Which antimicrobial peptide is secreted by sweat glands and disrupts membrane integrity and ion channels?

• A. Histatins
• B. Dermcidin
• C. Bacteriocins
• D. Cathelicidin

Answer: (B)

Antimicrobial peptides from the skin include dermcidin, which is secreted by eccrine sweat glands into sweat. Dermcidin remains active in the skin environment and kills microbes by inserting into their membranes and forming ion channels. This disrupts membrane integrity and disturbs ion balance, leading to leakage and cell death. This mechanism is well-suited to the salty, acidic conditions of sweat and provides broad protection at the skin surface. Histatins are mainly from saliva and target fungi; cathelicidin (LL-37) is produced by various tissues and immune cells with broad activity but not specifically from sweat glands; bacteriocins are produced by bacteria, not human skin.