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

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

Aims: This study aimed to evaluate recombinant outer membrane lipoprotein E (PlpE) from the ovine isolate, as a potential vaccine candidate

Methods: Recombinant PlpE was constructed using pET26 (b) expression vector in . Expressed recombinant PlpE was purified and injected subcutaneously to mice. The protection index of the vaccine was evaluated by challenge of mice intraperitoneally.

Results: Anti-PlpE antibody responses in the immunized mice was significantly increased in comparison with the control group which in turn, provided effective protection when challenged with strain of virulent .

Conclusion: Recombinant PlpE from ovine isolate had the potential to be used as a vaccine candidate against infection in sheep flocks.