Characterization of a mycoplasma agalactiae strain, candidate to an attenuated vaccine

Abstract

The aim of this work was to study the stability of a M. agalactiae attenuated strain after lyophilization and its characterization by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Immunoblot against homologous antisera showed that the attenuated M. agalactiae strain had 2 characteristic antigenic bands of 32 and 21 kDa. The assays related to strain lyophilization showed that the CFUs were decreased lesser than 2log(10) after 1 year storage at 4C with the exception of one vial, which lost all its viability. The subcutaneous inoculation dose (10(5) CFU), did not produce any symptom or sign of disease during the 45 days of the experiment. However, a local reaction was observed on the day after the inoculation. At necropsy, no macroscopic lesions were found which related to contagious agalactia or other disease. These results suggest that this attenuated strain has good possibilities as a live attenuated vaccine.