The Veterinary Record 161:853-857 (2007)
© 2007 British Veterinary Association
Carboxyl terminus of the 34 kDa protein of Mycobacterium paratuberculosis shares homologous B-cell epitopes with Mycobacterium avium and Mycobacterium intracellulare
M. Malamo, BVM, MSc1,2,
K. Okazaki, DVM, PhD1,
Y. Sakoda, DVM, PhD1 and
H. Kida, DVM, PhD1
1 Department of Disease Control, Graduate School of Veterinary Medicine,
Hakkaido University, Sapporo, 060-0818, Japan
2 Department of Clinical Studies, School of Veterinary Medicine, University of
Zambia, PO Box 32379, Lusaka, Zambia
Monoclonal antibodies (mAbs) against a recombinant carboxyl terminus of
the 34 kDa protein of Mycobacterium paratuberculosis were produced in
mice. Two of the mAbs cross-reacted with Mycobacterium avium and
Mycobacterium intracellulare in both an ELISA and
immunoblot. The recombinant protein also reacted with polyclonal sera produced
in rabbits against all three mycobacteria, indicating the presence of
cross-reactive epitopes in the protein. To determine the reactivity of cattle
sera against epitopes recognised by the mAbs, competition assays between
bovine sera and the mAbs were carried out. Two mAbs were significantly
inhibited by sera from cattle that were naturally infected with M
paratuberculosis. The results indicate that epitopes on the carboxyl
terminus of the 34 kDa protein common to M paratuberculosis, M avium
and M intracellulare readily induce antibody production in naturally
infected cattle. These epitopes reduce the diagnostic specificity of the
carboxyl terminus of the 34 kDa protein, which was originally thought to
contain only M paratuberculosis-specific epitopes.
Copyright © 2007 British Veterinary Association
