Detection of mycobacterim tuberculosis in clinical specimens has been dependent on direct microscopic examination of acid-fast bacilli and especially on mycobacterial cell culture. But, culture method had some limitations such as low sensitivity
and
long mycobacterial growth time. So, rapid and more sensitive detection method was demanded. In this report, the polymerase chain reactionf (pCR) was used to identify mycobacterial DNA sequences in uncultured sputum samples. Two sets of
oligonucleotide
primers, ISI and IS2, and IS3 and IS4, derived from the sequence of and insertion sequence-like element, IS6110, amplified specific DNA fragments only from the mycobacteria which belongs to the M. tuberculosis comples. After Pcr amplification and
subsequent Southern hybridization, apecific PCR products could be detected even from 0.3 fg of the purified M. tuberculosis H37Rv chromosomal DNA. 27 culture positive sputum samples proved to be all PCR positive. Of 73 culture negative sputums,
36(49%)
were PCR positive. However, PCR positive does not a always mean the existence of live M. tugerculosis in clinical samples because chromosomal DNAs from both live and dead M. tuberculosis can be amplified by PCR. InsoMuch as culture positive were
all PCR
positive, we concluded that detection of M. tuberculosis by PCR method could surpass mycobacterial culture method in its shorter detection time and higher sensitiveity.
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