Each of the following statements concerning Actinomyces and Nocardia is correct EXCEPT:

  •  Both Actinomyces and Nocardia are branching, filamentous rods.
  •  A. israelii is an anaerobic rod found as part of the normal flora in the mouth.
  •  N. asteroides causes infections primarily in immunocompromised patients.
  •  Infections are usually diagnosed by detecting a significant rise in antibody titer.