This story kicks off a new weekly series called “Planting the Seed,” which looks toward the new millennium. These stories will feature ideas and advances in agricultural and environmental sciences with implications for the future.

Every year in the United States, about 40,000 cases of
Salmonellosis are reported. Some
of those are related to contaminated poultry and egg products.
But University of Georgia
scientists are working with the poultry industry to cut that
number as close to zero as
possible.

“Overall, the industry is careful about cleaning and
sanitizing their processing
facilities,” said Scott Russell, a poultry science
microbiologist with the UGA
College of Agricultural and Environmental Sciences. “But
we’re finding ways to make
their cleaning procedures and sanitation even more
effective.”

A ‘Firefly’ Test

A special test kit uses “luciferase,” an enzyme
extracted from fireflies, to
test for bacteria. The tester takes a swab sample from a
counter top, sink or other part
of the processing line. That swab goes into a mix of chemicals
that includes luciferase.

If bacteria are
present on the swab, their
ATP (adenosine triphosphate) reacts with the luciferase and
produces light within a minute. “The more light, the more
bacteria,” Russell
said.

The readings can be false, depending on what cleaners the
processor uses. Russell said
some acid cleaners inactivate the enzyme. So even though the
test shows low or no
bacteria, they may actually be present. Other cleaners like
quaternary ammonium show a
falsely high reading.

Safety With Chlorine

Fortunately, most poultry processors use chlorine, said
Julie Northcutt, a CAES poultry
technology scientist. “Just one-half to one part per
million of free chlorine (not
bound to organic material) is very effective against bacteria
that can be found in poultry
plants,” she said.

And chlorine has no effect on the luciferase enzyme tests.
“If the processor uses
chlorine to sanitize the line and then uses this test,”
Russell said, “the
results are accurate.”

U.S. Department of Agriculture tests show that the 1 ppm
free chlorine used in
processing plants is effective against bacteria and harmless to
humans. In fact, their
regulations approve using 20 to 50 ppm total chlorine with no
harmful effects on humans.

Faster Bacterial Tests

That’s just one of the projects Northcutt and Russell are
working on. Others include
improving the overall condition of the live chickens coming
into the plants and finding
even faster ways to detect bacteria in processing plants.

“Right now, most of the bacterial tests take two to
five days before the results
are known,” Russell said. “And processors can’t hold
their product that
long.”

They test their meat and egg products for bacteria,
including Campylobacter, E. coli
and Salmonella. But if the tests are positive, the company must
issue a costly product
recall.

“By the time they get the results, the products are
already in the stores, or they
may have already been bought and sometimes eaten,” Russell
said.

Russell is looking for tests that take 18 to 24 hours.
“But we’re hoping for a
test that will give accurate results in one to six hours,”
he said.

Quicker Test = Safer Food

That quick turnaround could enable the results of the test
to be confirmed before the
product leaves the processor. It would enable them to verify
the effectiveness of their
cleaning and sanitation practices, too, without shutting down
the plant.

Faster tests could make the processor perfectly sure its
whole or cut-up chickens or
egg products are safe when they leave the plant.

But consumers will still need to be food-safety conscious.
“Poultry processors do
all they can to ensure your safety,” Russell said.
“But consumers have to do
their part, too.”