Supplementary Material for: A case of Nocardia africana-related keratitis

Nocardia spp. is gram positive, aerobic, weakly acid-fast bacteria. Nocardia spp. keratitis is a rare ocular infection classically described following corneal injury or vegetative and soil exposure. However, keratitis caused by Nocardia africana had never been reported in the literature. We first reported a 70-year-old male who had a traumatic ocular injury to his left eye a month ago. With his complaint of left eye pain, reduced vision, and light sensitivity; the slit-lamp biomicroscopy showed the superficial multi-lobulated epithelial infiltration located at inferior cornea with positive fluorescein stain. Microscopic work up from corneal specimens demonstrated dry and chalky white colonies on blood agar and Lowenstein-Jensen media resembling Nocardia spp. The MALDI-TOF MS analyses using VITEK® MS exhibited Nocardia africana. The corneal lesion was treated with 2% amikacin topical eye drops and responded well. The careful history taking, precise clinical examinations and meticulous microscopic assessment were the cornerstone of diagnosis. Definite diagnosis and timely treatment were essential to prevention of ocular morbidity in Nocardia africana.