High-level association of bovine digital dermatitis Treponema spp. with contagious ovine digital dermatitis lesions and presence of Fusobacterium necrophorum and Dichelobacter nodosus.
Contagious ovine digital dermatitis (CODD) is an important foot disease in sheep, with significant animal welfare and economic implications. It is thought that CODD emerged from bovine digital dermatitis (BDD) via treponemal bacteria. With wildlife species such as elk now suffering a CODD-like disease, it is imperative to clarify these disease etiologies. A large investigation into treponemal association with CODD is warranted. CODD lesions (n = 58) and healthy sheep foot tissues (n = 56) were analyzed by PCR for the three BDD-associated Treponema phylogroups and two other lameness-associated bacteria, Dichelobacter nodosus and Fusobacterium necrophorum. Spirochete culture was also attempted on CODD lesions. "Treponema medium/Treponema vincentii-like," "Treponema phagedenis-like," and Treponema pedis spirochetes were identified in 39/58 (67%), 49/58 (85%), and 41/58 (71%) of CODD lesions, respectively. One or more BDD-associated Treponema phylogroups were detected in 100% of CODD lesions. Healthy foot tissues did not amplify BDD-associated Treponema phylogroup DNA. D. nodosus and F. necrophorum were present in 34/58 (59%) and 41/58 (71%) of CODD lesions and 22/56 (39%) and 5/56 (9%) of healthy foot tissues, respectively. Thirty-two spirochetes were isolated from CODD lesions, with representatives clustering with, and indistinguishable from, each of the three BDD-associated Treponema phylogroups based on 16S rRNA gene comparisons. This study for the first time demonstrates a high-level association for BDD treponeme phylogroups in CODD and their absence from healthy tissues, supporting the hypothesis that BDD treponemes play a primary causative role in CODD and confirming that the specific PCR assays are an effective differential diagnostic tool for CODD.
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom l.sullivan@liverpool.ac.uk.
L E
LE
Sullivan
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom.
S R
SR
Clegg
Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, Wirral, Cheshire, United Kingdom.
J W
JW
Angell
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom.
K
K
Newbrook
University of Liverpool & Wood Veterinary Group, Gloucester, Gloucestershire, United Kingdom.
R W
RW
Blowey
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom.
S D
SD
Carter
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom.
J
J
Bell
Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, Wirral, Cheshire, United Kingdom.
J S
JS
Duncan
Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, Wirral, Cheshire, United Kingdom.
D H
DH
Grove-White
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom.
R D
RD
Murray
Department of Infection Biology, School of Veterinary Science, Institute of Infection and Global Health, Liverpool, Merseyside, United Kingdom.
N J
NJ
Evans
D000818:Animals; D002417:Cattle; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020376:Dichelobacter nodosus / Q000302:isolation & purification*; D058066:Digital Dermatitis / Q000382:microbiology*; D005675:Fusobacterium necrophorum / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D034561:Sheep, Domestic; D014208:Treponema / Q000302:isolation & purification*
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S