jesse Kelley ◽  
Matthew F. Benoit ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Financial Burden ◽  
The United States ◽  
Diguanylate Cyclase ◽  
Chronic Infections ◽  
Content Type ◽  
Tract Infections ◽  
The Relationship ◽  
Sublethal Concentrations

ABSTRACTA hallmark of bacterial biofilms is the production of anextracellularmatrix (ECM) that encases and protects the community from environmental stressors. Biofilm formation is an integral portion of theuropathogenicEscherichiacoli(UPEC) life cycle. Approximately 2% of UPEC isolates are cysteine auxotrophs. Here, we investigated how cysteine homeostasis impacted UPEC UTI89 strain biofilm formation and, specifically, the production of the ECM components curli and cellulose. Cysteine auxotrophs produced less cellulose and slightly more curli compared to wild-type (WT) strains, and cysteine auxotrophs formed smooth, nonrugose colonies. Cellulose production was restored in cysteine auxotrophs when YfiR was inactivated. YfiR is a redox-sensitive regulator of the diguanylate cyclase, YfiN. The production of curli, a temperature-regulated appendage, was independent of temperature in UTI89 cysteine auxotrophs. In a screen of UPEC isolates, we found that ∼60% of UPEC cysteine auxotrophs produced curli at 37°C, but only ∼2% of cysteine prototrophic UPEC isolates produced curli at 37°C. Interestingly, sublethal concentrations of amdinocillin and trimethoprim-sulfamethoxazole inhibited curli production, whereas strains auxotrophic for cysteine continued to produce curli even in the presence of amdinocillin and trimethoprim-sulfamethoxazole. The dysregulation of ECM components and resistance to amdinocillin in cysteine auxotrophs may be linked to hyperoxidation, since the addition of exogenous cysteine or glutathione restored WT biofilm phenotypes to mutants unable to produce cysteine and glutathione.IMPORTANCEUropathogenicEscherichia coli(UPEC) bacteria are the predominant causative agent of urinary tract infections (UTIs). UTIs account for billions of dollars of financial burden annually to the health care industry in the United States. Biofilms are an important aspect of the UPEC pathogenesis cascade and for the establishment of chronic infections. Approximately 2% of UPEC isolates from UTIs are cysteine auxotrophs, yet there is relatively little known about the biofilm formation of UPEC cysteine auxotrophs. Here we show that cysteine auxotrophs have dysregulated biofilm components due to a change in the redox state of the periplasm. Additionally, we show the relationship between cysteine auxotrophs, biofilms, and antibiotics frequently used to treat UTIs.

scholarly journals Specific Control of Pseudomonas aeruginosa Surface-Associated Behaviors by Two c-di-GMP Diguanylate Cyclases

mBio ◽  
2010 ◽  
Vol 1 (4) ◽  
Author(s):  
Judith H. Merritt ◽  
Dae-Gon Ha ◽  
Kimberly N. Cowles ◽  
Wenyun Lu ◽  
Diana K. Morales ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Extracellular Polysaccharide ◽  
Diguanylate Cyclase ◽  
Flagellar Motility ◽  
Critical Question ◽  
Cyclic Diguanylate ◽  
Critical Signal ◽  
Content Type ◽  
Wide Range

ABSTRACT The signaling nucleotide cyclic diguanylate (c-di-GMP) regulates the transition between motile and sessile growth in a wide range of bacteria. Understanding how microbes control c-di-GMP metabolism to activate specific pathways is complicated by the apparent multifold redundancy of enzymes that synthesize and degrade this dinucleotide, and several models have been proposed to explain how bacteria coordinate the actions of these many enzymes. Here we report the identification of a diguanylate cyclase (DGC), RoeA, of Pseudomonas aeruginosa that promotes the production of extracellular polysaccharide (EPS) and contributes to biofilm formation, that is, the transition from planktonic to surface-dwelling cells. Our studies reveal that RoeA and the previously described DGC SadC make distinct contributions to biofilm formation, controlling polysaccharide production and flagellar motility, respectively. Measurement of total cellular levels of c-di-GMP in ∆roeA and ∆sadC mutants in two different genetic backgrounds revealed no correlation between levels of c-di-GMP and the observed phenotypic output with regard to swarming motility and EPS production. Our data strongly argue against a model wherein changes in total levels of c-di-GMP can account for the specific surface-related phenotypes of P. aeruginosa. IMPORTANCE A critical question in the study of cyclic diguanylate (c-di-GMP) signaling is how the bacterial cell integrates contributions of multiple c-di-GMP-metabolizing enzymes to mediate its cognate functional outputs. One leading model suggests that the effects of c-di-GMP must, in part, be localized subcellularly. The data presented here show that the phenotypes controlled by two different diguanylate cyclase (DGC) enzymes have discrete outputs despite the same total level of c-di-GMP. These data support and extend the model in which localized c-di-GMP signaling likely contributes to coordination of the action of the multiple proteins involved in the synthesis, degradation, and/or binding of this critical signal.

scholarly journals Linearmycins Activate a Two-Component Signaling System Involved in Bacterial Competition and Biofilm Morphology

2017 ◽  
Vol 199 (18) ◽  
Author(s):  
Reed M. Stubbendieck ◽  
Paul D. Straight
Keyword(s):  
Antibiotic Resistance ◽  
Abc Transporter ◽  
Bacterial Communities ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Bioactive Metabolites ◽  
Signaling System ◽  
Content Type ◽  
Two Component ◽  
Analytical Approaches

ABSTRACT Bacteria use two-component signaling systems to adapt and respond to their competitors and changing environments. For instance, competitor bacteria may produce antibiotics and other bioactive metabolites and sequester nutrients. To survive, some species of bacteria escape competition through antibiotic production, biofilm formation, or motility. Specialized metabolite production and biofilm formation are relatively well understood for bacterial species in isolation. How bacteria control these functions when competitors are present is not well studied. To address fundamental questions relating to the competitive mechanisms of different species, we have developed a model system using two species of soil bacteria, Bacillus subtilis and Streptomyces sp. strain Mg1. Using this model, we previously found that linearmycins produced by Streptomyces sp. strain Mg1 cause lysis of B. subtilis cells and degradation of colony matrix. We identified strains of B. subtilis with mutations in the two-component signaling system yfiJK operon that confer dual phenotypes of specific linearmycin resistance and biofilm morphology. We determined that expression of the ATP-binding cassette (ABC) transporter yfiLMN operon, particularly yfiM and yfiN, is necessary for biofilm morphology. Using transposon mutagenesis, we identified genes that are required for YfiLMN-mediated biofilm morphology, including several chaperones. Using transcriptional fusions, we found that YfiJ signaling is activated by linearmycins and other polyene metabolites. Finally, using a truncated YfiJ, we show that YfiJ requires its transmembrane domain to activate downstream signaling. Taken together, these results suggest coordinated dual antibiotic resistance and biofilm morphology by a single multifunctional ABC transporter promotes competitive fitness of B. subtilis. IMPORTANCE DNA sequencing approaches have revealed hitherto unexplored diversity of bacterial species in a wide variety of environments that includes the gastrointestinal tract of animals and the rhizosphere of plants. Interactions between different species in bacterial communities have impacts on our health and industry. However, many approaches currently used to study whole bacterial communities do not resolve mechanistic details of interspecies interactions, including how bacteria sense and respond to their competitors. Using a competition model, we have uncovered dual functions for a previously uncharacterized two-component signaling system involved in specific antibiotic resistance and biofilm morphology. Insights gleaned from signaling within interspecies interaction models build a more complete understanding of gene functions important for bacterial communities and will enhance community-level analytical approaches.

scholarly journals Fluorescence-Based Reporter for Gauging Cyclic Di-GMP Levels in Pseudomonas aeruginosa

2012 ◽  
Vol 78 (15) ◽  
pp. 5060-5069 ◽  
Author(s):  
Morten T. Rybtke ◽  
Bradley R. Borlee ◽  
Keiji Murakami ◽  
Yasuhiko Irie ◽  
Morten Hentzer ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Fluorescent Protein ◽  
Subsequent Development ◽  
Cellular Level ◽  
Host Immune System ◽  
Chronic Infections ◽  
Content Type ◽  
Genes Encoding ◽  
Green Fluorescent

ABSTRACTThe increased tolerance toward the host immune system and antibiotics displayed by biofilm-formingPseudomonas aeruginosaand other bacteria in chronic infections such as cystic fibrosis bronchopneumonia is of major concern. Targeting of biofilm formation is believed to be a key aspect in the development of novel antipathogenic drugs that can augment the effect of classic antibiotics by decreasing antimicrobial tolerance. The second messenger cyclic di-GMP is a positive regulator of biofilm formation, and cyclic di-GMP signaling is now regarded as a potential target for the development of antipathogenic compounds. Here we describe the development of fluorescent monitors that can gauge the cellular level of cyclic di-GMP inP. aeruginosa. We have created cyclic di-GMP level reporters by transcriptionally fusing the cyclic di-GMP-responsivecdrApromoter to genes encoding green fluorescent protein. We show that the reporter constructs give a fluorescent readout of the intracellular level of cyclic di-GMP inP. aeruginosastrains with different levels of cyclic di-GMP. Furthermore, we show that the reporters are able to detect increased turnover of cyclic di-GMP mediated by treatment ofP. aeruginosawith the phosphodiesterase inducer nitric oxide. Considering that biofilm formation is a necessity for the subsequent development of a chronic infection and therefore a pathogenicity trait, the reporters display a significant potential for use in the identification of novel antipathogenic compounds targeting cyclic di-GMP signaling, as well as for use in research aiming at understanding the biofilm biology ofP. aeruginosa.

scholarly journals Motility-Independent Formation of Antibiotic-TolerantPseudomonas aeruginosaAggregates

2019 ◽  
Vol 85 (14) ◽  
Author(s):  
Sally Demirdjian ◽  
Hector Sanchez ◽  
Daniel Hopkins ◽  
Brent Berwin
Keyword(s):  
Biofilm Formation ◽  
Bacterial Pathogen ◽  
Aggregate Formation ◽  
Flagellar Motility ◽  
Wild Type ◽  
Chronic Infections ◽  
Content Type ◽  
Temporal Adaptation ◽  
Bacterial Aggregates

ABSTRACTPseudomonas aeruginosais a bacterial pathogen that causes severe chronic infections in immunocompromised individuals. This bacterium is highly adaptable to its environments, which frequently select for traits that promote bacterial persistence. A clinically significant temporal adaptation is the formation of surface- or cell-adhered bacterial biofilms that are associated with increased resistance to immune and antibiotic clearance. Extensive research has shown that bacterial flagellar motility promotes formation of such biofilms, whereupon the bacteria subsequently become nonmotile. However, recent evidence shows that antibiotic-tolerant nonattached bacterial aggregates, distinct from surface-adhered biofilms, can form, and these have been reported in the context of lung infections, otitis media, nonhealing wounds, and soft tissue fillers. It is unclear whether the same bacterial traits are required for aggregate formation as for biofilm formation. In this report, using isogenic mutants, we demonstrate thatP. aeruginosaaggregates in liquid cultures are spontaneously formed independent of bacterial flagellar motility and independent of an exogenous scaffold. This contrasts with the role of the flagellum to initiate surface-adhered biofilms. Similarly to surface-attached biofilms, these aggregates exhibit increased antibiotic tolerance compared to planktonic cultures. These findings provide key insights into the requirements for aggregate formation that contrast with those for biofilm formation and that may have relevance for the persistence and dissemination of nonmotile bacteria found within chronic clinical infections.IMPORTANCEIn this work, we have investigated the role of bacterial motility with regard to antibiotic-tolerant bacterial aggregate formation. Previous work has convincingly demonstrated thatP. aeruginosaflagellar motility promotes the formation of surface-adhered biofilms in many systems. In contrast, aggregate formation byP. aeruginosawas observed for nonmotile but not for motile cells in the presence of an exogenous scaffold. Here, we demonstrate that both wild-typeP. aeruginosaand mutants that genetically lack motility spontaneously form antibiotic-tolerant aggregates in the absence of an exogenously added scaffold. Additionally, we also demonstrate that wild-type (WT) and nonmotileP. aeruginosabacteria can coaggregate, shedding light on potential physiological interactions and heterogeneity of aggregates.

scholarly journals Selenium and tellurium-based nanoparticles as interfering factors in quorum sensing-regulated processes: violacein production and bacterial biofilm formation

Metallomics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1104-1114 ◽  
Author(s):  
Beatriz Gómez-Gómez ◽  
Lucia Arregui ◽  
Susana Serrano ◽  
Antonio Santos ◽  
Teresa Pérez-Corona ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Persistent Infections ◽  
Violacein Production ◽  
New Strategies

The effect of SeNPs and TeNPs on different processes regulated by QS such as violacein production and biofilm formation is presented. The data open new strategies for controlling persistent infections.

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