Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway

ABSTRACTPseudomonas aeruginosa is a ubiquitous bacterium and a notorious opportunistic pathogen that forms biofilm structures in response to many environmental cues. Biofilm formation includes attachment to surfaces and the production of the exopolysaccharide Pel, which is present in both the PAO1 a...

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Main Authors: Somalisa Pan, Simon A. M. Underhill, Christopher W. Hamm, Mylissa A. Stover, Daxton R. Butler, Crystal A. Shults, Jacob R. Manjarrez, Matthew T. Cabeen
Format: Article
Language:English
Published: American Society for Microbiology 2024-04-01
Series:mSphere
Subjects:
Online Access:https://journals.asm.org/doi/10.1128/msphere.00786-23
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author Somalisa Pan
Simon A. M. Underhill
Christopher W. Hamm
Mylissa A. Stover
Daxton R. Butler
Crystal A. Shults
Jacob R. Manjarrez
Matthew T. Cabeen
author_facet Somalisa Pan
Simon A. M. Underhill
Christopher W. Hamm
Mylissa A. Stover
Daxton R. Butler
Crystal A. Shults
Jacob R. Manjarrez
Matthew T. Cabeen
author_sort Somalisa Pan
collection DOAJ
description ABSTRACTPseudomonas aeruginosa is a ubiquitous bacterium and a notorious opportunistic pathogen that forms biofilm structures in response to many environmental cues. Biofilm formation includes attachment to surfaces and the production of the exopolysaccharide Pel, which is present in both the PAO1 and PA14 laboratory strains of P. aeruginosa. Biofilms help protect bacterial cells from host defenses and antibiotics and abet infection. The carbon source used by the cells also influences biofilm, but these effects have not been deeply studied. We show here that glycerol, which can be liberated from host surfactants during infection, encourages surface attachment and magnifies colony morphology differences. We find that glycerol kinase is important but not essential for glycerol utilization and relatively unimportant for biofilm behaviors. Among downstream enzymes predicted to take part in glycerol utilization, Edd stood out as being important for glycerol utilization and for enhanced biofilm phenotypes in the presence of glycerol. Thus, gluconeogenesis and catabolism of anabolically produced glucose appear to impact not only the utilization of glycerol but also glycerol-stimulated biofilm phenotypes. Finally, waxworm moth larvae and nematode infection models reveal that interruption of the Entner-Doudoroff pathway, but not abrogation of glycerol phosphorylation, unexpectedly increases P. aeruginosa lethality in both acute and chronic infections, even while stimulating a stronger immune response by Caenorhabditis elegans.IMPORTANCEPseudomonas aeruginosa, the ubiquitous environmental bacterium and human pathogen, forms multicellular communities known as biofilms in response to various stimuli. We find that glycerol, a common carbon source that bacteria can use for energy and biosynthesis, encourages biofilm behaviors such as surface attachment and colony wrinkling by P. aeruginosa. Glycerol can be derived from surfactants that are present in the human lungs, a common infection site. Glycerol-stimulated biofilm phenotypes do not depend on phosphorylation of glycerol but are surprisingly impacted by a glucose breakdown pathway, suggesting that it is glycerol utilization, and not its mere presence or cellular import, that stimulates biofilm phenotypes. Moreover, the same mutations that block glycerol-stimulated biofilm phenotypes also impact P. aeruginosa virulence in both acute and chronic animal models. Notably, a glucose-breakdown mutant (Δedd) counteracts biofilm phenotypes but shows enhanced virulence and stimulates a stronger immune response in Caenorhabditis elegans.
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spelling doaj.art-fd78cce273a4451d9fab2413b949651c2024-04-23T13:00:40ZengAmerican Society for MicrobiologymSphere2379-50422024-04-019410.1128/msphere.00786-23Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathwaySomalisa Pan0Simon A. M. Underhill1Christopher W. Hamm2Mylissa A. Stover3Daxton R. Butler4Crystal A. Shults5Jacob R. Manjarrez6Matthew T. Cabeen7Department of Microbiology, Oklahoma State University, Stillwater, Oklahoma, USADepartment of Microbiology, Oklahoma State University, Stillwater, Oklahoma, USADepartment of Microbiology, Oklahoma State University, Stillwater, Oklahoma, USADepartment of Biochemistry and Microbiology, OSU Center for Health Sciences, Tulsa, Oklahoma, USADepartment of Microbiology, Oklahoma State University, Stillwater, Oklahoma, USADepartment of Biochemistry and Microbiology, OSU Center for Health Sciences, Tulsa, Oklahoma, USADepartment of Biochemistry and Microbiology, OSU Center for Health Sciences, Tulsa, Oklahoma, USADepartment of Microbiology, Oklahoma State University, Stillwater, Oklahoma, USAABSTRACTPseudomonas aeruginosa is a ubiquitous bacterium and a notorious opportunistic pathogen that forms biofilm structures in response to many environmental cues. Biofilm formation includes attachment to surfaces and the production of the exopolysaccharide Pel, which is present in both the PAO1 and PA14 laboratory strains of P. aeruginosa. Biofilms help protect bacterial cells from host defenses and antibiotics and abet infection. The carbon source used by the cells also influences biofilm, but these effects have not been deeply studied. We show here that glycerol, which can be liberated from host surfactants during infection, encourages surface attachment and magnifies colony morphology differences. We find that glycerol kinase is important but not essential for glycerol utilization and relatively unimportant for biofilm behaviors. Among downstream enzymes predicted to take part in glycerol utilization, Edd stood out as being important for glycerol utilization and for enhanced biofilm phenotypes in the presence of glycerol. Thus, gluconeogenesis and catabolism of anabolically produced glucose appear to impact not only the utilization of glycerol but also glycerol-stimulated biofilm phenotypes. Finally, waxworm moth larvae and nematode infection models reveal that interruption of the Entner-Doudoroff pathway, but not abrogation of glycerol phosphorylation, unexpectedly increases P. aeruginosa lethality in both acute and chronic infections, even while stimulating a stronger immune response by Caenorhabditis elegans.IMPORTANCEPseudomonas aeruginosa, the ubiquitous environmental bacterium and human pathogen, forms multicellular communities known as biofilms in response to various stimuli. We find that glycerol, a common carbon source that bacteria can use for energy and biosynthesis, encourages biofilm behaviors such as surface attachment and colony wrinkling by P. aeruginosa. Glycerol can be derived from surfactants that are present in the human lungs, a common infection site. Glycerol-stimulated biofilm phenotypes do not depend on phosphorylation of glycerol but are surprisingly impacted by a glucose breakdown pathway, suggesting that it is glycerol utilization, and not its mere presence or cellular import, that stimulates biofilm phenotypes. Moreover, the same mutations that block glycerol-stimulated biofilm phenotypes also impact P. aeruginosa virulence in both acute and chronic animal models. Notably, a glucose-breakdown mutant (Δedd) counteracts biofilm phenotypes but shows enhanced virulence and stimulates a stronger immune response in Caenorhabditis elegans.https://journals.asm.org/doi/10.1128/msphere.00786-23biofilmglycerolPseudomonasinfectionEntner-Doudoroffmetabolism
spellingShingle Somalisa Pan
Simon A. M. Underhill
Christopher W. Hamm
Mylissa A. Stover
Daxton R. Butler
Crystal A. Shults
Jacob R. Manjarrez
Matthew T. Cabeen
Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway
mSphere
biofilm
glycerol
Pseudomonas
infection
Entner-Doudoroff
metabolism
title Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway
title_full Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway
title_fullStr Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway
title_full_unstemmed Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway
title_short Glycerol metabolism impacts biofilm phenotypes and virulence in Pseudomonas aeruginosa via the Entner-Doudoroff pathway
title_sort glycerol metabolism impacts biofilm phenotypes and virulence in pseudomonas aeruginosa via the entner doudoroff pathway
topic biofilm
glycerol
Pseudomonas
infection
Entner-Doudoroff
metabolism
url https://journals.asm.org/doi/10.1128/msphere.00786-23
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