title: The first case of keratitis caused by Nocardia exalbida.
abstract: BACKGROUND
  Nocardia exalbida was first reported in 2006. We describe a first case of keratitis caused by Nocardia exalbida.
  
  
  METHODS
  Case report
  
  
  RESULTS
  A patient presented after two weeks of unsuccessful treatment of a corneal ulcer in her right eye. Nocardia keratitis was diagnosed from her culture results, and the species Nocardia exalbida was determined by phylogenetic studies using gene sequence analysis of 16S RNA. The disk diffusion method showed that this Norcardia sp. was sensitive to many antibiotics. Initially, the patient was treated with topical and systemic antibiotics, and corneal epithelium quickly regenerated. But when corticosteroid eyedrops were added, there was a recurrence of the keratitis. Corticosteroids were stopped, and systemic trimethoprim-sulfamethoxazole and topical tobramycin, colistin, chloramphenicol and sulfisoxazole were given. Within one month the corneal ulcer and infiltration disappeared.
  
  
  CONCLUSIONS
  This is the first report of keratitis caused by Nocardia exalbida. This species is susceptible to many antibiotics in vitro and clinically. However, supplementation with corticosteroids can lead to recurrence, and care should be taken when corticosteroids are being considered.
authors.affiliation: Department of Ophthalmology, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Japan. mizota@juntendo-urayasu.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizota
authors.forename: Kyoko
authors.initials: K
authors.lastname: Haki
authors.forename: Chikako
authors.initials: C
authors.lastname: Shiina
authors.forename: Minoru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Katsukiyo
authors.initials: K
authors.lastname: Yazawa
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Mikami
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects / Q000627:therapeutic use; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003320:Corneal Ulcer / Q000382:microbiology; D004359:Drug Therapy, Combination; D019573:Epithelium, Corneal / Q000187:drug effects / Q000503:physiopathology; D005260:Female; D006801:Humans; D007634:Keratitis / Q000382:microbiology* / Q000473:pathology; D009617:Nocardia Infections / Q000150:complications / Q000188:drug therapy; D012008:Recurrence; D012038:Regeneration
chemical_list: D000305:Adrenal Cortex Hormones; D000900:Anti-Bacterial Agents