Swine dysentery (SD) is a mucohaemorrhagic colitis of pigs resulting from 
infection of the large intestine with the anaerobic intestinal spirochaete 
Brachyspira hyodysenteriae. Whole-cell bacterin vaccines are available to help 
control SD, but their performance has been inconsistent. This study aimed to use 
a reverse vaccinology approach to identify B. hyodysenteriae proteins for use as 
recombinant vaccine components. Nineteen open reading frames (ORFs) predicted to 
encode potential vaccine candidate molecules were identified from in silico 
analysis of partial genomic sequence data. The distribution of these ORFs among 
strains of B. hyodysenteriae was investigated by PCR, and widely distributed 
ORFs were cloned. The products were screened with a panel of immune pig sera, 
and from these a subset of conserved, immunogenic proteins was selected. Mice 
immunized intramuscularly with these recombinant proteins developed specific 
systemic antibody responses to them, and their sera agglutinated B. 
hyodysenteriae cells in vitro. In a pilot experiment, eight pigs were vaccinated 
twice intramuscularly with a combination of four of the proteins. The pigs 
developed antibodies to the proteins, and following experimental challenge only 
one developed SD compared to five of nine non-vaccinated control pigs. Although 
these differences in incidence were not significant, they indicated a trend 
towards protection using the recombinant proteins as immunogens. This study 
demonstrates that the reverse vaccinology approach has considerable potential 
for use in developing novel recombinant vaccines for SD.