title: Identification of putative biomarkers for the serodiagnosis of drug-resistant Mycobacterium tuberculosis.
abstract: BACKGROUND
  Early diagnosis and treatment of Mycobacterium tuberculosis infection can prevent most deaths resulting from this pathogen; however, multidrug-resistant strains present serious threats to global tuberculosis control and prevention efforts. In this study, we identified antigens that could be used for the serodiagnosis of drug-resistant M. tuberculosis strains, using a proteomics-based analysis.
  
  
  RESULTS
  Serum from patients infected with drug-resistant or drug-susceptible M. tuberculosis strains and healthy controls was subjected to two-dimensional gel electrophoresis using a western blot approach. This procedure identified nine immunoreactive proteins, which were subjected to MALDI-TOF-MS analysis. Six recombinant proteins, namely rRv2031c, rRv0444c, rRv2145c, rRv3692, rRv0859c, and rRv3040, were expressed and used to determine the immuno-reactivity of 100 serum samples. Antibody reactivity against rRv2031c, rRv3692, and rRv0444c was consistently observed. Among them, the best sensitivity and specificity of rRv3692 were 37% and 95% respectively. Furthermore, when rRv2031c and rRv3692 or rRv2031c, rRv3692, and rRv0444c were combined in 2:1 or equal amounts, the assay sensitivity and specificity were improved to 56.7% and 100% respectively.
  
  
  CONCLUSIONS
  These results suggest that Rv2031c, Rv3692, and Rv0444c are possible candidate biomarkers for effective use in the serodiagnosis of drug-resistant tuberculosis infections, and a combined formula of these antigens should be considered when designing a subunit assay kit.
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, 220 Handan Road, 200433 Shanghai, Peoples Republic of China. zhanglu407@fudan.edu.cn.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Wang
authors.forename: Wenjie
authors.initials: W
authors.lastname: Wang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Yue
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Wenxi
authors.initials: W
authors.lastname: Xu
authors.forename: Zhenling
authors.initials: Z
authors.lastname: Cui
authors.forename: Xuelian
authors.initials: X
authors.lastname: Zhang
authors.forename: Honghai
authors.initials: H
authors.lastname: Wang