scholarly journals Ανάπτυξη ενός μοντέλου για την μελέτη της επίδρασης της έλλειψης της ενδογενούς παραγωγής υδρόθειου στην ανθεκτικότητα πολυανθεκτικών μικροοργανισμών (Pseudomonas aeruginosa & Klebsiella pneumoniae) ενάντια στην αντιμικροβιακή αγωγή

2021 ◽  
Author(s):  
Γεώργιος Ρενιέρης
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Klebsiella Pneumoniae ◽  
Sodium Thiosulfate ◽  
Aminooxyacetic Acid

Το υδρόθειο (H2S) έχει πρόσφατα αναγνωριστεί ως ένας νέος αέριος διαβιβαστής μεαντιφλεγμονώδεις δράσεις. Ο ρόλος του παραγόμενου από τον ξενιστή H2S σελοιμώξεις από αεριογόνο ψευδομονάδα Pseudomonas (P.) aeruginosa διερευνήθηκεσε ένα κλινικό και ζωικό μοντέλο. Μελετήθηκαν οι συγκεντρώσεις του H2S και ηεπιβίωση σηπτικών ασθενών με λοιμώξεις του κατώτερου αναπνευστικού. Στησυνέχεια αναπτύχθηκε ένα ζωικό μοντέλο σοβαρής συστηματικής λοίμωξης απόπολυανθεκτική P. aeruginosa iχρησιμοποιώντας μύες με έλλειψη του γονιδίου της γ-λυάσης της κυσταθειονίνης (Cse) (Cse-/- μύες) και μύες με φυσιολογική έκφραση τουγονιδίου (Cse+/+ μύες). Πειράματα επαναλήφθηκαν σε μύες μετά από α) θεραπεία μεκυκλοφωσφαμίδη, β) μεταμόσχευση μυελού των οστών από δότη Cse+/+, γ) θεραπείαμε τους αναστολείς της σύνθεσης H2S αμινοοξεϊκό οξύ (aminooxyacetic acid, ΑΟΑΑ)ή προπαργυλγλυκίνη (propargylglycine, PAG) και δ) τους δότες H2S θειοθειικό νάτριο(sodium thiosulfate, STS) ή το GYY3147. Το μικροβιακό φορτίο και ημυελουπεροξειδάση προσδιορίστηκαν σε δείγματα ιστών. Η έκφραση του τωνγόνιδίων του συτήματος quorum sensing (QS) της ψευδομονάδας προσδιορίσθηκε invivo και in vitro. Μετρήθηκαν οι συγκεντρώσεις κυτταροκινών στον ορό και διεγερμένασπληνοκύτταρα. Οι ασθενείς που επιβίωσαν 28 ημέρες μετά τη λοίμωξη είχανσημαντικά υψηλότερα επίπεδα H2S ορού σε σύγκριση με ασθενείς που δεν επιβίωσαν.Επίπεδα H2S ορού 5.3 μΜ διαχωρίζουν τους επιβιώσαντες με ευαισθησία 92.3%. Ηθνητότητα στις 28 ημέρες ήταν 30.9% και 93.7% σε ασθενείς με επίπεδα H2Sυψηλότερα ή χαμηλότερα από 5.3 μΜ αντίστοιχα (p= 7 x 10-6). Η φυσιολογική έκφρασητου Cse καθώς και η θεραπεία με δότη H2S δρα προστατευτικά ενάντια σε λοίμωξη μεπολυανθεκτική P. aeruginosa. Η προθεραπεία με κυκλοφωσφαμίδη εξάλειψε τοπλεονέκτημα επιβίωσης των Cse+/+ μυών, ενώ η μεταμόσχευση μυελού των οστώναύξησε την επιβίωση των Cse-/- μυών. Οι Cse-/- μύες εμφάνισαν αυξημένα μικροβιακάφορτία σε σύγκριση με τους Cse+/+ μύες. Η φαγοκυτταρική δράση των λευκοκυττάρωντων Cse-/- μυών ήταν μειωμένη ενώ αποκαταστάθηκε μετά από προσθήκη H2S. Μίασχετιζόμενη με το H2S μείωση της έκφρασης των γονιδίων του QS P.aeruginosaαναδείχθηκε in vivo και in vitro. Η ενδογενής παραγωγή H2S είναι ένας πιθανόςανεξάρτητος προστατευτικός παράγοντας για την έκβαση λοίμωξης από P.aeruginosa. Το H2S παρέχει προστασία ενάντια σε πολυανθεκτικά βακτηριακάπαθογόνα.

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

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.

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

Pathogens ◽  
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.

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

Microbiology ◽  
2005 ◽  
Vol 151 (2) ◽  
pp. 373-383 ◽  
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.

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

Antioxidants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1498
Author(s):  
Guanhua Xuan ◽  
Chuanjuan Lü ◽  
Huangwei Xu ◽  
Kai Li ◽  
Huaiwei Liu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Hydrogen Sulfide ◽  
Quorum Sensing ◽  
Sulfide Oxidation ◽  
Pseudomonas Aeruginosa Pao1 ◽  
Sulfane Sulfur ◽  
Target Dna ◽  
Production Of Hydrogen

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.

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

2019 ◽  
Vol 131 ◽  
pp. 128-134 ◽  
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

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

2015 ◽  
Vol 5 (1) ◽  
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.

scholarly journals In Vitro and In Vivo Activities of β-Lactams in Combination with the Novel β-Lactam Enhancers Zidebactam and WCK 5153 against Multidrug-Resistant Metallo-β-Lactamase-Producing Klebsiella pneumoniae

2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Bartolome Moya ◽  
Isabel M. Barcelo ◽  
Gabriel Cabot ◽  
Gabriel Torrens ◽  
Snehal Palwe ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Molecular Targets ◽  
Multidrug Resistant ◽  
The Novel ◽  
Penicillin Binding Protein ◽  
Content Type ◽  
Time Kill

ABSTRACT Zidebactam and WCK 5153 are novel bicyclo-acyl hydrazide (BCH) agents that have previously been shown to act as β-lactam enhancer (BLE) antibiotics in Pseudomonas aeruginosa and Acinetobacter baumannii. The objectives of this work were to identify the molecular targets of these BCHs in Klebsiella pneumoniae and to investigate their potential BLE activity for cefepime and aztreonam against metallo-β-lactamase (MBL)-producing strains in vitro and in vivo. Penicillin binding protein (PBP) binding profiles were determined by Bocillin FL assay, and 50% inhibitory concentrations (IC50s) were determined using ImageQuant TL software. MICs and kill kinetics for zidebactam, WCK 5153, and cefepime or aztreonam, alone and in combination, were determined against clinical K. pneumoniae isolates producing MBLs VIM-1 or NDM-1 (plus ESBLs and class C β-lactamases) to assess the in vitro enhancer effect of BCH compounds in conjunction with β-lactams. Additionally, murine systemic and thigh infection studies were conducted to evaluate BLE effects in vivo. Zidebactam and WCK 5153 showed specific, high PBP2 affinity in K. pneumoniae. The MICs of BLEs were >64 μg/ml for all MBL-producing strains. Time-kill studies showed that a combination of these BLEs with either cefepime or aztreonam provided 1 to >3 log10 kill against MBL-producing K. pneumoniae strains. Furthermore, the bactericidal synergy observed for these BLE–β-lactam combinations translated well into in vivo efficacy even in the absence of MBL inhibition by BLEs, a characteristic feature of the β-lactam enhancer mechanism of action. Zidebactam and WCK 5153 are potent PBP2 inhibitors and display in vitro and in vivo BLE effects against multidrug-resistant (MDR) K. pneumoniae clinical isolates producing MBLs.

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

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.

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

2019 ◽  
Vol 226 ◽  
pp. 19-26 ◽  
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

scholarly journals Quinic acid: a potential antibiofilm agent against clinical resistant Pseudomonas aeruginosa

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Lan Lu ◽  
Yuting Zhao ◽  
Guojuan Yi ◽  
Mingxing Li ◽  
Li Liao ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Plant Extracts ◽  
Active Ingredient ◽  
Biofilm Formation ◽  
Quinic Acid ◽  
Underlying Mechanism ◽  
Active Ingredients

Abstract Background The biofilm state of pathogens facilitates antimicrobial resistance which makes difficult-to-treat infections. In this regard, it has been found that the compounds screened from plant extracts represent one category of the most promising antibiofilm agents. However, the antibiofilm activities and the active ingredients of plant extracts remain largely unexplored. In this background, the study is (1) to screen out the plant extracts with antibiofilm ability against Pseudomonas aeruginosa, and (2) to identify the active ingredients in the plant extracts and elucidate the underlying mechanism of the antibiofilm activities. Methods Micro-broth dilution method, in vitro biofilm model, LC–MS/MS analysis and P. aeruginosa-mouse infection model were adopted to assess the antibiofilm activity. GC–MS analysis was performed to detect the active ingredients in plasma. RNA-Seq, GO analysis, KEGG analysis and RT-qPCR were adopted to elucidate the underlying mechanism of antibiofilm activities against P. aeruginosa. Results Lonicerae Japonicae Flos (LJF) among 13 plants could exert significant inhibitory effects on bacterial biofilm formation, mobility and toxin release in vitro, and it could exert antibiofilm effect in vivo too. Moreover, quinic acid, as one metabolite of chlorogenic acid, was found as an active ingredient in LJF against the biofilm of P. aeruginosa. The active ingredient significantly inhibited EPS secretion in biofilm formation and maturity and could achieve synergistic antibiofilm effect with levofloxacin. It reduced the biofilm formation by regulating core targets in quorum sensing system. In GO process, it was found that the core targets were significantly enriched in multiple biological processes involving locomotion, chemotaxis and motility mediated by flagellum/cilium, which was related to KEGG pathways such as bacterial chemotaxis, oxidative phosphorylation, ribosome, biofilm formation, cyanoamino acid metabolism and quorum sensing. Finally, the binding of quinic acid with core targets rhlA, rhlR and rhlB were validated by molecular docking and RT-qPCR. Conclusions In summary, the study verified the in vitro and in vivo antibiofilm effects of LJF against P. aeruginosa and elucidated the active ingredients in LJF and its conceivable pharmacological mechanism, indicating that quinic acid could have the potential of an antibiofilm agent against P. aeruginosa and related infections. Graphic abstract

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