Mycobacteriaceae

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Mycobacteriaceae Part IISpecimen Collection

• Created by Michele L. Jurgensmeier MT(ASCP)
• Edited by Kathy Talmon MT(ASCP)SM
• Voice over lecturer Carol Larson MSEd, MT(ASCP)
• Clinical Laboratory Science Program

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Specimen Collection

• Sterile disposable container
• Collect before antibiotic therapy
• Deliver promptly to laboratory
• Refrigerate if delay in delivery
• Swabs not acceptable in most laboratories

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Specimen Types

• Respiratory - sputum, induced sputum, BAL
• Urine
• Gastric lavage
• Feces (not accepted in most labs)
• Wound drainage
• Blood
• Body fluids
• Tissues

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Respiratory Specimens

• Sputum, induced sputum and BAL
• Irregular and intermittent release of
  mycobacteria into bronchial lumen
• Recommend minimum of 3 to 5 early morning
  specimens on consecutive days
• 10 mL or less per 50 mL tube
• NO pooled specimens

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Urine Specimens

• 3 to 5 early morning midstream or catheterized
  specimens
• Entire volume or minimum 15 mls
• Centrifuge to concentrate specimen

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Gastric Lavage

• Obtained when unable to obtain sputum samples
• Preferred specimen for children
• Must neutralize acids in specimen

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Feces

• NOT acceptable for culture
• Some institutions do accept this specimen
• Immunocompromized patients (AIDS)
• Risk for disseminated mycobacterial disease

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Aspirated Wound Drainages

• Fluid collected
• Swabs not acceptable

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Blood Cultures

• Lysis centrifugation
• Release intracellular mycobacteria
• Concentrate organisms if present
• Or inoculate directly to broth media
• Direct inoculation to solid media should not be
  done

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Sterile Body Fluids

• Sterility strictly maintained
• Centrifuge and plate sediment
• CSF
• Large volumes needed
• Difficult to diagnosis tuberculous meningitis

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Tissues

• Sterility strictly maintained
• Saline added to avoid dehydration
• In the lab, tissue is ground to release organisms

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In review

• Specimen collection
• Mycobacteria isolated from variety of specimens
• Most common respiratory
• Sterile technique in collecting body fluids and
  tissue
• Concentrate specimens since mycobacteria may be
  present in small numbers

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References

1. Mahon, C.R. Manuselis, G., Textbook of
   Diagnostic Microbiology, 2nd Ed., W.B. Saunders,
   2000
2. Forbes, B.A., Sahm, D. F., Weissfeld, A.S.,
   Bailey and Scotts Diagnostic Microbiology, 11th
   Ed., Mosby, 2002.
3. Koneman, Color Atlas and Textbook of Diagnostic
   Microbiology, 5th Ed., J.B. Lippincott Co., 1997
4. Murray PK, et al., Manual of Clinical
   Microbiology, 7th ed., ASM Publishing, Washington
   DC, 1999.