Immunofluorescent Staining of Salmonella Species with Flagellar Sera

Salmonellae stained with flagellar sera by either the direct or indirect fluorescent-antibody technique fluoresced at the cell surface. Investigations showed that fimbriae, flagellar material, and capsule antigens were not the participating antigens in this reaction. Cell surface staining was inhibited by mannose but was unaffected by glucose, galactose, lactose, maltose, and sucrose. Specific absorption of the flagellar sera by intact cells and purified somatic antigen showed that O antigens were the site of the surface staining. The advantages of using flagellar sera in fluorescent-antibody screening of materials for the presence of salmonellae are discussed.