Skip to main content
Doctoral thesis, 2014

Treponema spp. in porcine skin ulcers

Karlsson, Frida


The hypothesis tested in this work is that bacteria of genus Treponema play a main role when shoulder ulcers and ear necrosis occur in an infectious or severe form, and perhaps also in other skin conditions in the pig. Samples were collected from pigs in 19 Swedish herds 2010-2011. The sampled skin lesions included 52 shoulder ulcers, 57 ear necroses, 4 facial necroses and 5 other skin ulcers. Occurrence of spirochetes was detected by phase contrast microscopy, Warthin-Starry silver staining, PCR and Fluorescent In Situ Hybridization (FISH). Treponemal diversity was investigated by sequencing of 16S-23S rRNA intergenic spacer region 2 (ISR2) and high-throughput sequencing (HTS) of a part of the 16S rRNA gene. Culturing and characterization of treponemes by biochemical analyses, testing of antimicrobial susceptibility and fingerprinting by random amplified polymorphic DNA (RAPD) were carried out. A challenge study was performed to test if Treponema pedis induced skin lesions. Serological response towards TPE0673, a T. pedis protein, was tested with ELISA. Spirochetes were found in all types of skin ulcers and in all herds. The occurrence of Treponema spp. detected by PCR was 52% in shoulder ulcers, 46% in ear necrosis and 9.7% in gingiva. Treponemes were identified in 69% of the shoulder ulcers and in 59% of the ear necroses by FISH. A phylogenetic tree revealed a great variability of treponemes. Three main phylotypes were identified; T. pedis, Treponema parvum and one phylotype without designation. Twelve isolates of T. pedis, T. parvum, and one phylotype most similar to Treponema sp. OMZ 840 were obtained. All except two had unique RAPD fingerprints. Biochemical tests could not differentiate between the isolates and they were generally susceptible to tested antimicrobials. By FISH, treponemes were visualized deep in the ulcers and a predominance of T. pedis was noted, and confirmed by HTS. Challenged pigs did not develop any lesions or IgG response towards the T. pedis protein. Most sows with shoulder ulcers showed a strong, and most cases of ear necrosis a weak IgG response towards TPE0673. In conclusion, Treponema spp. are frequently abundant in ear necroses and shoulder ulcers in pigs. Identical phylotypes and ISR2 sequences from ulcers and gingiva indicate spreading from mouth to ulcer. A broad diversity of phylotypes was revealed, but the predominance of T. pedis suggests specific importance of this species. Our results point towards an important role of treponemes in chronic and severe skin ulcers in pigs.


Treponema; skin ulcer; shoulder ulcer; decubital ulcer; ear necrosis; ear biting; facial necrosis; facial ulcer; pig

Published in

Acta Universitatis Agriculturae Sueciae
2014, number: 2014:35
ISBN: 978-91-576-8018-1, eISBN: 978-91-576-8019-8
Publisher: Department of Clinical Sciences, Swedish University of Agricultural Sciences

Authors' information

Swedish University of Agricultural Sciences, Department of Clinical Sciences

UKÄ Subject classification

Clinical Science
Medical Bioscience
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

URI (permanent link to this page)