Pasteurellosis in laboratory rabbits: characterization of lipopolysaccharides of Pasteurella multocida by polyacrylamide gel electrophoresis, immunoblot techniques, and enzyme-linked immunosorbent assay

Abstract

The lipopolysaccharides (LPSs) of five isolates of Pasteurella multocida from rabbits were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblots, and enzyme-linked immunosorbent assay. Silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles of purified unaggregated LPSs resembled those of semirough strains of gram-negative enterobacteria and consisted of one or two bands that migrated within an interval just ahead or slightly behind the migration of the Ra chemotype of "Salmonella minnesota," which has a molecular size of 4.3 kilodaltons. Polyclonal rabbit antisera to P. multocida whole cells used in Western blots and enzyme-linked immunosorbent assays of unabsorbed and LPS-absorbed antisera revealed that the LPS of these isolates of P. multocida contained at least two types of antigens: a nonserospecific antigen and a serospecific antigen. The LPSs of four isolates each had a different serospecific antigen. The nonserospecific antigen was expressed in two isolates and was the only demonstrable LPS antigen in one other isolate.