Evaluation of Propidium Monoazide Real-Time PCR for Early Detection of Viable Mycobacterium tuberculosis in Clinical Respiratory Specimens
Annals of Laboratory Medicine
; : 203-209, 2014.
Article
in En
| WPRIM
| ID: wpr-163733
Responsible library:
WPRO
ABSTRACT
BACKGROUND: Conventional acid-fast bacilli (AFB) staining cannot differentiate viable from dead cells. Propidium monoazide (PMA) is a photoreactive DNA-binding dye that inhibits PCR amplification by DNA modification. We evaluated whether PMA real-time PCR is suitable for the early detection of viable Mycobacterium tuberculosis (MTB) in clinical respiratory specimens. METHODS: A total of 15 diluted suspensions from 5 clinical MTB isolates were quadruplicated and subjected to PMA treatment and/or heat inactivation. Eighty-three AFB-positive sputum samples were also tested to compare the DeltaC(T) values (C(T) value in PMA-treated sputum samples-C(T) value in non-PMA-treated sputum samples) between culture-positive and culture-negative specimens. Real-time PCR was performed using Anyplex MTB/NTM Real-Time Detection (Seegene, Korea), and the C(T) value changes after PMA treatment were compared between culture-positive and culture-negative groups. RESULTS: In MTB suspensions, the increase in the C(T) value after PMA treatment was significant in dead cells (P=0.0001) but not in live cells (P=0.1070). In 14 culture-negative sputum samples, the median DeltaC(T) value was 5.3 (95% confidence interval [CI], 4.1-8.2; P<0.0001), whereas that in 69 culture-positive sputum samples was 1.1 (95% CI, 0.7-2.0). In the ROC curve analysis, the cutoff DeltaC(T) value for maximum sensitivity (89.9%) and specificity (85.7%) for differentiating dead from live cells was 3.4. CONCLUSIONS: PMA real-time PCR is a useful approach for differentiating dead from live bacilli in AFB smear-positive sputum samples.
Key words
Full text:
1
Index:
WPRIM
Main subject:
Propidium
/
Sputum
/
Azides
/
Tuberculosis
/
DNA, Bacterial
/
Pilot Projects
/
ROC Curve
/
Area Under Curve
/
Real-Time Polymerase Chain Reaction
/
Lung Diseases
Type of study:
Diagnostic_studies
/
Prognostic_studies
/
Screening_studies
Limits:
Adult
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Aged
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Female
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Humans
/
Male
Language:
En
Journal:
Annals of Laboratory Medicine
Year:
2014
Type:
Article