Inoculation of Growth Control Tube/Drug Containing Tubes

It is extremely important to perform quality control of drug susceptibility testing periodically. The minimum requirement is to test each new batch of reagents, such as SIRE drugs or MGIT medium. If the batch QC fails, all the results obtained within that batch, as well as the new batch of a reagent, should be thoroughly reviewed, and the testing should be repeated. Use M. tuberculosis H37Rv (ATCC [American Type Culture Collection] number 27294) as a QC strain susceptible to all anti-tuberculosis drugs. 

It is not necessary to include a resistant strain, as most of the resistant strains against a drug which are available from ATCC and other culture collections are highly resistant and do not give any added benefit in quality control. The test procedure for QC organisms is the same as described above for clinical isolates. The inoculum should be from a freshly grown culture in the MGIT medium or on an LJ slant. In case the suspension of QC bacteria is made from growth on a solid medium, follow the procedure for suspension preparation as described above. The suspension may be stored in aliquots frozen for up to 6 months at    -70 ºC ±10 ºC.

Resource

Mycobacteriology Laboratory Manual 

Assessment