A solid medium test for measuring growth inhibition and neutralization of Mycoplasma mycoides by immune Bovine Serum

Abstract

The growth of Mycoplasma mycoides var. mycoides was inhibited and neutralized by immune serum from cattle which had recovered from infection with M. mycoides. Although mycoplasmal neutralization is not necessarily the same as virus neutralization, it is suggested that this terminology be retained since it is accepted and is descriptively appropriate. The effect of immune serum on colony growth was determined by incubating test serum in plastic cylinders on nutrient agar with pre-incubated microscopic M. mycoides colonies. Optimal inhibition and neutralization occurred when serum and colonies were incubated at 30° before final incubation at 37°. Inhibition of growth and neutralization also occurred at 37° and 21° inhibition, but no neutralization occurred at 5°