May 22, 2000 (Los Angeles) -- Modern medicine has successfully waged a war against infection with antibiotics. Now, there's growing concern that the widespread use of these powerful drugs is creating bacteria that are resistant to them. But a new study presented here at a microbiology meeting shows that there may be a kinder, gentler way to stop infection that won't create the headaches of antibiotic resistance. Instead of killing the bacteria, the new strategy may be to just render them unable to cause infection. What revolutionary weapon will bring infection to its knees? The potato.
The potato was used as a natural remedy in traditional medicine for centuries before it was eaten as a food. A substance in the common potato, the investigators found, prevents invading bacteria from latching onto vulnerable cells in the human body.
"Without attachment [to human cells], 99% of infections can't [occur], " Marjorie Kelly Cowan, PhD, tells WebMD. She explains that a protein on the surface of the bacteria attaches to a sugar on the surface of the body cell like a key in a lock. Once attached, the bacteria invade the cell and infection begins. But if that lock can be blocked by another substance or the shape of the lock can be changed in some way, the key won't fit. The bacteria can't attach to the cell, and eventually the microorganism is carried out of the body without causing harm.
Other studies have found that certain naturally occurring chemicals can inhibit this attachment, so Cowan, an associate professor of microbiology at the University of Miami in Oxford, Ohio, and her student Madeline Gassert, concocted extracts of different parts of the vegetable. They discovered that a substance in the potato did just that -- it prevented the bacteria from taking hold of cells.
The extract inhibited the attachment of bacteria normally found in the mouth -- one associated with cavities -- to the surfaces of teeth. The extract also inhibited the adhesion of another bacteria, E. coli, which can cause urinary tract infection, says Cowan.
Cowan and her colleagues also found that the active component in the potato is a substance that is common in fruits and vegetables and is the chemical that causes them to turn brown as they age. They are now looking at ways to use this natural defense system as a way to fight infections, says Cowan.
One of the main purposes of this study, says Cowan, is to encourage scientists looking into the anti-infection activity of plants to test them for their ability to block attachment of bacteria to cells. Now, plants are primarily tested for their ability to kill bacteria. If there is a kinder, gentler way to fight infection, it may be missed if those testing the plant aren't looking for it.
In India, potato skins are still commonly used to treat burns, Jacob Dankert, MD, PhD, tells WebMD. He was not involved in Cowan's study, but says he finds it very important and a possible explanation for why the traditional use of potato skins decreases the rate of infection following burns and reduces scaring.
"Everybody is trying to prevent adhesion as the first step in the development of infection disease," says Dankert, chairman of medical microbiology and infectious disease at the Academic Medical Center in Amsterdam. "Antibiotics are one approach, but it's dangerous because resistance is developing."