Identification of weakly haemolytic Brachyspira isolates recovered from pigs with diarrhoea in Spain and Portugal and comparison with results from other countries

Abstract

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.

Confirmation that “Brachyspira hampsonii” clade I (Canadian strain 30599) causes mucohemorrhagic diarrhea and colitis in experimentally infected pigs

“…“B. pulli ” is the provisional name for a spirochete originally identified in birds [20], which has recently also been isolated from pigs [21]. One CTRL had watery diarrhea on D-8 and D-7, immediately after arrival in the animal care facility, but Brachyspira was not isolated, and normal feces were observed during all other days pre-inoculation.…”

Molecular Epidemiology of Novel Pathogen “Brachyspira hampsonii” Reveals Relationships between Diverse Genetic Groups, Regions, Host Species, and Other Pathogenic and Commensal Brachyspira Species

“…Multilocus sequence typing (MLST) is a high-resolution method that uses nucleotide sequence differences between conserved housekeeping genes to characterize and differentiate genotypes of a pathogen (19). This technique has been used for local and global molecular epidemiological studies of various Brachyspira species (20), including B. hyodysenteriae (5,21,22), Brachyspira pilosicoli (23), Brachyspira intermedia (24), Brachyspira murdochii, and Brachyspira innocens (25), thus warranting its application for the characterization of B. hampsonii.…”

Suidae and Tayassuidae

“…Information about Brachyspira infection in wild boars or in other wild suid genera is limited. Several studies in free-ranging wild boar in Sweden and Spain failed to demonstrate Brachyspira in fecal samples, which seemed to indicate that these spirochetes are not a natural part of the intestinal flora (Jacobson et al, 2005;Osorio et al, 2013;Vadillo et al, 2017). However, in one study in Spain that included 40 wild boars from several intensive growth farms, B. intermedia, B. pulli, and B. hyodysenteriae were isolated and associated with clinical disease in 3 animals (Vadillo et al, 2017).…”