The Rural Voice, 2004-06, Page 58The leading edge
Genetic research could be key to
unlocking BSE mysteries: scientist
Genetic research could be the key
to solving the mystery of BSE, scrapie
and other brain -wasting diseases, a
Scottish scientist says.
John Williams of the Roslin
Institute in Scotland, a leading animal
research centre, is part of a team of
international scientists searching for a
genetic link among the family of
transmissible spongiform
encephalopathies that also includes
Creutzfeldt-Jakob disease in people
and chronic wasting disease in deer
and elk.
Promising research involves a scan
of bovine genes displaying mutation
or variations in expression. Finding a
genetic marker could lead to a reliable
live test among animals susceptible to
the fatal condition. Current live tests
using blood samples are not reliable
enough. By the time the agent appears
in the blood, the animal is likely
showing other symptoms.
Another line of genetic research
which Williams revealed in a lecture
at the University of Calgary, is
looking at sheep genotypes to see if
some are resistant to scrapie. There is
a plan in Britain to eventually select
rams for specific genotypes to curb
scrapie.
"It's coming together but we
certainly don't have evidence that we
could go through to diagnosis for
breeding animals that are resistant or
susceptible," Williams said.
Scrapie has been known for 250
years. BSE was first diagnosed in
Britain in 1986. Scientists theorized
that cattle developed the disease after
being fed rendered protein from
diseased sheep. Feeding ruminant
protein back to ruminants was banned
in Britain in 1988 and in 1996 the
government banned feeding any
ruminant proteins to any livestock.
Once the feed ban was implemented
the number of BSE cases declined but
there are still unexplained outbreaks.
The unofficial count for 2003 was 147
cases and during January 2004, 11
cases appeared in 60,000 samples.
"As time goes on and we still see
these cases, it begs the question:
where are they coming from and do
we potentially have spontaneous BSE
in the population?" Williams said.
Recently, two Italian samples
displayed a different form of BSE,
similar to cases of sporadic
Creutzfeldt-Jakob disease found in
humans. 11 could mean a second strain
of the disease exists.
Similar information has come from
Japan and Germany, where the
disease did not follow the pattern seen
in the British cases.0
— Source: Western Producer
Alternative measures control swine E. coli
An American government scientist has devised an alternative to antibiotics to
control E. coli, the leading cause of sickness and death in young pigs.
Roger Harvey, a veterinary medical officer with the U.S. Department of
Agriculture, leads an effort to develop a mixed culture of beneficial bacteria
called recombined porcine continuous -flow, or RPCF. Scientists think that RPCF
might one day be able to replace today's antibiotic treatments when combined
with ambient temperature regulation, hygiene improvement and zinc oxide
applications. A growing resistance of E. coli to today's antibiotics makes it
especially important to develop an effective replacement.
Harvey's method involves colonizing young pigs' intestinal tracts with a
mixture of beneficial bacteria obtained from other pigs. This helps establish
healthy microbial populations in the gut much quicker than would otherwise
occur. These good bacteria attach to the intestinal walls, blocking sites so
disease -causing bacteria can't attach and compete for needed nutrients. So far
among 35,000 pigs tested the RPCF mixture has been shown to reduce illness,
death and medication costs from E. coli infections compared to untreated pigs.0
— Source: United States Department of Agriculture Press Release
54 THE RURAL VOICE
Common fungus could
control dandelions
A common fungus could
blanch dandelions out of existence
by robbing the pesky weeds of the
green -coloured chlorophyll they
need to live, Agriculture Canada
scientists say.
The fungus could replace some
chemical herbicides that have
been banned because of
environmental and health
concerns in a growing number of
cities. Ag Canada scientists found
the naturally -occurring fungus,
called Phoma macrostoma, can be
spread on soil to prevent weeds
from growing, without harming
grass.
"It causes those plants to turn
white so they don't produce any
chlorophyll," said Karen Bailey, a
weed pathologist at the
department's research centre in
Saskatoon.
"If plants don't produce
chlorophyll they don't grow, so
they die very quickly," Bailey
explained.
The fungi was isolated from
sickly Canada thistles across the
country. Trials show that
spreading the flour -like fungi on
freshly -planted or clean lawns
prevents more than 80 per cent of
weeds from growing, Bailey said.
"If you're seeding a lawn or
want to prevent seeds from enter-
ing into an area, that would be
how it would be used," she said.
The organisms live about four
months in soil before they start to
die. By the following year they are
gone.
"We don't want (the fungi) to
really change that microbial
balance because that's ,not the
only living thing in soil," she said.
The market for the fungi is
huge among golf courses and
homeowners, said Barry Maynard,
vice-president and general
manager of Scotts Canada Ltd.,
the maker of Killex, which helped
fund the research. The fungi could
be on store shelves in four to six
years.0
—Source: Reuters News Agency