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Surface antigen 8, one of pathogenicity factors of P.pseudomallei and having an antiphagocytic action, contains glycoprotein with a mol. wt. of 200 kD and proteins with mol wt. of 25, 30 and 34 kD. According to its chemical structure, the carbohydrate part of antigen 8 is the homogeneous polymer of 6-d-D-mannoheptose, and its protein component is a collection of monomer proteins with mol. wt. of 12-120 kD. The consecutive fractionation of antigen 8 by gel and ion exchange chromatography has made it possible to isolate its individual fragments, differing by the collection of antigenic components, as well as by their antiphagocytic and protective activity. Experiments have shown that glycoprotein with a mol. wt. of 200 kD is an active immunosuppressive agent, while protein with a mol. wt. of 34 kD produces a pronounced immunogenic effect.

As established with the use of electron-immunochemical techniques, glycoprotein antigen 6 is the outer membrane component of P. pseudomallei cell wall, while glycoprotein antigen 8 is localized on the cell surface as a capsule-like formation. Antigen 6 plays no perceptible role in the realization of the pathogenic properties of the infective agent, but serves as a reliable sign in the differentiation of P. pseudomallei strains into serovars. Subcultures, defective in the synthesis of antigen 8, have sharply reduced virulence for laboratory animals. As revealed in this study, the pathogenetic action of antigen 8 is linked with its pronounced antiphagocytic function. Thus, antigen 8 is considered to be one of the key pathogenicity factors of P. pseudomallei.

The 96% ethanol has been found fairly effective for the fixation and disinfection of Yersinia pestis, Vibrio cholerae, Pseudomonas mallei, and Pseudomonas pseudomallei after their contact with magnetic polyacrylamide sorbents containing specific immunoglobulins for ligands. Such step is recommended for the quantitative immunofluorescence test employed for rapid analysis, diagnosis, and identification of the above microorganisms.

The adsorption capacity of microgranulated polyacrylamide magnetic immunosorbents has been studied by the method of quantitative immunofluorescence as applied to the causative agents of plague, cholera, and melioidosis. Similar regularity in the dynamics of antigen adsorption on the granules of magnetic immunoadsorbents has been established. This regularity consists in the direct relationship between this process and the concentration of infective agents interacting with magnetic sorbents.