Biopesticide Threatens Those with Cystic Fibrosis

Since 1992, unbeknownst to most of us, Burkholderia cepacia (Bc), a soil bacterium which has caused serious disease and death in patients with cystic fibrosis (CF), was approved as an agricultural pesticide for use in seeds and soil. Now, in an alarming development for the 30,000 Americans afflicted with this terrible pulmonary disease, the U.S. Environmental Protection Agency (EPA) is considering an application by the Agrium Company for aerial spraying of this product. A variant of pseudomonas, which can cause pneumonia in people with CF, "Bc is not as toxic, except in cystic fibrosis victims -- it's been found in the sputum of children who've died," says Herbert L. Needleman, M.D., a professor of pediatrics at the University of Pittsburgh Medical School and member of EPA's Science Advisory Panel.

Three strains of Bc developed by the Stine Microbial Products Company had been approved by EPA because they were thought to be distinguishable from strains that cause disease in humans. However, in 1998, tests of one strain found a genetic marker that correlated with human infection. Stine voluntarily removed this strain from use on crops and turf, and all three strains from use on turf. Tests of Agrium's new strain -- to be applied aerially to trees -- have not revealed toxicity or ability to cause disease.

But there's a risk that, once released, the bacterium might switch genes and mutate into a more dangerous strain. An EPA memo refers to Bc's "versatility and resistance to many antibiotics and disinfectants," which have caused outbreaks of infection in hospitals. EPA notes, "The percent of the population with chronic diseases that may predispose them to opportunistic infection has also increased." At an EPA Science Advisory Panel hearing in July, Dr. Arnold Smith, chair of microbiology at the University of Missouri Medical School, said that Bc was beginning to be found in adult patients with chronic obstructive pulmonary disease, who number 300,000 in the United States. EPA is reviewing the case through August 20.

[July 1, 1999 background memo, Office of Pesticide Programs, Biopesticides and Pollution Prevention Division, U.S. EPA]