Mycobacteria

Note: both fungal and mycobacterial tests can be performed on the same specimen.

Methodology

Culture and/or PCR.

Smear positive specimens are automatically reflexed to PCR for M. tuberculosis complex.

Sensitivities to INH, RIF, ETH and PZA are automatically performed on all M. tuberculosis complex isolates.

CPT Code

87206 - AFB smear
87015 - Prelim Culture
87116 - Final Culture
87188 (x4 - Susceptibly (INH, ETH, RIF, PZA)

Acceptable Specimens

Sputum and Bronchial washes/aspirates: Ideally, three early morning sputums (expectorated or induced) samples should be collected. Pooled specimens are discouraged because of the increase in contamination rates. Bronchial washes/aspirates may be collected on patients unable to produce sputum.

Body fluids (pleural, peritoneal, pericardial, synovial): Aseptically collect a minimum of 3mls.

Gastric lavage: These specimens must be processed within four hours of collection. Please time the collection of such specimens accordingly.

Urine: Ideally, three first-morning, clean-catch specimens should be collected. Pooled 24 hour urine and catheter bag specimens are unacceptable.

CSF

Tissue: The tissue should NOT be submitted in formalin.

Blood: Acceptable anti-coagulants include sodium polyethole sulfonate, sodium heparin (green-top), and sodium citrate (blue-top). EDTA (purple-top) and coagulated blood (red-top) are not acceptable.

Skin and soft tissues: skin lesions, cutaneous lesions, subcutaneous lesions, skin ulcers, skin nodules, wounds (wound infections), abscesses and abscess contents, aspirated pus, papulonodular lesions, cellulites, draining fistula, osteomyelitis sites, masses, etc.

Stool: pea-size minimum

In general, swabs are not optimal for the recovery of AFB as they provide limited material and the hydrophobicity of the mycobacterial cell envelope compromises the transfer from swabs onto solid media and into liquid media.

Specimen Storage

Store specimens in the refrigerator.

Specimen Transport

Transport specimens to the lab on cold pack.

Setup Days

Processing takes place every morning (Monday - Friday). Submit specimens by 10:00 a.m. to ensure they are included in the day's processing run. Processing also takes place Friday afternoons. Submit specimens by 2pm at the latest to ensure they are included.

Turn-around-time

Smear results are available in 24 hours, preliminary results are available in 2 weeks and final results are available approximately in 8 weeks upon arrival at the lab.

Lab Slip

monster form(PDF: 108 Kb)