Question

Which of the following Gram-positive cocci are found in biofilm of dental plaque?

• A. Gonococcus
• B. Streptococcus mutans
• C. Streptococcus sobrinus
• D. Fusobacterium species

Hint:

Streptococcus mutans and Streptococcus sobrinus are the main Gram-positive cocci responsible for tooth decay and plaque formation.

Answer 1

The Correct Option is B, C

Step 1: Understanding dental plaque biofilm.
Dental plaque is a biofilm that forms on teeth, primarily consisting of various bacteria. Gram-positive cocci, such as Streptococcus species, are dominant in this biofilm.

Step 2: Analyzing the options.
- (A) Incorrect, Gonococcus is a Gram-negative bacterium, not a Gram-positive coccus.
- (B) Correct, Streptococcus mutans is a Gram-positive coccus commonly found in dental plaque, contributing to tooth decay.
- (C) Correct, Streptococcus sobrinus is also a Gram-positive coccus found in dental plaque, often associated with cavities.
- (D) Incorrect, Fusobacterium species are Gram-negative bacteria, not Gram-positive cocci.
Step 3: Conclusion.
Streptococcus mutans and Streptococcus sobrinus are Gram-positive cocci found in dental plaque.