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  • • Actinomycosis and nocardiosis are not communicable


  • Actinomyces israelii

    • -Gram-positive, non-acid-fast, filamentous organism that usually shows branching and may break up into short bacterial forms

      -Anaerobe, part of the normal flora of the human oropharynx and upper intestinal tract

    • Chronic, slowly progressive infection that may involve many tissues, resulting in the formation of granulomas and abscesses that drain through sinuses and fistulas

    • Lesions resemble those produced by mycobacteria, fungi, and cancer, although the causative organisms are bacteria

    • Sinus tracts or fistulas usually become secondarily infected with other bacteria

    • Abdominal infection may produce an abdominal mass mimicking a malignant process or may give rise to appendicitis


  • Nocardiae are gram-positive, aerobic, branching, filamentous organisms that may be acid-fast

    Nocardia asteroides is the most common isolate

    • May present in 2 forms:

    • 1. Localized, chronic granuloma with suppuration, abscess, and sinus tract formation resembling actinomycosis

      2. Systemic infection, usually beginning as pneumonitis with suppuration and progressing via the bloodstream to involvement of other organs



  • • Inflammatory nodular masses, abscesses, and draining sinuses occur most commonly in the head and neck (50%)

    • 20% of patients have primary lesions in the chest and an equal proportion in the abdomen, most commonly involving the appendix and cecum

    • Pelvic actinomycosis can occur in women with prolonged use of an intrauterine device


  • • More apt to occur as a complication of immunodeficiency in patients with chronic obstructive pulmonary disease, cancer, HIV-associated disease, or corticosteroid-induced immunosuppression

Symptoms and Signs


  • • Multiple draining sinuses with pus containing "sulfur granules"

    • Lesions are often hard and relatively painless and nontender

    • Systemic symptoms, including fever, are variably present

    • Abdominal actinomycosis may mimic appendicitis

    • Thoracic actinomycosis may give rise to cough, pleural pain, fever, and weight loss


  • • Systemic nocardiosis produces fever, cough, and weight loss and resembles mycobacterial or mycotic infections

Laboratory Findings


  • • Culture reveals gram-positive branching rods, with sulfur granules

    • Organisms may be identified by immunofluoresence


  • • Culture reveals branching rods or filaments that are gram-positive or acid-fast


  • • Abdominal neoplasm

    • Appendicitis

    • Mycobacterial or mycotic infection


  • • Systemic infection resembles mycobacterial or mycotic infections

Rule Out

  • • Mycobacterial and mycotic infection

    • Appendicitis

    • Neoplasms

  • • Complete history and physical exam

    • Culture draining sinus tracts

    • CT scanning and needle aspiration may be helpful diagnostically

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