Voltammetric profiling of redox-active metabolites expressed by Pseudomonas aeruginosa for diagnostic purposes

2015 ◽  
Vol 51 (18) ◽  
pp. 3789-3792 ◽  
Author(s):  
T. Seviour ◽  
L. E. Doyle ◽  
S. J. L. Lauw ◽  
J. Hinks ◽  
S. A. Rice ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Potential Bias ◽  
Active Metabolites ◽  
Voltammetric Analysis ◽  
Redox Active

Voltammetric analysis ofPseudomonas aeruginosagrowth cultures unveils the interplay between PQS and phenazines under a potential bias.

scholarly journals Extracellular DNA promotes efficient extracellular electron transfer by pyocyanin in Pseudomonas aeruginosa biofilms

2019 ◽  
Author(s):  
Scott H. Saunders ◽  
Edmund C.M. Tse ◽  
Matthew D. Yates ◽  
Fernanda Jiménez Otero ◽  
Scott A. Trammell ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Electron Transfer ◽  
Redox Reactions ◽  
Extracellular Dna ◽  
Extracellular Electron Transfer ◽  
Bacterial Biofilms ◽  
Active Metabolites ◽  
Electron Shuttles ◽  
Redox Active

SUMMARYExtracellular electron transfer (EET), the process whereby cells access electron acceptors or donors that reside many cell lengths away, enables metabolic activity by microorganisms, particularly under oxidant-limited conditions that occur in multicellular bacterial biofilms. Although different mechanisms underpin this process in select organisms, a widespread strategy involves extracellular electron shuttles, redox-active metabolites that are secreted and recycled by diverse bacteria. How these shuttles catalyze electron transfer within biofilms without being lost to the environment has been a long-standing question. Here, we show that phenazine electron shuttles mediate efficient EET through interactions with extracellular DNA (eDNA) in Pseudomonas aeruginosa biofilms, which are important in nature and disease. Retention of pyocyanin (PYO) and phenazine carboxamide in the biofilm matrix is facilitated by binding to eDNA. In vitro, different phenazines can exchange electrons in the presence or absence of DNA and phenazines can participate directly in redox reactions through DNA; the biofilm eDNA can also support rapid electron transfer between redox active intercalators. Electrochemical measurements of biofilms indicate that retained PYO supports an efficient redox cycle with rapid EET and slow loss from the biofilm. Together, these results establish that eDNA facilitates phenazine metabolic processes in P. aeruginosa biofilms, suggesting a model for how extracellular electron shuttles achieve retention and efficient EET in biofilms.

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 Redox regulation as a platform for search and design of new type drugs. Search of gastroprotectors among sunstituted coumarins

2014 ◽  
Vol 12 (4) ◽  
pp. 22-42
Author(s):  
Edgar Andreevich Parfenov ◽  
Vladimir Alexandrovich Trapkov ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Redox Regulation ◽  
Redox Homeostasis ◽  
Complex Compounds ◽  
Active Metabolites ◽  
Defence Mechanisms ◽  
Redox Active ◽  
Acute Ethanol ◽  
New Type ◽  
Important Position ◽  
Effective Drugs

Redox homeostasis controls most or all processes of normal and pathological physiology. Important position in the defence mechanisms are redox active metabolites As a robust platform for the development of new effective drugs is not screened, but directed the design and search for low molecular weight metabolites natural redox active compounds. This statement confirms the synthesis and study of new gastroprotektors of complex compounds of copper and zinc with coumarin ligands. On the model of acute ethanol rat gastric ulcer shown that preprocessing all tested complex compounds in equimolar doses of 0.15 mmol/kg leads to a considerable reduction in the size of the damage to the wall of the stomach, compared to control, and sucralfat (for 72,5-87,9 %, sucralfat - 52,3%).

scholarly journals PhdA Catalyzes the First Step of Phenazine-1-Carboxylic Acid Degradation in Mycobacterium fortuitum

2018 ◽  
Vol 200 (10) ◽  
Author(s):  
Kyle C. Costa ◽  
Leon S. Moskatel ◽  
Lucas A. Meirelles ◽  
Dianne K. Newman
Keyword(s):  
Carboxylic Acid ◽  
Biofilm Formation ◽  
Flavin Mononucleotide ◽  
Mycobacterium Fortuitum ◽  
Active Metabolites ◽  
Gene Encoding ◽  
Content Type ◽  
Acid Degradation ◽  
Fitness Advantage ◽  
Redox Active

ABSTRACT Phenazines are a class of bacterially produced redox-active metabolites that are found in natural, industrial, and clinical environments. In Pseudomonas spp., phenazine-1-carboxylic acid (PCA)—the precursor of all phenazine metabolites—facilitates nutrient acquisition, biofilm formation, and competition with other organisms. While the removal of phenazines negatively impacts these activities, little is known about the genes or enzymes responsible for phenazine degradation by other organisms. Here, we report that the first step of PCA degradation by Mycobacterium fortuitum is catalyzed by a ph enazine- d egrading decarboxylase (PhdA). PhdA is related to members of the UbiD protein family that rely on a prenylated flavin mononucleotide cofactor for activity. The gene for PhdB, the enzyme responsible for cofactor synthesis, is present in a putative operon with the gene encoding PhdA in a region of the M. fortuitum genome that is essential for PCA degradation. PhdA and PhdB are present in all known PCA-degrading organisms from the Actinobacteria . M. fortuitum can also catabolize other Pseudomonas -derived phenazines such as phenazine-1-carboxamide, 1-hydroxyphenazine, and pyocyanin. On the basis of our previous work and the current characterization of PhdA, we propose that degradation converges on a common intermediate: dihydroxyphenazine. An understanding of the genes responsible for degradation will enable targeted studies of phenazine degraders in diverse environments. IMPORTANCE Bacteria from phylogenetically diverse groups secrete redox-active metabolites that provide a fitness advantage for their producers. For example, phenazines from Pseudomonas spp. benefit the producers by facilitating anoxic survival and biofilm formation and additionally inhibit competitors by serving as antimicrobials. Phenazine-producing pseudomonads act as biocontrol agents by leveraging these antibiotic properties to inhibit plant pests. Despite this importance, the fate of phenazines in the environment is poorly understood. Here, we characterize an enzyme from Mycobacterium fortuitum that catalyzes the first step of phenazine-1-carboxylic acid degradation. Knowledge of the genetic basis of phenazine degradation will facilitate the identification of environments where this activity influences the microbial community structure.

scholarly journals Selenomethionine: A Pink Trojan Redox Horse with Implications in Aging and Various Age-Related Diseases

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 882
Author(s):  
Muhammad Jawad Nasim ◽  
Mhd Mouayad Zuraik ◽  
Ahmad Yaman Abdin ◽  
Yannick Ney ◽  
Claus Jacob
Keyword(s):  
Mammalian Cells ◽  
Active Metabolites ◽  
Selenium Compounds ◽  
Redox Biology ◽  
Physiological Conditions ◽  
Organic Selenium ◽  
Age Related ◽  
Redox Active ◽  
Aging Health ◽  
Sulfur Analog

Selenium is an essential trace element. Although this chalcogen forms a wide variety of compounds, there are surprisingly few small-molecule organic selenium compounds (OSeCs) in biology. Besides its more prominent relative selenocysteine (SeCys), the amino acid selenomethionine (SeMet) is one example. SeMet is synthesized in plants and some fungi and, via nutrition, finds its way into mammalian cells. In contrast to its sulfur analog methionine (Met), SeMet is extraordinarily redox active under physiological conditions and via its catalytic selenide (RSeR’)/selenoxide (RSe(O)R’) couple provides protection against reactive oxygen species (ROS) and other possibly harmful oxidants. In contrast to SeCys, which is incorporated via an eloquent ribosomal mechanism, SeMet can enter such biomolecules by simply replacing proteinogenic Met. Interestingly, eukaryotes, such as yeast and mammals, also metabolize SeMet to a small family of reactive selenium species (RSeS). Together, SeMet, proteins containing SeMet and metabolites of SeMet form a powerful triad of redox-active metabolites with a plethora of biological implications. In any case, SeMet and its family of natural RSeS provide plenty of opportunities for studies in the fields of nutrition, aging, health and redox biology.

scholarly journals Pseudomonas aeruginosa Pyocyanin Is Critical for Lung Infection in Mice

2004 ◽  
Vol 72 (7) ◽  
pp. 4275-4278 ◽  
Author(s):  
Gee W. Lau ◽  
Huimin Ran ◽  
Fansheng Kong ◽  
Daniel J. Hassett ◽  
Dimitri Mavrodi
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Epithelial Cells ◽  
Respiratory Tract ◽  
Tissue Damage ◽  
Lung Infection ◽  
Lung Epithelial Cells ◽  
Cellular Processes ◽  
Redox Active ◽  
Lung Epithelial

ABSTRACT Pseudomonas aeruginosa secretes copious amounts of the redox-active phenazine, pyocyanin (PCN), during cystic fibrosis lung infection. PCN has been shown to interfere with a variety of cellular processes in cultured lung epithelial cells. Here, by using two respiratory tract models of infection, we demonstrate that PCN mediates tissue damage and necrosis during lung infection.

scholarly journals The lytic polysaccharide monooxygenase CbpD promotes Pseudomonas aeruginosa virulence in systemic infection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fatemeh Askarian ◽  
Satoshi Uchiyama ◽  
Helen Masson ◽  
Henrik Vinther Sørensen ◽  
Ole Golten ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Catalytic Activity ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Systemic Infection ◽  
Lytic Polysaccharide Monooxygenase ◽  
Redox Active ◽  
Polysaccharide Monooxygenases ◽  
Dynamics Simulations

AbstractThe recently discovered lytic polysaccharide monooxygenases (LPMOs), which cleave polysaccharides by oxidation, have been associated with bacterial virulence, but supporting functional data is scarce. Here we show that CbpD, the LPMO of Pseudomonas aeruginosa, is a chitin-oxidizing virulence factor that promotes survival of the bacterium in human blood. The catalytic activity of CbpD was promoted by azurin and pyocyanin, two redox-active virulence factors also secreted by P. aeruginosa. Homology modeling, molecular dynamics simulations, and small angle X-ray scattering indicated that CbpD is a monomeric tri-modular enzyme with flexible linkers. Deletion of cbpD rendered P. aeruginosa unable to establish a lethal systemic infection, associated with enhanced bacterial clearance in vivo. CbpD-dependent survival of the wild-type bacterium was not attributable to dampening of pro-inflammatory responses by CbpD ex vivo or in vivo. Rather, we found that CbpD attenuates the terminal complement cascade in human serum. Studies with an active site mutant of CbpD indicated that catalytic activity is crucial for virulence function. Finally, profiling of the bacterial and splenic proteomes showed that the lack of this single enzyme resulted in substantial re-organization of the bacterial and host proteomes. LPMOs similar to CbpD occur in other pathogens and may have similar immune evasive functions.

scholarly journals Pseudomonas aeruginosa-Candida albicans Interactions: Localization and Fungal Toxicity of a Phenazine Derivative

2008 ◽  
Vol 75 (2) ◽  
pp. 504-513 ◽  
Author(s):  
Jane Gibson ◽  
Arpana Sood ◽  
Deborah A. Hogan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Small Molecules ◽  
Solid Medium ◽  
Genetic Screen ◽  
Red Pigment ◽  
Pigment Formation ◽  
Intracellular Targeting ◽  
Phenazine Derivative ◽  
Redox Active

ABSTRACT Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa and Candida albicans were cocultured on solid medium, a red pigmentation developed that was dependent on P. aeruginosa phenazine biosynthetic genes. Through a genetic screen in combination with biochemical experiments, it was found that a P. aeruginosa-produced precursor to pyocyanin, proposed to be 5-methyl-phenazinium-1-carboxylate (5MPCA), was necessary for the formation of the red pigmentation. The 5MPCA-derived pigment was found to accumulate exclusively within fungal cells, where it retained the ability to be reversibly oxidized and reduced, and its detection correlated with decreased fungal viability. Pyocyanin was not required for pigment formation or fungal killing. Spectral analyses showed that the partially purified pigment from within the fungus differed from aeruginosins A and B, two red phenazine derivatives formed late in P. aeruginosa cultures. The red pigment isolated from C. albicans that had been cocultured with P. aeruginosa was heterogeneous and difficult to release from fungal cells, suggesting its modification within the fungus. These findings suggest that intracellular targeting of some phenazines may contribute to their toxicity and that this strategy could be useful in developing new antifungals.

scholarly journals CMOS Electrochemical Sensing Platform for Spatially Resolved Detection of Redox-Active Metabolites Released by Multicellular Films

2014 ◽  
Vol 106 (2) ◽  
pp. 812a ◽  
Author(s):  
Daniel L. Bellin ◽  
Hassan Sakhtah ◽  
Jacob K. Rosenstein ◽  
Peter M. Levine ◽  
Jordan Thimot ◽  
...  
Keyword(s):  
Electrochemical Sensing ◽  
Active Metabolites ◽  
Spatially Resolved ◽  
Sensing Platform ◽  
Redox Active
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