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Studies of Pseudomonas aeruginosa Mutants Indicate Pyoverdine as the Central Factor in Inhibition of Aspergillus fumigatus Biofilm.
Sass, Gabriele; Nazik, Hasan; Penner, John; Shah, Hemi; Ansari, Shajia Rahman; Clemons, Karl V; Groleau, Marie-Christine; Dietl, Anna-Maria; Visca, Paolo; Haas, Hubertus; Déziel, Eric; Stevens, David A.
  • Sass G; California Institute for Medical Research, San Jose, California, USA.
  • Nazik H; California Institute for Medical Research, San Jose, California, USA.
  • Penner J; Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.
  • Shah H; Department of Microbiology, Istanbul University, Istanbul, Turkey.
  • Ansari SR; California Institute for Medical Research, San Jose, California, USA.
  • Clemons KV; California Institute for Medical Research, San Jose, California, USA.
  • Groleau MC; California Institute for Medical Research, San Jose, California, USA.
  • Dietl AM; California Institute for Medical Research, San Jose, California, USA.
  • Visca P; Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.
  • Haas H; INRS-Institut Armand-Frappier, Laval, Quebec, Canada.
  • Déziel E; Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
  • Stevens DA; Department of Sciences, Roma Tre University, Rome, Italy.
J Bacteriol ; 200(1)2018 01 01.
Article en En | MEDLINE | ID: mdl-29038255
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. fumigatusin 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. fumigatusIMPORTANCE 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.
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Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Oligopéptidos / Pseudomonas aeruginosa / Aspergillus fumigatus / Biopelículas / Antibiosis / Mutación Tipo de estudio: Prognostic_studies Límite: Humans Idioma: En Año: 2018 Tipo del documento: Article

Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Oligopéptidos / Pseudomonas aeruginosa / Aspergillus fumigatus / Biopelículas / Antibiosis / Mutación Tipo de estudio: Prognostic_studies Límite: Humans Idioma: En Año: 2018 Tipo del documento: Article