Indexed on: 10 Aug '13Published on: 10 Aug '13Published in: Research in Veterinary Science
Weakly haemolytic anaerobic intestinal spirochaetes of the genus Brachyspira are commonly identified based on species-specific gene sequences. Apart from the pathogenic Brachyspira pilosicoli, the distribution and disease associations of the other weakly haemolytic Brachyspira species in pigs have not been comprehensively investigated. In this study weakly haemolytic Brachyspira isolates (n=67) from Spanish and Portuguese pigs with diarrhoea, negative in a routine diagnostic PCR for B. pilosicoli, were identified by sequencing their NADH oxidase genes (nox). Nearly half the isolates were identified as Brachyspira murdochii (n=31; 46.3%). The others were Brachyspira innocens (n=26; 38.8%), Brachyspira intermedia (n=7; 10.4%), "Brachyspira pulli" (n=1; 1.5%) and a potentially novel Brachyspira species (n=2; 3%). Multilocus sequence typing (MLST) on a subset of 18 isolates confirmed their species designations, including the potential new species, and identified similarities to strains from other countries.