Mycobacteria (non-tuberculosis) – drug resistance testing

Alternative Names/Synonyms	Antimicrobial susceptibility testing of Non-tuberculous mycobacteria (NTM)
Laboratory	Microbiology
Sub-section	Bacteriology
Specimen Type	○ Any specimen submitted for Mycobacterial culture that grows a non-tuberculous Mycobacterial species

Other Information

○ PHOL must be notified if susceptibility testing on an NTM species is requested as it is not performed routinely. Clinical justification is necessary. Respiratory samples must meet the American Thoracic Society (ATS) guidelines for clinical significance (https://www.thoracic.org/statements/resources/mtpi/nontuberculous-mycobacterial-diseases.pdf)

○ Approval is based on following criteria: 1) sterile site isolation, BAL, bronch isolation, multiple specimens with growth, 2) treatment is planned or ongoing, 3) susceptibilities are needed to plan or modify treatment.
○ Susceptibility testing is performed once a year per organism

Sample Stability

Refer to section Sample Processing / Delivery

Referral Laboratory

PHOL to NML

Routine Turnaround Time

○ For M. abscessus testing, 7-10 days after culture identification
○ Up to 45 days from receipt of specimen by NML

Laboratory Contact Information

416-586-4800 extension 4573

Approval Required

Sample Processing / Delivery

○ The specimen will be referred to the Public Health Ontario Laboratory for testing.

○ PHOL will identify the subspecies of all new patient isolates of M. abscessus and will identify mutations predictive of macrolide resistance. Phenotypic drug susceptibility testing is referred to NML.

○ The Public Health Ontario Laboratory will facilitate the transfer of other NTM isolates that grow in culture to the National Microbiology Laboratory/National Reference Centre for Mycobacteriology for susceptibility testing upon request.