A pair of American scientists believe Bermuda has a bacterium which could play a vital part in battling AIDS.

They have been researching a bacterium in a pink sponge found in Shark Hole in Harrington Sound for more than 15 years and are now urging drug companies to take it up.

Montana Tech Professor of Chemistry Don Stierle said the bacterium works in a similar way to current AIDS drugs by stopping the virus from reproducing in the body by crippling a cell growth promoting enzyme.

He said: "The virus can't wreak havoc with the white blood cells if it can't reproduce itself. It will essentially die."

So far the bacterium has only battled with compounds from AIDS cells in plates of jelly. Live testing on animals and humans will need the backing of a pharmaceutical company, said Professor Stierle.

"The preliminary tests are really good. One of the things we are trying to do is decide how it does what it does."

However he is not hopeful of getting a sponsor. He said: "The chances of getting a drug company to market it are particularly low."

He said it was difficult to get drugs developed - even AIDS drugs which were fast tracked for testing if they looked like working.

The AIDS virus has killed more than 21 million people worldwide while in 2000 there were 36 million sufferers living with the disease.

The virus cannot be killed by antibiotics while the body's own antibodies are unable to defeat it and, unchecked, it will destroy the body's immune system.

Professor Stierle's wife Andrea, also a professor, said a compound from the bacterium also acted as an antibiotic which could help AIDS patients under attack from all sorts of infections because of their damaged immune system.

And she said the bacterium attacked different enzymes currently targeted by anti-AIDS drugs and it was vital to keep developing new drugs as the AIDS virus could end up becoming immune to existing ones which currently kept the virus in check.

She said of their discovery: "It doesn't look like curing AIDS but it's another drug in the fight against HIV."

She refused to name the bacterium or the host sponge, which they have nicknamed the Big Pink, because a patent was being filed.

Professor Stierle said he did not know what the bacteria's role was in the pink sponge, which is about four to six inches long, but he said it was possible it lived symbiotically in the sponge - enjoying living in the host's body while helping break down other bacteria and fungi which the sponge eats.

Professor Stierle and his wife and researcher Andrea spent a week at the Bermuda Biological Station for Research in the mid 1980s looking at sponges and other marine organisms.

The Big Pink bacterium was sent to the National Institute for Health and test results showed it was active against AIDS. The Stierles are set to publish those results this year.