Evaluation of Scnn1b-Tg mice as murine model of pulmonary infection with Mycobacterium avium Complex

<bold>Introduction:</bold> <italic>Mycobacterium avium</italic> complex is one of the leading causes of non-tuberculous mycobacterial lung infection. Its treatment is difficult, based on a combination of antibiotics (with clarithromycin as the cornerstone) sometimes ineffective and potentially toxic. Experimental models, especially animal models, are needed for the development of new therapeutic strategies. The objective of our study was to evaluate Scnn1b-Tg mice, genetically modified to develop bronchiectasis as murine model of MAC pulmonary infection. <bold>Methods:</bold> Pulmonary infection with <italic>Mycobacterium avium</italic> complex has been evaluated for Scnn1b-Tg mice and BALB/c mice, a validated mouse model of MAC infection. We therefore compared histological sections, bacterial load and cytokines inflammatory profile for these two strains as well as response to clarithromycin treatment. <bold>Results:</bold> Scnn1b-Tg mice exhibited more lung gross lesions. Bacterial load was significantly higher for these mice in the first four weeks. In contrast, response to clarithromycin treatment was poorer compared to control mice. <bold>Discussion:</bold> Beside their susceptibility to <italic>Mycobacterium avium</italic> complex infection and their inflammatory profile, Scnn1b-Tg mice could provide a pathophysiological model for the development of MAC infections and provide a better understanding of the difficulties in treating patients with bronchiectasis. <bold>Key words:</bold> <italic>Mycobacterium avium</italic> complex, murine model, Scnn1b-Tg mice, bronchiectasis, clarithromycin.