Mycobacterium massiliense keratitis.

PURPOSE: The aim of this study is to report a case of keratitis caused by Mycobacterium massiliense, which is a subtype of non-tuberculous mycobacteria. METHODS: A 23-year-old Chinese man with a history of metal corneal foreign body removal was diagnosed with keratitis of his right eye 4 days after corneal trauma. He presented with intractable redness and continued corneal lesion with further vision loss after 2 weeks of conventional therapy. Pathogen testing and drug susceptibility testing were done. RESULTS: Corneal scraping and culture showed acid-fast staining positive bacilli. Polymerase chain reaction and sequencing confirmed that it was M. massiliense. The corneal ulcer was ultimately cured with 2 months treatment of amikacin and levofloxacin according to antibiotic susceptibility tests. CONCLUSIONS: Based on this case, multiple gene sequencing is required for identification of M. massiliense. Early diagnosis and prompt treatment will minimize the risk of sequelae, such as corneal scar and neovascularization.