LL-37: Review of antimicrobial profile against sensitive and antibiotic-resistant human bacterial pathogens

By the development of drug-resistant bacterial infections, the world is rapidly heading toward the post-antibiotic era. Antimicrobial peptides are highly potential to be used as a promising alternative to antibiotics. One of the most widely known members of this group is a cationic peptide with an alpha-helical structure, called LL-37, naturally produced by many human cells. The aim of this study was the quantitative determination of the antimicrobial profile of LL-37 against human pathogens. All articles in which the antimicrobial activity of LL-37 was evaluated quantitatively were selected and assessed using the Google Scholar search engine and three databases of Scopus, Web of Science, and PubMed. LL-37 was able to combat a wide range of resistant and sensitive bacterial pathogens which classified into three groups. 1. Gram-positive: at least one of the species in the genus of Staphylococcus, Streptococcus, Enterococcus, Clostridium, Listeria, Nocardia, Bacillus, Aggregatibacter, Peptostreptococcus, Capnocytophaga, and Actinomyces. 2. Gram-negative: at least one of the species in the genus of Acinetobacter, Pseudomonas, Escherichia, Salmonella, Klebsiella, Yersinia, Vibrio, Neisseria, Moraxella, Haemophilus, Porphyromonas, Helicobacter, Campylobacter, Fusobacterium, Prevotella, Eikenella, Tanerella, Burkholderia, and Stenotrophomonas. 3. Other bacterial pathogens (non-detectable or poor results of gram-staining): at least one of the species in the genus Leptospira, Borrelia, Treponema, Mycoplasma, Ureaplasma, and Mycobacterium. Due to the broad-spectrum activity, ability to combat drug-resistant bacterial pathogens, and having a human source, LL-37 could be an appropriate candidate for research, development, and production of novel antimicrobial drugs based on antimicrobial peptides.