Identification of Brachyspira hyodysenteriae and Other Pathogenic Brachyspira Species in Chickens from Laying Flocks with Diarrhea or Reduced Production or Both

Abstract

Cecal samples from laying chickens from 25 farms with a history of decreased egg production, diarrhea, and/or increased feed conversion ratios were examined for anaerobic intestinal spirochetes of the genus Brachyspira. Seventy-three samples positive in an immunofluorescence assay for Brachyspira species were further examined using selective anaerobic culture, followed by phenotypic analysis, species-specific PCRs (for Brachyspira hyodysenteriae, B. intermedia, and B. pilosicoli), and a Brachyspira genus-specific PCR with sequencing of the partial 16S rRNA gene products. Brachyspira cultures were obtained from all samples. Less than half of the isolates could be identified to the species level on the basis of their biochemical phenotypes, while all but four isolates (5.2%) were speciated by using PCR and sequencing of DNA extracted from the bacteria. Different Brachyspira spp. were found within a single flock and also in cultures from single chickens, emphasizing the need to obtain multiple samples when investigating outbreaks of avian intestinal spirochetosis. The most commonly detected spirochetes were the pathogenic species B. intermedia and B. pilosicoli. The presumed nonpathogenic species B. innocens, B. murdochii, and the proposed "B. pulli" also were identified. Pathogenic B. alvinipulli was present in two flocks, and this is the first confirmed report of B. alvinipulli in chickens outside the United States. Brachyspira hyodysenteriae, the agent of swine dysentery, also was identified in samples from three flocks. This is the first confirmed report of natural infection of chickens with B. hyodysenteriae. Experimental infection studies are required to assess the pathogenic potential of these B. hyodysenteriae isolates.Avian intestinal spirochetosis (AIS) is a disease complex that affects commercial laying and meat breeder chickens, characterized by the colonization of the ceca by members of one or more species of anaerobic intestinal spirochetes of the genus Brachyspira (formerly Serpulina) (11,14,36). The condition is associated with delayed or reduced egg production and a chronic diarrhea in adult birds that can result in wet litter and fecal staining of eggshells. Moreover, reduced performance has been reported for broiler chicks hatched from eggs of breeder chickens infected with Brachyspira spp. (7,33). AIS was first clearly described in the 1980s, in both The Netherlands (5, 7, 8) and the United Kingdom (10), and subsequently has been reported in the United States (39, 43), Australia (24,35), and a number of other European countries (2, 3). The nonspecific nature of the disease and the lack of availability of simple and specific diagnostic tests for these anaerobic spirochetes from chickens may have resulted in the condition being greatly underreported (14).Studies using multilocus enzyme electrophoresis showed that intestinal spirochetes from chickens could be divided into at least six species groupings (25). These included the three species currently considered to be pathogenic to chickens, Brachys...

Detection of Brachyspira hyodysenteriae, Lawsonia intracellularis and Brachyspira pilosicoli in feral pigs

“…hyodysenteriae has been found in rats and mice living on infected piggeries ( Joens andKinyon, 1982 andHampson et al, 1991), and in captive rheas ( Jensen et al, 1996) and commercial laying chickens ( Feberwee et al, 2008). The only wildlife species so far that has been identified as being naturally colonized with B. hyodysenteriae are feral mallards, and to date this has only been demonstrated in Scandinavia ( Jansson et al, 2004).…”

Antimicrobial susceptibility ofBrachyspiraspp. isolated from commercial laying hens and free-living wild mallards (Anas platyrhynchos)

“…In chickens, a wide range of potentially pathogenic and commensal species may be found, including Brachyspira alvinipulli, Brachyspira intermedia and Brachyspira pilosicoli that have been linked to diarrhoea, wet litter, faecal staining of egg shells and impaired laying performance in adult chickens (Stanton et al, 1998;Hampson & McLaren, 1999;Stephens & Hampson, 2002). Among the remaining recognized and proposed species found in chickens, Brachyspira murdochii, Brachyspira innocens and ''Brachyspira pulli'' are presumed non-pathogenic species, and the swine dysentery agent Brachyspira hyodysenteriae, although an unusual finding in chickens (Feberwee et al, 2008), has not yet been linked to disease. Free-living wild mallards host a wide range of Brachyspira spp.…”

Multiple-Locus Variable-Number Tandem-Repeat Analysis of the Swine Dysentery Pathogen, Brachyspira hyodysenteriae

“…Moreover, B. hyodysenteriae survives in the environment for long periods, especially in liquid feces contained in pits and lagoons, where it may remain infective for up to 60 days (16). This spirochete also can naturally colonize mice, rheas, chickens, and mallards (9,30), and together with mechanical vectors or fomites, this increases the ways in which B. hyodysenteriae may be spread within and between herds.…”