PLS1 (R 2 X = 0.0701, Cisplatin cell line R 2 Y = 0.232, Q 2  = 0.0467) and PLS

2 (R 2 X = 0.0477, R 2 Y = 0.124, Q 2  = 0.0601) are given. The solid ellipse indicates Hotellings T 2 range, at 95% confidence. Patient samples falling outside of the ellipse are deemed to be the major outliers. Some sample labels have been removed for ease of interpretation. Figure 5 Partial least squares discriminant analysis (PLS-DA) loading plot showing the contributing microbial community members towards the separation of the PLS-DA scores between patients are frequent exacerbators (>3 exacerbation events per annum) and sputum from patients who are stable (≤3 exacerbation events per annum). Taxa deemed clinically relevant (based on those screened during standard culture) are highlighted

in blue. Some sample labels have been removed for ease of interpretation. Discussion Microbial culture techniques have proven highly effective in identifying pathogens and managing acute infections. However, current sequencing approaches add doubts about the utility of these techniques in explaining the clinical paradigms in chronic polymicrobial infections Sepantronium cost [8]. Data on the polymicrobial communities in the lower airway of non CF Bronchiectasis using 16S rRNA gene amplicon sequencing is currently sparse. However, we identified, in common with previous studies, that in this NCFBr patient cohort, three taxa, Streptococcaceae, Pseudomonadaceae and Pasturellaceae were dominant (Additional file 2: Figure S1) [2, 9, 10]. We also showed that similar to CF bronchiectasis, the bacterial community was much more diverse than revealed by culture [2, 11]. Contamination of the samples by oral flora is likely to occur during the production of the sputum. Although samples were washed [12] to minimise their impact, it is inevitable that oral bacteria are present in the samples and affect the bacterial communities found. The relationship between bacterial diversity, patient factors and disease progression in NCFBr remains many to be determined. Rogers et al. [11] demonstrated a positive correlation between microbial diversity of the NCFBr lung with gender

and lung function. In SP600125 mw contrast, we and other studies [10] found no significant correlation between microbiome diversity and lung function, nor does our data support a significant difference in bacterial diversity between genders or gender significantly affecting the bacterial community structure in the NCFBr lung (Figure 1). As previously reported [4] we found that 27% of the sputum samples tested were culture negative for recognised pathogens, although pyrosequencing demonstrated all had diverse bacterial communities. These included the anaerobic genera Prevotellaceae, Streptococcaceae, Veillonellaceae and Actinomycetaceae (Figure S1) that have been identified in other NCFBr microbial communities [9, 11] as well as the bacterial communities found in CF and COPD lungs [13, 14].