Cloning and sequence analysis of outer membrane protein genes of pasteurella multocida serotype B:2

Haemorrhagic septicaemia (HS) results from the infection of Pasteurella multocida serotype B:2, a Gram-negative bacteria in the family Pasteurellaceae. P. multocida can cause a variety of diseases in animals, but only serotypes B:2 has been reported to cause HS in cattle and buffalo. Various virulence factors expressed on the surface of the bacteria including HgbA (Haemoglobin-binding protein) and HasR (outer membrane receptor) play important role in pathogenesis of the disease. In the present study, HgbA and HasR gene fragments of P. multocida serotype B:2 were amplified using self designed primers and subsequently cloned and sequenced. The sequences were analysed and compared with the reported sequences of various strains of P. multocida. Sequence analysis showed that there was high similarity among the isolates. The sequence homology of HasR and HgbA were more than 96% and 99% respectively among various isolates. The similarity among the isolates revealed the conserved nature of genes which may be indispensible for disease pathogenesis in different hosts.