Saturday, April 12, 2008

Gator Blood May Be New Source of Antibiotics

Call it a case of gator aid. New research suggests that alligator blood could serve as the basis for new antibiotics targeting infections caused by ulcers, burns and even drug-resistant "superbugs."

The research is in its early stages -- extracts of alligator blood have only been tested in the laboratory -- and there's no guarantee that it will work in humans. Still, the findings are promising, researchers said.

"We need new antibiotics. Anything like this is a step forward," said Dr. Stuart Levy, a professor of medicine at Tufts University School of Medicine, who's an expert in antibiotic-resistant infections and is familiar with the new study. "But there are hurdles that this kind of antibiotic poses that others might not."

The study authors, from McNeese State University and Louisiana State University, said their research is the first to take an in-depth look at alligator blood's prospects as an antibiotic source. According to the researchers, alligators can automatically fight germs such as bacteria and viruses without having been exposed to them before launching a defense.

For the study, the researchers extracted proteins known as peptides from white cells in alligator blood. As in humans, white cells are part of the alligator's immune system. The researchers then exposed various types of bacteria to the protein extracts and watched to see what happened.

In laboratory tests, tiny amounts of these protein extracts killed a so-called "superbug" called methicillin-resistant Staphylococcus aureus, or MRSA. The bacteria has made headlines in recent years because of its killing power in hospitals and its spread among athletes and others outside of hospitals.

The extracts also killed six of eight strains of a fungus known as Candida albicans, which causes a condition known as thrush, and other diseases that can kill people with weakened immune systems.

The researchers, who presented their findings April6 at the national meeting of the American Chemical Society in New Orleans, said the blood extract could be used to develop an antibiotic in a topical cream form. They suggest that it could be called "alligacin."

Levy said the human body might reject alligator proteins, thinking they're foreign invaders. "Our bodies love to make antibodies to proteins," he said. "After you get the first dose, the body sees it as foreign, and the next dose gets scooped up by the immune system, and it's done."

But study lead author Lancia Darville, a doctoral student at Louisiana State University in Baton Rouge, La., said scientists might be able to create drugs that copy the blood proteins once they figure out their structure. The idea would be to make a chemical that the body doesn't think is a protein. Even so, Darville said, "it is not easy to mimic any antimicrobial peptide for clinical use."

Levy noted that many pharmaceutical companies have stopped investigating new antibiotics, because other areas of medicine are more profitable. The gap "has to be filled by more discovery," said Levy, who's also president of the Alliance for the Prudent Use of Antibiotics.

The study authors said alligator blood could become a drug source for humans within a decade.

Still, Emily Ackiss, a clinical epidemiologist at Scripps Mercy Hospital in Chula Vista, Calif., who's familiar with the study findings, said, "The research discussed in this article is basic research. More extensive research and experimentation are needed before drug development could be expected."

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