A Porcine Aerosol Infection Model for Studying Dose Dependent Effects Caused by <i>Actinobacillus pleuropneumoniae</i> Bacteria

Abstract

To establish a reproducible bacterial infection model that mimics the natural route of respiratory tract infection, we developed a computer-controlled nose-only aerosol exposure system for pigs. Actinobacillus pleuropneumoniae aerosols were generated, characterized, and administered dose dependently. Four groups of three unanesthetized pigs were exposed to defined aerosols ranged between 9.2 × 103 to 3.4 × 109 CFU per dose. Graded clinical stages and pathomorphological changes from inapparent carrier state to fatal septicaemia were induced in a dose dependent fashion. Pleuropneumonia in pigs offers a large animal inhalation model to study respiratory tract infections and the origin and function of the local immune system.