Pseudomonas aeruginosa is a gram-negative rod that is both an aerobic and facultative anaerobic organism. It is commonly spread through contact with exposed water, medical equipment, or human contact. As an opportunistic infection, it causes mild disease in healthy, immunocompetent hosts. In patients who are immunocompromised or have systemic health problems, the pathogen can cause devastating health consequences. In Ophthalmology, it is the leading cause of gram-negative ocular infections, as well as gram negative bacterial keratitis worldwide. While it can be treated with a variety of antibiotics, the prevalence of multidrug resistant Pseudomonas strains is on the rise. In ocular infections, the AMOR study has revealed low antibiotic resistance rates for Pseudomonas between 2009-2019; however, worldwide, antibiotic resistance for Pseudomonas has been increasing, particularly in countries where antibiotics are over-prescribed and over-used. P. aeruginosa is an adaptable and pathogenic organism secondary to virulence factors, intrinsic and extrinsic antibiotic resistance. Through these mechanisms, the pathogen is able to adapt to environmental stressors and supersede the host immune response and antibiotic treatment. Here, we present a case of pan-drug resistant Pseudomonas keratitis, as well as four other subsequent cases of multi-drug resistant Pseudomonas keratitis. We review treatment regimens that include antibiotic therapy, photodynamic antimicrobial therapy, and novel therapies, such as phage and genomic editing therapy. While outcomes of multi-drug resistant Pseudomonas keratitis are often dire, older antibiotics and novel therapies are showing efficacious results in treating this virulent pathogen.
Presentation Date: 11/10/2022
Issue Date: 12/16/2022