RT Journal Article SR Electronic T1 Influence of biofim on the bronchial microbiome in COPD patients colonized or infected by pseudomonas aeruginosa JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA5028 DO 10.1183/13993003.congress-2015.PA5028 VO 46 IS suppl 59 A1 Marian Garcia-Nuñez A1 Sara Marti A1 Carmen Puig A1 Vicente Perez-Brocal A1 Laura Millares A1 Fina Liñares A1 Eduard Monso YR 2015 UL http://erj.ersjournals.com/content/46/suppl_59/PA5028.abstract AB The recovery of Pseudomonas aeruginosa from respiratory samples of COPD patients has been associated with impaired lung function and recurrent exacerbations, partly due to strain-dependent factors such as biofilm formation.Aims: To analyse the bronchial microbiome of COPD patients with positive cultures for P.aeruginosa associated with either colonization or infection, and differentiated according to biofilm production, both in stability and exacerbation.Methods: Sputum samples with positive cultures for P.aeruginosa were obtained from 21 COPD patients during stability (n=18) and exacerbation (n=23), and analysed by 16S rRNA gene amplification and pyrosequencing. Biofilm-forming capacity of P. aeruginosa was examined using crystal violet in a static microtiter plate assay. Sputum samples were classified according to the biofilm-forming capacity of P.aeruginosa (low/high), assessing the differences between both groups, both in stability and exacerbation.RESULTS:No significant differences in biodiversity parameters (Shannon and Chao1) were found between low and high biofilm-forming groups. However, the bronchial microbiome of the high biofilm-forming group showed higher relative abundance of bacterial Operational Taxonomic Units (12 and 9 OTUs during stability and exacerbation, respectively), and represented up to 10% of the relative abundance in the sample.Conclusions: In COPD patients colonized or infected by P. aeruginosa, biofilm production was associated with an overgrowth of some bacterial OTUs, which attained a relative abundance of up to 10%. Accordingly, a biofilm environment undermined a change in the bronchial microbiome identifiable through 16srRNA analyses.