This electron micrograph depicted large numbers of Staphylococcus aureus
bacteria, which were fond 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; Magnified 2363x.
S. aureus, often referred to simply as "staph," are bacteria commonly carried on the skin, or in the nose of healthy people. Approximately 25% to 30% of the population is colonized, i.e., when bacteria are present, but not causing an infection, in the nose with staph bacteria.