Campylobacter jejuni (C. jejuni) is the leading cause of bacterial food poisoning. Infection with the bacteria leads to Campylobacteriosis, which causes diarrhea, fever, and vomiting. The disease can also result in more serious complications, including arthritis, inflammatory bowel disease, and paralysis. C. jejuni is transmitted from animals and birds to humans, where it causes infection. The exact mechanism of how it colonizes in humans and causes disease is unknown. C. jejuni is capable of surviving for long periods of time outside of a host, indicating that it must have several ways of dealing with the stresses associated with a less than ideal environment. Carbohydrate structures covering the surface of C. jejuni play an important role in interactions between the bacteria and its surroundings and may be involved in environmental survival, as well as in the host infection process. Dr. Emilisa Frirdich contributed to a study that identified a new C. jejuni cell surface carbohydrate (polysaccharide), which was found to be involved in C. jejuni stress survival and formation of biofilms (the layer of microorganisms that enables bacteria to adhere to a surface). Many bacteria produce biofilms to increase their ability to survive stress inside and outside of a host. Frirdich is investigating this cell surface carbohydrate to determine its nature, identify the gene products involved in making it, and characterize its biological importance. The research may lead to a better understanding of how C. jejuni causes disease, and ultimately contribute to development of an effective vaccine.