The intact bronchial mucosa, lined with ciliated cells, traps bacteria and small particles above 2 µm in size (scanning electron micrograph)   Bacteria such as Bordetella, Mykoplasma, and Staphylococcus induce ciliar stasis. Others, like Pseudomonas, damage the bronchial epithelium directly and increase viscosity of the bronchial mucus. Altered mucociliary defense predisposes the patient to bacterial invasion. Broad destruction of epithelium and cilia in chronic bronchitis. Infection processes, which are not properly controlled by inadequate antiinfective therapy, become chronic and recurrent.   Increased production of mucus of high viscosity inhibit movement of the ciliae and thereby clearance of pathogenic bacteria from the respiratory tract. Baytril concentrates in respiratory secretions and acts directly against the relevant primary and secondary bacterial invaders. Electron micrograph of a bronchiole with an alveolar macrophage having phagocytised large quantities of bacteria and foreign material. Baytril actively concentrates in macrophages, where it increases their killing ability. It also attacks intracellular pathogens, which may have survived phagocytosis and later cause recurrence of the infection.   Infiltrative peribronchitis in chronic bacterial infections. Baytril concentrates at the site of infection due to the large amount of inflammatory cells transporting the drug to this area. Photographs: Prof. Dr. W. Drommer/Hanover © 2001 Bayer AG, Germany close window