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. Refer to M. tuberculosis Nucleic Acid Amplification Testing (NAAT) Frequently Asked Questions at

Isolates: Identification/speciation by nucleic acid (DNA) probe. Isolates that are not identified by probe by the RISHL and meet the criteria for identification by CDC are forwarded to CDC for identification by molecular means (16s sequencing).

Drug Susceptibility Testing: Isolates of M.tuberculosis complex only are forwarded to the California Microbial Diseases Laboratory for susceptibility testing. Contact the Mycobacteriology section of the Special Pathogens Lab at (401) 222-5587 for further information regarding susceptibility testing on Mycobacterium species.

Special Instructions

Specimens: Refer to Rhode Island State Health Laboratories "Guidelines for the Collection and Transport of Specimens for Tuberculosis Testing."

TB NAAT: must meet CDC recommended guidelines (see Test Description)

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

CLIA regulations require two patient identifiers on the specimen container and the test requisition

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

Specimens: AFB Smear & Culture

Isolates: AFB Identification


Refer to Rhode Island State Health Laboratories "Guidelines for the Collection and Transport of Specimens for Tuberculosis Testing."

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 RISHL 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

Reporting Requirement Providers must report patient information on Tuberculosis within 4 days using the RIDOH reportable disease form.
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: DNA probe testing is performed within 1 working day of isolate receipt

Antimicrobial Susceptibility Testing: 21 days from identification of M.tuberculosis complex. Testing performed at the California Microbial Diseases Laboratory.

Kit Kits are available from the RISHL Center for Laboratory Support Services and may be obtained Monday - Friday between 8:30 am and 4:30 pm. Test order forms can be faxed to (401) 222-6985