title: Comparative study of diagnostic accuracy of established PCR assays and in-house developed sdaA PCR method for detection of Mycobacterium tuberculosis in symptomatic patients with pulmonary tuberculosis.
abstract: OBJECTIVE
  Indian contribution to global burden of tuberculosis is about 26%. In the present study we have developed an in-house PCR assay using primers for sdaA gene of Mycobacterium tuberculosis and evaluated against already established primers devR, IS6110, MPB64, rpoB primers for diagnosis of pulmonary tuberculosis.
  
  
  METHODS
  Using universal sample preparation (USP) method, DNA was extracted from sputum specimens of 412 symptomatic patients from Delhi, India. The DNA so extracted was used as template for PCR amplification using primers targeting sdaA, devR, IS6110, MPB64 and rpoB genes.
  
  
  RESULTS
  Out of 412, 149 specimens were considered positive based on composite reference standard (CRS) criteria. The in-house designed sdaA PCR showed high specificity (96.5%), the high positive likelihood ratio (28), the high sensitivity (95.9%), and the very low negative likelihood ratio (0.04) in comparison to CRS.
  
  
  CONCLUSIONS
  Based on our results, the sdaA PCR assay can be considered as one of the most reliable diagnostic tests in comparison to other PCR based detection methods.
authors.affiliation: Dr B R Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110 007, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Nimesh
authors.forename: Deepali
authors.initials: D
authors.lastname: Joon
authors.forename: Anil Kumar
authors.initials: AK
authors.lastname: Pathak
authors.forename: Daman
authors.initials: D
authors.lastname: Saluja
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D016903:Drug Monitoring; D006801:Humans; D007194:India; D058889:Molecular Typing / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial
keywords: Diagnosis; Mycobacterium tuberculosis; Polymerase chain reaction; Tuberculosis