Campylobacter (meaning "curved bacteria") is a genus of Gram-negative, microaerophilic, oxidase-positive,catalase-positive, nonfermentative bacteria. Campylobacter species are typically spiral-shaped and able to move via unipolar or bipolar flagella. Most Campylobacter species are pathogenic and can infect humans and other animals. At least a dozen species of Campylobacter have been implicated in human disease, with C. jejuni and C. coli the most common. C. jejuni is now recognized as one of the main causes of bacterial foodborne disease in many developed countries. C. fetus is a cause of spontaneous abortions in cattle and sheep, as well as an opportunistic pathogen in humans.