Risk Management Paratuberculosis

TAFS published its first position paper on a non-TSE animal disease today. It is a recommended risk management plan for paratuberculosis and available for download from the TAFS website.

Fish study holds hope for CJD drug

We know that rogue prions cause CJD and mad cow disease, but what normally folded prion proteins do has been a mystery, because experimental mice without them are almost normal.

Now Edward Málaga-Trillo and colleagues at the University of Konstanz in Germany have discovered that depriving zebrafish of prions has a much more obvious effect. This holds out hope for future drug development (PLoS Biology, DOI: 10.1371/journal.pbio.1000055).

Zebrafish have two versions of the protein. Blocking one stops the brain forming correctly; blocking the other stops the cell migration that guides embryo growth. Time-lapse photos show that the prions help cells to signal and stick to each other.

The finding may explain why disrupting normal prion production causes the dementia of CJD. "In fish embryos we see the protein helping cells communicate," Málaga-Trillo told New Scientist. "It may do something analogous in the mammalian brain, such as building synapses. That may be what goes wrong in prion diseases."

The work also means zebrafish might be useful in drug development. Because disrupting prions has such dramatic effects in these embryos, a drug that protects the protein should be easy to identify.

Source: New Scientist, 2699, March 11, 2009

2 more position papers on TSE updated

Two more updated versions of TAFS Position Papers on TSE have been posted today:
- Testing of cattle for BSE
- Slaughter practices and the dangers of carcase contamination with BSE.

The papers can be downloaded from the TAFS website.

3 position papers on TSE updated

Three updated versions of TAFS Position Papers on TSE have been posted today:
- BSE in small ruminants
- Transmission of scrapie via milk
- Specified risk materials.

The papers can be downloaded from the TAFS website.

Metro Group represented in TAFS

As per January 1st, 2009, TAFS welcomes Mr. Hans-Jürgen Matern of MGB Metro, Düsseldorf, Germany, as its latest member.

Mr. Matern is Division Manager Quality Assurance at MGB Metro.

Welcome!

New website of OIE reference laboratory for paratuberculosis

If you are interested in paratuberculosis, you will either know already or find it good to know now that the Veterinary Research Institute, Brno, Czech Republic, opened new web pages of the OIE reference laboratory for paratuberculosis.

In particular the weekly updated list of publications on paratuberculosis/Johne's disease will be very useful for the community.

Source: Centaur news flash information

New form of 'mad cow' disease could infect humans

• 13 September 2008
• From New Scientist Print Edition.
• Andy Coghlan

JUST when it looked as if we had mad cow disease licked, a new threat may be lurking down on the farm - bovine amyloidic spongiform encephalopathy. First discovered in Italian cows in 2003, BASE has infected a monkey, suggesting that the disease may also be capable of spreading to humans.

Alarmingly, the disease took hold - and killed - the monkey faster than strains of classical BSE and variant Creutzfeldt-Jakob Disease (vCJD), the human version of mad cow disease, injected into other monkeys as part of the same experiment. What's more, the symptoms and brain damage look very like a rare form of "sporadic" vCJD, called MM2, which has no known cause, raising the prospect that BASE may already infect people.

Emmanuel Comoy of the Institute of Emerging Diseases and Innovative Therapies in Fontenay-aux-Roses, France, and his colleagues made the discovery after injecting brain material from an Italian cow with BASE into the monkey's brain. After 26 months, it was dead (PLoS ONE, DOI: 10.1371/journal.pone.0003017).

The monkey's symptoms were different from those of other monkeys injected with human vCJD or classical BSE, and from people and cows with these diseases, whose cerebellum and brain stem are damaged. Instead of becoming aggressive and losing their appetite and ability to move, both the cow and the monkey with BASE lost their memories and the ability to orientate. This fits with damage to the cortex. "It's as if they're lost," says Comoy. Significantly, humans with MM2 have similar symptoms and patterns of brain damage.

"We have here an atypical cattle strain of BSE that's clearly transmissible to primates, that's more easily transmissible than classical BSE, and which causes a different disease," says Comoy.
“We have a strain of BSE that's more easily transmissible than classical BSE and which causes a different disease”.

He is now trying to find out if MM2 and BASE are the same disease by injecting mice with material from people infected with MM2, BASE cows and the dead monkey. He is also exploring whether monkeys can catch BASE by eating infected brain from cows, just as people contracted vCJD by eating beef contaminated with brain material from BSE-infected cows. "We're four years into the eating trial, and the animals remain healthy, but we can't be complacent as monkeys take five years to succumb to infection with classical BSE," says Comoy.

"It's entirely possible that some diseases we think are spontaneous CJD are actually caused by BASE, but it's by no means proven," says Chris Higgins, chairman of the UK government's Spongiform Encephalopathy Advisory Committee.

Even if MM2 turns out be the human form of BASE, Higgins says, the "health implications are minimal", because the disease is so rare in cows and infective material remains banned from consumption. But Comoy says that the discovery should temper any temptation to ever relax screening for BSE.