Influence of Amphibian Antimicrobial Peptides and Short Lipopeptides on Bacterial Biofilms Formed on Contact Lenses

Abstract

The widespread use of contact lenses is associated with several complications, including ocular biofilm-related infections. They are very difficult to manage with standard antimicrobial therapies, because bacterial growth in a biofilm is associated with an increased antibiotic resistance. The principal aim of this study was to evaluate the efficacy of antimicrobial peptides (AMPs) in eradication of bacterial biofilms formed on commercially available contact lenses. AMPs were synthesized according to Fmoc/tBu chemistry using the solid-phase method. Minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of the compounds were determined. Anti-biofilm activity of the antimicrobial peptides determined at different temperatures (25 °C and 37 °C) were compared with the effectiveness of commercially available contact lens solutions. All of the tested compounds exhibited stronger anti-biofilm properties as compared to those of the tested lens solutions. The strongest activity of AMPs was noticed against Gram-positive strains at a temperature of 25 °C. Conclusions: The results of our experiments encourage us toward further studies on AMPs and their potential application in the prophylaxis of contact lens-related eye infections.

Effect of Disulfide Cyclization of Ultrashort Cationic Lipopeptides on Antimicrobial Activity and Cytotoxicity

“…In another study, lipopeptides C 16 -KK-NH 2 and C 16 -RR-NH 2 exhibited high antimicrobial activity (MIC between 4 and 32 μg/mL) and substantially lower antibiofilm potential (MBEC between 32 and >512 μg/mL) against bacteria ( S. aureus , S. epidermidis , E. coli , P. aeruginosa ). This general observation is comparable with that of this study [ 47 ]. Presumably, the increasing net charge improves antibiofilm activity of lipopeptides.…”

Ultrashort Cationic Lipopeptides–Effect of N-Terminal Amino Acid and Fatty Acid Type on Antimicrobial Activity and Hemolysis

“…In general, antimicrobial activity of lipopeptides depended on their hydrophobicity, in agreement with the literature [33]. Regressions of log 2 MIC vs. tR' for reference lipopeptides (3)(4)(5)(6) and lipopeptides with aliphatic (8-10, 28-30, 36-38, 43-46, 64-66, 68-70, 72-74, 92-94) and aromatic (23-26, 95-98, 100-102) amino acids were found to be either quadratic or linear (R 2 between 0.9418 and 0.9985) with all three strains ( Figures S1, S2, S4, S5, S7 and S8). Despite the fact that MIC depended on lipopeptide hydrophobicity, analogs with similar lipophilicity to reference lipopeptides had different MICs.…”

“…In general, lipopeptides have dispersing, foaming, de-emulsificating, and moisturizing properties [1]. Furthermore, it is worth nothing that USCLs offer promising antimicrobial activities against planktonic cells and biofilms of bacteria and fungi [2][3][4][5]. USCLs were also applied to modify materials to prevent bacterial colonization crucial to hard-to-treat biomaterial-associated infections [6].…”

Activity of Temporin A and Short Lipopeptides Combined with Gentamicin against Biofilm Formed by Staphylococcus aureus and Pseudomonas aeruginosa

“…Moreover, the compounds did not show any interaction against PA in planktonic form. L-1 has shown the ability to increase the effectiveness of contact lens solutions against PA biofilm formed on contact lenses, which was the most difficult biofilm to eliminate from the surface of contact lenses using contact lens solutions, amphibian peptides and short lipopeptides containing hexadecanoic acid [ 40 , 51 ]. Polymyxin B and colistin—AMPs that are used in medicine—have shown synergistic activity with fluoroquinolones against PA biofilm [ 50 ].…”