scholarly journals Exopolysaccharide-Repressing Small Molecules with Antibiofilm and Antivirulence Activity against Pseudomonas aeruginosa

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Erik van Tilburg Bernardes ◽  
Laetitia Charron-Mazenod ◽  
David J. Reading ◽  
Shauna L. Reckseidler-Zenteno ◽  
Shawn Lewenza
Keyword(s):  
Extracellular Matrix ◽  
Pseudomonas Aeruginosa ◽  
Small Molecules ◽  
Biofilm Formation ◽  
Flow Chamber ◽  
Growth Strategy ◽  
Antibiofilm Activity ◽  
Biofilm Growth ◽  
Content Type ◽  
High Throughput Gene Expression

ABSTRACT Biofilm formation is a universal virulence strategy in which bacteria grow in dense microbial communities enmeshed within a polymeric extracellular matrix that protects them from antibiotic exposure and the immune system. Pseudomonas aeruginosa is an archetypal biofilm-forming organism that utilizes a biofilm growth strategy to cause chronic lung infections in cystic fibrosis (CF) patients. The extracellular matrix of P. aeruginosa biofilms is comprised mainly of exopolysaccharides (EPS) and DNA. Both mucoid and nonmucoid isolates of P. aeruginosa produce the Pel and Psl EPS, each of which have important roles in antibiotic resistance, biofilm formation, and immune evasion. Given the central importance of the EPS for biofilms, they are attractive targets for novel anti-infective compounds. In this study, we used a high-throughput gene expression screen to identify compounds that repress expression of the pel genes. The pel repressors demonstrated antibiofilm activity against microplate and flow chamber biofilms formed by wild-type and hyperbiofilm-forming strains. To determine the potential role of EPS in virulence, pel/psl mutants were shown to have reduced virulence in feeding behavior and slow killing virulence assays in Caenorhabditis elegans. The antibiofilm molecules also reduced P. aeruginosa PAO1 virulence in the nematode slow killing model. Importantly, the combination of antibiotics and antibiofilm compounds increased killing of P. aeruginosa biofilms. These small molecules represent a novel anti-infective strategy for the possible treatment of chronic P. aeruginosa infections.

scholarly journals Inhibition of Biofilm Formation by Esomeprazole in Pseudomonas aeruginosa and Staphylococcus aureus

2012 ◽  
Vol 56 (8) ◽  
pp. 4360-4364 ◽  
Author(s):  
Vandana Singh ◽  
Vaneet Arora ◽  
M. Jahangir Alam ◽  
Kevin W. Garey
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Antimicrobial Properties ◽  
Antibiofilm Activity ◽  
Biofilm Growth ◽  
Content Type ◽  
Conventional Antibiotics ◽  
And Staphylococcus Aureus

ABSTRACTStaphylococcus aureusandPseudomonas aeruginosaare common nosocomial pathogens responsible for biofilm-associated infections. Proton pump inhibitors (PPI), such as esomeprazole, may have novel antimicrobial properties. The objective of this study was to assess whether esomeprazole prevents sessile bacterial growth and biofilm formation and whether it may have synergistic killing effects with standard antibiotics. The antibiofilm activity of esomeprazole at 0.25 mM was tested against two strains each ofS. aureusandP. aeruginosa. Bacterial biofilms were prepared using a commercially available 96-peg-plate Calgary biofilm device. Sessile bacterial CFU counts and biomass were assessed during 72 hours of esomeprazole exposure. The killing activities after an additional 24 hours of vancomycin (againstS. aureus) and meropenem (againstP. aeruginosa) treatment with or without preexposure to esomeprazole were also assessed by CFU and biomass analyses.P. aeruginosaandS. aureusstrains exposed to esomeprazole displayed decreased sessile bacterial growth and biomass (P< 0.001, each parameter). After 72 h of exposure, there was a 1-log10decrease in the CFU/ml of esomeprazole-exposedP. aeruginosaandS. aureusstrains compared to controls (P< 0.001). After 72 h of exposure, measured absorbance was 100% greater inP. aeruginosacontrol strains than in esomeprazole-exposed strains (P< 0.001). Increased killing and decreased biomass were observed for esomeprazole-treated bacteria compared to untreated controls exposed to conventional antibiotics (P< 0.001, each parameter). Reduced biofilm growth after 24 h was visibly apparent by light micrographs forP. aeruginosaandS. aureusisolates exposed to esomeprazole compared to untreated controls. In conclusion, esomeprazole demonstrated an antibiofilm effect against biofilm-producingS. aureusandP. aeruginosa.

scholarly journals Tryptophan Inhibits Biofilm Formation by Pseudomonas aeruginosa

2013 ◽  
Vol 57 (4) ◽  
pp. 1921-1925 ◽  
Author(s):  
Kenneth S. Brandenburg ◽  
Karien J. Rodriguez ◽  
Jonathan F. McAnulty ◽  
Christopher J. Murphy ◽  
Nicholas L. Abbott ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Tissue Culture ◽  
Biofilm Formation ◽  
Chronic Wounds ◽  
Inhibitory Effect ◽  
Equimolar Ratio ◽  
Biofilm Growth ◽  
Content Type ◽  
Swimming Motility

ABSTRACTBiofilm formation byPseudomonas aeruginosahas been implicated in the pathology of chronic wounds. Both thedandlisoforms of tryptophan inhibitedP. aeruginosabiofilm formation on tissue culture plates, with an equimolar ratio ofdandlisoforms producing the greatest inhibitory effect. Addition ofd-/l-tryptophan to existing biofilms inhibited further biofilm growth and caused partial biofilm disassembly. Tryptophan significantly increased swimming motility, which may be responsible in part for diminished biofilm formation byP. aeruginosa.

scholarly journals An integrated model system to gain mechanistic insights into biofilm formation and antimicrobial resistance development in Pseudomonas aeruginosa MPAO1

2020 ◽  
Author(s):  
Adithi R. Varadarajan ◽  
Raymond N. Allan ◽  
Jules D. P. Valentin ◽  
Olga E. Castañeda Ocampo ◽  
Vincent Somerville ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Soft Lithography ◽  
Flow Chamber ◽  
Model System ◽  
Secretion Systems ◽  
Phenotypic Data ◽  
Biofilm Growth ◽  
Mutant Collection

AbstractPseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and antibiotic resistance.Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and missed genes by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq datasets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth. Experiments conducted across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated both known and novel genes involved in biofilm growth and antibiotic resistance identified in screens of the mutant collection. Differential protein expression data from planktonic cells versus biofilm confirmed upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type six secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance and resistance evolution.

scholarly journals An integrated model system to gain mechanistic insights into biofilm-associated antimicrobial resistance in Pseudomonas aeruginosa MPAO1

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Adithi R. Varadarajan ◽  
Raymond N. Allan ◽  
Jules D. P. Valentin ◽  
Olga E. Castañeda Ocampo ◽  
Vincent Somerville ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Soft Lithography ◽  
Flow Chamber ◽  
Model System ◽  
Secretion Systems ◽  
Phenotypic Data ◽  
Biofilm Growth ◽  
Resistance Evolution

Abstract Pseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and biofilm-associated antibiotic resistance. Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and genes missed within existing assemblies by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq data sets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth and a screen with the Tn-mutant library in microtiter plates. The screen identified hitherto unknown genes involved in biofilm growth and antibiotic resistance. Experiments conducted with the flow chamber across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated the function of both known genes and genes identified in the Tn-mutant screens. Differential protein abundance data from planktonic cells versus biofilm confirmed the upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type VI secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance, and resistance evolution in biofilms.

scholarly journals Small molecules with antibiofilm, antivirulence and antibiotic synergy activities againstPseudomonas aeruginosa

2016 ◽  
Author(s):  
Erik van Tilburg Bernardes ◽  
Laetitia Charron-Mazenod ◽  
David Reading ◽  
Shauna L. Reckseidler-Zenteno ◽  
Shawn Lewenza
Keyword(s):  
Cystic Fibrosis ◽  
Extracellular Matrix ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Small Molecules ◽  
Biofilm Formation ◽  
Chronic Infections ◽  
Term Survival ◽  
Lung Infections

AbstractBiofilm formation is a universal bacterial strategy for long-term survival in nature and during infections. Biofilms are dense microbial communities enmeshed within a polymeric extracellular matrix that protects bacteria from antibiotic exposure and the immune system and thus contribute to chronic infections.Pseudomonas aeruginosais an archetypal biofilm-forming organism that utilizes a biofilm growth strategy to cause chronic lung infections in Cystic Fibrosis (CF) patients. The extracellular matrix ofP. aeruginosabiofilms is comprised mainly of exopolysaccharides (EPS) and DNA. Both mucoid and non-mucoid isolates ofP. aeruginosaproduces the Pel and Psl EPS, each of which have important roles in antibiotic resistance, biofilm formation and immune evasion. Given the central importance of the Pel and Psl EPS in biofilm structure, they are attractive targets for novel anti-infective compounds. In this study we used a high throughput gene expression screen to identify compounds that repress expression ofpelandpslgenes as measured by transcriptionalluxfusions. Testing of thepel/pslrepressors demonstrated an antibiofilm activity against microplate and flow chamber biofilms formed by wild type and hyperbiofilm forming strains. To determine the potential role of EPS in virulence, mutants inpel/pslwere shown to have reduced virulence in the feeding behavior and slow killing virulence assays inCaenorhabditis elegans. The antibiofilm molecules also reducedP. aeruginosaPAO1 virulence in the nematode slow killing model. Importantly, the combination of antibiotics and antibiofilm compounds were synergistic in killingP. aeruginosabiofilms. These small molecules represent a novel anti-infective strategy for the possible treatment of chronicP. aeruginosainfections.Author summaryBacteria use the strategy of growing as a biofilm to promote long-term survival and therefore to cause chronic infections. One of the best examples isPseudomonas aeruginosaand the chronic lung infections in individuals with Cystic Fibrosis (CF). Biofilms are generally a dense community of bacteria enmeshed in an extracellular matrix that protects bacteria from numerous environmental stresses, including antibiotics and the immune system. In this study we developed an approach to identifyP. aeruginosabiofilm inhibitors by repressing the production of the matrix exopolysaccharide (EPS) polymers. Bacteria treated with compounds and then fed to the nematode also had showed reduced virulence by promoting nematode survival. To tackle the problem of biofilm tolerance of antibiotics, the compounds identified here also had the beneficial property of increasing the biofilm sensitivity to different classes of antibiotics. The compounds disarm bacteria but they do not kill or limit growth like antibiotics. We provide further support that disarmingP. aeruginosamay be a critical anti-infective strategy that limits the development of antibiotic resistance, and provides a new way for treating chronic infections.

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

scholarly journals An In Vitro Coumarin-Antibiotic Combination Treatment of Pseudomonas aeruginosa Biofilms

2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Combination Treatment ◽  
Crude Extract ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antibacterial Properties ◽  
Biofilm Growth ◽  
Antibiotic Combination

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.

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 Phytochemical Profiling of Lavandula coronopifolia Poir. Aerial Parts Extract and Its Larvicidal, Antibacterial, and Antibiofilm Activity Against Pseudomonas aeruginosa

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1710
Author(s):  
Mahmoud Emam ◽  
Doaa R. Abdel-Haleem ◽  
Maha M. Salem ◽  
Lina Jamil M. Abdel-Hafez ◽  
Rasha R. Abdel Latif ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Wild Plant ◽  
Resistant Bacteria ◽  
Control Group ◽  
Antibiofilm Activity ◽  
Left Behind ◽  
Aerial Parts ◽  
Socioeconomic Burden ◽  
Cytochrome P 450

Infections associated with the emergence of multidrug resistance and mosquito-borne diseases have resulted in serious crises associated with high mortality and left behind a huge socioeconomic burden. The chemical investigation of Lavandulacoronopifolia aerial parts extract using HPLC–MS/MS led to the tentative identification of 46 compounds belonging to phenolic acids, flavonoids and their glycosides, and biflavonoids. The extract displayed larvicidal activity against Culex pipiens larvae (LC50 = 29.08 µg/mL at 72 h). It significantly inhibited cytochrome P-450 monooxygenase (CYP450), acetylcholinesterase (AChE), and carboxylesterase (CarE) enzymes with the comparable pattern to the control group, which could explain the mode of larvae toxification. The extract also inhibited the biofilm formation of Pseudomonas aeruginosa by 17–38% at different Minimum Inhibitory Concentrations (MICs) (0.5–0.125 mg/mL) while the activity was doubled when combined with ciprofloxacin (ratio = 1:1 v:v). In conclusion, the wild plant, L.coronopifolia, can be considered a promising natural source against resistant bacteria and infectious carriers.

Differential surface competition and biofilm invasion strategies of Pseudomonas aeruginosa PA14 and PAO1

2021 ◽  
Author(s):  
Swetha Kassety ◽  
Stefan Katharios-Lanwermeyer ◽  
George A. O’Toole ◽  
Carey D. Nadell
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Matrix Composition ◽  
Model Organisms ◽  
Culture Methods ◽  
Biofilm Growth ◽  
Biofilm Production ◽  
Direct Competition ◽  
Planktonic Phase ◽  
Do So

Pseudomonas aeruginosa strains PA14 and PAO1 are among the two best characterized model organisms used to study the mechanisms of biofilm formation, while also representing two distinct lineages of P. aeruginosa . Previous work has shown that PA14 and PAO1 use different strategies for surface colonization; they also have different extracellular matrix composition and different propensities to disperse from biofilms back into the planktonic phase surrounding them. We expand on this work here by exploring the consequences of these different biofilm production strategies during direct competition. Using differentially labeled strains and microfluidic culture methods, we show that PAO1 can outcompete PA14 in direct competition during early colonization and subsequent biofilm growth, that they can do so in constant and perturbed environments, and that this advantage is specific to biofilm growth and requires production of the Psl polysaccharide. In contrast, the P. aeruginosa PA14 is better able to invade pre-formed biofilms and is more inclined to remain surface-associated under starvation conditions. These data together suggest that while P. aeruginosa PAO1 and PA14 are both able to effectively colonize surfaces, they do so in different ways that are advantageous under different environmental settings. Importance Recent studies indicate that P. aeruginosa PAO1 and PA14 use distinct strategies to initiate biofilm formation. We investigated whether their respective colonization and matrix secretion strategies impact their ability to compete under different biofilm-forming regimes. Our work shows that these different strategies do indeed impact how these strains fair in direct competition: PAO1 dominates during colonization of a naïve surface, while PA14 is more effective in colonizing a pre-formed biofilm. These data suggest that even for very similar microbes there can be distinct strategies to successfully colonize and persist on surfaces during the biofilm life cycle.

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