Bacteria Fight Back
The fight against one particular bacterium, Staphylococcus aureus (staph) typifies the war between antibiotics and bacteria.
Infants encounter staph shortly after birth—the bacteria live on the surface of the umbilical cord. As we grow older staph live on the skin, the lining of the nose, and sometimes the intestines. Everyone harbors staph at some point during their life, most for their entire life.
Most people who harbor staph are never infected. But some people with staph on their skin develop boils, abscesses (collections of pus under the skin), or impetigo (an infection of the skin usually found in children)—infections which, although bothersome, usually heal without antibiotics. But staph can also cause severe and even fatal infections like sepsis (infection of the bloodstream), pneumonia, and endocarditis (infection of the heart valves). Before antibiotics were used, staph was one of the most feared bacteria in the world, causing millions of deaths each year.
To understand how antibiotics kill staph—and how staph has learned to fight back—you first need to know how bacteria survive and grow.
Staph, like most bacteria, are very simple organisms. All they are trying to do is survive in a harsh environment and re