Australian scientists have discovered that crocodiles - as well as boasting a fine set of teeth and a nice line in drowning and subsequently consuming buffalo - have a highly robust immune system capable of seeing off some penicillin-resistant bacteria.

Crocs in Oz's Northern Territories need it, too, says US boffin Mark Merchant. He's been collecting crocodile blood with a view to its potential therapeutic properties, and told Reuters: "[Crocodiles] 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."

Among the nasties which come to grief in the croc's system are penicillin-mocking Staphylococcus aureus. HIV, too, has a hard time of it, as Adam Britton of Darwin's Crocodylus Park, explains: "If you take a test tube of HIV and add crocodile serum it will have a greater effect than human serum. It can kill a much greater number of HIV viral organisms."

Warming to the theme, Britton enthuses: "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."

Those readers wondering just how Merchant and Britton extract the blood from crocs without indulging in the zoological equivalent of putting a gun to their own heads and pulling the trigger, should note that crocodiles have a large vein behind the head - called a sinus - from which it's a simple matter of slurping out the vital essence with a big needle. After, of course, strapping the jaws shut...

Merchant and Britton hope one day to use croc serum to produce antibiotics for human use, although they admit it may currently be a bit too strong for our feeble bodies. Merchant concludes: "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." ®

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