Subject(s)
Bacterial Vaccines , Cattle Diseases/prevention & control , Mycoplasma Infections/veterinary , Animals , Antibodies/analysis , Cattle , Complement Fixation Tests , Female , Fetus , Lung/pathology , Mycoplasma Infections/pathology , Mycoplasma Infections/prevention & control , Pregnancy , Time FactorsABSTRACT
A highly significant correlation coefficient (r = 0.97, n = 18) was found between the concentration of lactate dehydrogenase measurable after the organisms had been disrupted and the concentration of colony-forming units during the logarithmic phase of growth of a broth culture of the T(1) strain of Mycoplasma mycoides var. mycoides. A concentration of 4.60 x 10(-7) milliunits of lactate dehydrogenase for each colony-forming unit was established. This relationship was used to convert the concentration of lactate dehydrogenase in the culture into an estimate of the concentration of viable mycoplasma. The lactate dehydrogenase was estimated by following the oxidation of reduced nicotinamide adenine dinucleotide, in the presence of pyruvate substrate, at 366 nm in a spectrophotometer. The nicotinamide adenine dinucleotide oxidase system probably contributed a small amount of enzyme activity to the test when lactate dehydrogenase was measured in this way. The method has been described and evaluated for the estimation of titers from 10(7) to 5 x 10(9) colony-forming units per ml.
Subject(s)
Bacteriological Techniques , Culture Media , L-Lactate Dehydrogenase/metabolism , Mycoplasma/growth & development , Bacteriological Techniques/standards , Cell-Free System , Freezing , Methods , Mycoplasma/enzymology , NAD/metabolism , Oxidation-Reduction , Spectrophotometry , Ultrasonics , VibrationABSTRACT
The measurement of lactate dehydrogenase activity has been used to evaluate the growth of the T(1) vaccine strain of Mycoplasma mycoides var. mycoides in broth during the production of vaccine. Estimations were made during incubation at 37 C and storage at 4 C. The results were compared with titers of the vaccine obtained by two conventional methods of assessing viability titers: the counting of colonies formed on solid medium and a 50% end point titer found after dilutions were made in broth. The method of measuring lactate dehydrogenase activity allowed the rapid enumeration of organisms during incubation of the culture, but estimations made on vaccine stored at 4 C did not compare well with the two conventional methods of assessing viability. The lactate dehydrogenase activity of the culture has enabled rapid monitoring of the production stages of this vaccine.
