Scientists in
Australia's tropical north are collecting blood from
crocodiles in the hope of developing powerful antimicrobial
drugs for humans, after tests showed that the
reptile's immune system kills HIV. The crocodile's
immune system is much more powerful than that of humans,
preventing life-threatening infections after savage
territorial fights that often leave the animals with
gaping wounds and missing limbs.
"They tear limbs
off each other, and despite the fact that they live in
this environment with all these microbes, they heal up very
rapidly and normally almost always without infection,"
said U.S. scientist Mark Merchant, who has been taking
crocodile blood samples in the Northern Territory.
Initial studies
of the crocodile immune system in 1998 found that several
antibodies in the reptile's blood killed bacteria resistant
to penicillin, such as Staphylococcus aureus,
Australian scientist Adam Britton told Reuters on
Tuesday. It was also a more powerful killer of HIV
than the human immune system.
"If you take a
test tube of HIV and add crocodile serum, it will have
a greater effect than human serum," Britton said from
Darwin's Crocodylus Park, a tourism park and research
center.
Britton said the
crocodile immune system works differently from the human
system by directly attacking microbes immediately after
an infection occurs. "The crocodile has an immune
system which attaches to bacteria and tears it apart,
and it explodes. It's like putting a gun to the head
of the bacteria and pulling the trigger," he said.
The scientists
hope to collect enough crocodile blood to isolate the
powerful antibodies and eventually develop an antibiotic for
use by humans. "We may be able to have antibiotics
that you take orally; potentially, also antibiotics
that you could run topically on wounds—say,
[a] diabetic ulcer wound," said Merchant.
However, drugs
derived from the crocodile's immune system may need to be
synthesized for human consumption. "There is a lot of work
to be done. It may take years before we can get to the
stage where we have something to market," said
Britton. (Reuters)
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