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Updated: Aug 15, 2026
Visualization of Pseudomonas aeruginosa within the Sputum of Cystic Fibrosis Patients
Published on: July 16, 2020
Detection of bacterial extracellular vesicles in patients with cystic fibrosis - a pilot study
Celina von Mauch1, Lisa-Maria Edrich2, Julia Sobel3
1Department of Pediatrics, Gastroenterology, Hepatology and Endoscopy, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany; Department of Medicine 1, Universitätsklinikum Erlangen, Erlangen, Germany.
Background And Aims:
Pseudomonas (P.) aeruginosa is an opportunistic pathogen closely linked to Cystic Fibrosis (CF). Recent publications emphasize that an accumulation of bacterial derived extracellular vesicles within the circulation might be associated with the pathogenesis of various chronic inflammatory diseases and could potentially be used as diagnostic tool.
Methods:
Bacterial extracellular vesicles (bEVs) were isolated and characterized via Nanoparticle Tracking Analysis (NTA) and Transmission Electron Microscopy (TEM) from plasma samples of persons with CF (pwCF) without infection with P. aeruginosa (PsA-, n = 31), pwCF with confirmed P. aeruginosa infection (PsA+, n = 29), and control individuals (HC, n = 30). Size and concentration of bEVs were evaluated and correlated with clinical parameters. Western blot analyses were implemented to study the species-specific origin of bEVs, using lysates and reference vesicles.
Results:
bEVs could be detected in all samples from both, HC and pwCF. Relative NF‑κB induction, assessed via a TLR4 reporter assay, was significantly elevated in pwCF than in HC, with the strongest responses observed in PsA+ patients. emphasize bEV-associated activity. Surprisingly, CFTR modulator treatment (ETI) enhanced LPS concentration of bEVs in pwCF independent of P. aeruginosa colonization. Moreover, NF-kB induction correlated negatively with serum IgA levels in PsA+ patients. Direct detection of bEVs in plasma samples via Western blot was technically not possible.
Conclusion:
Our findings suggest a potential link between pulmonary P. aeruginosa colonization and increased systemic bEVs-associated activity as potential consequence of deficient mucosal barrier function. However, further research is required in order to validate our findings and to clarify the influence of ETI on bEV accumulation.
Insights
Bacterial extracellular vesicles (bEVs) are elevated in cystic fibrosis (CF) patients, particularly those with Pseudomonas aeruginosa infection. CFTR modulator treatment also impacts bEVs, suggesting a link to CF pathogenesis.
Area of Science:
- Microbiology
- Immunology
- Pulmonology
Background:
- Pseudomonas aeruginosa is an opportunistic pathogen frequently associated with Cystic Fibrosis (CF).
- Bacterial extracellular vesicles (bEVs) accumulation in circulation is implicated in chronic inflammatory diseases.
- bEVs show potential as diagnostic tools for various conditions.
Purpose of the Study:
- To investigate the presence and activity of bEVs in plasma of individuals with CF.
- To correlate bEV levels and activity with P. aeruginosa infection status in CF patients.
- To explore the impact of CFTR modulator therapy on bEVs.
Main Methods:
- Isolation and characterization of bEVs from plasma using Nanoparticle Tracking Analysis (NTA) and Transmission Electron Microscopy (TEM).
- Analysis of bEVs in healthy controls (HC), CF patients without P. aeruginosa (PsA-), and CF patients with P. aeruginosa (PsA+).
- Assessment of NF-κB induction via TLR4 reporter assay and correlation with clinical parameters and CFTR modulator treatment (ETI).
Main Results:
- bEVs were detected in all study groups (HC, PsA-, PsA+).
- Elevated NF-κB induction was observed in CF patients compared to HC, with the highest levels in PsA+ patients.
- CFTR modulator treatment (ETI) increased bEV LPS concentration in CF patients, irrespective of P. aeruginosa colonization.
Conclusions:
- Pulmonary P. aeruginosa colonization may be linked to increased systemic bEV activity in CF patients.
- Deficient mucosal barrier function could contribute to elevated bEVs in CF.
- Further research is needed to validate findings and understand ETI's influence on bEV accumulation.
