ACTINOMYCES

1. General

   1. Gram +

   2. Non-acid fast

   3. Normal flora (non-contagious) of RT, GI, female UGT

   4. Facultative or strict anaerobic bacilli

   5. Non-spore forming

   6. Form filaments

   7. Culture difficult- 2 weeks or longer

   8. Yellow-orange sulfur granules are macroscopic colonies bound by calcium phosphate

   9. In tissue, organism looks like sulfur granules which can be stained for branching, filamentous bacteria

2. Pathogenesis

   1. Break through mucosal barrier

   2. Opportunistic infx

3. Clinical syndromes

   1. Cervicofacial disease- tissue swelling, fibrosis, and scarring along sinus tracts along angle of the jaw

   2. Pelvic, thoracic, abdominal, CNS disease

   3. Chronic granulomatous infx

   4. Mycetomas

   5. Salpingitis from IUD

4. Epidemiology

   1. Cervicofacial- poor oral hygiene, invasive dental procedure, or oral trauma

   2. Thoracic- aspiration establishes infx in lungs and spreads to adjoining tissues

   3. Abdominal- surgery or bowel trauma

   4. Pelvic- secondary infx or IUD

   5. CNS- secondary infx

5. Treatment- debridement and 4-12 month Tx with penicillin

6. Clinically relevant species

   1. A. isrealii- “molar tooth colonies after 7 day on medium

      1. Commonly non-pathogenic in nose and throat

      2. Actinomycosis, “lumpy jaw”

         1. facial trauma, surgery, or primary infx

         2. abscess produces a hard red-to purplish lump, often on jaw

         3. abscess breaks though skin and drain a sinus tract

   2. A. naeslundii, A. viscosus, A. odontolyticus, A. pyogenes, A. meyeri

7. Other dieases

   1. Actinomycetoma

      1. Chronic, suppurative granulomatous infx of subcu tissue

      2. Tropical or subtropical regions with barefooted natives

      3. Soil actinomycetes A. madurae or Streptomyces somaliensis

   2. Allergic pneumonitis (Farmer’s lung)

      1. Inhale thermophilic Micropolspora faeni or thermoactinomyces vulgaris

      2. Haystacks, compost pile, storage silos at 45-60C

      3. Type I or II hypersensitivity

Category: Microbiology Notes