Periodontics · single question
Which microorganism is most characteristically associated with localized aggressive periodontitis?
Show answer and explanation
Correct answer: C. Aggregatibacter actinomycetemcomitans
- A. Lactobacillus contributes to caries progression, not aggressive periodontitis.
- B. S. mutans is the key CARIES organism, not the aggressive-periodontitis pathogen.
- C. Correct. Aggregatibacter actinomycetemcomitans, a gram-negative facultative anaerobe (leukotoxin-producing), is the hallmark organism of localized aggressive periodontitis (along with red-complex anaerobes such as Porphyromonas gingivalis and Tannerella forsythia).
- D. Candida albicans is a fungus causing candidiasis, not a periodontal pathogen here.
Note: The source phrased this as 'how many bacteria,' but the testable point is the SPECIFIC organism — A. actinomycetemcomitans. Item reconstructed accordingly.