Abstract
Mycobacterium kansasii is a slow-growing non-tuberculous mycobacteria responsible for co-infections particularly in patients with human immunodeficiency virus. To date, our knowledge of M. kansasii infection has been hampered due to the lack of an effective animal model to study pathogenesis. Here, we show the zebrafish embryo is permissive to M. kansasii infection, causing a chronic infection and forming granulomas. Upon macrophage depletion, we identified M. kansasii forms extracellular cords, resulting in acute infection and rapid larval death. These findings highlight the feasibility of zebrafish to study M. kansasii pathogenesis, and for the first time identify extracellular cords in this species.