scholarly journals Bacteriophage-Based Biosensing of Pseudomonas aeruginosa: An Integrated Approach for the Putative Real-Time Detection of Multi-Drug-Resistant Strains

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 124
Author(s):  
Liliam K. Harada ◽  
Waldemar Bonventi Júnior ◽  
Erica C. Silva ◽  
Thais J. Oliveira ◽  
Fernanda C. Moreli ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Research Effort ◽  
Acquired Resistance ◽  
Integrated Approach ◽  
Healthcare Services ◽  
Host Cells ◽  
Color Changes ◽  
Metabolic Versatility ◽  
The Matrix

During the last decennium, it has become widely accepted that ubiquitous bacterial viruses, or bacteriophages, exert enormous influences on our planet’s biosphere, killing between 4–50% of the daily produced bacteria and constituting the largest genetic diversity pool on our planet. Currently, bacterial infections linked to healthcare services are widespread, which, when associated with the increasing surge of antibiotic-resistant microorganisms, play a major role in patient morbidity and mortality. In this scenario, Pseudomonas aeruginosa alone is responsible for ca. 13–15% of all hospital-acquired infections. The pathogen P. aeruginosa is an opportunistic one, being endowed with metabolic versatility and high (both intrinsic and acquired) resistance to antibiotics. Bacteriophages (or phages) have been recognized as a tool with high potential for the detection of bacterial infections since these metabolically inert entities specifically attach to, and lyse, bacterial host cells, thus, allowing confirmation of the presence of viable cells. In the research effort described herein, three different phages with broad lytic spectrum capable of infecting P. aeruginosa were isolated from environmental sources. The isolated phages were elected on the basis of their ability to form clear and distinctive plaques, which is a hallmark characteristic of virulent phages. Next, their structural and functional stabilization was achieved via entrapment within the matrix of porous alginate, biopolymeric, and bio-reactive, chromogenic hydrogels aiming at their use as sensitive matrices producing both color changes and/or light emissions evolving from a reaction with (released) cytoplasmic moieties, as a bio-detection kit for P. aeruginosa cells. Full physicochemical and biological characterization of the isolated bacteriophages was the subject of a previous research paper.

scholarly journals Pseudomonas aeruginosa GroEL Stimulates Production of PTX3 by Activating the NF-κB Pathway and Simultaneously Downregulating MicroRNA-9

2016 ◽  
Vol 85 (3) ◽  
Author(s):  
Heesung Shin ◽  
Jisu Jeon ◽  
Jung-Hoon Lee ◽  
Shouguang Jin ◽  
Un-Hwan Ha
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Therapeutic Potential ◽  
Host Cells ◽  
Soluble Form ◽  
Heat Shock Protein 60 ◽  
Toll Like Receptor 4 ◽  
Content Type ◽  
Host Immune Responses ◽  
Recognition Receptor

ABSTRACT As one of the first lines of host defense, monocytes play important roles in clearing infected microbes. The defensive response is triggered by recognition of diverse microbial moieties, including released factors, which modulate host immune responses to establish a harsh environment for clinically important bacterial pathogens. In this study, we found that the expression of PTX3, a soluble form of pattern recognition receptor, was induced by infection with live Pseudomonas aeruginosa or treatment of cells with its supernatant. P. aeruginosa GroEL, a homolog of heat shock protein 60, was identified as one of the factors responsible for inducing the expression of PTX3 in host cells. GroEL induced PTX3 expression by activating the Toll-like receptor 4 (TLR4)-dependent pathway via nuclear factor-kappa B (NF-κB), while simultaneously inhibiting expression of microRNA-9, which targets the PTX3 transcript. Finally, by acting as an opsonin, GroEL-induced PTX3 promoted the association and phagocytosis of Staphylococcus aureus into macrophages. These data suggest that the host defensive environment is supported by the production of PTX3 in response to GroEL, which thus has therapeutic potential for clearance of bacterial infections.

Ceramide in bacterial infections and cystic fibrosis

2008 ◽  
Vol 389 (11) ◽  
Author(s):  
Heike Grassmé ◽  
Katrin Anne Becker ◽  
Yang Zhang ◽  
Erich Gulbins
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
De Novo ◽  
Acid Sphingomyelinase ◽  
Temporal Organization ◽  
Host Cells ◽  
Host Responses ◽  
Mammalian Host ◽  
Membrane Domains

AbstractCeramide is formed by the activity of sphingomyelinases, by degradation of complex sphingolipids, reverse ceramidase activity orde novosynthesized. The formation of ceramide within biological membranes results in the formation of large ceramide-enriched membrane domains. These domains serve the spatial and temporal organization of receptors and signaling molecules. The acid sphingomyelinase-ceramide system plays an important role in the infection of mammalian host cells with bacterial pathogens such asNeisseria gonorrhoeae,Escherichia coli,Staphylococcus aureus,Listeria monocytogenes,Salmonella typhimuriumandPseudomonas aeruginosa. Ceramide and ceramide-enriched membrane platforms are also involved in the induction of apoptosis in infected cells, such as in epithelial and endothelial cells after infection withPseudomonas aeruginosaandStaphylococcus aureus, respectively. Finally, ceramide-enriched membrane platforms are critical regulators of the release of pro-inflammatory cytokines upon infection. The diverse functions of ceramide in bacterial infections suggest that ceramide and ceramide-enriched membrane domains are key players in host responses to many pathogens and thus are potential novel targets to treat infections.

scholarly journals Neutron crystallography reveals novel mechanisms used by Pseudomonas aeruginosa for host-cell binding

2021 ◽  
Author(s):  
Lukas Gajdos ◽  
Matthew P Blakeley ◽  
Michael Haertlein ◽  
V Trevor Forsyth ◽  
Juliette M Devos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Calcium Ions ◽  
Bacterial Infections ◽  
Opportunistic Pathogen ◽  
Host Cells ◽  
Carbohydrate Binding ◽  
Hydrogen Atoms ◽  
High Affinity ◽  
Structural Details ◽  
Neutron Crystallography

The opportunistic pathogen Pseudomonas aeruginosa, a major cause of nosocomial infections, uses carbohydrate-binding proteins (lectins) as part of its binding to host cells. The fucose-binding lectin, LecB, displays a unique carbohydrate-binding site that incorporates two closely located calcium ions bridging between the ligand and protein, providing specificity and unusually high affinity. Here, we investigate the mechanisms involved in binding based on neutron crystallography studies of a fully deuterated LecB/fucose/calcium complex. The neutron structure, which includes the positions of all the hydrogen atoms, reveals that the high affinity of binding may be related to the occurrence of a low barrier hydrogen bond induced by the proximity of the two calcium ions, the presence of coordination rings between the sugar, calcium and LecB, and the dynamic behaviour of bridging water molecules at room temperature. These key structural details may assist in the design of anti-adhesive compounds to combat multi-resistance bacterial infections.

scholarly journals Comprehensive Host Cell-Based Screening Assays for Identification of Anti-Virulence Drugs Targeting Pseudomonas aeruginosa and Salmonella Typhimurium

2020 ◽  
Vol 8 (8) ◽  
pp. 1096
Author(s):  
Julia von Ambüren ◽  
Fynn Schreiber ◽  
Julia Fischer ◽  
Sandra Winter ◽  
Edeltraud van Gumpel ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Host Cell ◽  
Bacterial Infections ◽  
Host Cells ◽  
Infection Model ◽  
Serovar Typhimurium ◽  
New Antibiotics ◽  
Screening Assays ◽  
Screening Platform

The prevalence of bacterial pathogens being resistant to antibiotic treatment is increasing worldwide, leading to a severe global health challenge. Simultaneously, the development and approval of new antibiotics stagnated in the past decades, leading to an urgent need for novel approaches to avoid the spread of untreatable bacterial infections in the future. We developed a highly comprehensive screening platform based on quantification of pathogen driven host-cell death to detect new anti-virulence drugs targeting Pseudomonas aeruginosa (Pa) and Salmonella enterica serovar Typhimurium (ST), both known for their emerging antibiotic resistance. By screening over 10,000 small molecules we could identify several substances showing promising effects on Pa and ST pathogenicity in our in vitro infection model. Importantly, we could detect compounds potently inhibiting bacteria induced killing of host cells and one novel comipound with impact on the function of the type 3 secretion system (T3SS) of ST. Thus, we provide proof of concept data of rapid and feasible medium- to high-throughput drug screening assays targeting virulence mechanisms of two major Gram-negative pathogens.

scholarly journals A Cationic Porphyrin, ZnPor, Disassembles Pseudomonas aeruginosa Biofilm Matrix, Kills Cells Directly, and Enhances Antibiotic Activity of Tobramycin

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 875
Author(s):  
Neha Patel ◽  
Shawn Swavey ◽  
Jayne Robinson
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Opportunistic Pathogen ◽  
Uptake System ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Antibiotic Resistant ◽  
The Matrix ◽  
Life Threatening ◽  
Pre Treatment

One of the greatest threats to human health is the rise in antibiotic-resistant bacterial infections. Pseudomonas aeruginosa (PsA) is an “opportunistic” pathogen known to cause life-threatening infections in immunocompromised individuals and is the most common pathogen in adults with cystic fibrosis (CF). We report here a cationic zinc (II) porphyrin, ZnPor, that effectively kills planktonic and biofilm-associated cells of PsA. In standard tests against 16–18 h-old biofilms, concentrations as low as 16 µg/mL resulted in the extensive disruption and detachment of the matrix. The pre-treatment of biofilms for 30 min with ZnPor at minimum inhibitory concentration (MIC) levels (4 µg/mL) substantially enhanced the ability of tobramycin (Tobra) to kill biofilm-associated cells. We demonstrate the rapid uptake and accumulation of ZnPor in planktonic cells even in dedicated heme-uptake system mutants (ΔPhu, ΔHas, and the double mutant). Furthermore, uptake was unaffected by the ionophore carbonyl cyanide m-chlorophenyl hydrazine (CCCP). Cells pre-exposed to ZnPor took up the cell-impermeant dye SYTOXTM Green in a concentration-dependent manner. The accumulation of ZnPor did not result in cell lysis, nor did the cells develop resistance. Taken together, these properties make ZnPor a promising candidate for treating multi-drug-resistant infections, including persistent, antibiotic-resistant biofilms.

scholarly journals Neutron crystallography reveals mechanisms used by Pseudomonas aeruginosa for host-cell binding

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Lukas Gajdos ◽  
Matthew P. Blakeley ◽  
Michael Haertlein ◽  
V. Trevor Forsyth ◽  
Juliette M. Devos ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Calcium Ions ◽  
Bacterial Infections ◽  
Opportunistic Pathogen ◽  
Host Cells ◽  
Carbohydrate Binding ◽  
Hydrogen Atoms ◽  
High Affinity ◽  
Structural Details ◽  
Neutron Crystallography

AbstractThe opportunistic pathogen Pseudomonas aeruginosa, a major cause of nosocomial infections, uses carbohydrate-binding proteins (lectins) as part of its binding to host cells. The fucose-binding lectin, LecB, displays a unique carbohydrate-binding site that incorporates two closely located calcium ions bridging between the ligand and protein, providing specificity and unusually high affinity. Here, we investigate the mechanisms involved in binding based on neutron crystallography studies of a fully deuterated LecB/fucose/calcium complex. The neutron structure, which includes the positions of all the hydrogen atoms, reveals that the high affinity of binding may be related to the occurrence of a low-barrier hydrogen bond induced by the proximity of the two calcium ions, the presence of coordination rings between the sugar, calcium and LecB, and the dynamic behaviour of bridging water molecules at room temperature. These key structural details may assist in the design of anti-adhesive compounds to combat multi-resistance bacterial infections.

Ethanol Extract Of Centella Asiatica (L.) Urban Leaves Effectively Inhibit Streptococcus pyogenes and Pseudomonas aeruginosa by Invitro Test

2020 ◽  
Vol 2 (2) ◽  
pp. 69-76
Author(s):  
Dini Aulia Azmi ◽  
Nurlailah Nurlailah ◽  
Ratih Dewi Dwiyanti
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Streptococcus Pyogenes ◽  
Bacterial Infections ◽  
Herbal Medicines ◽  
Centella Asiatica ◽  
Ethanol Extract ◽  
Dilution Method ◽  
Initial Stage ◽  
Independent Variable

Streptococcus pyogenes and Pseudomonas aeruginosa are some of the causes of infectious diseases. Centella asiatica (L.) Urban has many benefits for humans, including overcoming fever, anti-bacterial, and anti-inflammatory. This study aims to determine the inhibition of Centella asiatica (L.) Urban leaves ethanol extract on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. This research is the initial stage of the development of herbal medicines to treat Streptococcus pyogenes and Pseudomonas aeruginosa infections. The independent variable was the concentration of ethanol extract of Centella asiatica (L.) Urban leaves and the dependent variable was the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. The anti-bacterial activity test was carried out by the liquid dilution method. The concentrations used are 20%, 40%, 60%, 80%. 100% The results showed that the minimum inhibitory concentration (MIC) against Streptococcus pyogenes: 40% and Pseudomonas aeruginosa: 40%. Minimum bactericidal concentration (MBC) results for Streptococcus pyogenes: 60% and Pseudomonas aeruginosa: 60%. So it can be concluded that there is inhibition of the ethanol extract of Centella asiatica (L.) Urban leaves on the growth of Streptococcus pyogenes and Pseudomonas aeruginosa. Centella Asiatica (L.) Urban extract has potential as herbal medicine against bacterial infections but requires further research to determine its effect in vivo.

scholarly journals Genome-Scale Metabolic Network Analysis of the Opportunistic Pathogen Pseudomonas aeruginosa PAO1

2008 ◽  
Vol 190 (8) ◽  
pp. 2790-2803 ◽  
Author(s):  
Matthew A. Oberhardt ◽  
Jacek Puchałka ◽  
Kimberly E. Fryer ◽  
Vítor A. P. Martins dos Santos ◽  
Jason A. Papin
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Metabolic Network ◽  
Opportunistic Pathogen ◽  
Scale Model ◽  
Modeling Framework ◽  
Major Life ◽  
Metabolic Versatility ◽  
A Genome ◽  
Scale Properties ◽  
Genome Scale

ABSTRACT Pseudomonas aeruginosa is a major life-threatening opportunistic pathogen that commonly infects immunocompromised patients. This bacterium owes its success as a pathogen largely to its metabolic versatility and flexibility. A thorough understanding of P. aeruginosa's metabolism is thus pivotal for the design of effective intervention strategies. Here we aim to provide, through systems analysis, a basis for the characterization of the genome-scale properties of this pathogen's versatile metabolic network. To this end, we reconstructed a genome-scale metabolic network of Pseudomonas aeruginosa PAO1. This reconstruction accounts for 1,056 genes (19% of the genome), 1,030 proteins, and 883 reactions. Flux balance analysis was used to identify key features of P. aeruginosa metabolism, such as growth yield, under defined conditions and with defined knowledge gaps within the network. BIOLOG substrate oxidation data were used in model expansion, and a genome-scale transposon knockout set was compared against in silico knockout predictions to validate the model. Ultimately, this genome-scale model provides a basic modeling framework with which to explore the metabolism of P. aeruginosa in the context of its environmental and genetic constraints, thereby contributing to a more thorough understanding of the genotype-phenotype relationships in this resourceful and dangerous pathogen.

scholarly journals Tackling Virulence of Pseudomonas aeruginosa by the Natural Furanone Sotolon

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 871
Author(s):  
Mohammed F. Aldawsari ◽  
El-Sayed Khafagy ◽  
Ahmed Al Saqr ◽  
Ahmed Alalaiwe ◽  
Hisham A. Abbas ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Bacterial Infections ◽  
Therapeutic Agent ◽  
Bacterial Resistance ◽  
Inhibitory Concentration ◽  
Bacterial Biofilm ◽  
Resistant Bacteria ◽  
Resistance Development

The bacterial resistance development due to the incessant administration of antibiotics has led to difficulty in their treatment. Natural adjuvant compounds can be co-administered to hinder the pathogenesis of resistant bacteria. Sotolon is the prevailing aromatic compound that gives fenugreek its typical smell. In the current work, the anti-virulence activities of sotolon on Pseudomonas aeruginosa have been evaluated. P. aeruginosa has been treated with sotolon at sub-minimum inhibitory concentration (MIC), and production of biofilm and other virulence factors were assessed. Moreover, the anti-quorum sensing (QS) activity of sotolon was in-silico evaluated by evaluating the affinity of sotolon to bind to QS receptors, and the expression of QS genes was measured in the presence of sotolon sub-MIC. Furthermore, the sotolon in-vivo capability to protect mice against P. aeruginosa was assessed. Significantly, sotolon decreased the production of bacterial biofilm and virulence factors, the expression of QS genes, and protected mice from P. aeruginosa. Conclusively, the plant natural substance sotolon attenuated the pathogenicity of P. aeruginosa, locating it as a plausible potential therapeutic agent for the treatment of its infections. Sotolon can be used in the treatment of bacterial infections as an alternative or adjuvant to antibiotics to combat their high resistance to antibiotics.

scholarly journals Repeated isolation of an antibiotic-dependent and temperature-sensitive mutant of Pseudomonas aeruginosa from a cystic fibrosis patient

2020 ◽  
Author(s):  
Daniel J Wolter ◽  
Alison Scott ◽  
Catherine R Armbruster ◽  
Dale Whittington ◽  
John S Edgar ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Lipid A ◽  
Clinical Laboratory ◽  
Membrane Phospholipid ◽  
Growth Defect ◽  
Genetic Mutations ◽  
Temperature Sensitive ◽  
Isolation And Characterization

Abstract Background Bacteria adapt to survive and grow in different environments. Genetic mutations that promote bacterial survival under harsh conditions can also restrict growth. The causes and consequences of these adaptations have important implications for diagnosis, pathogenesis, and therapy. Objectives We describe the isolation and characterization of an antibiotic-dependent, temperature-sensitive Pseudomonas aeruginosa mutant chronically infecting the respiratory tract of a cystic fibrosis (CF) patient, underscoring the clinical challenges bacterial adaptations can present. Methods Respiratory samples collected from a CF patient during routine care were cultured for standard pathogens. P. aeruginosa isolates recovered from samples were analysed for in vitro growth characteristics, antibiotic susceptibility, clonality, and membrane phospholipid and lipid A composition. Genetic mutations were identified by whole genome sequencing. Results P. aeruginosa isolates collected over 5 years from respiratory samples of a CF patient frequently harboured a mutation in phosphatidylserine decarboxylase (psd), encoding an enzyme responsible for phospholipid synthesis. This mutant could only grow at 37°C when in the presence of supplemented magnesium, glycerol, or, surprisingly, the antibiotic sulfamethoxazole, which the source patient had repeatedly received. Of concern, this mutant was not detectable on standard selective medium at 37°C. This growth defect correlated with alterations in membrane phospholipid and lipid A content. Conclusions A P. aeruginosa mutant chronically infecting a CF patient exhibited dependence on sulphonamides and would likely evade detection using standard clinical laboratory methods. The diagnostic and therapeutic challenges presented by this mutant highlight the complex interplay between bacterial adaptation, antibiotics, and laboratory practices, during chronic bacterial infections.

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