Predominance of ancestral lineages of Mycobacterium tuberculosis in India

Emerg Infect Dis. 2006 Sep;12(9):1367-74. doi: 10.3201/eid1209.050017.

Abstract

Although India has the highest prevalence of tuberculosis (TB) worldwide, the genetic diversity of Mycobacterium tuberculosis in India is largely unknown. A collection of 91 isolates originating from 12 different regions spread across the country were analyzed by genotyping using 21 loci with variable-number tandem repeats (VNTRs), by spoligotyping, by principal genetic grouping (PGG), and by deletion analysis of M. tuberculosis-specific deletion region 1. The isolates showed highly diverse VNTR genotypes. Nevertheless, highly congruent groupings identified by using the 4 independent sets of markers permitted a clear definition of 3 prevalent PGG1 lineages, which corresponded to the "ancestral" East African-Indian, the Delhi, and the Beijing/W genogroups. A few isolates from PGG2 lineages and a single representative of the presumably most recent PGG3 were identified. These observations suggest a predominance of ancestral M. tuberculosis genotypes in the Indian subcontinent, which supports the hypothesis that India is an ancient endemic focus of TB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • DNA, Bacterial / analysis
  • DNA, Bacterial / isolation & purification
  • Evolution, Molecular*
  • Female
  • Genetic Variation*
  • Genotype
  • Humans
  • India / epidemiology
  • Male
  • Middle Aged
  • Minisatellite Repeats
  • Mycobacterium tuberculosis / classification*
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / isolation & purification
  • Oligonucleotides / analysis
  • Polymorphism, Single Nucleotide
  • Tuberculosis / epidemiology*
  • Tuberculosis / microbiology*

Substances

  • DNA, Bacterial
  • Oligonucleotides