title: Transmission of multi-drug resistant tuberculosis in Mongolia is driven by Beijing strains of Mycobacterium tuberculosis resistant to all first-line drugs.
abstract: Mongolia has high and rising rates of multi-drug resistant tuberculosis (MDR-TB). Spatio-temporal and programmatic evidence suggests a major contribution from MDR-TB transmission, but genotypic evidence has not been assessed.
  
  
  
  All MDR-TB cases identified during 2012 were examined. Demographic and bacteriological data were obtained from the National Tuberculosis Reference Laboratory. Isolates of Mycobacterium tuberculosis from culture-confirmed category 1 treatment failures were genotyped using 24-loci mycobacterium interspersed repetitive unit (MIRU-24) analysis.
  
  
  
  Of the 210 MDR-TB cases identified, 115 (54.8%) were treatment failures (34.8% category 1; 20.0% category 2). Streptomycin resistance was present in 156 (74.3%) cases; including 55/73 (75.3%) category 1 treatment failures who had never been exposed to streptomycin. Among category 1 treatment failures, Beijing lineage strains predominated (88.0%; 59/67 of genotyped isolates). MIRU-24 clustering was documented in 62.7% (42/67) of strains; 55.2% (37/67) remained clustered when drug susceptibility test results were considered. In total 59.5% (25/42) of clustered strains were Beijing lineage and demonstrated in-vitro resistance to all first-line drugs tested.
  
  
  
  The MDR-TB epidemic in Mongolia appears to be driven by primary transmission of Beijing lineage strains resistant to all first-line drugs. Enhanced infection control strategies together with early MDR-TB case detection and appropriate treatment are necessary to limit escalation of the MDR-TB epidemic.
authors.affiliation: Sydney Medical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia; Centre for Infectious Diseases and Microbiology - Public Health, Westmead Hospital, Sydney, Australia. Electronic address: ugur6096@uni.sydney.edu.au.
authors.forename: Ulziijargal
authors.initials: U
authors.lastname: Gurjav
authors.affiliation: National Tuberculosis Reference Laboratory, National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
authors.forename: Baasansuren
authors.initials: B
authors.lastname: Erkhembayar
authors.affiliation: National Tuberculosis Reference Laboratory, National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
authors.forename: Buyankhishig
authors.initials: B
authors.lastname: Burneebaatar
authors.affiliation: National Tuberculosis Reference Laboratory, National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
authors.forename: Erdenegerel
authors.initials: E
authors.lastname: Narmandakh
authors.affiliation: National Tuberculosis Reference Laboratory, National Center for Communicable Diseases, Ulaanbaatar, Mongolia.
authors.forename: Oyuntuya
authors.initials: O
authors.lastname: Tumenbayar
authors.affiliation: Sydney Medical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia; Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia.
authors.forename: Grant A
authors.initials: GA
authors.lastname: Hill-Cawthorne
authors.affiliation: Sydney Medical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Marais
authors.affiliation: Sydney Medical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia; Centre for Infectious Diseases and Microbiology - Public Health, Westmead Hospital, Sydney, Australia.
authors.forename: Vitali
authors.initials: V
authors.lastname: Sintchenko
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015373:Bacterial Typing Techniques / Q000379:methods; D016000:Cluster Analysis; D016208:Databases, Factual; D024901:Drug Resistance, Multiple, Bacterial; D058872:Epidemics; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D008986:Mongolia / Q000453:epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D012189:Retrospective Studies; D017211:Treatment Failure; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents
keywords: Genotyping; Multi-drug resistance; Transmission; Treatment failure; Tuberculosis