Vaccination against progressive atrophic rhinitis with a recombinant Pasteurella multocida toxin derivative

Area of Science:

• Veterinary immunology
• Swine disease prevention
• Bacterial toxin research

Background:

• Progressive atrophic rhinitis is a significant swine respiratory disease.
• Pasteurella multocida toxin (PMT) is a key virulence factor in atrophic rhinitis.
• Developing effective vaccines against PMT is crucial for swine health.

Purpose of the Study:

• To evaluate the efficacy of a nontoxic Pasteurella multocida toxin (PMT) derivative vaccine against atrophic rhinitis in pigs.
• To compare the immunoprotective effects of a recombinant nontoxic PMT derivative (dO) with a formaldehyde-treated native PMT vaccine.
• To assess the impact of vaccination on disease development, bacterial colonization, and growth performance in piglets.

Main Methods:

• Pregnant gilts were vaccinated twice with either a nontoxic PMT derivative (dO) or a native PMT vaccine; controls were unvaccinated.
• Piglets were intranasally inoculated with Bordetella bronchiseptica and toxigenic P. multocida.
• Clinical signs, turbinate atrophy, anti-PMT antibody titers, P. multocida infection rates, and weight gain were monitored.

Main Results:

• Vaccination with the nontoxic PMT derivative (dO) significantly reduced clinical signs and turbinate atrophy in piglets post-challenge.
• Offspring from vaccinated gilts showed reduced infection rates and bacterial loads of toxigenic P. multocida.
• A significant improvement in weight gain (over 9%) was observed in piglets from vaccinated gilts compared to controls.

Conclusions:

• The nontoxic PMT derivative (dO) vaccine demonstrated excellent immunoprotective properties against progressive atrophic rhinitis.
• Vaccination effectively reduces disease severity and enhances growth performance in pigs challenged with P. multocida and B. bronchiseptica.
• The study highlights the potential of recombinant nontoxic PMT derivatives as a viable strategy for atrophic rhinitis prevention.