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Microbiology Society logo Microbiology

Volume 172, Issue 3

gene expression changes during established biofilm infection in a cystic fibrosis lung model Open Access

Abstract

The opportunistic pathogen forms biofilm infections in the lungs of people with the genetic condition cystic fibrosis (CF) that can persist for decades. There are numerous lifestyle changes associated with chronic biofilm infection that are cued by the CF lung environment. These include a loss of virulence, metabolic changes and increased antimicrobial tolerance. We have investigated PA14 biofilm infection over 7 days in an pig lung (EVPL) model for CF, previously shown to facilitate formation of a clinically relevant biofilm structure with expression of key genes comparable to human infection. We have compared gene expression between sequential time points: 24 h, 48 h and 7 days post-infection, and investigated tolerance to polymyxins. Our results demonstrate that the EVPL model can maintain a biofilm population, which exhibits increased antibiotic tolerance, for at least 7 days. Differential expression of antimicrobial resistance-associated genes was not observed; however, there was significant upregulation of sulphur metabolism and maintenance of a structured biofilm. Our findings demonstrate that 7 days is a viable time point for studying established, chronic biofilm infection in the EVPL model and provide insight into the accompanying gene expression changes.

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  • Accepted:
  • Published Online:
Keyword(s): antimicrobial resistance (AMR) , biofilm , chronic infection , cystic fibrosis (CF) , ex vivo model , Pseudomonas aeruginosa , quorum sensing (QS) , RNA sequencing , sulphur metabolism and transcriptome
Funding
This study was supported by the:
  • Medical Research Council (Award MR/R001898/1)
    • Principal Award Recipient: FreyaHarrison
  • Biotechnology and Biological Sciences Research Council (Award BB/M01116X/1)
    • Principal Award Recipient: NiamhE. Harrington
  • Medical Research Council (Award MR/N014294/1)
    • Principal Award Recipient: RamónGarcia Maset
  • University of Warwick
    • Principal Award Recipient: FreyaAllen
© 2026 The Authors
  • This is an open-access article distributed under the terms of the Creative Commons Attribution License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution.
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2026-03-05
2026-04-13

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Pseudomonas aeruginosa gene expression changes during established biofilm infection in a cystic fibrosis lung model
Microbiology 172, 001678 (2026); https://doi.org/10.1099/mic.0.001678
/content/journal/micro/10.1099/mic.0.001678
/content/journal/micro/10.1099/mic.0.001678
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