Clinical Specimen Submission Guidance

Submit all specimens to 50 Orms St, Providence RI 02915. Open Monday to Friday 8:30 AM to 4:30 PM

Mycobacterium tuberculosis

Lab Bioterrorism Response & Special Pathogens Lab (401) 222-5586
Mycobacteriology Section: (401)222-5587
Organism Mycobacterium tuberculosis
Disease Tuberculosis
Test Description

Specimens: Smear (fluorochrome stain) for presence of acid fast bacilli and culture (liquid and solid media) for presence of Mycobacterium sp. Nucleic acid amplification testing (NAAT) is available for specimens from patients meeting the CDC recommended guidelines for testing. NAAT is reflexively ordered for all new smear positive patients with no known history of tuberculosis or recent infection/colonization with non tuberculosis mycobacteria (NTM).

Isolates: Identification/speciation by nucleic acid (DNA) probe or biochemical profile. Isolates that can't be speciated by the HEALTH laboratory and meet the criteria for identification by CDC are forwarded to CDC for identification by molecular means (16s sequencing).

Drug Susceptibility Testing: Performed on isolates of M.tuberculosis complex only. Susceptibility testing on other clinically significant Mycobacterium sp. is available by special request; contact the Mycobacteriology section of the Special Pathogens Lab at (401) 222-5587 for further information.

Specimen

Specimens: Refer to Rhode Island State Health Laboratories "Guide to Mycobacteriology Laboratory Services" under the section: "Specimen Collection and Transport"

Isolate: 4 ml liquid media. Lowenstein Jensen slant or Middlebrook 7H-10 or 7H-11 slant/plate is also acceptable)

Form Required Rhode Island State Health Laboratories test requisition form
Test Request

Specimens: AFB Smear & Culture

Isolates: AFB Identification

Transport

Refer to Rhode Island State Health Laboratories "Guide to Mycobacteriology Laboratory Services" under the section: "Specimen Collection and Transport"

All specimens and isolates must be in leak proof containers with properly fastened screw caps. Isolates in liquid media are to be sealed with parafilm or other appropriate barrier film. All submissions must be properly packaged in accordance with current federal shipping regulations. Containers specifically labeled for transport of specimens and isolates to the HEALTH Mycobacteriology Laboratory are available in all microbiology labs and laboratory send out departments. Shipments that meet the definition for 'Category A' infectious substances as defined by federal regulation require additional packaging/labeling.

Normal Value

Smear: No AFB seen in smear

Culture: Culture negative for Mycobacteria

NAAT: PCR negative for M. tuberculosis complex

Turnaround Time

Smear: within 1 working day of specimen receipt

NAAT: within 2 working days

Culture: culture plates are held for 8 weeks before being reported as negative for growth of Mycobacteria species

Isolate identification: dependent on method of identification. DNA probe testing is performed within 1 working day of isolate receipt

Antibiotic Susceptibility: 10-21 days from isolation and identification of M.tuberculosis complex

Kit Kits are available at HEALTH Laboratories Central Receiving and may be obtained Monday - Friday between 8:30 am and 4:30 pm. Test order forms can be faxed to (401) 222-6985