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Identification of Surface Exposed Elementary Body Antigens of Cowdria ruminantium the Causative Agent of Cowdriosis in Ruminants

K. A. Chingi
K.J. Sumption
E.A. Paxton


This study sought to identify the surface exposed antigenic components of Cowdria ruminantium elementary body (EB) by biotin labeling, determine effect of reducing and non-reducing conditions and heat on the mobility of these antigens and their reactivity to antibodies from immunized animals by Western blotting. Six surface exposed antigens of the C. ruminantium EB were identified by biotin labeling with molecular masses of 21kDa, 28kDa, 31kDa, 62kDa, 74kDa and 115kDa and are therefore outer membrane proteins. The effect of reducing agents was to increase the number antigens bands, indicating there may be 2-5 antigenic (polypeptides) on the surface of the EB. On the other hand, heating did not affect the number of antigen bands. The identification of six surface exposed antigens of C. ruminantium and the successful purification of two of these antigens, makes it possible to use them for immunization so as to determine which of them induce protective responses.

Keywords: Cowdria ruminantium, Elementary body, biotin-labelling, surface antigens, mobilities, ruminants

[IJARD Vol.3 2002: 78-86]