Tiny blobs of slime cover your teeth. They also lurk inside your body, on the walls of swimming pools and on boats in the ocean. Sometimes they even grow on the smooth surfaces of medical devices. These slimes are called biofilms. They’re like miniature cities. Each one can house tens of millions of bacteria. All these bacteria need to grow are food and water. And food for these tiny microbes could be anything from sugar to sewage.
As gross as they sound, these slime cities often prove helpful. Without bacteria and biofilms, we’d be wading through piles of garbage: These tiny microbes love to eat human and animal wastes. And most biofilms inside the body promote health. Many have been with you since birth. When good biofilms flourish, they leave little room for bad germs to move in.
Stephen Dexter calls biofilms “one of the wonders of the environmental system on Earth.” An engineer at the University of Delaware in Newark, he studies how biofilms and seawater affect materials.
But biofilms can be harmful, hosting large populations of disease-causing germs. Others rust through pipes, boat hulls and other important equipment. And biofilms are especially dangerous when they grow on medical equipment. For example, a heart surgeon may put a device called a pacemaker inside someone’s heart to regulate its beating. If a biofilm forms on that device, it could nurture germs capable of spawning a deadly infection.
How can researchers wage war against these slime dwellers? First, they can try to set up barriers to halt their growth. Second, they can target medicines or chemicals against biofilms that are already in place. And lately, some researchers have been learning how to “talk” to bacteria inside a biofilm. If they can learn the microbes’ language, they might recruit only good guys to settle into a slime city.
