Antimicrobial activity of cathelicidin peptides and defensin against oral yeast and bacteria

Fungal resistance to traditional drugs calls for new antimicrobial agents. In mammals, defensins and cathelicidins are two major families of antimicrobial peptides. Cathelicidins are cationic peptides with a conserved N-terminal cathelin-like domain and a variable C-terminal antimicrobial domain. Cathelicidins rapidly kill Candida and other yeast spp.1 Candida infection with C albicans is the fourth most common cause of hospital-acquired bloodstream infection in the USA. Defensins are cationic cysteine-rich peptides found in mammals, fungi, insects, and plants.2 Defensins interact with membrane phospholipids leading to compromised membrane permeability. Defensins gain entry into the cells to interact with intracellular targets and interfere with cellular activity.3 This study aimed to (1) determine whether human cathelicidin LL37 and its fragments LL13-37 and LL17-32 can inhibit C albicans, and (2) purify an antifungal defensin from Phaseolus vulgaris cv. ‘king pole bean’ seeds to investigate its antimicrobial activity on the growth of pathogenic fungi and yeasts.