scholarly journals Effects of ε-Polylysine on Pseudomonas Aeruginosa and Aspergillus Fumigatus Biofilm In Vitro

2017 ◽  
Vol 23 ◽  
pp. 4225-4229
Author(s):  
Lianhua Wei ◽  
Run Wu ◽  
Chuan Wang ◽  
Zixiang Wu
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Aspergillus Fumigatus

scholarly journals Studies of Pseudomonas aeruginosa Mutants Indicate Pyoverdine as the Central Factor in Inhibition of Aspergillus fumigatus Biofilm

2017 ◽  
Vol 200 (1) ◽  
Author(s):  
Gabriele Sass ◽  
Hasan Nazik ◽  
John Penner ◽  
Hemi Shah ◽  
Shajia Rahman Ansari ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Aspergillus Fumigatus ◽  
Fungal Pathogens ◽  
Human Pathogens ◽  
Biofilm Growth ◽  
Content Type ◽  
Iron Deprivation

ABSTRACT Pseudomonas aeruginosa and Aspergillus fumigatus are common opportunistic bacterial and fungal pathogens, respectively. They often coexist in airways of immunocompromised patients and individuals with cystic fibrosis, where they form biofilms and cause acute and chronic illnesses. Hence, the interactions between them have long been of interest and it is known that P. aeruginosa can inhibit A. fumigatus in vitro. We have approached the definition of the inhibitory P. aeruginosa molecules by studying 24 P. aeruginosa mutants with various virulence genes deleted for the ability to inhibit A. fumigatus biofilms. The ability of P. aeruginosa cells or their extracellular products produced during planktonic or biofilm growth to affect A. fumigatus biofilm metabolism or planktonic A. fumigatus growth was studied in agar and liquid assays using conidia or hyphae. Four mutants, the pvdD pchE, pvdD, lasR rhlR, and lasR mutants, were shown to be defective in various assays. This suggested the P. aeruginosa siderophore pyoverdine as the key inhibitory molecule, although additional quorum sensing-regulated factors likely contribute to the deficiency of the latter two mutants. Studies of pure pyoverdine substantiated these conclusions and included the restoration of inhibition by the pyoverdine deletion mutants. A correlation between the concentration of pyoverdine produced and antifungal activity was also observed in clinical P. aeruginosa isolates derived from lungs of cystic fibrosis patients. The key inhibitory mechanism of pyoverdine was chelation of iron and denial of iron to A. fumigatus. IMPORTANCE Interactions between human pathogens found in the same body locale are of vast interest. These interactions could result in exacerbation or amelioration of diseases. The bacterium Pseudomonas aeruginosa affects the growth of the fungus Aspergillus fumigatus. Both pathogens form biofilms that are resistant to therapeutic drugs and host immunity. P. aeruginosa and A. fumigatus biofilms are found in vivo, e.g., in the lungs of cystic fibrosis patients. Studying 24 P. aeruginosa mutants, we identified pyoverdine as the major anti-A. fumigatus compound produced by P. aeruginosa. Pyoverdine captures iron from the environment, thus depriving A. fumigatus of a nutrient essential for its growth and metabolism. We show how microbes of different kingdoms compete for essential resources. Iron deprivation could be a therapeutic approach to the control of pathogen growth.

scholarly journals Factoring in the Complexity of the Cystic Fibrosis Lung to Understand Aspergillus fumigatus and Pseudomonas aeruginosa Interactions

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 639 ◽  
Author(s):  
Emily Beswick ◽  
Jorge Amich ◽  
Sara Gago
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Aspergillus Fumigatus ◽  
Clinical Evidence ◽  
Respiratory Pathogen ◽  
Complex Environment ◽  
Comprehensive Overview ◽  
The Common ◽  
Combined Infection

Pseudomonas aeruginosa has long been established as the most prevalent respiratory pathogen in Cystic Fibrosis (CF) patients, with opportunistic infection causing profound morbidity and mortality. Recently, Aspergillus fumigatus has also been recognised as a key contributor to CF lung deterioration, being consistently associated with decreased lung function and worsened prognosis in these patients. As clinical evidence for the common occurrence of combined infection with these two pathogens increases, research into the mechanism and consequences of their interaction is becoming more relevant. Clinical evidence suggests a synergistic effect of combined infection, which translates into a poorer prognosis for the patients. In vitro results from the laboratory have identified a variety of possible synergistic and antagonistic interactions between A. fumigatus and P. aeruginosa. Here, we present a comprehensive overview of the complex environment of the CF lung and discuss how it needs to be considered to determine the exact molecular interactions that A. fumigatus and P. aeruginosa undergo during combined infection and their effects on the host.

scholarly journals Estudio in vitro de la acción microbicida del monopersulfato de potasio y el hipoclorito de sodio sobre los microorganismos más frecuentes en ambientes odontológicos

2019 ◽  
Author(s):  
◽  
Ezequiel Escudero Giacchella
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Aspergillus Fumigatus ◽  
Acinetobacter Baumanii

Las enfermedades transmitidas en los ambientes odontológicos constituyen un problema relevante en salud pública a nivel mundial; incluyendo en su etiología microorganismos oportunistas. Estos pueden adherirse fácilmente a distintas superficies de trabajo (mesadas, pisos, canillas, platinas de equipos odontológicos) desarrollando rápidamente la formación de biopelículas contaminantes (estructuras que contienen polisacáridos que originan una malla viscosa que permite la adhesión de otros gérmenes oportunistas). Las bacterias instaladas en la película son menos sensibles a desinfectantes que las planctónicas (libres o inmersas en un medio líquido). Entre los microorganismos oportunistas más frecuentes que se adhieren a diferentes sustratos figuran: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumanii y Aspergillus fumigatus. El objetivo general de esta investigación fue estudiar y comparar la acción microbicida del monopersulfato de potasio y el hipoclorito de sodio sobre los cinco microorganismos. Para cumplimentar el objetivo se utilizó in-vitro el método de dilución neutralización (AFNOR), para analizar el efecto microbicida del hipoclorito de sodio y el monopersulfato de potasio en cada unidad muestral (4 bacterias y 1 hongo). Las variables consideradas fueron: suspensión bacteriana/ fúngica, desinfectante y neutralizante. Los resultados obtenidos indicaron que el hipoclorito de sodio desarrolló acción microbicida en todas las cepas, mientras que el monopersulfato de potasio presentó sólo acción bactericida. Respecto a la acción fungicida del monopersulfato de potasio no hubo coincidencia con las indicaciones del fabricante en relación al tiempo de exposición, lográndose el efecto a las 10 horas de contacto. El conocimiento del mejor desinfectante en cada instancia particular; su acción; concentración; tiempo de exposición; técnica; almacenamiento y el control de las indicaciones del fabricante optimizan los resultados esperados.

scholarly journals Microbial glycoside hydrolases as antibiofilm agents with cross-kingdom activity

2017 ◽  
Author(s):  
Brendan D. Snarr ◽  
Perrin Baker ◽  
Natalie C. Bamford ◽  
Yukiko Sato ◽  
Hong Liu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mouse Model ◽  
Invasive Aspergillosis ◽  
Aspergillus Fumigatus ◽  
Antimicrobial Agents ◽  
Cell Damage ◽  
Antifungal Drugs ◽  
Glycoside Hydrolases ◽  
Intratracheal Administration

AbstractGalactosaminogalactan and Pel are cationic heteropolysaccharides produced by the opportunistic pathogens, Aspergillus fumigatus and Pseudomonas aeruginosa, respectively. These exopolysaccharides both contain 1,4-linked N-acetyl-D-galactosamine and play an important role in biofilm formation by these organisms. Proteins containing glycoside hydrolase domains have recently been identified within the biosynthetic pathway of each exopolysaccharide. Recombinant hydrolase domains from these proteins (Sph3h from A. fumigatus and PelAh from P. aeruginosa) were found to degrade their respective polysaccharides in vitro. We therefore hypothesized that these glycoside hydrolases could exhibit anti-biofilm activity, and further, given the chemical similarity between galactosaminogalactan and Pel, that they might display cross-species activity. Treatment of A. fumigatus with Sph3h disrupted A. fumigatus biofilms with an EC50 of 0.4 nM. PelAh treatment also disrupted pre-formed A. fumigatus biofilms with EC50 values similar to those obtained for Sph3h. In contrast, Sph3h was unable to disrupt P. aeruginosa Pel-based biofilms, despite being able to bind to the exopolysaccharide. Treatment of A. fumigatus hyphae with either Sph3h or PelAh significantly enhanced the activity of the antifungals posaconazole, amphotericin B and caspofungin, likely through increasing antifungal penetration of hyphae. Both enzymes were non-cytotoxic and protected A549 pulmonary epithelial cells from A. fumigatus-induced cell damage for up to 24 hours. Intratracheal administration of Sph3h was well tolerated, and reduced pulmonary fungal burden in a neutropenic mouse model of invasive aspergillosis. These findings suggest that glycoside hydrolases can exhibit activity against diverse microorganisms and may be useful as therapeutic agents by degrading biofilms and attenuating virulence.SignificanceThe production of biofilms is an important strategy used by both bacteria and fungi to colonize surfaces and to enhance resistance to killing by immune cells and antimicrobial agents. We demonstrate that glycoside hydrolases derived from the opportunistic fungus Aspergillus fumigatus and Gram-negative bacterium Pseudomonas aeruginosa can be exploited to disrupt pre-formed fungal biofilms and reduce virulence. Additionally, these glycoside hydrolases can be utilized to potentiate antifungal drugs by increasing their hyphal penetration, to protect human cells from fungal-induced injury and to attenuate virulence of A. fumigatus in a mouse model of invasive aspergillosis. The findings of this study identify recombinant microbial glycoside hydrolases as promising therapeutics with the potential for anti-biofilm activity against pathogens across different taxonomic kingdoms.

Bioactivity of Phenolic Compounds Extracted from Strawberry against Formation of Pseudomonas aeruginosa Biofilm

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Baydaa Hussein ◽  
Zainab A. Aldhaher ◽  
Shahrazad Najem Abdu-Allah ◽  
Adel Hamdan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phenolic Compounds ◽  
Biofilm Formation ◽  
Opportunistic Infections ◽  
Formation Rate ◽  
Hydrocarbon Chain ◽  
Health Concern ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenolic Contents

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.

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