J Clin Pathol Qual Control.  1997 Jun;19(1):237-244.

Evaluation of Commercial PCR Test Kits for the Detection of Mycobacterium tuberculosis from Clinical Specimens

• Joo SI
• Cho SI
• Choi HS
• Kim EC

Abstract

BACKGROUND: Mycobacterium tuberculosis is one of the most important infectious agents presently known. There are many methods for detection of this organism, but culture method has been a gold standard method for the detection of M. tuberculosis, although which is time-consuming. Polymerase chain reaction (PCR) methods were developed for mycobacteria with high sensitivity and specificity are now well established and good for clinical use. Recently, a nested-PCR system for detection of Mycobacterium tuberculosis DNA was imported by ILYANG Pharm. Co. We were evaluated this kit against mycobacteria culture, a commonly used commercial kit, and home-made PCR method by using new primers (TB1-TB2) selected within M. tuberculosis-specific 1.6 kb DNA fragments isolated previously by us.
METHODS
200 clinical specimens which contained 38 culture positive was evaluated and consisted of 140 respiratory specimens and 60 of others. Specimens were introduced to mycobacteria culture and smear, and then the remained pellets were stored at -70degrees C until DNA preparation. For Amplicore PCR kit (Roche Diagnostic Sys., USA), DNA were isolated by using sputum preparation reagent in the kit. For the ILYANG kit and the TB1-TB2 PCR, we used InstaGene matrix (Bio-Rad Lab., USA) in this process. PCRs were followed by kit manuals and their results were compared with culture.
RESULTS
Sensitivities and specificities of each PCR methods were estimated against culture results which were regarded as true values. Sensitivities and specificities of the Amplicor PCR kit, the ILYANG kit and the TB1-TB2 PCR were 81.6% and 94.4%, 71.5% and 96.9%, 92.1% and 94.4%, respectively. Predicitive values of positive test were 77.5%, 84.4%, and 79.5%, respectively.
CONCLUSIONS
The ILYANG PCR kit for M. tuberculosis showed similar specificity and lower sensitivity than Roche product. We recommend some modified protocols of the DNA extraction and precautions of contamination for clinical laboratory use of this kit.

MeSH Terms

DNA
Mycobacterium tuberculosis*
Mycobacterium*
Polymerase Chain Reaction*
Sensitivity and Specificity
Sputum
Tuberculosis
DNA