Comparison of antimicrobial resistance genes on the ocular surface of patients with corneal infections in California and Malawi

Background: Antimicrobial resistance (AMR) determinants on the ocular surface may contribute to poor treatment responses. Results: Mutations conferring macrolide resistance were present on the ocular surface in 58% (95% CI 44 to 71%) of the participants in Malawi and 32% (95% CI 20 to 46%) of the participants in San Francisco. Amino-glycosides resistance genes were also common on the ocular surface with 58% (95% CI 44 to 71%) prevalence in Malawi and 21% (95% CI 12 to 35%) in San Francisco. AMR was associated with poorer visual outcomes in a subset of patients. Conclusions: As determined by RNA-seq, ocular surface AMR gene mutations are common in patients with infectious keratitis. Surveillance may be important for infectious keratitis treatment selection as well as providing guidance for antibiotic stewardship.