'Healing clays' show promise for fighting deadly MRSA superbug infections, other diseases

In the new study, funded by the National Institutes of Health, Willams and her colleagues collected more than 20 different clay samples from around the world to investigate their antibacterial activities. In collaboration with study co-leader Shelley Haydel, Ph.D., a microbiologist with Arizona State, the researchers tested each of the clays against several different bacteria known to cause human diseases. These bacteria include MRSA (methicillin-resistant Staphylococcus aureus), Mycobacterium ulcerans (a microbe related to the tuberculosis bacterium that causes a flesh-eating disease known as Buruli ulcer), as well as E. coli and Salmonella (which cause food poisoning). The researchers identified at least three clays that killed or significantly reduced the growth of these bacteria.

The researchers are working to identify the specific compounds in the clays that may be responsible for its antibacterial activity. Using electron and ion microscopy, the researchers are also exploring how these antibacterial clays interact with the cell membranes of the bacteria in order to find out how they kill.

Williams and Haydel are continuing to test new clay samples from around the world to determine their germ-fighting potential. They hope that the more promising clays will be developed into a skin ointment or pill to fight a variety of bacterial infections or possibly as an agricultural wash to prevent food poisoning. Several companies have expressed interest in forming partnerships to develop the clays as antimicrobial agents, the scientists say.

But ordinary mud can contain dangerous bacteria as well as toxic minerals like arsenic and mercury, the researchers point out. Until healing clays are developed that are scientifically proven, which could take several years, handwashing and other proper hygiene techniques may be your best bet for keeping MRSA and other harmful bacteria at bay, they say.

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— Mark T. Sampson