What are the two virulence factors of cariogenic bacteria?

• A. Acid production and acid tolerance
• B. Adhesion and colonization
• C. Biofilm formation and motility
• D. Enamel demineralization and saliva inhibition

Answer: (A)

The main idea is that cariogenic bacteria cause tooth decay primarily by creating and surviving in an acidic environment at the tooth surface. They metabolize fermentable carbohydrates into acids, mainly lactic acid, which lowers the local pH. When the surface pH drops below about 5.5, enamel begins to demineralize, and repeated cycles of acid attack with insufficient remineralization drive caries progression. Equally important is the bacteria’s ability to tolerate and survive in acidic conditions—acid tolerance or aciduricity—so they can persist and keep producing acid even after the pH drops. This combination of producing acid and thriving in acid makes these bacteria particularly virulent in caries. Factors like adhesion and colonization help establish the biofilm, or biofilm formation with motility can aid spread, but they don’t directly describe the acid-centered mechanism that damages enamel. Enamel demineralization and saliva inhibition describe outcomes or host-related factors rather than the bacterial traits driving the process.