COMPANIES in North America want to spray crops with a bacterium that might
cause a deadly lung infection in people with cystic fibrosis. Experts on the
bacterium, Burkholderia cepacia, are calling for a ban on its use in
pest control until it is proved safe.
Good Bugs of Madison, a spin-off from the University of Wisconsin, hopes that
the bacterium will outcompete fungi that can grow on peas, maize 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 US Environmental Protection Agency (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鈥檚 microbial
branch in Washington DC, says: 鈥淲e have not yet received information we feel is
adequate to make that judgment.鈥�
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The EPA, together with the Canadian Pest Management Regulatory Authority, is
also reviewing a similar application by another company, Agrium of Calgary,
Alberta. And Jonathan Barry, president of Good Bugs, told 快猫短视频
he was confident that he could gain permission to test the bacterial spray in
Britain.
Barry believes the strain of B. cepacia used by Good Bugs, isolated
from soil, is quite safe. But that doesn鈥檛 reassure Robert Beall, president of
the US Cystic Fibrosis Foundation. 鈥淲e don鈥檛 think it should be used in any
agricultural setting until we know what鈥檚 safe and what鈥檚 not. We don鈥檛 know yet
if there are any truly nonpathogenic forms of this organism.鈥�
There may be none. 鈥淢olecular genetic evidence indicates there might be a
threat to health regardless of which strains are selected,鈥� 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鈥檚 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. 鈥淚t suggests non-CF patients may be a source of
infection,鈥� says Goldstein. 鈥淭his is incredibly important if they鈥檙e going to
start spraying it in the environment.鈥�
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. 鈥淚t seems very premature to start spraying it
around before we know what the risk is going to be,鈥� he says.
Alison Hamer of the British agriculture ministry鈥檚 Pesticides Safety
Directorate says that no new biopesticide could get a licence without meeting
strict British and European regulations. 鈥淭he whole process is very rigorous,鈥�
she says.