Mycoplasma gallisepticum:: influence of cell invasiveness on the outcome of experimental infection in chickens

Recently we have shown that a low, (R-low) and a high laboratory passage (R-high) of the poultry pathogen Mycoplasma gallisepticum prototype strain R differ markedly in their capability to invade non-phagocytic eukaryotic cells. In the present studs the infection traits of these two mycoplasma passages were compared in an in vivo setting. After aerosol inoculation of chickens. M. gallisepticum was re-isolated from the inner organs of birds infected with R-low, whereas no mycoplasma was recovered from the inner organs of birds infected,with R-high. These results indicate that the two mycoplasma populations derived from strain R differ in their capacity to cross the mucosal barrier and suggest that cell invasion may play a major role in the observed systemic spreading of U. gallisepticum? in its chicken host. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.