Prosthetic joint infection due to Mycobacterium moriokaense in an immunocompetent patient after a total knee replacement.

Nontuberculous mycobacteria (NTM) are a rare cause of prosthetic joint infection (PJI) that is documented to affect immunocompromised patients primarily. In this case report, we describe an immunocompetent patient with a rare case of PJI caused by Mycobacterium moriokaense after a total knee replacement. This patient is the eighth reported case of PJI caused by NTM and the first reported case in an immunocompetent individual. Because PJI caused by NTM is rare and difficult to treat, it is essential to include it in the differentials during initial workup of suspected PJI, especially in the context of negative preliminary bacterial cultures.