Bovine Genital Campylobacteriosis

Abstract

Definition of the disease: Bovine genital campylobacteriosis (BGC) is a venereal disease also known as bovine venereal campylobacteriosis (BVC). The causal agent of this sexually transmissible disease is Campylobacter fetus subsp. venerealis. The species is divided into two closely related subspecies: C. fetus subsp. venerealis and C. fetus subsp. fetus. By definition C. fetus subsp. venerealis is associated with BGC, causing fertility problems with considerable economic losses, particularly in endemic regions. Bovine infections with C. fetus subsp. fetus are associated with abortion and have a more sporadic occurrence. Description of the disease: BGC is a venereal disease that is characterised by infertility, early embryonic death, and abortion. The disease is caused by C. fetus subsp. venerealis, a bacterium with pronounced tropism for the genital system of cattle. Transmission of the causal agent takes place mainly during natural mating, and the presence of C. fetus subsp. venerealis in the semen of bulls creates the risk of spread of the disease through artificial insemination. Identification of the agent: Samples taken from bulls, cows or aborted fetuses can be analysed for the presence of the causal organism. The organism is a thin Gram-negative curved rod that may form S-shapes, seagull-shapes and spirals, and can be cultured at 37°C for at least 3 days in a microaerobic atmosphere. Confirmation of the isolate and discrimination between the subspecies of C. fetus can be performed by biochemical or molecular methods. Immunofluorescence may also be used to identify the organism, but it will not differentiate between different subspecies. Serological tests: Enzyme-linked immunosorbent (ELISA) can be used for testing herd immunity, but is not suitable for diagnosis of the infection in individual animals. This test can not differentiate between infections caused by the two subspecies. Requirements for vaccines and diagnostic biologicals: A vaccine may be prepared from C. fetus subsp. venerealis and/or C. fetus subsp. fetus that shares antigens with C. fetus subsp. venerealis. This vaccine is inactivated with formalin, and may be administered in an oil-emulsion adjuvant.