Characterization of envelope proteins from Pasteurella haemolytica and

A method was devised for the reproducible isolation of envelopes from Pasteureffu huemofyfica serotype A2. It was also possible to prepare envelopes from other serotypes of P. haemofytica and Pasfeurelu multocida using this methodology. Examination of these preparations by SDS-PAGE showed major differences between strains of P. huemlyticrr and strains of P. muftocida which allowed the clear distinction of isolates of these species. Amongst the P. lraemofyticu serotypes it was possible to distinguish envelope preparations made from A biotype and T biotype organisms easily, but it was not possible to identify individual serotypes from each other. Envelope profiles were suliiciently different between the individual P. multocida serotypes examined to allow eacb to be identified by its polypeptide profile. Experiments using radiolabelling, antibody absorption, and susceptibility to protease digestion, together with heat modifiability and detergent solubility characteristics indicated that 13 of the envelope proteins were probably surface-located. A high molecular mass immunogenic envelope protein was shown, by immunoblotting, to be present in all strains of P. haemofytica and P. multocida examined