High prevalence of Beijing and EAI4-VNM genotypes among M. tuberculosis isolates in northern Vietnam: sampling effect, rural and urban disparities

PLoS One. 2012;7(9):e45553. doi: 10.1371/journal.pone.0045553. Epub 2012 Sep 24.

Abstract

A total of 221 isolates of M. tuberculosis were sampled from hospitals and the general population in the northern plain of Vietnam, one of the most populated region of the country. Genotypic composition and diversity were characterized, and we investigated how they are affected by sampling (hospital vs. general population), correcting for potential confounding effects (location, age and gender of the patients). Spoligotyping and 12 MIRU-VNTR typing were used as first line. Then 15 MIRU-VNTR standard set was used, making 21 MIRU-VNTR typing for the clustered isolates. Result showed that 8 lineages and 13 sub-lineages were circulating in the region. The most predominant lineages were Beijing (38.5%) and EAI (38.5%). Others appeared with small proportions H (1.4%), LAM (1.8%), T (8.1%), X (0.9%), MANU (2.3%), and Zero (0.4%). Higher clustering rate was found in the hospital samples (17.9% in urban and 19.2% in rural areas) compared to the population ones (0%). The typical Vietnamese EAI4-VNM sub-lineage of EAI lineage accounted for 67% of EAI strains and was associated with older ages. Beijing genotypes were associated with younger, urban population and were characterized by high clustering rates. These characteristics strongly suggest that Beijing strains are invading the population, replacing the local EAI-VNM4, thus predicting a more serious tuberculosis situation in the future in the absence of more effective control strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA, Bacterial
  • Female
  • Genetic Variation
  • Genotype*
  • Humans
  • Male
  • Mycobacterium tuberculosis / genetics*
  • Mycobacterium tuberculosis / isolation & purification
  • Phylogeny
  • Prevalence
  • Rural Population
  • Tuberculosis / epidemiology*
  • Urban Population
  • Vietnam / epidemiology

Substances

  • DNA, Bacterial

Grants and funding

This study was supported by Ministry of Science and Technology of Vietnamese through the project “Molecular Epidemiology of Tuberculosis in Vietnam” and by Le Centre national de la recherche scientifique through the project called “Biodiversity and Infectious Diseases in Vietnam” (GDRI). Data used in this work were partly produced through the technical facilities of the “Centre Méditerranéen Environnement Biodiversité”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.