Licking the mixing spoon — one of baking’s most valued privileges — has long been cautioned against because of the risk of salmonella in raw eggs.

However, the pleasurable activity may soon be much safer due to the ongoing research conducted by North Carolina State U. poultry scientist Matthew Koci and microbiologist Hosni Hassan. Koci and Hassan are working toward the prevention of one of America’s leading causes of food poisoning by developing a salmonella vaccine for chickens.

According to Hassan, salmonella is a rod-shaped bacterium that looks like E. coli and attacks the digestive system.

“It cannot be seen by the naked eye,” Hassan said. “But you can feel its effect if you get hit by it.”

On an annual basis, more than 1.2 million people are infected with salmonellosis in the U.S., according to the Center for Disease Control and Prevention; about 400 die from the disease each year.

On the North Carolina Department of Health and Human Services’ list of reported communicable diseases, salmonellosis ranked third in 2010. More than 2,300 were reported in 2010, but so far the numbers for 2011 are only climbing upward.

“It is a big problem,” Hassan said. “But some people get sick and don’t report it.”

The disease doesn’t just come from chickens either. Meat heavyweight Cargill, Inc. recalled 36 million pounds of ground turkey on Aug. 4, when a salmonella outbreak caused one death and sickened 75 others across the U.S., including North Carolina residents.

Michael Martin, director of communications for Cargill, Inc., said in an email Aug. 10 that the problems were complex and the outbreak was not necessarily due to one single factor.

Regardless of the specific circumstances at Cargill, however, contamination boils down to animal feces because salmonella thrives in the intestinal track, according to Hassan.

“The intestinal track can accidentally be cut [in the slaughterhouse], and then you get feces contaminating the carcass and you cannot wash it well, and so on,” he said.

Hassan said cooking food to at least 160 degrees will kill the bacteria.

“But people like to eat uncooked stuff sometimes, like sushi, and that is where you get it from,” Hassan said.

Furthermore, produce can be infected when manure is used as fertilizer.

“Salmonella can get inside the fruit,” Hassan said. “And then you take this and process it and make peanut butter and then you have contamination.”

Hassan and Koci saw the potential for a vaccine when studying salmonella at the basic level.

“We saw that under certain genetic manipulations, that organism becomes what we call attenuated,” Hassan said. “In other words, it doesn’t cause illness. And so as an extension to that, it could become a vaccine strain.”

The pair aims to get as much work done in the year of funding they have been granted. But due to the inadequate air conditioning where the chickens are kept, testing will have to wait until temperatures cool down so a proper environment can be obtained.

“If the temperature outside is 100,” Hassan said, “we cannot have a chicken inside, or it will die.”

Martin said Cargill, Inc. is working with U. Arkansas to explore a vaccine as well, but said it is a difficult task.

“The challenge is that vaccines are very strain specific, which makes it daunting to address the numerous strains of salmonella that pose human health risks,” Martin said.

Koci and Hassan have their target family of strains and are confident in its effectiveness. They believe that by reducing the amount of salmonella in the animal, it will reduce the amount in the environment. Ultimately, this should reduce future infections, including those in wild animals that cannot be vaccinated.

Regardless of how effective the vaccine may be, however, Koci said nothing can replace good food preparation.

“Handling food properly and reducing fecal-oral transmission to as little as possible is essentially the only way we will ever eliminate salmonella,” Koci said.

Koci emphasized washing hands, not cooking for others if sick and cooking meat promptly after thawing instead of leaving it out.

“If the temperature is too hot or too cold, salmonella doesn’t like it,” Koci said. “Anywhere in the middle it can grow a little bit, and the best indicator for whether or not it is there or not is how you feel 24 to 36 hours later.”