Under a magnification of 2363X, this scanning electron microscopic (SEM) image depicted numbers of Staphylococcus aureus bacteria, which were found on the luminal surface of an indwelling catheter.

Of importance is the sticky-looking substance woven between the round cocci bacteria, which was composed of polysaccharides, and is known as “biofilm.” This biofilm has been found to protect the bacteria that secrete the substance from attacks by antimicrobial agents such as antibiotics.