Brachyspira

Bacteria of Brachyspira genus are involved in different digestive diseases of swine. Brachyspira hyodysenteriae (serpulina) is the etiological agent of swine dysentery, a mucohemorrhagic diarrheal disease in which lesions are confined to the large intestine of pigs (Harris and Glock, 1986).

B. hyodysenteriae has a strong beta-hemolytic activity and is enteropathogenic for swine. B. pilosicoli causes a relatively mild intestinal infection, which has been named porcine intestinal spirochaetosis. B. intermedia has also been described as probable causes of mild colitis. B. innocens is described as non pathogenic for pigs (Stanton et al, 1997). Strong complete hemolysis is well-established characteristic differentiating the highly pathogenic B. hyodysenteriae from others Brachyspira groups. Weak -haemolytic strains (B. pilosicoli, innocens, intermedia) are more difficult to identify. B. pilosicoli strains can be differentiated from others by their hippurate activity (Fellström et al, 1997).

Nevertheless, Brachyspira species are difficult to cultivate and their identifications are time consuming. So, a PCR test has been developed to detect all Brachyspira species and differentiate B. hyodysenteriae, B. pilosicoli and B. innocens or intermedia.