Electron microscopic visualization of the capsule of Pasteurella multocida.

The results of electron microscopic visualization of capsules of Pasteurella multocida by means of negative staining and section methods are described. Using ruthenium red or a complex of platinum in negative staining, relatively homogeneous capsules were visualized, using alcian-blue, coarse-fibrous structured capsules appeared. The incubation with antiserum partially revealed narrow capsule zones in the sections. Ferritin-linked IgG labelled amorphous material between the bacteria or floccular appendages on the bacterial surface. Gold-linked Con A deposited on thick cord structures, on loose material between the bacteria and sometimes on their cell wall.