Fighting Campylobacter in Turkeys by Going to the Source
By The Food Safety Consortium - The pathogen Campylobacter, Dan Donoghue says, is “a very interesting organism.” His team recently found that it occurs naturally in turkeys’ male and female reproductive tracts.
To make things more complicated, it
appears that artificial insemination
procedures at turkey farms could expand
the pathogen’s prevalence.
But another procedure used on the
farm — placing antibiotics in turkey
semen — could offer some hope for
fighting Campylobacter there. Donoghue’s
Food Safety Consortium research
project at the University of Arkansas is
testing these antibiotics to determine
their effectiveness against foodborne
pathogens.
Campylobacter bacteria are commonly
found in poultry intestinal tracts.
“Campylobacter doesn’t cause disease in
birds, it causes disease in people,” said
Donoghue, a poultry science researcher
in the U of A Division of Agriculture. “It
apparently doesn’t hurt the productivity
of the birds.”
The U.S. Department of Agriculture
says Campylobacter can exist in the intestinal
tracts of people
and animals without
causing any symptoms
or illness. However, if
people consume live
bacteria in raw milk,
contaminated water,
or undercooked meat
or poultry, they may
acquire a Campylobacter
infection (also called
campylobacteriosis).
The illness symptoms
include diarrhea, stomach pain and
nausea.
Thorough cooking of poultry will
eliminate the pathogen, but food safety
researchers want to reduce or eliminate
it at the source as much as possible.
On the turkey farms, Donoghue
explained, artificial insemination is the
means by which nearly all turkeys are
produced. A male turkey’s semen is used
to inseminate multiple females. But the
current concern is over the possibility
that semen contaminated with Campylobacter
could be spreading the pathogen
to females and the next generations.
“Semen collection by nature of
the tom’s anatomy is predisposed to
fecal contamination,” Donoghue said.
Additionally, semen on commercial
turkey farms is pooled before it is used
to inseminate hens,
making it possible
that contaminated
semen could spread
through entire
flocks.
With these
hurdles facing producers,
Donoghue
sees some possible
solutions for
research to pursue.
One approach takes
advantage of semen extenders, which are
added to turkey semen to increase the
volume and extend their usage.
“Some extenders have antibiotics,
some don’t have antibiotics and some
have different antibiotic combinations,”
he said. “We’re hoping that some of these
with antibiotic combinations will be
more effective against Campylobacter.”
Semen has not been considered a
potential source of pathogenic bacteria
until recently, so its extenders have not
been tested against foodborne pathogens
to measure their effectiveness. “We’re
hoping to find one that is already being
used that will be effective against foodborne
pathogens,” Donoghue noted.
In addition to searching for the
right antibiotic, Donoghue is also testing
whether cooling the semen would reduce
or eliminate Campylobacter. The catch
is to cool the semen enough to hurt the
pathogens without damaging the viability
of the sperm.
“We can get rid of Campylobacter
in semen,” Donoghue said in reference
to the cooling process. “It would be easy
enough to do. But, unfortunately, you’re
also going to kill the sperm.”
One procedure that hasn’t eliminated
the pathogen is to oxygenate the
semen, an important procedure for in
vitro storage. Campylobacter generally
does not react well to high oxygen
content, but Donoghue’s studies show it
is apparently strong enough to survive
under these conditions.
The experiments continue among
scientists inside and outside the Food
Safety Consortium, Donoghue said. “We
are looking at different approaches and
trying to eliminate that segment of the
contamination or reduce it. We’re trying
to eliminate it in the bird.”
Source: The Food Safety Consortium Newsletter - May 2004
