Genetic analysis of a Treponema phagedenis locus encoding antigenic lipoproteins with potential for antigenic variation.
Digital dermatitis (DD) is a painful and debilitating claw disease in cattle. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The occurrence of Treponema phagedenis in DD lesions, especially near the interface of healthy and diseased tissue, suggests that this species contributes to the development and/or progression of the lesions. In this study we characterized a genetic locus in T. phagedenis that contains coding regions for three antigenic proteins, PrrA, VpsA, and VpsB. Comparative analysis of homologous loci from fifteen strains suggests that prrA may be transposed into or out of this locus. Alterations in the copy number of TA repeats within the putative promoter region may regulate VpsA/B expression. The vpsA and prrA genes occur in allelic variants in different T. phagedenis isolates and may provide one explanation for the antigenic variation observed in T. phagedenis DD isolates.
Department of Animal Breeding and Genetics Science, Swedish University of Agricultural Science, SLU-Global Bioinformatics Centre, Uppsala, SE 750 07, Sweden; Department of Bioinformatics and Biotechnology, International Islamic University, Islamabad, Pakistan. Electronic address: mamoona.mushtaq@iiu.edu.pk.
Mamoona
M
Mushtaq
Department of Animal Breeding and Genetics Science, Swedish University of Agricultural Science, SLU-Global Bioinformatics Centre, Uppsala, SE 750 07, Sweden.
Erik
E
Bongcam-Rudloff
Department of Microbiology, National Veterinary Institute, SE-751 89 Uppsala, Sweden.
Heidur
H
Loftsdottir
Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, SE-751 89 Uppsala, Sweden.
Märit
M
Pringle
Department of Microbiology, National Veterinary Institute, SE-751 89 Uppsala, Sweden.
Bo
B
Segerman
Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Science, SE-750 07 Uppsala, Sweden.
Richard
R
Zuerner
Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Science, SE-750 07 Uppsala, Sweden.
Anna
A
Rosander
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D000940:Antigenic Variation / Q000235:genetics*; D000942:Antigens, Bacterial / Q000235:genetics*; D058066:Digital Dermatitis / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D008074:Lipoproteins / Q000235:genetics*; D016415:Sequence Alignment; D014208:Treponema / Q000235:genetics* / Q000472:pathogenicity; D014211:Treponemal Infections / Q000382:microbiology / Q000662:veterinary
D000942:Antigens, Bacterial; D008074:Lipoproteins
Antigenic variation; Digital dermatitis; Genome; Phase variation; Proline-rich repeat