The University of Arizona

Issue

Most people are familiar with Salmonella and its potential to make people ill. But fewer know about Campylobacter jejuni—even though it makes more people sick. Raw chicken is one of the most common carriers of the bacteria. Campylobacter is now the number one food-borne pathogen in the United States and the world, surpassing Salmonella. In the United States alone, 2.4 million cases are reported annually, with costs exceeding $1 billion. Americans consumed 86 pounds of chicken per person in 2006, the most recent numbers available.

What has been done?

Funded by the USDA, faculty and graduate students in the Department of Veterinary Science and Microbiology developed a new poultry vaccine using Salmonella to induce chicks to make antibodies to Campylobacter proteins in their intestines, where the infection begins. The vaccination process is simple, easy to produce and protective to the chick. The Salmonella lives four to five days, enough time to stimulate antibody production, and dies. Chickens need to be vaccinated early because they become infected at just two to three weeks of age. The goal is to halt the contamination before it spreads and survives on raw chicken sold in stores. The vaccine may be available in 3 to 5 years.

Impact

Ongoing research trials show the vaccine has significantly reduced the pathogen’s ability to colonize young chickens’ intestines. In the first study, Campylobacter infection was reduced by 98 percent compared with a control group: 270 million Campylobacter organisms were present in non-vaccinated birds, compared to 67,000 organisms in the vaccinated birds. At least 500 organisms are needed to produce the disease in humans, but the chlorine in the packinghouse chillers usually reduces bacteria by 1,000 to 100,000 organisms. Vaccinated chickens should be free of Campylobacter after processing, according to the researchers. The vaccine’s effect could be significant: about 8.9 billion broilers go to market annually in the U.S., with a value of $21.5 billion. Europe has similar broiler production figures. The vaccine could serve as an intervention method for Campylobacter when the USDA and FDA mandate reduced numbers of food-borne pathogens in chicken, most likely in the next few years.

Contact

Lynn Joens
(520) 621-4148
email: joens@ag.arizona.edu