MYCOBACTERIAL CULTURE, DETECTION, & IDENTIFICATION

Laboratory: Microbial Reference

Test Description: Culture, detection, and identification of mycobacteria including Mycobacterium tuberculosis complex (MTBC)

Order Approval Required?

Specimen Type:

Pure Mycobacterium tuberculosis complex isolate; pure nontuberculous mycobacteria isolate
Clinical specimens (abscess/exudate, blood, bone marrow, body fluid, cerobrospinal fluid (CSF), gastric lavage, respiratory (lower respiratory and sputum), stool, tissue/biopsy, urine)

Collection Container:

Isolates: Slant (i.e. LJ slant), broth (i.e. 7H9 broth), or plate media (i.e. 7H10 plate)
Blood: isolator, sodium polyanethol sulfonate (SPS), or heparin containing tube
Bone marrow: sodium polyanethol sulfonate (SPS) or heparin containing tube
All other specimens: sterile, leakproof container

Optimal Volume:

Collection Guidelines:

Collection kits are provided to VDH for sputum specimens. First morning, observed collection preferred for sputum.
Gastric Lavage: Health Department or TB Control should consult prior to specimen submission. If specimens cannot be processed within 4 hours of collection, 100 mg of sodium carbonate must be added to the container within one hour of collection and mixed in order to neutralize the acidity of the specimen.

DCLS approved submitters can request collection kits at DCLS_SSSKits@dgs.virginia.gov.

Storage Container: Sterile, leakproof container (except blood and bone marrow)

Storage Instructions:

Store lower respiratory (including sputum), abscess/exudate, body fluid, tissue, stool, urine at 2-8°C
Tissue/biopsy specimens should be stored in 2-3 mL sterile nonbacteriostatic saline
Store blood, bone marrow, CSF, gastric lavage specimens at 15-25°C
Clinical specimens should be sent with minimal delay but must be received within 7 days of collection
Store isolates at 2-30°C

Transportation Instructions:

Transport lower respiratory (including sputum), abscess/exudate, body fluid, tissue, stool, urine at 2-8°C (preferred); 2-30°C is acceptable
Transport blood, bone marrow, CSF, gastric lavage specimens at 15-25°C
Clinical specimens should be sent with minimal delay but must be received within 7 days of collection
Isolate transport: 2-30°C

Test Methodology:

PCR for Mybacterium tuberculosis complex and Mycobacterium avium complex identification (sputum and isolate)
MALDI-TOF identification
MGIT 960 Antimycobacterial Susceptibility Testing (AST), MTBC only (1.0 ug/mL Rifampin, 0.1 ug/mL Isoniazid, 0.4 ug/mL Isoniazid, 5.0 ug/mL Ethambutal, 100 ug/mL Pyrazinimide, 0.25 ug/mL Moxifloxacin)
Xpert MTB/RIF
Culture and Fluorochrome Smear (smear not performed on blood and bone marrow specimens)

Additional Information: TBD

Causes for Rejection:

Samples with no name/identifier or mismatched sample labels and test request forms
Incorrect collection or transport conditions
Evidence of exposure to temperature extremes during transport (isolates only)
Broken or leaking collection containers.
Twenty-four-hour urine collections are not suitable for culture and will be rejected
Swab specimens are not recommended for specimen collection and will be rejected
Specimen visibly contaminated with foreign substances
Blood not submitted in isolator, SPS, or heparin tube
Bone marrow not submitted in SPS or heparin tube
Specimen too old; greater than 7 days from collection date
Gastric lavage specimens not submitted with sodium carbonate
Duplicate MTBC isolates sent for compliance
Isolates on media that expired prior to inoculation
Specimen received out of the appropriate temperature range

Fluorochrome Microscopy

Negative or Positive with grading

MTBC/MAC PCR

Detected or Not Detected

Xpert MTB/RIF

MTBC Detected or Not Detected; RIF rpoB mutation Detected, Not Detected, or Indeterminate

AST

Sensitive or Presumptive Resistant

Culture and Organism Identification if applicable

Culture Negative or Positive for

Acid fast bacilli (AFB);

Mycobacterium complex/group or

species