title: Phenotypic and genotypic analysis of anti-tuberculosis drug resistance in Mycobacterium tuberculosis isolates in Myanmar.
abstract: BACKGROUND
  Tuberculosis (TB) is one of the most serious health problems in Myanmar. Because TB drug resistance is associated with genetic mutation(s) relevant to responses to each drug, genotypic methods for detecting these mutations have been proposed to overcome the limitations of classic phenotypic drug susceptibility testing (DST). We explored the current estimates of drug-resistant TB and evaluated the usefulness of genotypic DST in Myanmar.
  
  
  METHODS
  We determined the drug susceptibility of Mycobacterium tuberculosis isolated from sputum smear-positive patients with newly diagnosed pulmonary TB at two main TB centers in Myanmar during 2013 by using conventional phenotypic DST and the GenoType MTBDRplus assay (Hain Lifescience, Germany). Discrepant results were confirmed by sequencing the genes relevant to each type of resistance (rpoB for rifampicin; katG and inhA for isoniazid).
  
  
  RESULTS
  Of 191 isolates, phenotypic DST showed that 27.7% (n=53) were resistant to at least one first-line drug and 20.9% (n=40) were resistant to two or more, including 18.3% (n=35) multidrug-resistant TB (MDR-TB) strains. Monoresistant strains accounted for 6.8% (n=13) of the samples. Genotypic assay of 189 isolates showed 17.5% (n=33) MDR-TB and 5.3% (n=10) isoniazid-monoresistant strains. Genotypic susceptibility results were 99.5% (n=188) concordant and agreed almost perfectly with phenotypic DST (kappa=0.99; 95% confidence interval 0.96-1.01).
  
  
  CONCLUSIONS
  The results highlight the burden of TB drug resistance and prove the usefulness of the genotypic DST in Myanmar.
authors.affiliation: Advanced Molecular Research Centre, Department of Medical Research, Yangon, Myanmar. drwahwahaung@gmail.com.
authors.forename: Wah Wah
authors.initials: WW
authors.lastname: Aung
authors.affiliation: Advanced Molecular Research Centre, Department of Medical Research, Yangon, Myanmar.
authors.forename: Phyu Win
authors.initials: PW
authors.lastname: Ei
authors.affiliation: National Tuberculosis Program, Nay Pyi Taw, Myanmar.
authors.forename: Wint Wint
authors.initials: WW
authors.lastname: Nyunt
authors.affiliation: National Tuberculosis Program, Nay Pyi Taw, Myanmar.
authors.forename: Thyn Lei
authors.initials: TL
authors.lastname: Swe
authors.affiliation: National Tuberculosis Program, Nay Pyi Taw, Myanmar.
authors.forename: Thandar
authors.initials: T
authors.lastname: Lwin
authors.affiliation: Advanced Molecular Research Centre, Department of Medical Research, Yangon, Myanmar.
authors.forename: Mi Mi
authors.initials: MM
authors.lastname: Htwe
authors.affiliation: Department of Laboratory Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: Kyung Jun
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: International Tuberculosis Research Center, Changwon, Korea.
authors.forename: Jong Seok
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Korean Institute of Tuberculosis, Osong, Korea.
authors.forename: Chang Ki
authors.initials: CK
authors.lastname: Kim
authors.affiliation: Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sang Nae
authors.initials: SN
authors.lastname: Cho
authors.affiliation: International Tuberculosis Research Center, Changwon, Korea.
authors.forename: Sun Dae
authors.initials: SD
authors.lastname: Song
authors.affiliation: Department of Laboratory Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea. cchl@pusan.ac.kr.|Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
authors.forename: Chulhun L
authors.initials: CL
authors.lastname: Chang
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D002052:Myanmar; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013183:Sputum / Q000382:microbiology; D014376:Tuberculosis / Q000175:diagnosis / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D004269:DNA, Bacterial
keywords: Drug; Genotype; Myanmar; Mycobacterium tuberculosis; Resistance