Sulfane Sulfur Regulates LasR-Mediated Quorum Sensing and Virulence in Pseudomonas aeruginosa PAO1

Sulfane sulfur, such as inorganic and organic polysulfide (HSn− and RSn−, n > 2), is a common cellular component, produced either from hydrogen sulfide oxidation or cysteine metabolism. In Pseudomonas aeruginosa PAO1, LasR is a quorum sensing master regulator. After binding its autoinducer, LasR binds to its target DNA to activate the transcription of a suite of genes, including virulence factors. Herein, we report that the production of hydrogen sulfide and sulfane sulfur were positively correlated in P. aeruginosa PAO1, and sulfane sulfur was able to modify LasR, which generated Cys188 persulfide and trisulfide and produced a pentasulfur link between Cys201 and Cys203. The modifications did not affect LasR binding to its target DNA site, but made it several-fold more effective than unmodified LasR in activating transcription in both in vitro and in vivo assays. On the contrary, H2O2 inactivates LasR via producing a disulfide bond between Cys201 and Cys203. P. aeruginosa PAO1 had a high cellular sulfane sulfur and high LasR activity in the mid log phase and early stationary phase, but a low sulfane sulfur and low LasR activity in the declination phase. Thus, sulfane sulfur is a new signaling factor in the bacterium, adding another level of control over LasR-mediated quorum sensing and turning down the activity in old cells.

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Mosloflavone attenuates the quorum sensing controlled virulence phenotypes and biofilm formation in Pseudomonas aeruginosa PAO1: In vitro, in vivo and in silico approach

Microbial Pathogenesis ◽

10.1016/j.micpath.2019.04.005 ◽

2019 ◽

Vol 131 ◽

pp. 128-134 ◽

Cited By ~ 7

Author(s):

Sairengpuii Hnamte ◽

Paramanantham Parasuraman ◽

Sampathkumar Ranganathan ◽

Dinakara Rao Ampasala ◽

Dhanasekhar Reddy ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

In Silico ◽

Biofilm Formation ◽

Pseudomonas Aeruginosa Pao1

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Host cystathionine-γ lyase derived hydrogen sulfide protects against Pseudomonas aeruginosa sepsis

PLoS Pathogens ◽

10.1371/journal.ppat.1009473 ◽

2021 ◽

Vol 17 (3) ◽

pp. e1009473

Author(s):

Georgios Renieris ◽

Dionysia-Eirini Droggiti ◽

Konstantina Katrini ◽

Panagiotis Koufargyris ◽

Theologia Gkavogianni ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Hydrogen Sulfide ◽

Quorum Sensing ◽

Sodium Thiosulfate ◽

Multidrug Resistant ◽

Aminooxyacetic Acid ◽

Myeloperoxidase Activity ◽

Synthesis Inhibitor

Hydrogen sulfide (H2S) has recently been recognized as a novel gaseous transmitter with several anti-inflammatory properties. The role of host- derived H2S in infections by Pseudomonas aeruginosa was investigated in clinical and mouse models. H2S concentrations and survival was assessed in septic patients with lung infection. Animal experiments using a model of severe systemic multidrug-resistant P. aeruginosa infection were performed using mice with a constitutive knock-out of cystathionine-γ lyase (Cse) gene (Cse-/-) and wild-type mice with a physiological expression (Cse+/+). Experiments were repeated in mice after a) treatment with cyclophosphamide; b) bone marrow transplantation (BMT) from a Cse+/+ donor; c) treatment with H2S synthesis inhibitor aminooxyacetic acid (ΑΟΑΑ) or propargylglycine (PAG) and d) H2S donor sodium thiosulfate (STS) or GYY3147. Bacterial loads and myeloperoxidase activity were measured in tissue samples. The expression of quorum sensing genes (QS) was determined in vivo and in vitro. Cytokine concentration was measured in serum and incubated splenocytes. Patients survivors at day 28 had significantly higher serum H2S compared to non-survivors. A cut- off point of 5.3 μΜ discriminated survivors with sensitivity 92.3%. Mortality after 28 days was 30.9% and 93.7% in patients with H2S higher and less than 5.3 μΜ (p = 7 x 10−6). In mice expression of Cse and application of STS afforded protection against infection with multidrug-resistant P. aeruginosa. Cyclophosphamide pretreatment eliminated the survival benefit of Cse+/+ mice, whereas BMT increased the survival of Cse-/- mice. Cse-/- mice had increased pathogen loads compared to Cse+/+ mice. Phagocytic activity of leukocytes from Cse-/- mice was reduced but was restored after H2S supplementation. An H2S dependent down- regulation of quorum sensing genes of P.aeruginosa could be demonstrated in vivo and in vitro. Endogenous H2S is a potential independent parameter correlating with the outcome of P. aeruginosa. H2S provides resistance to infection by MDR bacterial pathogens.

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Anti-quorum sensing and anti-biofilm activity of 5-hydroxymethylfurfural against Pseudomonas aeruginosa PAO1: Insights from in vitro, in vivo and in silico studies

Microbiological Research ◽

10.1016/j.micres.2019.05.001 ◽

2019 ◽

Vol 226 ◽

pp. 19-26 ◽

Cited By ~ 8

Author(s):

Jobina Rajkumari ◽

Subhomoi Borkotoky ◽

Dhanasekhar Reddy ◽

Saswat Kumar Mohanty ◽

Ranjith Kumavath ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

In Silico ◽

Pseudomonas Aeruginosa Pao1 ◽

In Silico Studies

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A Novel Infection Protocol in Zebrafish Embryo to Assess Pseudomonas aeruginosa Virulence and Validate Efficacy of a Quorum Sensing Inhibitor In Vivo

Pathogens ◽

10.3390/pathogens10040401 ◽

2021 ◽

Vol 10 (4) ◽

pp. 401

Author(s):

Pauline Nogaret ◽

Fatima El El Garah ◽

Anne-Béatrice Blanc-Potard

Keyword(s):

Pseudomonas Aeruginosa ◽

Animal Model ◽

Quorum Sensing ◽

Drug Testing ◽

Drug Efficacy ◽

Embryo Viability ◽

Immersion Method ◽

Opportunistic Human Pathogen

The opportunistic human pathogen Pseudomonas aeruginosa is responsible for a variety of acute infections and is a major cause of mortality in chronically infected cystic fibrosis patients. Due to increased resistance to antibiotics, new therapeutic strategies against P. aeruginosa are urgently needed. In this context, we aimed to develop a simple vertebrate animal model to rapidly assess in vivo drug efficacy against P. aeruginosa. Zebrafish are increasingly considered for modeling human infections caused by bacterial pathogens, which are commonly microinjected in embryos. In the present study, we established a novel protocol for zebrafish infection by P. aeruginosa based on bath immersion in 96-well plates of tail-injured embryos. The immersion method, followed by a 48-hour survey of embryo viability, was first validated to assess the virulence of P. aeruginosa wild-type PAO1 and a known attenuated mutant. We then validated its relevance for antipseudomonal drug testing by first using a clinically used antibiotic, ciprofloxacin. Secondly, we used a novel quorum sensing (QS) inhibitory molecule, N-(2-pyrimidyl)butanamide (C11), the activity of which had been validated in vitro but not previously tested in any animal model. A significant protective effect of C11 was observed on infected embryos, supporting the ability of C11 to attenuate in vivo P. aeruginosa pathogenicity. In conclusion, we present here a new and reliable method to compare the virulence of P. aeruginosa strains in vivo and to rapidly assess the efficacy of clinically relevant drugs against P. aeruginosa, including new antivirulence compounds.

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Structure–function studies of Rgg binding to pheromones and target promoters reveal a model of transcription factor interplay

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2008427117 ◽

2020 ◽

Vol 117 (39) ◽

pp. 24494-24502

Author(s):

Glenn C. Capodagli ◽

Kaitlyn M. Tylor ◽

Jason T. Kaelber ◽

Vasileios I. Petrou ◽

Michael J. Federle ◽

...

Keyword(s):

Quorum Sensing ◽

Structure Function ◽

Transcriptional Activation ◽

Molecular Basis ◽

Streptococcus Thermophilus ◽

X Ray ◽

Target Dna ◽

Dna Promoters

Regulator gene of glucosyltransferase (Rgg) family proteins, such as Rgg2 and Rgg3, have emerged as primary quorum-sensing regulated transcription factors in Streptococcus species, controlling virulence, antimicrobial resistance, and biofilm formation. Rgg2 and Rgg3 function is regulated by their interaction with oligopeptide quorum-sensing signals called short hydrophobic peptides (SHPs). The molecular basis of Rgg–SHP and Rgg–target DNA promoter specificity was unknown. To close this gap, we determined the cryoelectron microscopy (cryo-EM) structure of Streptococcus thermophilus Rgg3 bound to its quorum-sensing signal, SHP3, and the X-ray crystal structure of Rgg3 alone. Comparison of these structures with that of an Rgg in complex with cyclosporin A (CsA), an inhibitor of SHP-induced Rgg activity, reveals the molecular basis of CsA function. Furthermore, to determine how Rgg proteins recognize DNA promoters, we determined X-ray crystal structures of both Streptococcus dysgalactiae Rgg2 and S. thermophilus Rgg3 in complex with their target DNA promoters. The physiological importance of observed Rgg–DNA interactions was dissected using in vivo genetic experiments and in vitro biochemical assays. Based on these structure–function studies, we present a revised unifying model of Rgg regulatory interplay. In contrast to existing models, where Rgg2 proteins are transcriptional activators and Rgg3 proteins are transcriptional repressors, we propose that both are capable of transcriptional activation. However, when Rgg proteins with different activation requirements compete for the same DNA promoters, those with more stringent activation requirements function as repressors by blocking promoter access of SHP-bound conformationally active Rgg proteins. While a similar gene expression regulatory scenario has not been previously described, in all likelihood it is not unique to streptococci.

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Pseudomonas aeruginosa tolerance to tobramycin, hydrogen peroxide and polymorphonuclear leukocytes is quorum-sensing dependent

Microbiology ◽

10.1099/mic.0.27463-0 ◽

2005 ◽

Vol 151 (2) ◽

pp. 373-383 ◽

Cited By ~ 312

Author(s):

Thomas Bjarnsholt ◽

Peter Østrup Jensen ◽

Mette Burmølle ◽

Morten Hentzer ◽

Janus A. J. Haagensen ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Polymorphonuclear Leukocytes ◽

Present Report ◽

Cell Communication ◽

A Cell ◽

Opportunistic Human Pathogen ◽

Conventional Antibiotics

The opportunistic human pathogen Pseudomonas aeruginosa is the predominant micro-organism of chronic lung infections in cystic fibrosis (CF) patients. P. aeruginosa colonizes the CF lungs by forming biofilm structures in the alveoli. In the biofilm mode of growth the bacteria are highly tolerant to otherwise lethal doses of antibiotics and are protected from bactericidal activity of polymorphonuclear leukocytes (PMNs). P. aeruginosa controls the expression of many of its virulence factors by means of a cell–cell communication system termed quorum sensing (QS). In the present report it is demonstrated that biofilm bacteria in which QS is blocked either by mutation or by administration of QS inhibitory drugs are sensitive to treatment with tobramycin and H2O2, and are readily phagocytosed by PMNs, in contrast to bacteria with functional QS systems. In contrast to the wild-type, QS-deficient biofilms led to an immediate respiratory-burst activation of the PMNs in vitro. In vivo QS-deficient mutants provoked a higher degree of inflammation. It is suggested that quorum signals and QS-inhibitory drugs play direct and opposite roles in this process. Consequently, the faster and highly efficient clearance of QS-deficient bacteria in vivo is probably a two-sided phenomenon: down regulation of virulence and activation of the innate immune system. These data also suggest that a combination of the action of PMNs and QS inhibitors along with conventional antibiotics would eliminate the biofilm-forming bacteria before a chronic infection is established.

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Autoinducer-2 Facilitates Pseudomonas aeruginosa PAO1 Pathogenicity in Vitro and in Vivo

Frontiers in Microbiology ◽

10.3389/fmicb.2017.01944 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 10

Author(s):

Hongdong Li ◽

Xingyuan Li ◽

Chao Song ◽

Yunhui Zhang ◽

Zhengli Wang ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Pseudomonas Aeruginosa Pao1 ◽

Autoinducer 2

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Tea polyphenols as an antivirulence compound Disrupt Quorum-Sensing Regulated Pathogenicity of Pseudomonas aeruginosa

Scientific Reports ◽

10.1038/srep16158 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 49

Author(s):

Hongping Yin ◽

Yifeng Deng ◽

Huafu Wang ◽

Wugao Liu ◽

Xiyi Zhuang ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Water Extract ◽

Tea Polyphenols ◽

Infection Model ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Treatment Groups

Abstract Green tea, a water extract of non-fermented leaves of Camellia sinensis L., is one of the nonalcoholic beverages in China. It is becoming increasingly popular worldwide, because of its refreshing, mild stimulant and medicinal properties. Here we examined the quorum sensing inhibitory potentials of tea polyphenols (TP) as antivirulence compounds both in vitro and in vivo. Biosensor assay data suggested minimum inhibitory concentrations (MICs) of TP against selected pathogens were 6.25 ~ 12.5 mg/mL. At sub-MIC, TP can specifically inhibit the production of violacein in Chromobacterium violaceum 12472 with almost 98% reduction at 3.125 mg/mL without affecting its growth rate. Moreover, TP exhibited inhibitory effects on virulence phenotypes regulated by QS in Pseudomonas aeruginosa. The total proteolytic activity, elastase, swarming motility and biofilm formation were reduced in a concentration-dependent manner. In vivo, TP treatment resulted in the reduction of P. aeruginosa pathogenicity in Caenorhabditis elegans. When its concentration was 3.125 mg/mL, the survival rate reached 63.3%. In the excision wound infection model, the wound contraction percentage in treatment groups was relatively increased and the colony-forming units (CFU) in the wound area were significantly decreased. These results suggested that TP could be developed as a novel non-antibiotic QS inhibitor without killing the bacteria but as an antivirulence compound to control bacterial infection.

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Repurposing Anti-diabetic Drugs to Cripple Quorum Sensing in Pseudomonas aeruginosa

Microorganisms ◽

10.3390/microorganisms8091285 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1285

Author(s):

Wael A. H. Hegazy ◽

Maan T. Khayat ◽

Tarek S. Ibrahim ◽

Majed S. Nassar ◽

Muhammed A. Bakhrebah ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

In Silico Analysis ◽

Resistance Mechanisms ◽

Chemical Structures ◽

Similar Chemical ◽

Almost All ◽

Encoding Genes

Pseudomonas aeruginosa is a significant human pathogen, it possesses almost all of the known antimicrobial resistance mechanisms. Quorum sensing (QS) is an intercellular communication system that orchestrates bacterial virulence and its targeting is an effective approach to diminish its pathogenesis. Repurposing of drugs is an advantageous strategy, in this study we aimed to repurpose the anti-diabetic drugs sitagliptin, metformin and vildagliptin as anti-QS in P. aeruginosa. The effects of sub-inhibitory concentrations of the tested drugs on the expression of QS-encoding genes and QS-regulated virulence factors were assessed. The protective activity of tested drugs on P. aeruginosa pathogenesis was evaluated in vivo on mice. In silico analysis was performed to evaluate the interference capabilities of the tested drugs on QS-receptors. Although the three drugs reduced the expression of QS-encoding genes, only sitagliptin inhibited the P. aeruginosa virulence in vitro and protected mice from it. In contrast, metformin showed significant in vitro anti-QS activities but failed to protect mice from P. aeruginosa. Vildagliptin did not show any in vitro or in vivo efficacy. Sitagliptin is a promising anti-QS agent because of its chemical nature that hindered QS-receptors. Moreover, it gives an insight to consider their similar chemical structures as anti-QS agents or even design new chemically similar anti-QS pharmacophores.

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