Pathogenesis and pathology of respiratory tularaemia in the rabbit.

The development of pathological lesions in the organs of rabbits was examined at intervals from 1 h to 4 days after aerosol infection with Francisella tularensis. The earliest change, accumulation of polymorphonuclear leucocytes (PMN) in ulmonary alveolar ducts, occurred at 19 h. From the 2nd day multiple foci of necrosis and PMN infiltration were present in large airways and alveoli throughout the lungs and progressively increased in size. Pulmonary arteritis was a prominent feature of the infection. Areas of necrosis were present in the nasal mucosa, pharynz and trachea, and pyogranolomatous lesions consistently developed in the liver, spleen, and lymph nodes.