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.

Bacterial contamination of slit lamps in veterinary ophthalmology

“…In case of Schaedler Bouillon turning turbid and containing gas, anaerobic culture on Schaedler agar was performed. Relevance of colonies was determined according to current literature and experience …”

Evaluation of accelerated collagen cross‐linking for the treatment of melting keratitis in ten cats

“…Keratitis evaluation was made under the following criteria: The specific clinical signs of keratitis were evaluated by slit‐lamp examination (Hawkeye TM , Dioptrix, Toulouse, France). A clinical score modified from Tajima et al . (0–3; 0 = absent, 1 = mild, 2 = moderate, and 3 = severe) was used to grade the severity of mucopurulent discharge, corneal edema, corneal vascularization, conjunctivitis, blepharitis, and uveitis.…”

Prevalence and risk factors for isolation of methicillin‐resistant Staphylococcus in dogs with keratitis

“…Prior to the present report, there was limited information published describing MRS ocular infections in dogs . A previous antimicrobial susceptibility study isolated bacteria from conjunctival samples of 68 dogs with clinical signs consistent with external ocular diseases .…”

“…A case report provided the first detailed description of methicillin‐resistant Staphylococcus aureus keratitis in a dog . The dog was a 7‐year‐old intact male American Cocker Spaniel who had undergone previous surgical removal of a nictitating membrane gland.…”

“…Methicillin‐resistant Staphylococcus species have also been isolated from ocular samples of dogs with and without ocular diseases; however, there are currently few descriptions in the literature of MRS keratitis in dogs and no specific information concerning the potential risk factors associated with canine MRS keratitis . The purpose of the study reported here was to determine the prevalence of, and risk factors for, MRS isolation from corneal samples of dogs with naturally acquired bacterial keratitis.…”