Heat modifiability of outer membrane protein of Pasteurella multocida serotype B:2.

Outer membrane proteins (OMP) are generally porins, functioning as molecular sieves assisting in the transmembrane transportation. Heat modifiable characteristics of OMP from P. multocida B: 2 have been explored to know their basic characteristics on event of temperature rise. A major band of 32 kDa and two minor bands of approximately 39 and approximately 28 kDa were found to be heat modifiable. It is suggested that boiling at 100 degrees C in presence of beta mercaptoethanol for 5 min is sufficient for characterisation of OMP by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis.

Immunologic reactivity of a lipopolysaccharide-protein complex of type A Pasteurella multocida in mice

The immunologic reactivity of a lipopolysaccharide (LPS)-protein complex isolated from a potassium thiocyanate extract of a Pasteurella multocida (capsular type A and somatic type 3) strain was evaluated in mice. The LPS-protein complex provided 100% protection in mice against a challenge with the homologous strain. However, when the complex was fractionated into LPS and protein moieties by phenol-water treatment, both components lacked immunogenicity. The complex and extracted components were mitogenic for mouse B lymphocytes with the protein moiety the most active. Although immune serum against the LPS-protein complex protected mice against challenge thereby indicating a role for humoral immunity, the LPS-protein complex of P. multocida was also found to induce cell-mediated immunity. This cell-mediated immunity was demonstrated in mice immunized with the complex by: (1). mitogenic responses of T lymphocytes, (2). induction of delayed type hypersensitivity reaction in the hind footpads, and (3). enhanced resistance to challenge infection with Salmonella enteritidis.