Immunization with recombinant PlpE of ovine Mannheimia haemolytica isolate provides protection against lethal challenge in mice

Mannheimia haemolytica primarily causes pneumonia leading to heavy morbidity and mortality in the domestic livestock world-wide. Recently, lipoproteins have emerged as targets for inducing protective immunity against the Pasteurella infection.

This study was aimed toevaluate recombinant outer membrane lipoprotein E (PlpE) from the isolate of ovine M. haemolytica, as potential vaccine candidate’.

Recombinant PlpE was constructed using pET26 (b) expression vector in Escherichia coli. Expressed recombinant PlpE was purified and injected subcutaneously in the mice. Protection index of the vaccine was evaluated by challenge of mice intraperitoneally.

Anti-PlpE antibody responses in the immunized mice was significantly increased which provided effective protection, when challenged with strain of virulent M. haemolytica.

Recombinant PlpE from ovine M. haemolytica isolate had potential to be used as ‘vaccine candidate against M. haemolytica infection in sheep flocks.