Antimicrobial peptides: a potential role in ocular therapy

Abstract

Bacterial pathogens are often involved in contact lens-related adverse responses. This study aimed to find antimicrobial peptides and proteins that effectively eradicate or inhibit ocular bacteria. The antimicrobials were screened against gram-negative and gram-positive bacteria originating from ocular sources. The viability of these ocular bacteria was measured after exposure to the peptides and proteins. Two conditions were used to grow bacteria, low nutrient phosphate-buffered saline and high nutrient tryptone soya broth. Samples were taken at different times up to 48 h. In low nutrient conditions, protamine was found to be the most effective against all strains. Melittin was very effectve against all strains except Serratia and one Pseudomonas isolate which were partially affected. In high nutrient condition, only melittin was effective in killing Staphylococcus aureus. Protamine and the combination of protamine and melittin had the greatest effect in eradicating the bacteria tested in low nutrient condition. Protamine alone and its combination with melittin may have potential therapeutic agents for ocular infections in an era of emerging antibiotic resistance.

Characterization of chemoselective surface attachment of the cationic peptide melimine and its effects on antimicrobial activity

“…The resulting surfaces were approximately four times more effective in reducing the total surface coverage of S. aureus than CysC, which has the cationic portion closer to the surface. A previous solution-based study by Aliwarga et al [37] determined that the mellitin portion (N-terminus) of melimine is essential to confer activity against Staphylococcus. However, the current study suggests that, once melimine is attached to the surface, the protamine portion (cationic portion) also confers activity against Staphylococcus.…”

Insect natural products and processes: New treatments for human disease

“…It is a powerful antimicrobial peptide (AMP) (see Section 7.1, below), killing bacteria such as E. coli, and S. aureus, as well as the spirochaete causing Lyme disease, Borrelia burgdorferi, the fungus, Candida albicans and even has anti-viral, HIV1, activity (eg. Lubke and Garon, 1997;Aliwaga et al, 2001;Meenakshisundaram et al, 2009;Park and Lee, 2010). Again the lysis of normal mammalian cells by melittin, and many other AMPs, has impeded its therapeutic development.…”

The Molecular Basis of Toxins’ Interactions with Intracellular Signaling via Discrete Portals

“…Cytotoxic and membrane penetrating properties of Melittin have rendered it useful in cancer therapy, either as an active ingredient or as an absorption enhancer [57]. Melittin has proven itself as a potent antimicrobial agent that may be used for the treatment of eye infections [58]. Recently some evidence was provided that Melittin inhibits HIV-1 gene expression at the transcriptional level and therefore may be used for anti-AIDS therapy [59].…”