Tuberculosis (TB), Non-Respiratory - Provincial
Discipline
Microbiology
Overview
Description
- Mycobacterium culture is considered the laboratory gold standard diagnostic test for diagnosis of mycobacterial infection. As Mycobacterium tuberculosis can virtually infect any body tissue, multiple specimen types are accepted. Mycobacterial culture also allows detection of nontuberculous mycobacteria (NTM), and susceptibility testing can be performed on cultured M. tuberculosis (routine) and NTM (on request only) isolates.
Specimen Information
Specimen types accepted
- CSF specimens should be collected aseptically into sterile leak-proof tubes prior to antimicrobial therapy. Submit as much sample volume as possible to maximize sensitivity of culture. If available, GeneXpert MTB PCR should also be performed. NOTE: Do not refrigerate or freeze specimen if shipping is delayed.
- Tissue: Collect tissue a in sterile container, minimum 1 gram. Yield of culture will increase with larger samples. NOTE: Do not place in fixative or preservative. If shipping will be delayed, refrigerate sample; DO NOT freeze.
- Urine: Genitalia must be appropriately cleansed with soap and water preceding collection of first morning voided urine specimen. Collect urine specimen into a sterile urine container; optimal minimum volume is 40 mL. Transport to lab refrigerated as soon as possible.
- NOTE: Submit early morning specimens from three consecutive days and do not pool specimens or submit 24 hour specimen.
- NOTE: Urine from a catheter bag is unacceptable.
- NOTE: Urine specimens are not examined by direct smear microscopy.
- Blood: Aseptically collect 1 - 5 mL (3-5 mL optimum) of venous blood into a Bactec MYCO/F Lytic blood culture bottle.
Performance
Maximum laboratory time
Result reporting
- Direct smear results (not performed on urine or blood) within 24 hours after received by lab. Positive culture results are reported as they become available. Positive M. tuberculosis cultures are reported to TB control.
- Negative cultures: 42 days (Myco/F Lytic blood); 49 days (others)
Other information
Any additional comments
- NOTE: Submit each TB sample in a separate, sealable, leak-proof biohazard bag, with the corresponding requisition in the side pocket of the bag.
- NOTE: Submit as soon as possible. Specimens should be refrigerated if shipping is delayed more than 1 hour. DO NOT freeze specimen.
Last Updated: June 4, 2024