Which of the following is NOT a significant factor in determining the virulence of Actinomyces actinomycetemcomitans?

• A. Affects chemotaxis
• B. Produces leukotoxins
• C. Destroys collagen
• D. Is immuno-suppressive

Answer: (D)

The determination of virulence factors in organisms like Actinomyces actinomycetemcomitans is key to understanding their pathogenic potential. Among the potential factors listed, immuno-suppression is not documented as a significant means by which this bacterium enhances its virulence.

Actinomyces actinomycetemcomitans is indeed known to affect chemotaxis, produce leukotoxins, and destroy collagen, all of which contribute to its ability to cause disease. By affecting chemotaxis, it can manipulate host immune responses to its advantage. The production of leukotoxins directly affects immune cells, compromising the host's ability to fight off the infection. Collagen destruction contributes to tissue damage and the progression of periodontal diseases, further establishing its virulence.

Since immuno-suppression is not a characteristic attributed to this organism's method of pathogenesis, it stands out as the factor that does not significantly contribute to its overall virulence.