Mycobacteria tuberculosis and Nontuberculous mycobacteria (NTM)
Clinical Specimen Submission Guidance
Submit all specimens to 50 Orms St, Providence RI 02904. Open Monday to Friday 8:30 AM to 4:30 PM
Special Pathogens & Biothreats Laboratory 401-222-5586
Mycobacterium tuberculosis, Nontuberculous mycobacteria (NTM)
Tuberculosis, Mycobacteriosis
Specimens: Smear (fluorochrome stain) for presence of acid-fast bacilli and culture (liquid and solid media) for presence of Mycobacterium spp.
Nucleic acid amplification testing (NAAT) (i.e. TB PCR) is available for specimens from patients meeting the CDC recommended guidelines for testing. Refer to M. tuberculosis (NAAT) Frequently Asked Questions at: "https://health.ri.gov/tbtuberculosis/information/tuberculosis-molecular-diagnostic-testing-information-healthcare-workers"
Isolates: All isolates positive for AFB that fit the testing criteria will be run on the Cepheid GeneXpert for M. tuberculosis complex rule out or confirmation. If M. tuberculosis complex is ruled out, then isolates will be processed for testing on the MALDI-TOF Mass Spectrometer for ID.
Drug Susceptibility Testing: Isolates of M. tuberculosis complex only are forwarded to a CDC-designated reference 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.
TB PCR
Sputum
The Cepheid Xpert MTB/RIF Assay uses nested real-time PCR to detect MTB-complex DNA and rifampin-resistance associated mutations of the MTB-complex rpoB gene. The Xpert MTB/RIF Assay has been cleared by the U.S. Food and Drug Administration (FDA) and the performance characteristics were verified by the Rhode Island State Health Laboratories.
Non-Sputum respiratory specimens (bronchial washing/lavage, bronchioalveolar lavage, lung washing, bronchial brushing)
The Cepheid Xpert MTB/RIF Assay used nested real-time PCR to detect MTB-complex DNA and rifampin-resistance associated mutations of the MTB-complex rpoB gene. The performance of the Xpert MTB/RIF Assay was validated by the Rhode Island State Health Laboratories for additional non-sputum respiratory specimens that have not been approved nor cleared by the U.S. Food and Drug Administration (FDA). Namely, bronchial washing/lavage, bronchioalveolar lavage, lung washing, and bronchial brushing.
AFB confirmation
The Cepheid Xpert MTB/RIF Assay uses nested real-time PCR to detect MTB-complex DNA and rifampin-resistance associated mutations of the MTB-complex rpoB gene. The performance of the Xpert MTB/RIF Assay for the identification of MTB-complex isolates for AFB positive culture was validated by the Rhode Island State Health Laboratories. The testing of AFB positive cultures using this assay has not been approved nor cleared by the U.S. Food and Drug Administration (FDA).
Nontuberculous Mycobacteria ID: Bruker MALDI-TOF Mass Spectrometer
The Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) Biotyper (Bruker Daltonics Inc.) and its nontuberculous mycobacteria (NTM) research use only (RUO) reference library of species were verified by the Rhode Island State Health Laboratories for the identification of NTM. The MALDI-TOF NTM RUO library has not been cleared by the FDA
RESULT INTERPRETATION
Refer to "https://health.ri.gov/publications/guidance/TBNucleicAcidImplificationTestingInterpretation.pdf"
Specimens: Refer to Rhode Island State Health Laboratories "Guidelines for the Collection and Transport of Specimens for Tuberculosis Testing."
TB PCR: must meet CDC recommended guidelines (see Test Description)
Isolate: Middlebrook 7H-11 plate/slant, (preferred), Lowenstein-Jensen slant or a minimum of 4.0 mL of liquid media.
CLIA regulations require specimens be labeled with at least two patient identifiers. Examples of identifiers are first and last name, date of birth, chart/medical record number. The specimen container must be labeled to match the test requisition or the electronic order.
Rhode Island State Health Laboratories (RISHL) test requisition form https://health.ri.gov/forms/LabRequisitionForm.pdf
Specimens: AFB Smear & Culture
TB PCR (requires AFB smear and culture)
Isolates: AFB Isolate ID
Refer to Rhode Island State Health Laboratories "Guidelines for the Collection and Transport of Specimens for Tuberculosis Testing."
Specimens must be packaged & transported in accordance with current federal shipping regulations.
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.
Refrigerated: Transport and deliver to the laboratory within 24 hours of collection at 2-8°C in a cooler able to maintain specimen temperature. A plug-in electric cooler is recommended, however, a cooler packed with excess frozen gel packs is acceptable as long as the transport temperature is maintained at 2-8°C.
Shipments that meet the definition for 'Category A' infectious substances as defined by federal regulation require additional packaging/labeling.
Smear: Smear negative for acid-fast bacilli (AFB)
Culture: Culture negative for Mycobacterium species
TB PCR: DNA of Mycobacterium tuberculosis complex is not detected
Providers must report patient information on Tuberculosis, Mycobacteriosis within 4 days using the RIDOH reportable disease form.
Smear: within 1 business day of specimen receipt
PCR: within 2 business days
Culture: culture plates are held for 8 weeks before being reported as negative for growth of Mycobacterium species
Isolate: M. tuberculosis complex rule out/confirmation testing is performed within 1 business day of isolate receipt
Isolate Identification by MALDI-TOF: varies depending on culture growth
Antimicrobial Susceptibility Testing: MTBC testing performed at a CDC-designated reference lab
Containers specifically labeled for transport of specimens and isolates to the RISHL Mycobacteriology Laboratory are available in all Microbiology Laboratories and Laboratory Sendout departments.
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. Kit order forms can be emailed to ridoh.centralservices@health.ri.gov