A PORCINE AEROSOL INFECTION MODEL FOR STUDYING DOSE-DEPENDENT EFFECTSCAUSED BY ACTINOBACILLUS-PLEUROPNEUMONIAE BACTERIA

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 administe red dose dependently. Four groups of three unanesthetized pigs were ex posed to defined aerosols ranged between 9.2 x 10(3) to 3.4 x 10(9) CF U 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 inhal ation' model to study respiratory tract infections and the origin and function of the local immune system.