among emerging threats to human health, few are more menacing than the methicillin-resistant “super bug” that attacks more than 100,000 Americans each year.
Methicillin-resistant Staphylococcus aureus, or MRSA, is a staph bacteria that is resistant to the beta-lactam class of antibiotics, including methicillin, oxacillin, penicillin, and amoxicillin. Most MRSA infections, according to the Centers for Disease Control and Prevention, occur on the skin. When treated promptly these are seldom life threatening. Infections in other parts of the body, however, are of far greater concern. MRSA infections in the bloodstream, at the site of a surgical wound, or in the lungs kill thousands. And the numbers are increasing.
Even as scientists across the globe work feverishly to come up with new drugs to fight MRSA, one of the more intriguing potential bacteria-busters may be sprouting — quite literally — here in our own backyards. Earlier this year Chung-Ho Lin, an MU research assistant professor at the MU Center for Agroforestry and the department of forestry, announced that he and two MU colleagues had discovered a chemical in the needles of Eastern Red Cedar trees that appears effective in controlling MRSA.
Because the Eastern Red Cedar has few commercial uses, and grows in large numbers throughout the Midwest, some have described it as a “trash tree.” Lin knew better. In a screening study, Lin had found that several chemical compounds derived from the cedar had shown strong anti-bacterial properties. The finding led Lin to surmise that MRSA might also be vulnerable.
Along with MU veterinary pathobiology chair and professor George Stewart and postdoctoral fellow Brian Thompson, Lin sought to confirm the hunch by identifying, then isolating and testing, 17 bioactive compounds from Eastern Red Cedar needles. He found that a small concentration of a chemical compound found in the tree’s foliage — 5 micrograms per milliliter — was sufficient to inhibit the growth of MRSA, at least in the test tube.
“We found this chemical from the cedar needles, an abundant and renewable resource that can be collected annually,” Thompson says. “Because the compound is in the needles, we don’t have to cut down the trees.”
Not that sacrificing a few red cedars would be a problem. State forestry officials estimate there are close to 500 million of them in Missouri alone. Lin says putting those trees to work, in fact, was a prime motivator in his research. “I wanted to find a use for a tree species that is considered a nuisance,” he says. “This discovery could help people fight the bacteria as well as give farmers another cash crop.”
Lin, Stewart and Thompson’s findings were presented at the 15th International Conference on Gram-Positive Pathogens, held in Omaha, Neb., last fall.