WASHINGTON -- A mutation in the protein responsible for mad cow disease and its equivalent in humans, Creutzfeldt-Jakob disease (VCJD) may help prevent the disease from developing in livestock, according to a U.S. study released Tuesday, AFP reported.

Researchers Stanley Prusiner and his University of California in San Francisco team, said that certain mutations of the protein prion (PRP) in cattle prevented the prion from turning into the pathogen that causes bovine spongiform encephalopathy (BSE), or mad cow disease.

The researchers worked with genetically modified mice in order to get the mutant PRP protein, then injected the mice with the pathogenic form of the protein.

According to the results published in The Proceedings of the National Academy of Sciences, the mice carrying the transgenic PRP developed pathological symptoms of spongiform encephalopathy much slower than those carrying the normal, or benign PRP gene, according to autopsies of the specimens.

In addition, said the report, mice from the same group that were allowed to live showed none of the neurological symptoms typically associated with the fatal brain-wasting disease.

The discovery "raises the possibility of producing prion-resistant livestock," the researchers concluded.

As yet, there is no vaccine or treatment against the human equivalent of BSE or other forms of transmittable forms of encephalitis.