Reducing pathogens in chickens

Some commercial poultry processors have begun using a bacterial culture developed at the University of Arkansas that can sharply reduce the levels of pathogenic Salmonella and Campylobacter in live poultry.

This probiotic is helping the poultry industry increase the safety of food products, and poultry science researcher Billy Hargis believes his research team can do more.

"We have not bothered to patent this specific culture because we don't think this is the best we can do," said Hargis, who is working on the Food Safety Consortium project in the UA Division of Agriculture. "We think we can find better cultures. This is just the best we have found so far. We think we can make it more effective."

The culture is unique because unlike previous cultures that have been tested, this is a "defined culture" " entirely derived from a single defined group of bacteria. "They're known organisms, specific isolates that are well characterised," Hargis said.

The probiotic cultures are applied to the concept of competitive exclusion, in which different species compete to coexist. The plan in poultry production is to introduce the beneficial good bacteria into a live bird to drive out the harmful pathogenic bacteria. The federal Food and Drug Administration does not allow undefined cultures to be used in competitive exclusion, so the defined cultures produced by Hargis' research group fill a need for industry.

"Our cultures are different because they can be truly defined and they can be reproduced from specific isolates that are stored back in the freezer," he said. "Then they can be propagated virtually forever."

At the poultry production farm level, the probiotic culture has been administered to chicks through their drinking water and by spray application. In addition to cutting down on pathogens in the live poultry, the culture has also been found in experiments to be effective in increasing the birds' weight, lowering production costs and reducing environmental contamination in poultry houses.

Emphasis on food safety is mostly concentrated at the processing plants where companies employ numerous techniques to eliminate bacterial contamination in the stages before a poultry product is packaged for sale. Processors can find their work made easier if they receive a supply of live birds at the plant that have already been exposed to pathogen-reducing exercises.

So producers of live poultry would have significant incentives to use a probiotic culture if it not only reduces pathogens but also provides financial benefits against the usual costs of doing business.

"Our premise has been that if we can do something that provides an economic advantage in addition to reducing foodborne pathogens, then we might see more rapid adoption of the technology," Hargis said. "We've had quite a bit of commercial adoption in the past year. We have several companies that are using the product at least intermittently."

In addition to seeking ways to perfect the probiotic culture, Hargis also wants to pursue more study of its ability to reduce carcass contamination. Some experiments have shown such reductions, but more data are needed.

"Salmonella does not occur by spontaneous generation in a processing plant. It comes in with the live animals. I think it's a pretty good bet that reducing Salmonella in live animals will end up reducing Salmonella in food because that's where it comes from," Hargis explained. "Our focus now is to make the culture better and find other isolates that are more effective."