As shown in Fig. 1, a 29 kDa protein was eluted from Niaffinity column and could react strongly with rabbit anti-M. hyopneumoniae serum in Western blot analysis. In
addition, the reactivity of P97R1 protein with rabbit anti-M. hyorhinis serum or rabbit anti-M. flocculare serum was not observed by Western blot assay (data not shown).