Previous research has shown that the clay fights against a "flesh-eating" bug (M. ulcerans) on the rise in Africa and the germ called MRSA, which was blamed for the recent deaths of two children in Virginia and Mississippi.
Now an interdisciplinary team of microbiologists and mineralogists is trying to determine exactly how the clay cures.
"There are very compelling reports of clay treating infections, but that's anecdotal evidence, not science. They would mix clay with water and make a paste and put it on the horrible wounds," said Lynda Williams, an associate research professor in the School of Earth and Space Exploration at Arizona State University, Tempe.
Williams is coordinating three teams of U.S. researchers (at ASU, USGS, and SUNY-Buffalo) studying healing clays under a two-year, 440,000 dollars grant from the National Institutes of Health-National Center for Complementary and Alternative Medicine.
"We're beginning to generate the first scientific evidence of why some minerals might kill bacterial organisms and others might not," said Williams.
In laboratory tests at ASU's Biodesign Institute, co-PI Haydel, an assistant professor in the School of Life Sciences, showed that one clay killed bacteria responsible for many human illnesses, including: Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), penicillin-resistant S. aureus (PRSA), and pathogenic Escherichia coli (E. coli).
It also killed Mycobacterium ulcerans, a germ related to leprosy and tuberculosis that causes the flesh-eating disease Buruli ulcer. This effect was first described in 2002, by Line Brunet de Courssou, a French humanitarian working in the Ivory Coast, Africa, who cured Buruli ulcers with daily applications of French clay she knew from childhood. Currently, advanced cases of Buruli ulcer can only be cured by surgical excision or amputation.
The new medicinal clay research will be presented on Monday, 29 October 2007, at the Geological Society of America Annual Meeting in Denver.