Abstract
Purpose :
There remains a need to reduce microbial contamination of contact lenses, and thus the rate of adverse events during wear. The purpose of the current study was to determine activity of the antimicrobial peptide Mel4 against drug resistant and clinical isolates of bacteria. In addition, the clinical performance of Mel4 as an antimicrobial contact coating was evaluated in a human trial.
Methods :
Antimicrobial activity of Mel4 (K-N-K-R-K-R-R-R-R-R-R-G-G-R-R-R-R) was determined against Serratia marcescens and drug-resistant Pseudomonas aeruginosa and Staphylococcus aureus by evaluating minimum inhibitory concentration (MIC) using a modified broth microdilution assay. Mel4 was covalently incorporated into etafilcon A contact lenses and its performance was evaluated in a prospective, randomized, contralateral, double masked clinical trial with 1 week daily contact lens wear which assessed subjective responses and ocular physiology.
Results :
Mel4 showed high antimicrobial activity with MIC ranging between 7 to 13 nmol/mL for drug resistant P. aeruginosa strains and 7 nmol/mL for S. aureus strains respectively. MIC for S. marcescens was 852 nmol/mL, indicating low activity. A total of 17 participants were recruited for clinical trial which determined no differences between Mel4 coated and uncoated contact lenses for lens performance indicators such as movement, lens wetting, deposition and centration. Mel4 coated contact lenses were not associated with increased corneal and conjunctival staining, bulbar, limbal or palpebral hyperemia.
Conclusions :
Mel4 has high antimicrobial activity against drug resistant bacteria in addition to presenting no adverse effects for human eyes as a contact lens coating, offering excellent potential for development as an antimicrobial agent and contact lens coating.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.