Results of hierarchical clustering and principal component analysis based on four characteristics: Sialidase activity, VLY production, and biofilm amount after 24 h and 48 h incubation.

<p>(A) Dendogram. The colors of the branches represent the three largest clusters. (B) PCA biplot. Axes represent the first and the second principal components (PCs). Percentages on the axes indicate the percentage of total variance explained by each PC. Arrows in the biplot represent the phenotypic characteristics. Dots indicate isolates, and the colors of the dots/isolate numbers correspond to particular clades. Closed lines indicate the areas in the space of PCs restricted by the isolates of the same clade. Shaded fields indicate areas restricted by the clusters determined in the dendogram.