Ordination of bacterial communities in whole and acellular BAL aliquots from the same BAL sample. Unsupervised principal component analysis (PCA) labeled as (A) sample groups [whole BAL aliquots (blue) and acellular BAL aliquots (green)]; (B) sample groups with centroids added; (C) sample groups with corresponding whole and acellular BAL aliquots connected via lines. X and Y (red and yellow circles, respectively) are regions with close proximity of corresponding whole and acellular BAL aliquots; region Z (purple circle) contains whole BAL aliquots far removed from their acellular BAL counterparts. (See text.) (D) Biplot analysis of PCA plot with prominent OTUs labeled.