What mechanism allows Streptococcus mutans to adhere to teeth and form dental plaque?

What mechanism allows Streptococcus mutans to adhere to teeth and form dental plaque?

• A. They produce dextran from glucose via glucosyltransferase to form a sticky matrix that traps bacteria and debris, forming plaque
• B. They produce lactic acid only
• C. They photosynthesize
• D. They cause periodontal pockets by proteases

Answer: (A)

The sticking power comes from forming a sticky extracellular matrix that lets Streptococcus mutans attach to tooth surfaces and to each other. It does this by secreting glucosyltransferase, which converts sugars into dextran, a glucan polymer. This dextran creates a sticky, gel-like matrix on the tooth enamel, enabling the bacteria to adhere and to trap debris, forming dental plaque as a biofilm. While S. mutans does produce lactic acid from carbohydrate metabolism, that acid production drives enamel demineralization after attachment rather than explaining how the bacteria attach in the first place. The organism does not photosynthesize, and periodontal-pocket–forming proteases describe a different disease process (periodontitis) rather than initial plaque formation by S. mutans.

The sticking power comes from forming a sticky extracellular matrix that lets Streptococcus mutans attach to tooth surfaces and to each other. It does this by secreting glucosyltransferase, which converts sugars into dextran, a glucan polymer. This dextran creates a sticky, gel-like matrix on the tooth enamel, enabling the bacteria to adhere and to trap debris, forming dental plaque as a biofilm. While S. mutans does produce lactic acid from carbohydrate metabolism, that acid production drives enamel demineralization after attachment rather than explaining how the bacteria attach in the first place. The organism does not photosynthesize, and periodontal-pocket–forming proteases describe a different disease process (periodontitis) rather than initial plaque formation by S. mutans.