title: Methicillin-resistant Staphylococcus aureus keratitis in a dog.
abstract: The purpose of this study is to report a case of methicillin-resistant Staphylococcus aureus (MRSA) keratitis in a dog. A 7-year-old intact male American cocker spaniel that had undergone removal of a nictitating gland was referred for severe ulcerative keratitis. Slit-lamp examination showed swelling of the eyelid, mucopurulent discharge, conjunctival injection and chemosis, diffuse corneal edema and opacity, and a deep ulcer in central cornea. Gram staining of discharge from the eye demonstrated Gram-positive cocci. Despite topical ofloxacin, oxytetracycline and polymyxin B ophthalmic solution and intravenous cefazolin, there was no improvement. Cultures revealed MRSA that was sensitive only to chloramphenicol, vancomycin, lincomycin, and clindamycin. The antibiotic regimen was changed to topical and systemic chloramphenicol. After 9 days of treatment, although inflammation started to be resolved, the dog developed nonregenerative anemia. The antimicrobial regimen was changed again to topical and systemic vancomycin. Inflammation continued to improve over the next week. MRSA should be considered a potential organism in infectious keratitis, especially when general antibiotics are not effective. Although topical and systemic chloramphenicol and/or vancomycin are effective for treating MRSA keratitis, vancomycin should only be used when culture and susceptibility results indicate it is appropriate and no other options are available. To our knowledge, this is the first detailed case report of MRSA keratitis in a dog.
authors.affiliation: Department of Ophthalmology, Tokyo Medical University, 6-7-1, Nishi-shinjuku, Shinjuku-ku, Tokyo, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Tajima
authors.forename: Akiko
authors.initials: A
authors.lastname: Sinjyo
authors.forename: Toshio
authors.initials: T
authors.lastname: Ito
authors.forename: Yoshizumi
authors.initials: Y
authors.lastname: Noda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Goto
authors.forename: Norihiko
authors.initials: N
authors.lastname: Ito
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002701:Chloramphenicol / Q000627:therapeutic use; D004283:Dog Diseases / Q000188:drug therapy / Q000382:microbiology*; D004285:Dogs; D007634:Keratitis / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*
chemical_list: D000900:Anti-Bacterial Agents; D002701:Chloramphenicol