New Pesticide May be Deadly to Cystic Fibrosis Victims

by Claire Bowles
New Scientist

Good Bugs -- a Madison Wisconsin spin-off from the state university -- hopes that the bacterium will outcompete fungi that can grow on peas, corn and potatoes, keeping the plants free from infection.

But B. cepacia can cause a severe and incurable lung infection in people with cystic fibrosis. The EPA is blocking an application for large-scale testing filed last year by Good Bugs until the company provides more evidence that its strain of B. cepacia represents no threat to human health. Phil Hutton, head of the EPA's microbial branch in Washington DC, says, "We have not yet received information we feel is adequate to make that judgment."

Barry believes the strain of B. cepacia used by Good Bugs, isolated from soil, is quite safe. But that doesn't reassure Robert Beall, president of the U.S. Cystic Fibrosis Foundation. "We don't think it should be used in any agricultural setting until we know what's safe and what's not. We don't know yet if there are any truly nonpathogenic forms of this organism."

There may be none. "Molecular genetic evidence indicates there might be a threat to health regardless of which strains are selected," says Alison Holmes of Imperial College School of Medicine in London.

In a paper to appear in Emerging Infectious Diseases, Holmes, John Govan of the University of Edinburgh and Richard Goldstein of Boston University document the bacterium's ability to mutate rapidly. The researchers call for a moratorium on its use in agriculture. Goldstein says that B. cepacia is resistant to most antibiotics and kills around a third of cystic fibrosis patients it infects within a year.

Goldstein has studied an outbreak of B. cepacia at the University of Mississippi Medical Center three years ago, in which 300 patients were hit. DNA analysis suggests that the infection had passed between patients with and without cystic fibrosis. "It suggests non-CF patients may be a source of infection," says Goldstein. "This is incredibly important if they're going to start spraying it in the environment."

Martin Scott, medical and scientific director of the UK Cystic Fibrosis Trust, says he is concerned about the possibility of an application being made in Britain to test the spray. "It seems very premature to start spraying it around before we know what the risk is going to be," he says.