Mycobacterium wolinskyi: A Rare Strain Isolated in a Persistent Prosthetic Knee Joint Infection

Case: A patient who underwent first-stage revision procedure elsewhere for prosthetic joint infection (PJI) of the knee with Kocuria rosea presented to us 9 months after the index surgery, with persistent infection. First-stage revision surgery was repeated and Mycobacterium wolinskyi , a rare rapidly growing nontuberculous mycobacterium (RGM), was isolated from samples obtained by sonication of the cement spacer. After a prolonged antibiotic course, definitive implantation surgery was done. One-year postimplantation, patient remains infection free. Conclusions: This is only the second known case of knee PJI caused by M. wolinskyi . This case highlights the possibility of RGM getting masked by other organisms.