Evaluation of peptide nucleic acid probe-based real-time PCR for detection of Mycobacterium tuberculosis complex and nontuberculous mycobacteria in respiratory specimens.
BACKGROUND
A peptide nucleic acid (PNA) probe-based real-time PCR (PNAqPCR™ TB/NTM detection kit; PANAGENE, Korea) assay has been recently developed for the simultaneous detection of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) in clinical specimens. The study was aimed at evaluation of the performance of PNA probe-based real-time PCR in respiratory specimens.


METHODS
To evaluate potential cross-reactivity, the extracted DNA specimens from Mycobacterium species and non-mycobacterial species were tested using PNA probe-based real-time PCR assay. A total of 531 respiratory specimens (482 sputum specimens and 49 bronchoalveolar washing fluid specimens) were collected from 230 patients in July and August, 2011. All specimens were analyzed for the detection of mycobacteria by direct smear examination, mycobacterial culture, and PNA probe-based real-time PCR assay.


RESULTS
In cross-reactivity tests, no false-positive or false-negative results were evident. When the culture method was used as the gold standard test for comparison, PNA probe-based real-time PCR assay for detection of MTBC had a sensitivity and specificity of 96.7% (58/60) and 99.6% (469/471), respectively. Assuming the combination of culture and clinical diagnosis as the standard, the sensitivity and specificity of the new real-time PCR assay for detection of MTBC were 90.6% (58/64) and 99.6% (465/467), respectively. The new real-time PCR for the detection of NTM had a sensitivity and specificity of 69.0% (29/42) and 100% (489/489), respectively.


CONCLUSIONS
The new real-time PCR assay may be useful for the detection of MTBC in respiratory specimens and for discrimination of NTM from MTBC.
Department of Laboratory Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea. clinpath@sch.ac.kr
Young Jin
YJ
Choi
Hwi Jun
HJ
Kim
Hee Bong
HB
Shin
Hae Seon
HS
Nam
Sang Han
SH
Lee
Joon Soo
JS
Park
Kwi Sung
KS
Park
Kyoung Ah
KA
Baek
D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D015342:DNA Probes / Q000737:chemistry / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis*; D006801:Humans; D058889:Molecular Typing / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D009170:Nontuberculous Mycobacteria / Q000235:genetics* / Q000302:isolation & purification; D009693:Nucleic Acid Hybridization; D020135:Peptide Nucleic Acids / Q000737:chemistry / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012137:Respiratory System / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology
D015342:DNA Probes; D004269:DNA, Bacterial; D020135:Peptide Nucleic Acids