title: Molecular typing of Mycobacterium leprae strains from northern India using short tandem repeats.
abstract: OBJECTIVE
  Due to the inability to cultivate Mycobacterium leprae in vitro and most cases being paucibacillary, it has been difficult to apply classical genotyping methods to this organism. The objective of this study was therefore, to analyze the diversity among M. leprae strains from Uttar Pradesh, north India, by targeting ten short tandem repeats (STRs) as molecular markers.
  
  
  METHODS
  Ninety specimens including 20 biopsies and 70 slit scrappings were collected in TE buffer from leprosy patients, who attended the OPD of National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra, and from villages of Model Rural Health Research Unit (MRHRU) at Ghatampur, Kanpur, Uttar Pradesh. DNA was extracted from these specimens and ten STRs loci were amplified by using published and in-house designed primers. The copy numbers were determined by electrophoretic mobility as well as sequence analysis. Phylogenetic analysis was done on variable number of tandem repeats (VNTRs) data sets using start software.
  
  
  RESULTS
  Diversity was observed in the cross-sectional survey of isolates obtained from 90 patients. Allelic index for different loci was found to vary from 0.7 to 0.8 except for rpoT for which allelic index was 0.186. Similarity in fingerprinting profiles observed in specimens from the cases from same house or nearby locations indicated a possible common source of infection. Such analysis was also found to be useful in discriminating the relapse from possible reinfection.
  
  
  CONCLUSIONS
  This study led to identification of STRs eliciting polymorphism in north Indian strains of M. leprae. The data suggest that these STRs can be used to study the sources and transmission chain in leprosy, which could be very important in monitoring of the disease dynamics in high endemic foci.
authors: National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India.
authors: Mallika
authors: M
authors: Lavania
authors: Kiran
authors: K
authors: Katoch
authors: Rahul
authors: R
authors: Sharma
authors: Pragya
authors: P
authors: Sharma
authors: Ram
authors: R
authors: Das
authors: Anuj Kumar
authors: AK
authors: Gupta
authors: D S
authors: DS
authors: Chauhan
authors: V M
authors: VM
authors: Katoch
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007194:India; D007918:Leprosy / Q000382:microbiology; D008297:Male; D018895:Microsatellite Repeats; D017720:Molecular Epidemiology; D058889:Molecular Typing / Q000379:methods*; D009166:Mycobacterium leprae / Q000145:classification* / Q000235:genetics*; D010802:Phylogeny; D011110:Polymorphism, Genetic
chemical_list: D004269:DNA, Bacterial