@article {Liang4666, author = {Jinhua Liang and Zhenqiang Zhang and Jinlong Li and Jinliang Kong and Wang Ke}, title = {Late Breaking Abstract - Biofilm formation by Pseudomonas aeruginosa in empyema}, volume = {56}, number = {suppl 64}, elocation-id = {4666}, year = {2020}, doi = {10.1183/13993003.congress-2020.4666}, publisher = {European Respiratory Society}, abstract = {Background: Whether there is biofilm (BF) formation in the pleural cavity of empyema is still inconclusive.Objectives: We assumed that there is BF formation in empyema, tried to verify this hypothesis.Methods: We established a model of rabbit empyema infected by Pseudomonas aeruginosa (P.a), and collected pleural tissue and pustule-like specimens. Scanning electron microscope (SEM) was used to observe the P.a-BF on the surface of the pleura. Peptide nucleic acid Fluorescence in situ hybridization (PNA-FISH) was used to observe the P.a-BF in the pus floc.Results: There were BF-like structures on the surface of the pleura observed by SEM (Fig. 1A), P.a-BF in the pus of pleural cavity confirmed by colony counting and PNA-FISH (Fig. 1B).Conclusions: To our knowledge, this was the first experiment to confirm the P.a-BF formation in the pleural cavity of empyema, and it was also a novel animal model.Fig 1A. Biofilm-like structures were observed using SEM at a magnification of 5,000{\texttimes} operating at 30.0 Kv.Fig1B. Fluorescence microscope image showing P.a-BF surrounded by host cell components. The P.a were stained with a Texas-Red-labeled P.aeruginosa-specific PNA-FISH probe ( red ), and the host cells were stained with DAPI ( blue ).FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4666.This abstract was presented at the 2020 ERS International Congress, in session {\textquotedblleft}Respiratory viruses in the "pre COVID-19" era{\textquotedblright}.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/56/suppl_64/4666}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }