FRIDAY, Jan. 19, 2007 (HealthDay News) -- In the future, hospital patients may have a new weapon to fight infection after surgery: powerful antibiotic coatings attached to implants, catheters, surgical instruments and other medical devices.
Researchers at the University of Southern Mississippi say they've developed a way to attach penicillin, and potentially other antibiotics, to these types of devices.
Almost 2 million patients in the United States get an infection in the hospital each year, and about 90,000 of those patients die each year as a result of their infection, according the U.S. Centers for Disease Control and Prevention (CDC).
Many of these infections are linked to medical devices. But, "modifying [device] surfaces to adhere penicillin kills bacteria," explained lead researcher and professor of polymer science Marek W. Urban. "The penicillin is able to destroy the colony of bacteria," he said.
Urban's team has found a way to modify the surface of poly(tetrafluoroethylene), a material similar to Teflon, so that penicillin sticks to it and remains highly active. This polymer is used in medical procedures ranging from blood vessel grafting to plastic and reconstructive surgery.
The trick was to modify the surface of poly(tetrafluoroethylene) so that arms would stick out from the surface, which the penicillin could stick to, and that would, in turn, surround bacteria and kill it, Urban said.
In their experiments, expected to be published in the Feb. 12 issue of the journal Biomacromolecules, the researchers showed that these penicillin-coated surfaces could effectively kill Staphylococcus aureus, a bacterium responsible for many serious infections.
However, since more than 70 percent of the bacteria that cause hospital-acquired infections are resistant to at least one of the antibiotics most commonly used to treat them, Urban's group is hoping to find other antibiotics that are able to coat the surfaces of medical devices.
In addition, the researchers are also working on modifying other types of surfaces to hold on to antibiotics.
"We want to develop coatings that can be applied to any surfaces to kill bacteria, Urban said. "This is the first step. The trick is to make the antibiotic remain active after it is attached," he said.
One expert believes this may be a breakthrough in reducing the number of hospital-acquired infections.
"It is a very good idea to affect surfaces not only to have an antimicrobial in place there, but also to disrupt bacterial activity," said Dr. Philip Tierno, the director of clinical microbiology and immunology at New York University Medical Center and author of The Secret Life of Germs. "Most artificial materials, when they are placed in or on the body, serve as a platform for the growth and proliferation of bacteria," he said.
This is a big problem with catheters, Tierno noted. "It seems that this method could cut down on infections, but you really have to test the hypothesis," he said. "However, based on this paper, it appears that you can disrupt the growth of bacteria by coating the surface of devices."
There's more on hospital infections at the U.S. Centers for Disease Control and Prevention.