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Test Menu Details

Mycobacterium - AFB PCR: Isolate Identification

Updated

4/24/2023

Search Terms M. tuberculosis complex ID; M. avium complex ID
How to Order

On the General Microbiology Test Request Form (OHA0060), in the “Mycobacteria” section, check the “AFBPCR: AFB Culture Identification and PCR; isolate” box. Enter Date Culture Positive next to test order.

Availability

All clients - Mycobacteriology labs

Performed

Wednesdays and Fridays on regular business days

Time to Reporting

Within 6 working days after receipt of specimen

CPT Code


Specimen Collection Details

Collection

Actively growing isolated acid fast organism, on solid or broth media

Detailed instructions for collection, packaging, and submission of specimens (pdf)

Optimal Volume

AFB Growth on solid media, or 1.0ml broth culture of AFB with turbidity > 1 Mcfarland turbidity

Minimum Volume

Solid media: visible growth. 

Broth media: 0.3 ml 
Handling

Seal tube, place in biohazard transport bag, place in a secondary transport container, and incubate at 37°C or store at room temperature (20-25°C) pending transport.

Transport

Package specimens to maintain room temperatures during transport.

Rejection Criteria

Isolates not confirmed as acid fast organisms.

Specimens are subject to the requirements of the OSPHL Specimen Submission Policy (pdf).

Comments

Isolates identified as MTBC are retained for 6 months after receipt at the laboratory. Isolates identified as MAC, non-speciated NTM, or Indeterminate, are retained for 3 months after receipt at the laboratory. 

For additional information or assistance, please contact the OSPHL at 503-693-4100.

Method Details

Methodology

Multiplex real-time semi-quantitative PCR

Performance Specifications
MTBC IS6110:
  • Percent Accuracy - 100%
  • Positive Predictive Value - 100%
  • Negative Predictive Value - 100%
  • Coefficient of Variation - 0.32
  • Misclassification Rate - 0%
  • Limit of Detection - <1 CFU/50 uL
MTBC RD9:
  • Percent Accuracy - 100%
  • Positive Predictive Value - 100%
  • Negative Predictive Value - 100%
  • Coefficient of Variation - 0.31
  • Misclassification Rate - 0%
  • Limit of Detection - <1 CFU/50 uL
MAC 15S-23S:
  • Percent Accuracy - 100%
  • Positive Predictive Value - 100%
  • Negative Predictive Value - 100%
  • Coefficient of Variation - 0.2
  • Misclassification Rate - 0%
  • Limit of Detection - <2 CFU/uL

Change Log

4/24/2023
Clarified How to Order; Updated Time to Reporting; Increased Optimal Volume from 0.5 to 1.0; Edited Comments
3/15/2021

Comprehensive changes to detailed instructions attachment, review as new; Edits to How to Order, Handling, Rejection Criteria, Performance Specifications