Submitted to: Infection and Immunity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/5/2003
Publication Date: 6/1/2003
Citation: Trott, D.J., Moeller, M.R., Zuerner, R.L., Goff, J.P., Waters, W.R., Alt, D.P., Walker, R.L., Wannemuehler, M.J. 2003. Characterization of treponema-phagedenis-like spirochetes isolated from papillomatous digital dermatitis lesions in dairy cattle. Infection and Immunity.
Interpretive Summary: Papillomatous digital dermatitis (PDD), also know as hairy heel wart, is the primary cause of lameness in dairy cattle in the U.S. Little is known about how this disease develops and no infectious agents have been proven to cause this disease, although several bacteria have been isolated from diseased tissue. In this study, bacteria belonging to the genus Treponema were isolated from Iowa dairy cattle with PDD and characterized. We show that these four strains of bacteria belong to the same species, but differ from each other at the genetic and antigenic level. These data are critical to understanding the progression of disease and form a basis of further study on this important cause of economic loss to the U.S. dairy industry.
Technical Abstract: Four spirochete strains were isolated from papillomatous digital dermatitis (PDD) lesions in Iowa dairy cattle and compared with two previously described spirochete strains isolated from dairy cattle in California. These six strains shared an identical 16S rDNA sequence that was 98% similar to Treponema phagedenis and 99% similar to the uncultivated PDD spirochete sequence DDLK-4. The whole cell protein profiles resolved by SDS-PAGE of these six strains were similar. However, these strains showed differences in the antigenic diversity of lipopolysacharide (LPS). Genetic diversity was also detected by pulsed field gel electrophoresis of genomic DNA digests, revealing differences among five of the six strains. Serum IgG antibodies from dairy cattle with active PDD lesions reacted with the LPS of all but one PDD spirochete strain. Likewise, peripheral blood mononuclear cells from cattle with active PDD lesions produced blastogenic responses to one of the two California isolates. Both antibody and lymphocyte blastogenic responses were reduced in convalescent dairy cattle suggesting the immune response to these spirochetes has short duration. These results demonstrate genetic and antigenic diversity among Treponema phagedenis-like treponemes, and provide further evidence for the involvement of these spirochetes in the pathogenesis of PDD.