Nocardia & Actinomyces

Nocardia asteroides

• Common inhabitant of soils rich in organic matter

• Produces opportunistic infections in numerous sites

  • Pulmonary infections

    • Develop from inhalation of the bacteria

  • Cutaneous infections

    • Result from introduction of the bacteria into wounds

    • May produce a mycetoma

  • Central nervous system infections

    • Result from spread of bacteria in the blood

N. asteroides Diagnosis

Presence of Nocardia in samples is usually diagnostic

Nocardia asteroides

• Common inhabitant of soils rich in organic matter

• Produces opportunistic infections in numerous sites

  • Pulmonary infections

    • Develop from inhalation of the bacteria

  • Cutaneous infections

    • Result from introduction of the bacteria into wounds

    • May produce a mycetoma

  • Central nervous system infections

    • Result from spread of bacteria in the blood

N. asteroides Diagnosis

Presence of Nocardia in samples is usually diagnostic

N. asteroides Treatment

Six-week course with sulfonamides

Immunocompromised patients have poor prognosis

N. asteroides Prevention

Avoiding exposure to bacterium in soil

Actinomyces

• Normal microbiota of human mucous membranes

• Opportunistic infections

  • Occur in the respiratory, gastrointestinal, urinary, and female genital tracts

• Actinomycosis

  • Bacteria enter through breaks in the mucous membrane

  • Develop abscesses connected by channels in skin or mucous membranes

Actinomyces Diagnosis

Diagnosis difficult

Other organisms cause similar symptoms

Actinomyces Prevention

Good oral hygiene

Prophylactic use of antimicrobials if breach of mucus membranes occurs