SPECIFIC STAINING OF BACILLI BY MEANS OF IMMUNO-INDIAN-INK METHOD AND IMMUNOFLUORESCENT METHOD

Abstract

Identification of Bacillus anthracis by the immuno-Indian-ink method (IIIM) and the immunofluorescent method (IFM) in their direct and indirect modifications is investigated. The specificity of sera against non-encapsulated cells of B. anthrasis increases by their adsorption with antigenically related strains of B. cereus as their vegetative cells and spores are previously killed with performic acid. Repeated uses of the Bacillus suspension for adsorption is possible by treating it with HCl to restore its antigenic properties. The adsorbed sera against non-encapsulated cells of B. anthracis in the direct and indirect modifications of IIIM and IFM stain specifically the 19 investigated B. anthracis strains but none of the 152 strains of saprophytic bacilli. Differentiation of B. anthracis from saprophytic bacilli is established by combination of cultivation on selective medium, facilitating the capsule formation of B. anthracis with IIIM and IFM, and is performed with sera against capsule antigens of the anthrax agent.