Conservation of expression and N-terminal sequences of the Pasteurella haemolytica 31-kilodalton and Pasteurella trehalosi 29-kilodalton periplasmic iron-regulated proteins

This study examined the conservation of expression of a 31-kDa iron-regulat ed protein by serotypes of Pasteurella haemolytica and Pasteurella trehalos i associated with pasteurellosis of cattle and sheep. A polyclonal antibody prepared against the purified 31-kDa periplasmic iron-regulated protein fr om P. haemolytica serotype A1 showed that all P. haemolytica serotypes expr essed similar 31-kDa proteins with identical N-terminal sequences, whereas P. trehalosi serotypes expressed immunologically different 29-kDa proteins with a different N-terminal sequence. Antibody to the 31-kDa iron-regulated protein was a useful tool to distinguish similarities and differences of t he iron-regulated proteins of P. haemolytica and P. trehalosi.