The French food safety authority said yesterday it found no risk of catching the human form of bovine spongiform encephalopathy (BSE) from eating beef steak or other animal muscle.
The Nobel Prize-winning American researcher Prof Stanley Prusiner last week suggested that infectious prion proteins implicated in variant Creutzfeld-Jakob Disease (vCJD) could accumulate and spread in certain kinds of muscle tissue in mice.
The French food safety agency AFSSA said it had carried out tests to assess any risks of prion infection from beef muscle from BSE-infected animals, and all the results were negative.
Prof Prusiner's paper was published in the Proceedings of National Academy of Sciences (PNAS), saying prion accumulation was found in the hind-leg muscles of lab mice.
The French food safety authority said it had tested for infectious prions on muscle samples taken from two cows, one of which had BSE while the other did not, and from four BSE-infected mice, two of which were in terminal stage while the other two had yet to develop symptoms.
It also tested samples from a sheep and a goat both infected with a related agent to BSE called scrapie and which had developed symptoms; and from two sheep artificially infected with BSE, which had symptoms.