A species of bacteria present in man and many kinds of animals and birds, often causing infertility and/or abortion.

A species of microaerophilic, Gram-negative, curved or spiral bacilli assigned to the phylum Proteobacteria. This species is motile using a single polar flagellum, oxidase positive, catalase positive, indole negative, reduces nitrates, and does not produce hydrogen sulfide. C. fetus is an opportunistic microbe that causes bacteremia, thrombophlebitis, septicemia, and is a suspected pathogen in immunocompromised patients with gastrointestinal symptoms. In sheep and cattle this bacterium is known to cause abortions, infertility, enteritis and bovine genital campylobacteriosis.

Any bacterial organism that can be assigned to the species Campylobacter fetus.