Recombinant transferrin binding protein A (rTbpA) fragments of Pasteurella multocida serogroup B:2 provide variable protection following homologous challenge in mouse model

Abstract Transferrin binding protein A (TbpA), an iron acquisition surface protein that also acts as virulence factor, is widely distributed among strains of Pasteurella multocida . In the present study, a total of seven clones of TbpA fragments ( 39 D to F 777 ; 39 D to Q 697 ; 188 V to F 777 ; 188 V to Q 697 ; 39 D to P 377 ; 188 V to P 377 and 39 D to F 187 ) belonging to P. multocida B:2 were constructed, over-expressed and purified as recombinant fusion proteins from Escherichia coli using affinity chromatography. Immunization of mice with rTbpA fragments resulted in a significant (p  50 of P. multocida B:2 resulted in a variable protective efficacy up to 50%. The study indicated the potential possibilities to incorporate full length TbpA in subunit vaccine formulation composed of synergistic subunit antigens against haemorrhagic septicaemia (HS) in cattle and buffalo.