Sébastien Boutin1, Michael Weitnauer2, Selina Hassel1, Simon Y Graeber3, Mirjam Stahl3, A Susanne Dittrich4, Marcus A Mall3, Alexander H Dalpke5. 1. Department of Infectious Disease, Medical Microbiology and Hygiene, University Hospital Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany. 2. Department of Infectious Disease, Medical Microbiology and Hygiene, University Hospital Heidelberg, Germany. 3. Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany; Department of Translational Pulmonology, University of Heidelberg, Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany. 4. Department of Translational Pulmonology, University of Heidelberg, Heidelberg, Germany; Department of Pneumology and Critical Care Medicine, Thoraxklinik at the University Hospital Heidelberg, Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany. 5. Department of Infectious Disease, Medical Microbiology and Hygiene, University Hospital Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany. Electronic address: alexander.dalpke@med.uni-heidelberg.de.
Abstract
BACKGROUND: Chronic airway infection with Pseudomonas aeruginosa is a major risk factor of progression of lung disease in patients with cystic fibrosis (CF). Chronic P. aeruginosa infection evolves from intermittent infection that is amenable to antibiotic eradication, whereas chronically adapted P. aeruginosa becomes resistant to antibiotic therapy. Discrimination of intermittent versus chronic infection is therefore of high therapeutic relevance, yet the available diagnostic methods are only partly satisfactory. The aim of the present study was, therefore, to evaluate the usage of quantitative PCR (qPCR) to measure pathogen abundance and to discriminate between intermittent and chronic Pseudomonas infection in patients with CF. METHOD: Using an established qPCR protocol, we analyzed the abundance of P. aeruginosa in 141 throats swabs and 238 sputa from CF patients with intermittent or chronic infection with P. aeruginosa, as determined by standard culture based diagnostics. RESULTS: We observed a large increase of abundance of P. aeruginosa in throat swabs and sputum samples from patients with chronic compared to intermittent infections with P. aeruginosa. The data show that abundance of P. aeruginosa as measured by qPCR is a valuable tool to discriminate intermittent from chronic infection. Of note, P. aeruginosa burden seems more sensitive than mucoidity phenotype to discriminate chronic from intermittent strains. Furthermore we observed that molecular detection in throat swabs was linked to a viable culture in the sputum when sputum was available. This result is of special interest in young patients with cystic fibrosis that often cannot expectorate sputum. We also observed that qPCR in comparison to culture detected the infection earlier. CONCLUSION: The results suggest that qPCR detection and quantification of P. aeruginosa is a precious tool to be added to the diagnostic toolbox in cystic fibrosis.
BACKGROUND:Chronic airway infection with Pseudomonas aeruginosa is a major risk factor of progression of lung disease in patients with cystic fibrosis (CF). Chronic P. aeruginosa infection evolves from intermittent infection that is amenable to antibiotic eradication, whereas chronically adapted P. aeruginosa becomes resistant to antibiotic therapy. Discrimination of intermittent versus chronic infection is therefore of high therapeutic relevance, yet the available diagnostic methods are only partly satisfactory. The aim of the present study was, therefore, to evaluate the usage of quantitative PCR (qPCR) to measure pathogen abundance and to discriminate between intermittent and chronic Pseudomonasinfection in patients with CF. METHOD: Using an established qPCR protocol, we analyzed the abundance of P. aeruginosa in 141 throats swabs and 238 sputa from CF patients with intermittent or chronic infection with P. aeruginosa, as determined by standard culture based diagnostics. RESULTS: We observed a large increase of abundance of P. aeruginosa in throat swabs and sputum samples from patients with chronic compared to intermittent infections with P. aeruginosa. The data show that abundance of P. aeruginosa as measured by qPCR is a valuable tool to discriminate intermittent from chronic infection. Of note, P. aeruginosa burden seems more sensitive than mucoidity phenotype to discriminate chronic from intermittent strains. Furthermore we observed that molecular detection in throat swabs was linked to a viable culture in the sputum when sputum was available. This result is of special interest in young patients with cystic fibrosis that often cannot expectorate sputum. We also observed that qPCR in comparison to culture detected the infection earlier. CONCLUSION: The results suggest that qPCR detection and quantification of P. aeruginosa is a precious tool to be added to the diagnostic toolbox in cystic fibrosis.
Authors: Dario L Frey; Calum Bridson; Susanne Dittrich; Simon Y Graeber; Mirjam Stahl; Sabine Wege; Felix Herth; Olaf Sommerburg; Carsten Schultz; Alexander Dalpke; Marcus A Mall; Sébastien Boutin Journal: Front Microbiol Date: 2022-05-13 Impact factor: 6.064
Authors: Peter H Gilligan; Damian G Downey; J Stuart Elborn; Patrick A Flume; Sebastian Funk; Deirdre Gilpin; Timothy J Kidd; John McCaughan; B Cherie Millar; Philip G Murphy; Jacqueline C Rendall; Michael M Tunney; John E Moore Journal: J Clin Microbiol Date: 2018-08-27 Impact factor: 5.948
Authors: Michael Sörensen; Julia Kantorek; Lauren Byrnes; Sébastien Boutin; Marcus A Mall; Felix Lasitschka; Heike Zabeck; Dao Nguyen; Alexander H Dalpke Journal: Front Immunol Date: 2020-02-04 Impact factor: 7.561