Oral amoxicillin-clavulanate: an alternative treatment to refractory Nocardia keratitis-a case report

Bacterial keratitis (bacterial corneal infection) is a serious, vision-threatening disease caused by a wide range of bacterial species. The gram-positive bacterium Nocardia spp. is increasingly recognized in keratitis, yet is particularly challenging to treat due to delayed diagnosis and limited efficacy of current ophthalmic therapeutics. Antimicrobial resistance among clinical Nocardia isolates is also rising, further complicating patient outcomes. Herein, we report a case of Nocardia amikacinitolerans keratitis, resistant to amikacin, ciprofloxacin, moxifloxacin, clarithromycin, and ceftriaxone, resulting in a complicated therapeutic course.

A 53-year-old female presented with bacterial keratitis of the right eye, which over the course of 32 months progressed to scleritis (infection of the sclera) and a progressive, significant decrease in visual acuity to hand motion despite exhaustive topical and systemic antimicrobial therapies. While there is a general lack of efficacy of systemic therapies for bacterial keratitis, oral amoxicillin-clavulanate ultimately proved successful in resolving the infection.

As Nocardia spp. ocular infections become more prevalent, this report underscores the highly virulent nature of this pathogen and provides insights into potential therapeutic modalities in the setting of multidrug resistance.