Abstract
Purpose :
Stenotrophomonas maltophilia, Delftia acidovorans, Elizabethkingia meningoseptica, and Burkholderia cepacia have been associated with corneal infiltrative events during contact lens wear. These bacteria are naturally resistant against many first line antibiotics. The purpose of this study was to determine the activity of the antimicrobial peptide Mel4 in solution and when attached on contact lens surface against these Gram-negative bacteria.
Methods :
In vitro antimicrobial activity of Mel4 was determined against the four Gram-negative bacteria by investigating growth curves for 24 hours by spectrophotometry followed by determination of minimum inhibitory concentration (MIC). The Gram negative bacteria were isolated from cornea or contact lens cases of adverse events during contcact lens wear. Mel4 was attached onto contact lenses following 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) coupling and characterized by amino acid analysis. Antimicrobial activity of the coated contact lenses against these bacteria was determined by viable plate count.
Results :
Mel4 was active against all the bacteria tested. Antimicrobial activity was highest against S. maltophilia (MIC = 31.2 μg/ml), and weaker activity was found against D. acidovorans, E. meningoseptica and B. cepacia (MIC = 500 to 1000 µg/ml). Amino acid analysis revealed that Mel4-coated contact lenses were associated with 93 ± 13 µg of peptide. Following surface attachment the inhibition of adhesion against the four bacteria was 90%, 91%, 77% and 53% respectively (P<0.05).
Conclusions :
Mel4 has varying antimicrobial activity against the Gram negative bacteria that are naturally resistant to antibiotics. Surface attachment this peptide to contact lenses was able to significantly reduce the attachment of these bacteria
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.