Genome-Wide Relatedness of Treponema pedis, from Gingiva and Necrotic Skin Lesions of Pigs, with the Human Oral Pathogen Treponema denticola

Abstract

Treponema pedis and T. denticola are two genetically related species with different origins of isolation. Treponema denticola is part of the human oral microbiota and is associated with periodontitis while T. pedis has been isolated from skin lesions in animals, e.g., digital dermatitis in cattle and necrotic ulcers in pigs. Although multiple Treponema phylotypes may exist in ulcerative lesions in pigs, T. pedis appears to be a predominant spirochete in these lesions. Treponema pedis can also be present in pig gingiva. In this study, we determined the complete genome sequence of T. pedis strain T A4, isolated from a porcine necrotic ear lesion, and compared its genome with that of T. denticola. Most genes in T. pedis were homologous to those in T. denticola and the two species were similar in general genomic features such as size, G+C content, and number of genes. In addition, many homologues of specific virulence-related genes in T. denticola were found in T. pedis. Comparing a selected pair of strains will usually not give a complete picture of the relatedness between two species. We therefore complemented the analysis with draft genomes from six T. pedis isolates, originating from gingiva and necrotic ulcers in pigs, and from twelve T. denticola strains. Each strain carried a considerable amount of accessory genetic material, of which a large part was strain specific. There was also extensive sequence variability in putative virulence-related genes between strains belonging to the same species. Signs of lateral gene-transfer events from bacteria known to colonize oral environments were found. This suggests that the oral cavity is an important habitat for T. pedis. In summary, we found extensive genomic similarities between T. pedis and T. denticola but also large variability within each species.

Oral flora in acute stroke patients: A prospective exploratory observational study

“…Treponema pedis was not in HOMD, but was found eight times in six participants, making it the thirteenth most common phylotype found in this study. T. pedis is an anaerobic gram‐negative bacterium associated with digital dermatitis in pigs, but it is very close phylogenetically to T. denticola , part of the known human oral flora associated with periodontitis . To the best of our knowledge, T. pedis has not previously been found in the human oral flora.…”

Complete Genome Sequence of the Oral Spirochete Bacterium Treponema putidum Strain OMZ 758 T (ATCC 700334 T )

“…This significantly broadens the genomic data available for studying the biology, physiology, and phylogeny of oral treponemes associated with periodontal diseases. It will also facilitate efforts to systematically analyze genetically related species of treponemes that inhabit oral and nonoral niches in animals, many of which are implicated in polymicrobial tissue-destructive diseases ( 15 , 16 ).…”

Digital Dermatitis in Cattle: Current Bacterial and Immunological Findings

“…Another example of treponeme involvement directly in chronic ulcerative or proliferative dermatosis is T. pedis . T. pedis , while also associated with DD, has also been implicated in porcine skin ulcers [ 73 , 74 , 75 ], cankers in horses [ 76 , 77 , 78 , 79 ], and a related treponeme is isolated from perioral and genital chronic ulcerations in European wild hares [ 80 ]. Virulence attributes present in DD-associated Treponema based on their involvement in other diseases, could indicate their role in bovine DD lesion development and perpetuation.…”

“…T. pedis , isolated from DD lesions of cattle, shares many virulence factors with T. vincentii , T. denticola , and T. phagedenis , including C4 and C8 esterase, serum dependence, trypsin, and chymotrypsin activity [ 69 ]. Comparative analysis of T. pedis to T. denticola genomes revealed similarities in virulence factors including several proteases, hemolysins, and a surface antigen involved in co-aggregation with Tannerella forsythia [ 75 ]. While similarities exist with dental or other treponemes, comparing isolates from widely differing ecological niches may diminish the unique attributes of the DD treponemes.…”