title: Phylogenetic associations with drug-resistant Mycobacterium tuberculosis isolates in a paediatric population.
abstract: METHODS
  Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
  
  
  OBJECTIVE
  As paediatric tuberculosis (TB) is a surrogate marker for actively transmitted disease in a community, we investigated drug resistance patterns of 97 Mycobacterium tuberculosis complex strains isolated from children and explored their phylogenetic associations.
  
  
  METHODS
  A total of 111 paediatric patients who attended the out-patient department during the study period 2009-2011 and whose sputum samples were sent to the Microbiology Department for liquid culture and drug susceptibility testing (DST) were included in this study. DST and spoligotyping were performed on cultures positive for M. tuberculosis complex.
  
  
  RESULTS
  DST against four first-line drugs showed that 31 of 97 (32%) strains were pan-susceptible, while 66/97 (68%) were resistant to at least one drug, including 55/97 (56.7%) that were resistant to at least isoniazid and rifampicin (i.e., multidrug-resistant). The majority of the isolates (n = 81/90, 90%) belonged to the principal genetic group 1 strains, the most predominant spoligotyping clusters being spoligotyping international type (SIT)1/Beijing (n = 28), SIT26/CAS1-Delhi (n = 27) and SIT53/T1 (n = 6).
  
  
  CONCLUSIONS
  The involvement of Beijing and CAS1-Delhi clades in paediatric TB patients suggests that these two lineages play a major role in ongoing active transmission.
authors.affiliation: Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: J
authors.initials: J
authors.lastname: Arora
authors.affiliation: Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: Z
authors.initials: Z
authors.lastname: Sidiq
authors.affiliation: Department of Paediatrics, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: R
authors.initials: R
authors.lastname: Singhal
authors.affiliation: Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: M
authors.initials: M
authors.lastname: Bhalla
authors.affiliation: World Health Organization Supranational Tuberculosis Reference Laboratory, Tuberculosis & Mycobacteria Unit, Institut Pasteur de la Guadeloupe, Abymes, France.
authors.forename: D
authors.initials: D
authors.lastname: Couvin
authors.affiliation: Department of TB and Chest, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: R
authors.initials: R
authors.lastname: Sarin
authors.affiliation: World Health Organization Supranational Tuberculosis Reference Laboratory, Tuberculosis & Mycobacteria Unit, Institut Pasteur de la Guadeloupe, Abymes, France.
authors.forename: N
authors.initials: N
authors.lastname: Rastogi
authors.affiliation: Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India.
authors.forename: V P
authors.initials: VP
authors.lastname: Myneedu
mesh_terms: D000293:Adolescent; D000995:Antitubercular Agents / Q000627:therapeutic use; D001209:Asia, Central / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007223:Infant; D007538:Isoniazid / Q000627:therapeutic use; D008297:Male; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics; D010045:Outpatients; D010802:Phylogeny; D015995:Prevalence; D012189:Retrospective Studies; D012293:Rifampin / Q000627:therapeutic use; D018571:Sentinel Surveillance; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid; D012293:Rifampin