EXCLUSIVE

A SCOTS scientist will fly to Las Vegas later this year to attempt to talk his colleagues out of what he sees as gambling with people's lives.

Professor John Govan, of Edinburgh University, is urging caution over the development of a pesticide crop spray that might prove lethal to people with cystic fibrosis.

It is based on one of a family of bacteria called Burkholderia cepacia, and the company that developed it, Good Bugs of Madison - a spin-off from Wisconsin University - hopes it will keep down fungi that infest peas, maize, and potatoes.

However, a close relative in the B. cepacia complex can cause a potentially lethal lung infection in people with cystic fibrosis, and the company has applied to the US Environmental Protection Agency for large-scale testing.

According to a report in the New Scientist, the agency is blocking the application until the company provides more evidence that it presents no threat to human health.

Meanwhile, Professor Govan, head of microbial pathogenicity at Edinburgh and an expert on infection in CF patients, is one of a group of scientists calling for a moratorium on the use of the spray, and he has been invited to express his fears to a conference of crop scientists in the desert resort.

He said yesterday: ''We are not in a position to say that this organism is safe. Even if this particular strain is safe, it is not so different from the strain that causes infection that we can rule out the possibility of it mutating when it mixes with other organisms in the soil. Agricultural workers could also be at risk.

''The infective strain is a big problem for cystic fibrosis sufferers. It is transmissible and resistant to antibiotics. The rate of infection in the CF population varies from 10% to 50%, but 20% of those who get it will die quite rapidly.

''You don't know if you are going to be among the one in five who will die. It is a lottery. Some kids can have it for years and nothing happens, but it affects their life - they have to be segregated from other CF sufferers and attend separate clinics, and they are warned to stay away from meetings and group events. This pathogen is holding the Cystic Fibrosis world to ransom.''

However, Professor Govan admits the possibility of using a neutered bacterium as a crop spray cannot simply be dismissed out of hand, since the risk has to be balanced against the toxicity of pesticides currently in use.

He and his colleagues, backed by a #11,990 grant from the Cystic Fibrosis Trust, have mounted a two-year research project with the aim of improving infection control and patient care by identifying which strains of B. cepacia colonise CF patients.

They will also seek to assess bacterial markers for identifying the highly transmissible strains, and to understand ways in which immune defences of CF patients respond to attack by this pathogen, which can also prey on patients in intensive care units or sufferers from chronic granulomatous disease.