Mycobacterium aurum keratitis: an unusual etiology of a sight-threatening infection

Atypical fast-growing Mycobacterium species are usually identified after laser-assisted in situ keratomileusis, cosmetic surgeries, and catheter-related, pulmonary or soft tissue infections. We herein present the case of a 56-year-old man with purulent discharge, redness, and foreign body sensation in his left eye. He underwent two surgeries that partially controlled the infection but were not curative. Corneal transplantation was performed, and a biopsy of the excised cornea indicated Mycobacterium aurum infection, which was confirmed by polymerase chain reaction-restriction fragment length polymorphism analysis. This appears to be the first documented case of keratitis attributable to the non-tuberculous mycobateria M. aurum. The intractable extra-ocular progression of the disease in the absence of general signs or symptoms was notable. We suggest considering non-tuberculous mycobacteria among the probable causes of complicated keratitis or keratitis that does not respond to drug treatment, especially in regions where tuberculosis is endemic.