Attempts to Differentiate Mycoplasma mycoides var. mycoides Immune Cattle from Susceptible Cattle

Abstract

Immunological tests were studied in an attempt to differentiate immune cattle from cattle susceptible to contagious bovine pleuropneumonia. Two serological tests, the complement fixation and the serum slide agglutination tests, and 3 cell-mediated tests, lymphocyte transformation, leucocyte migration and the intradermal allergic tests were studied. These tests were performed on cattle vaccinated I5 months previously with the T1 strain of Mycoplasma mycoides var. mycoides and on a group of susceptible cattle of the same age. Two months later, the cattle were challenged with the virulent Gladysdale strain of M. mycoides var. mycoides using the in-contact method. Although the vaccinated cattle were immune to challenge and the susceptible cattle were not, none of the tests studied could differentiate vaccinated from susceptible cattle.