We think of bacteria as being simple organisms, but they've developed an elaborate defense system to get into the body, evade the immune system of humans and cause disease. Humans are complex, so they should be able to fight off bacteria, she said, but bacteria have evolved so that they are able to outsmart the human immune system. This is what fascinates Stout. So far, Stout's experiments have shown that biofilms stick differently to different surfaces. Stout is now conducting experiments involving E. coli, one type of bacteria that causes urinary tract infections in humans, often due to the use of catheters.
Catheters are tubes placed inside hospital patients.
The tube is inserted into the bladder and extends out of their bodies and into a bag. The wastes of immobile or unconscious people are emptied out into the bag so they don't have to get up to go to the restroom while they are still recovering from an operation or illness. Doctors put catheters into most surgical patients. Resistant bacteria inside biofilms often begin growing on the walls of the urinary tract, so that a large number of people with catheters get infections. Stout thinks that if there was some way we could signal bacteria to stop making the EPSs, then there would be no biofilm.