Comparison Between Real-Time Polymerase Chain Reaction and DNA-Microarray in Detection and Identification of Mycobacterium Species
Low-cost and low-density (LCD) DNA arrays offer an
easy way to detect resistance as minimal laboratory instrumentation is
needed. Nucleic acid-based amplification tests allow the rapid detection
of Mycobacterium tuberculosis. Recently, a real-time PCR assay for M.
tuberculosis complex was introduced. Real-Time PCR and DNAmicroarray
techniques were compared with the classical methods of
Ziehl-Neelsen (ZN) staining and culturing. Regarding to the standard
culture method, 80 positive individuals were identified out of 140 urine
samples. RT- PCR showed 96.3% sensitivity and 96.7% specificity with
Mycobacterial tuberculosis complex (MTB) (n=10) and nontuberculous
mycobacteria (NTM) (n=70). The DNA-microarray analysis exhibited
100% sensitivity and specificity. One species belonging to (MTB) was
identified as M. tuberculosis and positively represented by 12.5%
(n=10). Five species belonging to nontuberculous mycobacteria (NTM)
were identified and represented as M. kansasii 37.5% (n=30), M.
celatum 21.25% (n=17), M. gordonae 11.25% (n=9), M. chelonae 10%
(n=8), and M. phlei 7.5% (n=6). The results recommend the use of our
simple and rapid PCR technique for early diagnosis of mycobacteria’s.
Also, the fast LCD-microarray protocol is very useful for species
identification and differentiation between MTB and NTM.