COVID-19 Update - This is to inform you that the Government of India has announced a complete lockdown in India 22nd March 2020 to 14th April 2020. As a result, our offices will now be closed till 14th April 2020 and all our employees will be working from home. Office telephones will not be answered, and therefore you are requested to direct all your queries related to manuscript submission, review process, publication etc. at below mentioned details. editor@innovativepublication.com, rakesh.its@gmail.com, Mob. 8826373757, 8826859373, 9910947804

Article view: 653

Article download: 175

IP International Journal of Medical Microbiology and Tropical Diseases


Polymerase chain reaction versus culture in the diagnosis of extrapulmonary tuberculosis-A comparative study


Full Text PDF Share on Facebook Share on Twitter


Author Details : Deepali Vagdalker, Roopa. C

Volume : 3, Issue : 4, Year : 2017

Article Page : 146-150


Suggest article by email

Abstract

 Introduction: Extrapulmonary tuberculosis (EPTB) accounts for approximately 40% of tuberculosis cases and is a significant health problem in both developing and developed countries. Extrapulmonary TB represents a greater diagnostic problem than pulmonary TB because it presents with less frequency and occurs with little liberation of bacilli, as well as the fact that it is localized in sites that are difficult to access.
Materials & Methods: Samples from 60 clinically diagnosed cases of extrapulmonary TB were included in the study. All tissue samples were homogenized in a homogenizer. Thick viscous samples were subjected to NALC-NaOH method and all fluid samples were centrifuged. For DNA extraction, 200µl of the homogenized tissue or 200µl of centrifuged deposit from fluid samples were taken. PCR testing was done using IVD approved commercial kits. Deposit was also inoculated on LJ medium and Middlebrook-7H9 medium (MB7H9) aseptically.
Results: A total of 60 samples from clinically diagnosed patients of extrapulmonary tuberculosis (EPTB) were studied. Maximum EPTB positivity was seen among pleural fluid samples followed by pus, CSF, tissue samples, ascitic fluid, synovial tissue, synovial fluid and pericardial fluid. The comparison of PCR versus culture was done and the sensitivity, specificity, PPV and NPV of PCR were 68%, 62.9%, 56.66% and 73.33% respectively considering culture as the gold standard. The comparison of duration taken for positivity by LJ and MB7H9 media showed that the mean duration of isolation on LJ and MB7H9 was 4.8 and 3.5 weeks respectively. Liquid culture showed growth earlier than the growth on solid medium. The period of maximum isolation on both media was 3rd week followed by 4th week.
Conclusion: As PCR is a rapid method, and when used along with the conventional diagnostic methods increases the overall isolation rate of M. tuberculosis in the diagnosis of extrapulmonary tuberculosis.

Keyword: Extrapulmonary tuberculosis; EPTB; PCR; LJ medium; MB7H9 medium.

How to cite : Vagdalker D, Roopa. C, Polymerase chain reaction versus culture in the diagnosis of extrapulmonary tuberculosis-A comparative study. IP Int J Med Microbiol Trop Dis 2017;3(4):146-150

Copyright © 2017 by author(s) and IP Int J Med Microbiol Trop Dis. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0) (creativecommons.org)