tailieunhanh - Detection of Pseudomonas aeruginosa in sputum headspace through volatile organic compound analysis

Soil samples stored in sealed vials have been shown to undergo significant biodegradation over time periods greater than 48 hours. Holding time guidelines for VOCs are given in SW846, Method 5035A, Appendix A, Table “Recommended VOC Sample Preservation Techniques and Holding Times.” The holding time for preserved soil samples should be interpreted as 14 days from the time of sample collection (stored at 4±2o C). Due to potential biodegradation, samples stored in sealed containers, but not chemically preserved, should not be stored for more than 48 hours prior to analysis or chemical preservation. . | Goeminne et al. Respiratory Research 2012 13 87 http content 13 1 87 RESPIRATORY RESEARCH RESEARCH Open Access Detection of Pseudomonas aeruginosa in sputum headspace through volatile organic compound analysis Pieter C Goeminne1 4 Thomas Vandendriessche2 Johan Van Eldere3 Bart M Nicolai2 Maarten LATM Hertog2 and Lieven J Dupont1 Abstract Introduction Chronic pulmonary infection is the hallmark of Cystic Fibrosis lung disease. Searching for faster and easier screening may lead to faster diagnosis and treatment of Pseudomonas aeruginosa P. aeruginosa . Our aim was to analyze and build a model to predict the presence of P. aeruginosa in sputa. Methods Sputa from 28 bronchiectatic patients were used for bacterial culturing and analysis of volatile compounds by gas chromatography-mass spectrometry. Data analysis and model building were done by Partial Least Squares Regression Discriminant analysis PLS-DA . Two analysis were performed one comparing P. aeruginosa positive with negative cultures at study visit PA model and one comparing chronic colonization according to the Leeds criteria with P. aeruginosa negative patients PACC model . Results The PA model prediction of P. aeruginosa presence was rather poor with a high number of false positives and false negatives. On the other hand the PACC model was stable and explained chronic P. aeruginosa presence for 95 with 4 PLS-DA factors with a sensitivity of 100 a positive predictive value of 86 and a negative predictive value of 100 . Conclusion Our study shows the potential for building a prediction model for the presence of chronic P. aeruginosa based on volatiles from sputum. Keywords Bronchiectasis Chronic colonization Gas chromatography mass spectrometry Cystic fibrosis Non-cystic fibrosis Introduction Chronic pulmonary infection is the hallmark of Cystic Fibrosis CF lung disease. Preventing or treating chronic infection plays a key role in these patients. Previous studies showed that .