The utility of polymerase chain reaction (PCR) in the diagnosis of pulmonary tuberculosis.

Department of Microbiology, University Hospital and Medical School, Valencia, Spain.
Chest (Impact Factor: 5.85). 07/1995; 107(6):1631-5.
Source: PubMed

ABSTRACT A fragment of DNA of 123 bp belonging to insertion sequence IS6110, specific of Mycobacterium tuberculosis complex, was amplified by polymerase chain reaction (PCR) of respiratory samples, for the diagnosis of pulmonary tuberculosis. A total of 314 samples (286 sputum and 28 bronchoalveolar lavages) from 242 patients were evaluated by PCR, and the results were compared with the those obtained by acid-fast-stained smears, culture, and clinical diagnosis. Mycobacterium tuberculosis was detected by PCR in 102 of 105 patients with clinical diagnosis of pulmonary tuberculosis. All smear and culture-positive samples were PCR positive. The sensitivity of PCR, culture, and staining was 97%, 88%, and 65%, respectively, and the specificity was 100% in all cases. In ten patients with old residual lesions, but no active disease, M tuberculosis genome was detected by PCR. In our experience, PCR proved to be a useful method for the rapid diagnosis of pulmonary tuberculosis.

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    ABSTRACT: The objective of the current study was to compare the efficacy of phenol ammonium sulphate (PhAS) and sodium hypochlorite (NaOCl) pretreatment methods for the direct microscopy with the Löwenstein-Jensen (LJ) culture to detect acid fast bacilli (AFB) from pulmonary tuberculosis suspected cases using sputum specimens. To evaluate PhAS and NaOCl methods, sputum specimens (n = 1145) were studied and the performance of each method was compared with LJ media. The, PhAS centrifuged smear and NaOCl centrifuged smear method demonstrated higher sensitivity (71.47% and 77%), specificity (99.61% and 98%), positive predictive value (98.8% and 94.88%) and negative predictive value (88.35% and 90.25%), respectively, when compared to LJ culture. However, the direct AFB smears and PhAS centrifugation method was ineffective to detect few Mycobacterium tuberculosis cases from sputum specimens, particularly in blood tinged specimens with scanty bacilli. Interestingly, NaOCl method could efficiently detect the Mycobacterium tuberculosis cases from blood tinged sputum specimens with scanty bacilli. The current study concluded that NaOCl method could be the most efficient and sensitive method than direct AFB smear and PhAS centrifuged smear method for the direct detection of AFB in suspected cases of pulmonary tuberculosis. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).
    Journal of Basic Microbiology 06/2012; · 1.20 Impact Factor
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    ABSTRACT: Background: Early diagnosis of tuberculosis is important in its control. The conventional techniques like smear microscopy and culture suffer from low sensitivity for diagnosis of extra-pulmonary tuberculosis like Pleural Tuberculosis (PTB) due to paucibacillary nature of the fluid. Polymerase Chain Reaction (PCR) is presently seen as a promising alternative to conventional techniques. In this study we have evaluated IS6110 sequence based nested PCR (nPCR) for the detection of Mycobacterium tuberculosis (MTB) DNA directly from clinical samples. The results of PCR were compared with the results of conventional methods like smear, culture and Adenosine Deaminase (ADA) activity. Material and Methods: A total of 50 pleural fluid samples from the patients with history suggestive of tuberculosis were taken. All the samples were processed for Ziehl-Neelsan (ZN) staining for Acid Fast Bacilli (AFB), culture ADA activity and PCR with primers targeting 123bp fragment of IS6110 of MTB complex. Results: A significant difference was seen in the sensitivities of conventional methods and PCR (p<0.05). Out of these 50 samples 3 were positive by smear, culture was positive in 5 samples, 21 samples showed high ADA activity and 29 were positive by PCR with overall 100% sensitivity of PCR using culture on LJ media as gold standard. Conclusions: The combined analysis of nPCR, ADA activity and other lab investigations can be very useful in the rapid diagnosis in cases of PTB.
    Journal of clinical and diagnostic research : JCDR. 11/2013; 7(11):2456-8.
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    ABSTRACT: The polymerase chain reaction (PCR) has recently been investigated for detecting Mycobacterium tuberculosis in clinical specimens and appears to have significant potential as a rapid, sensitive, and specific assay for diagnosing infections caused by this organism. One of the remaining issues regarding the use of this technique is the extraction of DNA from clinical material prior to performing the PCR. It requires the use of DNA extraction method that can efficiently lyse mycobacterial cells and recover small amounts of DNA. The method of heating the sample in a boiling water bath to break down the bacterial cell wall and to release the DNA was compared with that of enzymatic lysis of bacteria and then phenol-chloroform extraction of DNA (Modified chemical method). Modified chemical method was better than just boiling the sample to remove DNA for amplification with PCR. In this study 140 sputum samples were collected from suspected prisoners at Dhaka Central Jail. All of those samples were prepared by two DNA extraction methods and examined by PCR, and the results were compared with the results of acid-fast stained smears and cultures.
    edited by Imatvievici, 06/2012; LAP Lambert Academic Publisher., ISBN: 978-3-659-16144-5


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