Recurrent alcaligenes xylosoxidans keratitis

Purpose: To describe a case of postkeratoplasty recurrent Alcaligenes xylosoxidans keratitis. Methods: A 33-year-old man with a history of penetrating keratoplasty developed corneal infiltrate with intact epithelium and then was treated with broad-spectrum antibiotics. Corneal scraping was taken for microbiologic study. Results: The culture result identified A. xylosoxidans, sensitive to piperacillin and ceftazidime. There were 3 recurrent episodes within 2 months after each apparent resolution achieved after the instillation of topical piperacillin (10 mg/mL). During the fourth attack, the lesion responded poorly to piperacillin and ceftazidime (25 mg/mL), so therapeutic penetrating keratoplasty was performed to eradicate the recalcitrant infection. Conclusions: A. xylosoxidans has probably been underreported as a cause of ocular infection. It does not respond to conventional antibiotic therapy and may be difficult to eradicate. Therapeutic penetrating keratoplasty might be necessary if medical treatment fails.