First isolation of 'Brachyspira hampsonii' from pigs in Europe

Swine dysentery in Europe is classically attributed to Brachyspira hyodysenteriae. However, other Brachyspira species have been increasingly associated with intestinal disorders in pigs. This case report describes the first diagnosis of a “Brachyspira hampsonii” infection in European pigs. In a routine quarantine monitoring protocol, two gilts were presented for necropsy, in which soft watery non-haemorrhagic colonic content was found. Microbial culture from the colonic content and from faecal samples revealed the presence of strongly haemolytic, ring-phenomenon positive spirochetes indicative for Brachyspira hyodysenteriae. A diagnostic commercial PCR could not confirm the presence of B. hyodysenteriae. Phenotypic characterisation and PCRs targeting the 16S rRNA, 23S rRNA, nox, hlyA and tlyA genes of different swine-related Brachyspira spp. were performed. Phylogenetic analysis of sequences of the partial nox and 16S rRNA genes and multi locus sequence typing demonstrated that the isolates in this case were “B. hampsonii” isolates. This case report shows that the diagnosis of infections caused by new, emerging Brachyspira species is not self-evident and that the combination of microbial culture and PCR is recommended, completed with more extensive genotyping if necessary