Discovery could reduce chicken pathogens, improve safety

Proteins called bacteriocins, produced by bacteria, can reduce Campylobacter and Salmonella pathogens to very low levels in chicken intestines, helping to reduce human exposure to food-borneinfections, according to scientists at the US's Agricultural Research Service (ARS).

Campylobacter and Salmonella can potentially sicken people who eat undercooked or cross-contaminated food. Campylobacter is one of the main pathogens found in infected chicken.

"This work has confirmed that bacteriocins can reduce Campylobacter to nearly undetectable levels in the intestines of chickens, and that means less human exposure to this pathogen,"stated ARS microbiologist Norman Stern in publishing the results of the research.

The bacteriocins work in a chicken's gut by crowding out pathogenic bacteria, making it less likely that pathogens could infect poultry or humans. Bacteriocins could become an alternative toantibiotics for protecting poultry, the scientists stated.

In addition, the scientists developed a method to improve the production of bacteriocins, making it much more attractive for industrial testing.

In the research bacteriocins were purified and tested on broiler chickens colonized with either Salmonella or Campylobacter. Stern focused his endeavors on Campylobacter.

Stern and another scientist evaluated tens of thousands of bacterial isolates from poultry-production environments. They have found anti-Campylobacter activity in several organisms.

To find the promising bacteriocins, Stern and his colleagues started by examining more than 25,000 bacterial isolates. They narrowed the focus to 365 isolates, and found a few that combatCampylobacter.

Dozens of bacteriocins are still being analyzed for efficacy against Campylobacter. As a result of this research, Stern and his fellow researchers have applied for several patents.

"There has been substantial interest by industry to license the technology," he stated. "The work we've done with bacteriocins suggests they might someday beused as an alternative to antibiotics."

The research was coordinated by ARS scientists in collaboration with scientists from the former Soviet Union.