Background
Nontuberculous mycobacteria (NTM) are widespread worldwide. These bacteria can be transmitted to humans from environmental sources such as soil and water with no reported cases of person-to-person transmission [1].
Mycobacterium szulgai (M. szulgai ) is a slow-growing NTM and a rare human pathogen, representing <0.2% of all NTM infections. [2]. M. szulgai pulmonary infections are infrequently reported in those with a history of chronic obstructive pulmonary disease (COPD), tuberculosis, or immunosuppression [3]. Clinically, it is indistinguishable from Mycobacterium tuberculosis infection and neoplasm, therefore, it is critical to be diagnosed accurately [4]. Moreover, there is no consensus recommendation for treatment of M. szulgai infections, probably due to its low prevalence [5]. Herein, we present a case of M. szulgai pulmonary infection in an immunocompetent patient without any history of tuberculosis or consumption of immunosuppressive drugs but severely deficient in vitamin D that was successfully treated in Mashhad, Iran.