Protective effect of vaccination with culture supernate of M-hyopneumoniaeagainst experimental infection in pigs

The protective activity of Mycoplasma hyopneumoniae inactivated vaccine pre pared from sedimented whole cells and cell-free culture supernates was eval uated experimentally using hysterectomy-produced, colostrum-deprived pigs i n which mycoplasmal pneumonia had been induced. The culture supernate vacci ne containing less than 101 colour-changing units (CCU)/0.2 ml of M. hyopne umoniae significantly (P < 0.05) reduced the percentage of lung lesions com pared to controls (3.2 +/- 3.9 vs. 12.2 +/- 2.2%), whereas the sedimented w hole cells vaccine containing 10(10) CCU/0.2 ml of organisms provided varia ble protection (18.7 +/- 16.5 vs, 12.2 +/- 2.2%). Serum from the pigs vacci nated with culture supernate reacted with six protein bands of 97, 89, 65, 46, 42 and 41 kDa by immunoblot analysis. From these results, we conclude t hat vaccination with culture supernate of M. hyopneumoniae can provide prot ection against M. hyopneumoniae infection and that these antigens in the cu lture supernate may be closely related to the reduction of lung lesions.