Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.

Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbi...

Full description

Bibliographic Details
Main Authors: Eduardo Lopez-Medina, Di Fan, Laura A Coughlin, Evi X Ho, Iain L Lamont, Cornelia Reimmann, Lora V Hooper, Andrew Y Koh
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-08-01
Series:PLoS Pathogens
Online Access:http://europepmc.org/articles/PMC4552174?pdf=render
_version_ 1819114249606135808
author Eduardo Lopez-Medina
Di Fan
Laura A Coughlin
Evi X Ho
Iain L Lamont
Cornelia Reimmann
Lora V Hooper
Andrew Y Koh
author_facet Eduardo Lopez-Medina
Di Fan
Laura A Coughlin
Evi X Ho
Iain L Lamont
Cornelia Reimmann
Lora V Hooper
Andrew Y Koh
author_sort Eduardo Lopez-Medina
collection DOAJ
description Bacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa's ability to colonize the GI tract but does decrease P. aeruginosa's cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease.
first_indexed 2024-12-22T04:42:18Z
format Article
id doaj.art-54f19634643b41e3b0aa9de67eab08e4
institution Directory Open Access Journal
issn 1553-7366
1553-7374
language English
last_indexed 2024-12-22T04:42:18Z
publishDate 2015-08-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Pathogens
spelling doaj.art-54f19634643b41e3b0aa9de67eab08e42022-12-21T18:38:43ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742015-08-01118e100512910.1371/journal.ppat.1005129Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.Eduardo Lopez-MedinaDi FanLaura A CoughlinEvi X HoIain L LamontCornelia ReimmannLora V HooperAndrew Y KohBacterial-fungal interactions have important physiologic and medical ramifications, but the mechanisms of these interactions are poorly understood. The gut is host to trillions of microorganisms, and bacterial-fungal interactions are likely to be important. Using a neutropenic mouse model of microbial gastrointestinal colonization and dissemination, we show that the fungus Candida albicans inhibits the virulence of the bacterium Pseudomonas aeruginosa by inhibiting P. aeruginosa pyochelin and pyoverdine gene expression, which plays a critical role in iron acquisition and virulence. Accordingly, deletion of both P. aeruginosa pyochelin and pyoverdine genes attenuates P. aeruginosa virulence. Heat-killed C. albicans has no effect on P. aeruginosa, whereas C. albicans secreted proteins directly suppress P. aeruginosa pyoverdine and pyochelin expression and inhibit P. aeruginosa virulence in mice. Interestingly, suppression or deletion of pyochelin and pyoverdine genes has no effect on P. aeruginosa's ability to colonize the GI tract but does decrease P. aeruginosa's cytotoxic effect on cultured colonocytes. Finally, oral iron supplementation restores P. aeruginosa virulence in P. aeruginosa and C. albicans colonized mice. Together, our findings provide insight into how a bacterial-fungal interaction can modulate bacterial virulence in the intestine. Previously described bacterial-fungal antagonistic interactions have focused on growth inhibition or colonization inhibition/modulation, yet here we describe a novel observation of fungal-inhibition of bacterial effectors critical for virulence but not important for colonization. These findings validate the use of a mammalian model system to explore the complexities of polymicrobial, polykingdom infections in order to identify new therapeutic targets for preventing microbial disease.http://europepmc.org/articles/PMC4552174?pdf=render
spellingShingle Eduardo Lopez-Medina
Di Fan
Laura A Coughlin
Evi X Ho
Iain L Lamont
Cornelia Reimmann
Lora V Hooper
Andrew Y Koh
Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.
PLoS Pathogens
title Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.
title_full Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.
title_fullStr Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.
title_full_unstemmed Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.
title_short Candida albicans Inhibits Pseudomonas aeruginosa Virulence through Suppression of Pyochelin and Pyoverdine Biosynthesis.
title_sort candida albicans inhibits pseudomonas aeruginosa virulence through suppression of pyochelin and pyoverdine biosynthesis
url http://europepmc.org/articles/PMC4552174?pdf=render
work_keys_str_mv AT eduardolopezmedina candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT difan candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT lauraacoughlin candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT evixho candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT iainllamont candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT corneliareimmann candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT loravhooper candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis
AT andrewykoh candidaalbicansinhibitspseudomonasaeruginosavirulencethroughsuppressionofpyochelinandpyoverdinebiosynthesis