RT Journal Article SR Electronic T1 New algorithm of antibiotic selection reveals the abundance and reduces bacterial load in sputum of adult patients with cystic fibrosis JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA2194 DO 10.1183/13993003.congress-2021.PA2194 VO 58 IS suppl 65 A1 Tetz, George A1 Kardava, Cristina A1 Vecherkovskaya, Maria A1 Gembitskaya, Tatyana A1 Tetz, Victor YR 2021 UL https://publications.ersnet.org//content/58/suppl_65/PA2194.abstract AB Objectives: Traditional antibiotic selection tests take days and fail to select effective antibiotics against Multidrug-resistant strains (MDR-strains) because they do not account for critical characteristics of “real-life” infections. AtbFinder – a novel culture-based test system addresses these realities by using a novel principle of antibiotic selection, named “populational response”.Methods: 30 CF patients aged 18 to 65 years, with known chronic infection, receiving prophylactic antibiotic therapy with antibiotics selected based on AtbFinder results were monitored over 3 years. Sputum was obtained during yearly check-ups and the presence of several pathogens was assessed with (i)AtbFinder or (ii)standard microbiological media.Results: First we analyzed the effect of antibiotic therapy selected with the AtbFinder on eradication of P.aeruginosa. By year 1 and 2 after the switch, eradication of P.aeruginosa were noted in 16 (53%) and 22 (73%) out of 30 subjects who had P.aeruginosa infection respectively (p<0.001).The use of AtbFinder resulted in the growth of broader bacterial diversity in 97.1% patients compared to routine diagnostics methods and contributed to the isolation of critical for patients with CF pathogens missed by conventional microbiology lab. Along with P.aeruginosa S.aureus, A.xylosoxidans, S.maltophila including MDR strains, were isolated and successfully eradicated in patients following a switch to antibiotic therapy selected with the AtbFinder.Conclusion: Antibiotic optimization with therapy prescribed using AtbFinder results in progressive eradication of different MDR bacteria from airways of adults with CF.FootnotesCite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA2194.This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.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).