Methicillin‐Resistant Staphylococcus aureus and Methicillin‐Resistant Coagulase‐Negative Staphylococcus Ocular Surface Infection: Efficacy of Chloramphenicol Eye Drops

Purpose Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MR-CNS) are two major multidrug-resistant pathogens. In this paper we report the prevalence of MRSA and MR-CNS in ocular surface infections. Methods We investigated the proportion of MRSA and MR-CNS in bacterial isolates from conjunctiva of elderly patients with and without bacterial conjunctivitis. The relationship between conjunctival MRSA carriers and general background conditions was studied. We evaluated the efficacy of chloramphenicol eye drops in the treatment of MRSA conjunctivitis. We also investigated the presence of MRSA and MR-CNS in lid skin and conjunctiva of patients with atopic dermatitis. Results In conjunctival bacterial flora of elderly patients the proportion of MRSA in S. aureus was 57%, and the proportion of MR-CNS in coagulase-negative Staphylococcus was 25%. Conjunctival MRSA carriers were more likely to have anemia, malignant tumor, liver dysfunction, and dementia, and to be postoperation and chronically bedridden. The efficacy rate of chloramphenicol eye drops in the treatment of MRSA conjunctivitis was 81%. In conjunctival sacs of patients with atopic dermatitis, S. aureus was the most frequent species (48%), and the proportion of MRSA was 18%. Conclusion Methicillin-resistant S. aureus and MR-CNS are widespread in elderly hospitalized patients and in patients with atopic dermatitis. Chloramphenicol eye drops were useful for the treatment of MRSA ocular surface infections.