The recent DNA amplification assay using the polymerase chain reaction(PCR) technique opened the way for a rapid detection of Mycobaterium tuberculosis. To evaluated the value of this technique in routine laboratory work, the results obtained by
PCR at
Seoul Medical Science Institute Institute were compared with those obtained by standard microbiological culture method for 278 clinical specimens (sputum, urine, spinal fluid, gastric, pleural fluid, prostatic fluid, stool).
Specimens were tested for mycobacterium tuberculosis complex and atypical maycobacterium in two assays, one based on the target DNA for 320 base pair(bp) segment derived from the sequence of a gene that codes for the 19-kilodalton(kD) antigen of
Mycobacterium tuberculosis and is specific for the, M. tuberculosis complex, and the other on 236 bp segment derived from the E. coli and J gene sharing considerable sequence homology to the M. tuberculosis and is specific for the Mycobateria
species.
Of 140 sputum samples tested, 37 of these PCR positive. Of 37, 4 were culture negative. Thirty-five were culture positive, 2 of these were PCR negative. Of 57 urine samples tested, 10 were PCR positive.
Three of these were culture negative. Of 55 pleural fluids tested, 2 were PCR positive. Three of these were culture negative. Of 55 pleural fluids tested, 2 were PCR positive. One of these was culture negative. Of 17 cerebrospinal fluids fluids
tested,
2 were only PCR positive. One of 2 gastric washing and one stool tested was only PCR positive. No case of prostatic fluids was positive by both methods. Accordingly, Of 278 clinical samples tested, 222(79.8%) were negative by both culture and PCR
analysis, 43 were(15.3%) positive by both analysis, and 11(4.0%) were culture negative, but PCR positive.
Two(0.7%)PCR results were burned out to be false negative. There was no other case proved to be false positive. Five were turned out to be false negative. There was no other case proved to be false positive. Five were turned out to be
mycobacteria
other
than M. tuberculosis(MOTT) by PCR and biochemical identification.
In this study the PCR provided sensitive and specific means than standard microbiological methods for detection of mycobacteria.
It is our opinion that PCR method with proper primers is superior to the culture and is a rapid and reliable tool for the diagnosias fo Tuberculosis with clinical specimens.
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