Desenvolvimento e avaliação de um novo método para produção de maleína para diagnóstico de mormo

Abstract

Glanders is a disease of the equid, caused by the bacteria Burkholderia mallei. One of the most frequently used tests for diagnosis of Glanders is the allergic test of mallein. In the present work it was sought to purify the protein group which makes up for mallein, in an effort to segregatethe protein fractions with molecular weight above 350kDa, which is believed to hold the specific immuno-alergic activity of this reagent. The antigen was purified from a protein preconcentrate using a tangential-flow filtration system fitted with a regenerated cellulosemembrane with a molecular weight limit of 300kDa. The purified fractions were characterized by HPLC and revealed to have a molecular weight of about 660kDa. In the electrophoresis, these values stayed between 268 and 460kDa. The potency of the semi-purified experimental malleins was tested in comparison with an international standard by the intradermicinoculation of horses sensitized by an inactivated suspension of B. mallei. The specificity of the antigen was evaluated by the inoculation of negative controls. The means of the reactions elicited by the experimental malleins and by the standard in the sensitized horses were 6.41mmand 3.07mm, respectively. In the control group, these values were 1.72mm and 0.61mm, respectively. The statistical analysis of the potency and specificity tests showed that the experimental malleins have a good potential to be used as an auxiliary test for the diagnosis of Glanders.