TEM images of MSSA ATCC 25923 at mid-log phase (A and B). Untreated bacteria are spheroidal with a distinct septal midline (arrows in panel B). After incubation with ramoplanin at a concentration of 1× MIC for 3 h, bacteria presented with deformed septa (arrow in panel C), irregular thickening cell wall (D), mesosomes (arrows in panel E), and lysis of the membrane (F), resulting in leakage of cytosolic contents. Bars, 200 nm.