Document 0461
 DOCN  M9490461
 TI    Nocardia species: host-parasite relationships.
 DT    9411
 AU    Beaman BL; Beaman L; Department of Medical Microbiology and Immunology,
       University of; California, Davis 95616.
 SO    Clin Microbiol Rev. 1994 Apr;7(2):213-64. Unique Identifier : AIDSLINE
       MED/94332802
 AB    The nocardiae are bacteria belonging to the aerobic actinomycetes. They
       are an important part of the normal soil microflora worldwide. The type
       species, Nocardia asteroides, and N. brasiliensis, N. farcinica, N.
       otitidiscaviarum, N. nova, and N. transvalensis cause a variety of
       diseases in both normal and immunocompromised humans and animals. The
       mechanisms of pathogenesis are complex, not fully understood, and
       include the capacity to evade or neutralize the myriad microbicidal
       activities of the host. The relative virulence of N. asteroides
       correlates with the ability to inhibit phagosome-lysosome fusion in
       phagocytes; to neutralize phagosomal acidification; to detoxify the
       microbicidal products of oxidative metabolism; to modify phagocyte
       function; to grow within phagocytic cells; and to attach to, penetrate,
       and grow within host cells. Both activated macrophages and
       immunologically specific T lymphocytes constitute the major mechanisms
       for host resistance to nocardial infection, whereas B lymphocytes and
       humoral immunity do not appear to be as important in protecting the
       host. Thus, the nocardiae are facultative intracellular pathogens that
       can persist within the host, probably in a cryptic form (L-form), for
       life. Silent invasion of brain cells by some Nocardia strains can induce
       neurodegeneration in experimental animals; however, the role of
       nocardiae in neurodegenerative diseases in humans needs to be
       investigated.
 DE    Animal  AIDS-Related Opportunistic Infections/MICROBIOLOGY  Brain
       Diseases/MICROBIOLOGY  Human  Nocardia/*PHYSIOLOGY  Nocardia
       Infections/COMPLICATIONS/DIAGNOSIS/IMMUNOLOGY/  *MICROBIOLOGY
       Phagocytosis  Support, U.S. Gov't, P.H.S.  JOURNAL ARTICLE  REVIEW
       REVIEW, ACADEMIC

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