Among the following, which gram-negative periodontal pathogen is NOT typically elevated in this patient?

• A. Porphyromonas gingivalis
• B. Treponema denticola
• C. Tannerella forsythia
• D. Actinomyces naeslundii

Answer: (D)

In periodontal disease, the subgingival biofilm often shifts toward Gram-negative anaerobes that drive the active infection. Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia are classic Gram-negative pathogens commonly elevated in diseased sites. Actinomyces naeslundii, however, is a Gram-positive filamentous bacterium that is typically found in healthy plaque and early biofilm formation rather than in active periodontal infection. Because it is not a Gram-negative pathogen, it would not be expected to be elevated in this patient’s periodontal disease, making it the best choice.