Which salivary antimicrobial component is primarily responsible for sequestering iron and inhibiting growth?

Which salivary antimicrobial component is primarily responsible for sequestering iron and inhibiting growth?

• A. Lysozyme
• B. Peroxidase systems
• C. Lactoferrin
• D. Immunoglobulin A

Answer: (C)

Iron sequestration in saliva is a key antimicrobial strategy. Lactoferrin is an iron-binding glycoprotein present in saliva that tightly chelates ferric iron, making it unavailable to bacteria. Because many microorganisms require iron for growth, this limitation slows or stops their proliferation, so lactoferrin is the primary salivary component responsible for withholding iron and inhibiting growth. Other salivary components act through different means—lysozyme breaks down bacterial cell walls, peroxidase systems generate antimicrobial oxidants, and secretory IgA prevents adherence and neutralizes pathogens—but they don’t mainly function by iron sequestration.

Iron sequestration in saliva is a key antimicrobial strategy. Lactoferrin is an iron-binding glycoprotein present in saliva that tightly chelates ferric iron, making it unavailable to bacteria. Because many microorganisms require iron for growth, this limitation slows or stops their proliferation, so lactoferrin is the primary salivary component responsible for withholding iron and inhibiting growth. Other salivary components act through different means—lysozyme breaks down bacterial cell walls, peroxidase systems generate antimicrobial oxidants, and secretory IgA prevents adherence and neutralizes pathogens—but they don’t mainly function by iron sequestration.