title: Predictive Power of ETRE Polymorphism and Katg463 Mutation to INH-Resistance of M.tuberculosis.
abstract: BACKGROUND
  The MIRU-VNTR polymorphism and katG463 mutation are used to genotype the mycobacterium tuberculosis, but the correlation between them and INH-resistance were unknown. This study was aimed to explore whether ETRE polymorphism and katG463 mutation could predict the INH-resistance, and the relationship between ETRE polymorphism and katG463 mutation.
  
  
  METHODS
  The ETRE, katG463 mutation and drug resistance information of 109 M. tuberculosis strains were collected from online public database. We constructed the predictive diagnostic tool of ETRE polymorphism and katG463 mutation. Chi-square test was used to analyze the relationship between ETRE polymorphism, katG463 mutation and INH-resistance. ROC curve analysis and Z-test were used to evaluate the predictive ability of ETRE and katG463. The relationship between ETRE polymorphism and katG463 mutation was analyzed with Spearman correlation analysis.
  
  
  RESULTS
  The mutation rate of katG463 was 27.50%, and the h value of ETRE polymorphism was 0.67. KatG463 mutation was associated with INH resistance (OR=3.72). The INH drug resistance rate in VNTR≧5 group was 3.43 times higher than that in VNTR≦3 group (χ(2) =24.77, P<0.01), and there was no significant difference of INH resistance between the VNTR=4 group and VNTR≦3 group. The areas under the ROC curve of two loci prediction diagnostic tools were 0.64 and 0.70 respectively. The katG463 mutation was significantly related to the ETRE polymorphism (r=0.79, P<0.01).
  
  
  CONCLUSIONS
  Both katG463 mutation and the ETRE polymorphism can predict the INH-resistance of tuberculosis. The katG463 mutation was associated with ETRE VNTR polymorphism.
authors.affiliation: School of Public Health, Wan Nan Medical College, Wuhu, China.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Wen
authors.affiliation: School of Public Health, Wan Nan Medical College, Wuhu, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Jiang
authors.affiliation: School of Public Health, Wan Nan Medical College, Wuhu, China.
authors.forename: Xian-Feng
authors.initials: XF
authors.lastname: Cheng
authors.affiliation: Centre for Disease Prevention and Control of Anqing City, Anqing, China.
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Zhang
authors.affiliation: School of Public Health, Wan Nan Medical College, Wuhu, China.
authors.forename: Bai-Feng
authors.initials: BF
authors.lastname: Chen
authors.affiliation: School of Public Health, Wan Nan Medical College, Wuhu, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
keywords: Drug resistance; ETRE; M.tuberculosis; VNTR; katG463