Efficacy of a fluorescent-antibody procedure for identifying Bacillus cereus in foods.

One hundred and seventeen strains of Bacillus were examined by the fluorescent-antibody technique by using the globulin fraction of serum prepared against spores of B. cereus T. All but one strain of the 59 B. cereus tested fluoresced at the exosporium surface. Fluorescent staining of B. anthracis, B. thuringiensis, and B. mycoides was also observed. Absorption of the globulin fraction with B. anthracis and B. mycoides resulted in the elimination of staining of these organisms. Absorption with B. thuringiensis ATCC 10792 removed antibodies reacting with 6 of the strains of B. thuringiensis tested. Absorption with B. thuringiensis var. galleriae removed antibodies against B. cereus to such a degree that the globulin fraction was unusable.