title: Comparison of Two Molecular Assays For Detecting Smear Negative Pulmonary Tuberculosis.
abstract: OBJECTIVE
  To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis (PTB).
  
  
  METHODS
  Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi'an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test (DST). All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing.
  
  
  RESULTS
  A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex (MTBC) by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively.
  
  
  CONCLUSIONS
  MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.
authors.affiliation: National Tuberculosis Reference Laboratory, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: Anhui Chest Hospital, Hefei 230032, Anhui, China.
authors.forename: Xun Di
authors.initials: XD
authors.lastname: Bao
authors.affiliation: Xi'an Chest Hospital, Xi'an 710061, Shaanxi, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Tuberculosis Reference Laboratory, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Xi Chao
authors.initials: XC
authors.lastname: Ou
authors.affiliation: National Tuberculosis Reference Laboratory, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Pang
authors.affiliation: National Tuberculosis Reference Laboratory, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Yan Lin
authors.initials: YL
authors.lastname: Zhao
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology; D001431:Bacteriological Techniques / Q000379:methods*; D024881:Drug Resistance, Bacterial; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid
keywords: Diagnosis; Drug resistance; Smear negative pulmonary tuberculosis