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 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 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.

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.

scholarly journals Design of Epitope-Based Peptide Vaccine against Pseudomonas aeruginosa Fructose Bisphosphate Aldolase Protein Using Immunoinformatics

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mustafa Elhag ◽  
Ruaa Mohamed Alaagib ◽  
Nagla Mohamed Ahmed ◽  
Mustafa Abubaker ◽  
Esraa Musa Haroun ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Peptide Vaccine ◽  
Multidrug Resistant ◽  
Fructose Bisphosphate ◽  
Mhc I ◽  
Mhc Ii ◽  
Fructose Bisphosphate Aldolase ◽  
Hospital Acquired

Pseudomonas aeruginosa is a common pathogen that is responsible for serious hospital-acquired infections, ventilator-associated pneumonia, and various sepsis syndromes. Also, it is a multidrug-resistant pathogen recognized for its ubiquity and its intrinsically advanced antibiotic-resistant mechanisms. It usually affects immunocompromised individuals but can also infect immunocompetent individuals. There is no vaccine against it available till now. This study predicts an effective epitope-based vaccine against fructose bisphosphate aldolase (FBA) of Pseudomonas aeruginosa using immunoinformatics tools. The protein sequences were obtained from NCBI, and prediction tests were undertaken to analyze possible epitopes for B and T cells. Three B cell epitopes passed the antigenicity, accessibility, and hydrophilicity tests. Six MHC I epitopes were found to be promising, while four MHC II epitopes were found promising from the result set. Nineteen epitopes were shared between MHC I and II results. For the population coverage, the epitopes covered 95.62% worldwide excluding certain MHC II alleles. We recommend in vivo and in vitro studies to prove its effectiveness.

Peptide polymer displaying potent activity against clinically isolated multidrug resistant Pseudomonas aeruginosa in vitro and in vivo

2020 ◽  
Vol 8 (2) ◽  
pp. 739-745 ◽  
Author(s):  
Weinan Jiang ◽  
Ximian Xiao ◽  
Yueming Wu ◽  
Weiwei Zhang ◽  
Zihao Cong ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Host Defense ◽  
Multidrug Resistant ◽  
Host Defense Peptide

Host defense peptide mimicking peptide polymer displayed potent in vitro and in vivo antimicrobial activity against clinically isolated multidrug resistant Pseudomonas aeruginosa.

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 Synergistic Efficacy of Aedes aegypti Antimicrobial Peptide Cecropin A2 and Tetracycline against Pseudomonas aeruginosa

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Zhaojun Zheng ◽  
Nagendran Tharmalingam ◽  
Qingzhong Liu ◽  
Elamparithi Jayamani ◽  
Wooseong Kim ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Aedes Aegypti ◽  
Mammalian Cells ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Synergistic Activity ◽  
Content Type

ABSTRACT The increasing prevalence of antibiotic resistance has created an urgent need for alternative drugs with new mechanisms of action. Antimicrobial peptides (AMPs) are promising candidates that could address the spread of multidrug-resistant bacteria, either alone or in combination with conventional antibiotics. We studied the antimicrobial efficacy and bactericidal mechanism of cecropin A2, a 36-residue α-helical cationic peptide derived from Aedes aegypti cecropin A, focusing on the common pathogen Pseudomonas aeruginosa. The peptide showed little hemolytic activity and toxicity toward mammalian cells, and the MICs against most clinical P. aeruginosa isolates were 32 to 64 μg/ml, and its MICs versus other Gram-negative bacteria were 2 to 32 μg/ml. Importantly, cecropin A2 demonstrated synergistic activity against P. aeruginosa when combined with tetracycline, reducing the MICs of both agents by 8-fold. The combination was also effective in vivo in the P. aeruginosa/Galleria mellonella model (P < 0.001). We found that cecropin A2 bound to P. aeruginosa lipopolysaccharides, permeabilized the membrane, and interacted with the bacterial genomic DNA, thus facilitating the translocation of tetracycline into the cytoplasm. In summary, the combination of cecropin A2 and tetracycline demonstrated synergistic antibacterial activity against P. aeruginosa in vitro and in vivo, offering an alternative approach for the treatment of P. aeruginosa infections.

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 A Galleria mellonella infection model reveals double and triple antibiotic combination therapies with enhanced efficacy versus a multidrug-resistant strain of Pseudomonas aeruginosa

2014 ◽  
Vol 63 (7) ◽  
pp. 945-955 ◽  
Author(s):  
Jessica Krezdorn ◽  
Sophie Adams ◽  
Peter J. Coote
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistant Strain ◽  
Galleria Mellonella ◽  
Multidrug Resistant ◽  
Therapeutic Benefit ◽  
Infection Model ◽  
Combination Therapies ◽  
Multidrug Resistant Strain

The aim of this study was to compare the inhibitory effect of antibiotic combinations in vitro with efficacy in Galleria mellonella larvae in vivo to identify efficacious combinations that target Pseudomonas aeruginosa. P. aeruginosa NCTC 13437, a multidrug-resistant strain resistant to β-lactams and aminoglycosides, was used. Susceptibility to cefotaxime, piperacillin, meropenem, amikacin, levofloxacin and colistin alone, or in dual or triple combinations, was measured in vitro via a 24 h time-kill assay. In vitro results were then compared with the efficacy of the same dual or triple antibiotic combinations versus G. mellonella larvae infected with P. aeruginosa. G. mellonella haemolymph burden of P. aeruginosa was determined over 96 h post-infection and treatment with the most potent combination therapies. Many dual and triple combinations of antibiotics displayed synergistic inhibition of multidrug-resistant P. aeruginosa in vitro. There was little correlation between combinations that were synergistic in vitro and those that showed enhanced efficacy in vivo versus infected G. mellonella larvae. The most potent dual and triple combinations in vivo were cefotaxime plus piperacillin, and meropenem plus piperacillin and amikacin, respectively. Fewer combinations were found to offer enhanced therapeutic benefit in vivo compared with in vitro. The therapeutic benefit arising from treatment with antibiotic combinations in vivo correlated with reduced larval burden of P. aeruginosa. This study has identified antibiotic combinations that merit further investigation for their clinical potential and has demonstrated the utility of using G. mellonella to screen for novel antibiotic treatments that demonstrate efficacy in vivo.

scholarly journals Multicenter Evaluation of Ceftazidime-Avibactam and Ceftolozane-Tazobactam Inhibitory Activity against Meropenem-Nonsusceptible Pseudomonas aeruginosa from Blood, Respiratory Tract, and Wounds

2017 ◽  
Vol 61 (10) ◽  
Author(s):  
Mordechai Grupper ◽  
Christina Sutherland ◽  
David P. Nicolau
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Activity ◽  
Clinical Utility ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Broth Microdilution ◽  
Content Type ◽  
Carbapenem Resistant

ABSTRACT The recent escalation of occurrences of carbapenem-resistant Pseudomonas aeruginosa has been recognized globally and threatens to erode the widespread clinical utility of the carbapenem class of compounds for this prevalent health care-associated pathogen. Here, we compared the in vitro inhibitory activity of ceftazidime-avibactam and ceftolozane-tazobactam against 290 meropenem-nonsusceptible Pseudomonas aeruginosa nonduplicate clinical isolates from 34 U.S. hospitals using reference broth microdilution methods. Ceftazidime-avibactam and ceftolozane-tazobactam were active, with ceftolozane-tazobactam having significantly higher inhibitory activity than ceftazidime-avibactam. The heightened inhibitory activity of ceftolozane-tazobactam was sustained when the site of origin (respiratory, blood, or wound) and nonsusceptibility to other β-lactam antimicrobials was considered. An extensive genotypic search for enzymatically driven β-lactam resistance mechanisms revealed the exclusive presence of the VIM metallo-β-lactamase among only 4% of the subset of isolates nonsusceptible to ceftazidime-avibactam, ceftolozane-tazobactam, or both. These findings suggest an important role for both ceftazidime-avibactam and ceftolozane-tazobactam against carbapenem-nonsusceptible Pseudomonas aeruginosa. Further in vitro and in vivo studies are needed to better define the clinical utility of these novel therapies against the increasingly prevalent threat of multidrug-resistant Pseudomonas aeruginosa.

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