Characterization of an immunogenic fraction of Pasteurella multocida culture filtrates.

An immunogenic fraction (IF) of Pasteurella multocida strain P-1059 was separated from culture filtrate by Sephadex gel filtration. Additional fractionation of IF with aqueous ether resulted in the glycoprotein-like preparation (GLP) while extraction with aqueous phenol provided the lipopolysaccharide-like preparation (LPP). The unextracted IF contained carbohydrate, protein, and lipid; the GLP contained carbohydrate and protein; and the LPP contained carbohydrate and lipid. The GLP was maximally protective for mice against homologous challenge, and was medially toxic in rabbit skin when compared to the other culture-filtrate preparations; the LPP was maximally toxic in rabbit skin, and was least protective for mice; and the unextracted IF was medially protective for mice, and was least toxic in rabbit skin.