Caracterização de Mycoplasma agalactiae isolados no Brasil e produção de vacinas contra agalaxia contagiosa

Abstract

Mycoplasma agalactiae is the main causative organism of contagious agalactia (CA), a disease characterized by mastitis followed by agalactia, polyarthritis, and keratoconjunctivitis. In 2001, M. agalactiae was isolated and identified in Brazil, causing great economic losses. Considering the need for characterization of Brazilian strains of M. agalactiae and implementation of effective control, this work was performed in three steps. The first article describes the biochemical and protein profile of isolates of M. agalactiae in small ruminants through the culture in modified Hayflick medium, biochemical tests, polyacrylamide gel electrophoresis (SDS-PAGE) and immunogenicity of these proteins by Western blot (WB). The samples had similar protein in the profile bands ranging from 30-135 kDa in SDS-PAGE, in addition the presence of a protein of 48 kDa immunodominant WB was shown. To continue identifying the agent involved in the AC in Brazil, the second article describes the analysis of ten sequences of M. agalactiae isolated from goats and sheeps. A DNA fragment of 360 bp of the 16S rRNA gene was amplified by PCR and sequenced. The analysis revealed a high degree of similarity among all the sequences. The study revealed greater than 99% similarity with the reference samples of M. agalactiae. In the third article, efficacy of three inactivated vaccines prepared with a local of M. agalactiae sample and adsorbed with three adjuvants was evaluated in goats and sheep. The antibody response in vaccinated animals was analyzed using an indirect ELISA. The three vaccines induced antibody production, and can be an alternative to reduce economic losses and prevent contagious agalactia. These results confirms the presence and spread of M. agalactiae in the country and enhances the possibility of controlling the disease through the adoption of livestock vaccination.