Fig. 4

Principal component analysis (PCA) analysis of RNA-seq data to visualize sample to sample variation. The PCA plot depicted clear clustering control (S. aureus only, shape- circle) versus test samples (S. aureus + tonsillar cells, shape-triangle). The test samples, S. aureus after 1 h (n = 3; dark green) and 3 h (n = 3; dark red) exposure to tonsillar cells cluster separately to that of control samples (n = 2, light green) at 1 h and (n = 3, light red) at 3 h. The first two components PC1 and PC2 explained 79% and 9% of the variability in the expression data, respectively