Figure 5. Morphology of S. aureus NCTC8325 WT and ΔltaA mutant, and LTA abundance.

A. Phase contrast and fluorescence images. Bacteria were grown to mid-exponential phase in LB medium at 37°C with 5% CO₂ causing acidification of the medium. As membrane dye, Nile red was used. White arrows point to cells with aberrant morphology. B. Transmission electron microscopy (TEM) images. PM indicates plasma membrane. CW indicates cell wall. Low magnification images are shown in Extended Data Fig. 9C. C. Detection of LTA by immunoblotting. S. aureus NCT8325 were cultured in LB medium buffered with PBS to different pH (6.2 and 7.8). Cell lysates were normalized based on optical density. Samples were separated by 12% SDS-PAGE and LTA detected by LTA (polyglycerol-phosphate)- specific primary antibody. Histogram shows relative amounts of LTA determined from band intensities (n=4). Error bars indicate s.d. of technical replicates. Source data for C are available with the paper online.