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ARS Home » Research » Publications at this Location » Publication #85173
Title: CONSERVATION OF EXPRESSION AND N-TERMINAL SEQUENCES OF THE PASTEURELLA HAEMOLYTICA 31 KILODALTON AND PASTEURELLA TREHALOSI 29-KILODALTON PERIPLASMIC IRON-REGULATED PROTEINS

Author
item Tabatabai, Louisa
item Frank, Glynn

Submitted to: Clinical and Diagnostic Laboratory Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Pasteurella haemolytica is a bacterium that causes respiratory disease in cattle and sheep. Serotype A1 is the predominant organism found in bovine pneumonic pasteurellosis and serotype A2 is the predominant organism found in sheep. In sheep pasteurellosis there is often found a second Pasteurella haemolytica, formerly classified as bacteria belonging to the T serotypes, and now classified as P. trehalosi. We found that an abundant protein is expressed by all P. haemolytica serotypes, except the newly classified P. trehalosi serotypes. We plan to test this protein as a vaccine for respiratory disease in cattle and sheep.

Technical Abstract: We report that a major 31 kDa periplasmic iron-regulated protein that is present in all 12 serotypes of P. haemolytica when grown under conditions of iron-limitation, is expressed as two alternate forms of 31 kDa and 28 kDa by the four serotypes of P. trehalosi. P. trehalosi serotypes T3 and T4 express a 28 kDa protein, whereas serotypes T10 and T15 express an altered 31 kDa protein. The N-terminal sequence of P. haemolytica and P. trehalosi 31 kDa periplasmic iron-regulated proteins have the N-terminal sequence of EPKFV, whereas the 28 kDa protein has a N-terminal sequence of AQPFV. Immunoblots with rabbit antiserum prepared to the purified 31 kDa iron-regulated protein from P. haemolytica serotype A1 demonstrated the absence of the 31 kDa protein from P. trehalosi serotypes T3 and T4 and a faint reaction with a 31 kDa protein from P. trehalosi serotypes T10 and T15. Furthermore, the anti-31 kDa antibody showed a faint reaction with a protein of 28 kDa in the four P. trehalosi serotypes T3, T4, T10, and T15. These result suggest that the 28 kDa and the 31 kDa proteins from P. trehalosi are related to the 31 kDa protein from P. haemolytica. The 28 kDa protein is absent from the 12 P. haemolytica serotypes tested both in immunoblots of whole cell lysates and osmotic shock fluids. Whole-colony lysate enzyme-linked immunoassays using the anti-31 kDa antibody as the primary antibody were not successful. This was presumably due to the presence of one or more immunoglobulin-binding proteins of P. haemolytica and P. trehalosi. It is not known whether the expression of the alternate forms of the 31 kDa periplasmic iron-regulated protein is related to the different diseases caused by these two species.