title: Mycobacterial Interspersed Repetitive Unit Can Predict Drug Resistance of Mycobacterium tuberculosis in China.
abstract: BACKGROUND
  Recently, Mycobacterial Interspersed Repetitive Unit (MIRU) was supposed to be associated with drug resistance in Mycobacterium tuberculosis (M. tuberculosis), but whether the association exists actually in local strains in China was still unknown. This research was conducted to explore that association and the predictability of MIRU to drug resistance of Tuberculosis (TB).
  
  
  METHODS
  The clinical isolates were collected and the susceptibility test were conducted with Lowenstein-Jensen (LJ) medium for five anti-TB drug. Based on PCR of MIRU-VNTR (Variable Number of Tandem Repeat) genotyping, we tested the number of the repeat unite of MIRU. Then, we used logistic regression to evaluate the association between 15 MIRU and drug resistance. In addition, we explored the most suitable MIRU locus of identified MIRU loci for drug resistance by multivariate logistic regression.
  
  
  RESULTS
  Of the 102 strains, one isolate was resistant to rifampicin and one isolate was resistant to streptomycin. Among these fifteen MIRU, there was a association between MIRU loci polymorphism and anti-tuberculosis drug resistance, ETRB (P = 0.03, OR = 0.19, 95% CI 0.05-0.81) and ETRC (P = 0.01, OR = 0.14, 95% CI 0.03-0.64) were negatively related to isoniazid resistance; MIRU20 (P = 0.05, OR = 2.87, 95% CI 1.01-8.12) was positively associated with ethambutol resistance; and QUB11a (P = 0.02, OR = 0.79, 95% CI 0.65-0.96) was a negative association factor of p-aminosalicylic acid resistance.
  
  
  CONCLUSIONS
  Our research showed that MIRU loci may predict drug resistance of tuberculosis in China. However, the mechanism still needs further exploration.
authors.affiliation: School of Public Health, Wannan Medical CollegeWuhu, China; Clinical Laboratory, Institute of Dermatology, Chinese Academy of Medical Sciences - Peking Union Medical CollegeNanjing, China.
authors.forename: Xian-Feng
authors.initials: XF
authors.lastname: Cheng
authors.affiliation: School of Public Health, Wannan Medical College Wuhu, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Clinical Laboratory, Zhongda Hospital, School of Medicine, Southeast University Nanjing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: School of Public Health, Wannan Medical College Wuhu, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xia
authors.affiliation: Pediatric Research Institute, Nanjing Children's Hospital, Nanjing Medical University Nanjing, China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Chu
authors.affiliation: School of Public Health, Wannan Medical College Wuhu, China.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Wen
authors.affiliation: Clinical Laboratory, Ma'anshan Center for Disease Control and Prevention Ma'anshan, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Clinical Laboratory, Institute of Dermatology, Chinese Academy of Medical Sciences - Peking Union Medical CollegeNanjing, China; Clinical Laboratory, Ma'anshan Center for Disease Control and PreventionMa'anshan, China.
authors.forename: Yue-Gen
authors.initials: YG
authors.lastname: Jiang
keywords: Mycobacterial Interspersed Repetitive Unit; Mycobacterium tuberculosis; drug resistance; genotyping; repeat units