Occurrence of Treponema DNA in equine hoof canker and normal hoof tissue. (9th October 2014)

• Record Type: Journal Article
• Authors: Sykora, S.; Brandt, S.
• Is Part Of: Equine veterinary journal. Volume 47:Number 5(2015:Sep.)
• Page Start: 627
• Page End: 630
• Publication Date: 2014-10-09
• Subjects: Horses -- Diseases -- Periodicals; 636.108905
• DOI: 10.1111/evj.12327
• Languages: English
• ISSNs: 0425-1644

Abstract

<abstract abstract-type="main"> <title>Summary</title> <sec id="evj12327-sec-0001" sec-type="section"> <title>Reasons for performing study</title> <p>Equine hoof canker is a chronic pododermatitis of still unknown aetiology. Recent findings reported for 3 canker‐bearing individuals are suggestive for <italic>Treponema</italic> spp. having a role in disease pathogenesis.</p> </sec> <sec id="evj12327-sec-0002" sec-type="section"> <title>Objectives</title> <p>Based on this hypothesised association, we assessed a larger number of DNA samples from hooves with canker and normal hooves for the presence of treponemal DNA.</p> </sec> <sec id="evj12327-sec-0003" sec-type="section"> <title>Study design</title> <p>Retrospective survey of archived material.</p> </sec> <sec id="evj12327-sec-0004" sec-type="section"> <title>Methods</title> <p>The study involved 71 archival, PCR‐compatible DNA extractions purified from 59 canker samples obtained from 26 equine cases and from 12 hoof biopsies taken from 9 canker‐free control horses. Presence of treponemal DNA was assessed by qualitative PCR using 4 different primer pairs recognising in sum a broad range of <italic>Treponema</italic> ssp. Obtained amplification products were identified by bidirectional sequencing and BLAST alignment.</p> </sec> <sec id="evj12327-sec-0005" sec-type="section"> <title>Results</title> <p>Treponemal DNA was detected in 37 of 59 canker DNA samples from 19 of 26 cases and in 9 of 12 hoof DNA samples from 7 of 9 healthy individuals. Canine oral <italic>Treponema</italic> sp. and <italic>Treponema medium</italic> ssp. <italic>bovis</italic> were the most frequently detected treponemal sequences in hoof canker, while control tissues were mainly shown to harbour <italic>Treponema refringens</italic>‐like or canine oral <italic>Treponema</italic>‐like DNA. All control samples tested negative for <italic>T. medium</italic> ssp. <italic>bovis</italic> DNA.</p> </sec> <sec id="evj12327-sec-0006" sec-type="section"> <title>Conclusions</title> <p> <italic>Treponema</italic> DNA was detectable in the majority of hoof canker and control samples. The sample groups differed to some extent regarding identified <italic>Treponema</italic> phylotypes; however, this finding may be explained by the methodology used. Treponemes that are highly similar to bovine digital dermatitis treponemes are present in canker lesions. However, further work is needed to clarify the specific contribution of the identified <italic>Treponema</italic> phylotypes to the pathogenesis of disease.</p> </sec> </abstract>