The potentials of Pasteurella multocida OmpA protein as the candidate for sub-unit vaccine and for the development of an ELISA kit to evaluate the vaccine response in the animals

Abstract Pasteurella multocida is the primary causative agent of Hemorrhagic Septicemia (HS) in cattle and Buffalo. It is responsible for causing huge economic loses every year. The P. multocida vaccines are used for livestock, but because sensitive and specific serological tests are not available, sero-conversion in these animals is unknown. As a result, the vaccine and it’s the immune response cannot be evaluated. So, the present study was designed to evaluate immunogenic potential of OmpA gene of P. multocida. PCR primers designed to have restriction sites to cut amplicon and ligate product into expression vector. Purified PCR product was subjected to cloning PCR and the product was sequenced. The product was excised from cloning vector and ligated into expression vector (pET 40b (+)). Expression vector was transformed to chemically competent Escherichia coli strain DH5-α by heat shock method. Plasmid was extracted and ligation was confirmed by restriction digestion. IPTG was used to trigger expression. Total cell protein and medium were SDS-PAGE was used to analyze the expression. Recombinant proteins were injected into mice to test their immunogenicity. OmpA was proved to be highly immunogenic in nature, making it a more suitable candidate for sub-unit vaccine preparation and development of ELISA kit for the detection of immune responses in animals.