In recent years, chicken has vaulted to the top of the nutritional hit list. Low in fat and a good source of protein, it has become a staple in many meals. Carol Pickett is among those who regularly enjoy chicken, but the UK microbiologist also has a serious warning about this popular food: handled improperly, fresh chicken could make you ill or even kill you.
Pickett, an associate professor in the Department of Microbiology and Immunology, has found that every fresh, whole chicken she tested was contaminated with a bacterium called Campylobacter jejuni.
With flagella on both ends, Campylobacter jejuni is a unique bacterium. Journal of Infectious Diseases, University of Chicago Press, Volume 166, p. 311.
Although few have heard of it, Campylobacter jejuni is now believed to be the most common bacterial cause of human diarrhea in the United States and in many other countries. The Center for Disease Control in Atlanta estimates that about four million cases occur every year in the United States. Most people affected by the bacterium experience severe abdominal pain and diarrhea for seven to 10 days. A small percentage of people who get the diarrhea can develop a serious auto-immune response called Guillain-Barre syndrome that causes generalized paralysis and can even lead to death.
"This bacterium is very under-appreciated by the public," says Pickett, "but it is much more prevalent than the E. coli found in hamburger."
Pickett is researching how Campylobacter jejuni causes diarrhea and is delving into the little-known epidemiology of a toxin, CDT, produced by the bacteria. In the process, her research has also proven just how prevalent the bacterium is.
During the summers of 1996 and 1997, Pickett worked with a graduate student in animal sciences. The student went to every grocery chain in the Lexington area and purchased fresh, whole chickens. Pickett and the student then examined the birds and found that 100 percent were contaminated with Campylobacter.
"We quickly discovered that regardless of the store or the brand, if you buy a whole, fresh chicken, you can count on it having the bacteria," she says. (The bacterium does not survive freezing well so is much less prevalent on frozen chicken.)
The bacterium is so pervasive, Pickett believes, because it is hard to eliminate. "The bacteria can easily inhabit chickens, and processing lends itself to all the birds getting contaminated," Pickett says. "The USDA has new processing regulations designed to control Salmonella that might also be helping reduce the Campylobacter problem, but they by no means solve the problem."
The good news is that proper cooking will kill the bacteria, according to Pickett. The bad news is that it can easily contaminate other foods or other surfaces in the kitchen. Therefore, Pickett recommends thoroughly washing your hands and any surfaces where the chicken has been. She also recommends that small children not be allowed in the kitchen while fresh chicken is being prepared since diarrhea tends to affect children more severely than adults.
Pickett's research on this subject was published in the April 1999 issue of Applied and Environmental Microbiology. Intrigued by what she has discovered so far, the scientist is continuing research into what she calls a "unique and very interesting" toxin.