Fighting Campylobacter in Turkeys by Going to the Source
Article ID: 510446
Released: 15-Mar-2005 9:20 AM EST
Newswise — 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 bywhich 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."