for National Geographic News
Alligators often engage in violent fights over territories and mates, and scientists have puzzled over why their wounds rarely get infected.
Now researchers think the secret lies in the reptiles' blood.
Chemists in Louisiana found that blood from the American alligator can successfully destroy 23 strains of bacteria, including strains known to be resistant to antibiotics.
In addition, the blood was able to deplete and destroy a significant amount of HIV, the virus that causes AIDS.
Study co-author Lancia Darville at Louisiana State University in Baton Rouge believes that peptides—fragments of proteins—within alligator blood help the animals stave off fatal infections.
Such peptides are also found in the skin of frogs and toads, as well as in Komodo dragons and crocodiles. The scientists think that these peptides could one day lead to medicines that would provide humans with the same antibiotic protection.
"We are in the process of separating and identifying the specific peptides in alligator blood," said Darville, who presented the findings on Sunday at the 235th national meeting of the American Chemical Society in New Orleans.
"Once we sequence these peptides, we can obtain their chemical structure to potentially [create new] drugs."
Study co-author Mark Merchant, a biochemist at McNeese State University in Lake Charles, Louisiana, was among the first to notice alligators' unusual resistance.
He was intrigued that, despite living in swampy environments where bacteria thrive, alligators that suffered frequent scratches and bruises rarely developed fatal infections.
Merchant therefore created human and alligator serum—protein-rich blood plasma that has had clotting agents removed—and exposed each of them to 23 strains of bacteria.
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