Antigenic analysis of Pasteurella multocida (serotype 1) by crossed immunoelectrophoresis: characterization of cytoplasmic and cell envelope associated antigens.

The application of crossed immunoelectrophoresis to the analysis of a reference cytoplasm and cell envelope preparation from Pasteurella multocida serotype 1 revealed antigenic complexity not previously found. At least 55 cytoplasmic and 19 cell envelope antigens were clearly distinguished. Variation of anticytoplasm immunoglobulin concentration was a major determining factor in resolving the maximum array of cytoplasmic antigens. The use of intermediate gel modification of crossed immunoelectrophoresis permitted the recognition of antibodies in the preimmune rabbit serum against a number of cytoplasmic antigens and a single cell envelope antigen. This technique also demonstrated that reference cytoplasm obtained by 105,000 x g centrifugation of sonically disrupted pasteurellae and repeatedly washed reference cell envelope preparation contained antigens of either origin in amounts sufficient to elicit antibody responses in the host. Antisera to whole cells in the intermediate gel indicated that formalin killed P. multocida were capable of eliciting immune responses to both reference systems.