A Fatal Case Of Multidrug-Resistant Pseudomonas Aeruginosa Keratitis With Systemic Dissemination

This case report outlines the clinical progression and management of a rapidly advancing pan-resistant Pseudomonas aeruginosa bacterial keratitis. Such infections are particularly difficult to treat due to limited topical or systemic antibiotics with effective ocular penetration against these highly resistant organisms.

Pseudomonas aeruginosa keratitis is a rapidly progressive infection that may result in corneal melting and perforation within days. Treatment typically involves intensive topical therapy with fluoroquinolones or aminoglycosides. However, increasing antimicrobial resistance has reduced the effectiveness of many commonly used agents. The rise of pan-resistant strains causing keratitis is concerning due to paucity of effective topical and systemic medications.

A 71-year-old bedbound, non-communicative Chinese man was admitted for a mucocutaneous flare of pemphigus vulgaris. His ocular history included right eye end-stage glaucoma and cataract, and bilateral exposure keratopathy secondary to lagophthalmos. He was referred for evaluation of a white corneal lesion in the right eye. Examination revealed a mucopurulent infiltrate involving approximately 20% of the cornea with limbal extension. Visual acuity could not be assessed. Intraocular pressure was 17 mmHg.

Corneal scrapings were obtained and intensive hourly fortified cefazolin and gentamicin, topical atropine, and oral ciprofloxacin were initiated. Owing to lack of response, topical levofloxacin was added. Despite treatment with three classes of broad-spectrum topical antibiotics, the infiltrate enlarged. On day 6, cultures grew pan-resistant Pseudomonas aeruginosa, resistant to fluoroquinolones, carbapenems, cephalosporins, and monobactams, with only intermediate susceptibility to polymyxin B. Topical polymyxin B was commenced hourly, but his cornea infiltrate continued to worsen. He  subsequently developed pan-resistant pseudomonas bacteremia and septic shock. His ocular and systemic condition continued to deteriorate, and he died on day 13 despite aggressive therapy.

Pan-resistant Pseudomonas aeruginosa keratitis is uncommon but highly difficult to manage. Most reported cases occur in patients with systemic risk factors such as leukemia, Stevens–Johnson syndrome, diabetes, or ocular risk factors like contact lens wear, prior keratoplasty, topical steroids. When conventional therapy fails, agents such as meropenem, colistin, or polymyxin B may be considered, though further studies are needed to establish their safety and efficacy. This case highlights the critical importance of antimicrobial stewardship and responsible antibiotic use to prevent the emergence and spread of multidrug-resistant organisms.