Imaging Bacterial Shape, Surface, and Appendages Before and After Treatments With Antibiotics

Bacteria are typically smaller than eukaryotic cells. The average diameter of Staphylococcus aureus is 1�0.5 μm, whereas Escherichia coli is on average 0.5�1.5 μm. The bacterial cell is also characterized by the presence of a complex external rigid structure called cell wall, which protects the internal protoplast and gives also the cellular shape, that generally falls into one of the, three basic morphologic categories, spherical (cocci), rod-shaped (bacilli), and spiral. Some bacteria show an atypical bacterial shape.