CHICAGO (Reuters Health) – Garlic extract appears to be active against two types of drug-resistant bacteria, investigators reported here on Wednesday at the Annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
Dr. Ronald Cutler of the University of East London, UK, and colleagues a developed cream containing garlic's active ingredient, allicin, in an active, stable form that mask its odor. They tested the cream against 30 different samples of methicillin-resistant Staphylococcus aureus (MRSA) taken from patients. An allicin concentration of 32 ppm inhibited the growth of all of the bacteria samples, and all were killed by allicin at 256 ppm.
A topical treatment for MRSA infection is sorely needed, Dr. Cutler told Reuters Health. There is probably little danger that bacteria will develop resistance to allicin, he added. Although not all bacteria are susceptible to allicin, bacteria that are susceptible have never been seen to develop resistance to it, he explained.
Dr. Cutler told Reuters Health that his team will begin clinical trials of the allicin cream for MRSA infections next year. Nopex Ltd., the company that is developing the allicin creams, participated in the research.
Dr. Jaya Prakash of the National University of Health Sciences in Lombard, Illinois, presented her findings on allicin's effects on vancomycin-resistant enterococci (VRE).
Allicin did not kill the VRE, but it did slow the growth of these bacteria. Dr. Prakash told Reuters Health that this suggests that an allicin preparation could be given to hospital patients as prophylaxis against gastrointestinal VRE. She notes that allicin would be especially effective against intestinal bacteria, because up to 20% of garlic is not absorbed, but excreted in the feces.
"This was a very important first-step study," Dr. Prakash told Reuters Health.
Both Prakash and Cutler noted that the garlic preparations are very safe. "There's a huge margin of safety," Dr. Prakash said. "That's why it may be the ideal candidate."
The next step in her research, Dr. Prakash said, will be to try to figure out allicin's mechanism of action against VREs and to conduct clinical trials.