biostudies-literatureLlanos ANIEHS NIH HHSWellcome TrustCombating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator14208https://www.ebi.ac.uk/biostudies/studies/S-EPMC10468528biostudies-literatureUnknown13(1)Pseudomonas aeruginosa is a common pathogen in cystic fibrosis (CF) patients and a major contributor to progressive lung damage. P. aeruginosa elastase (LasB), a key virulence factor, has been identified as a potential target for anti-virulence therapy. Here, we sought to differentiate the P. aeruginosa isolates from early versus established stages of infection in CF patients and to determine if LasB was associated with either stage. The lasB gene was amplified from 255 P. aeruginosa clinical isolates from 70 CF patients from the Toulouse region (France). Nine LasB variants were identified and 69% of the isolates produced detectable levels of LasB activity. Hierarchical clustering using experimental and clinical data distinguished two classes of isolates, designated as 'Early' and 'EstabliScientific reportsHigher levels of Pseudomonas aeruginosa LasB elastase expression are associated with early-stage infection in cystic fibrosis patients.PMC1046852827302C0028WT22484275A50122C00028Llanos ASable CAchard PEverett MRevillet HLemonnier MLozano CMurris MMittaine MBousquet JZalacain MfalseHigher levels of Pseudomonas aeruginosa LasB elastase expression are associated with early-stage infection in cystic fibrosis patients.Pseudomonas aeruginosa is a common pathogen in cystic fibrosis (CF) patients and a major contributor to progressive lung damage. P. aeruginosa elastase (LasB), a key virulence factor, has been identified as a potential target for anti-virulence therapy. Here, we sought to differentiate the P. aeruginosa isolates from early versus established stages of infection in CF patients and to determine if LasB was associated with either stage. The lasB gene was amplified from 255 P. aeruginosa clinical isolates from 70 CF patients from the Toulouse region (France). Nine LasB variants were identified and 69% of the isolates produced detectable levels of LasB activity. Hierarchical clustering using experimental and clinical data distinguished two classes of isolates, designated as 'Early' and 'Establi2023-01-01T00:00:00Z2023 Aug2025-04-26T19:00:32.096Z2025-04-06T15:58:36.978ZS-EPMC104685283764873510.1038/s41598-023-41333-9