Multi locus sequence typing of Burkholderia pseudomallei isolates from India unveils molecular diversity and confers regional association in Southeast Asia

PLoS Negl Trop Dis. 2018 Jun 27;12(6):e0006558. doi: 10.1371/journal.pntd.0006558. eCollection 2018 Jun.

Abstract

Objectives: Burkholderia pseudomallei, the causative agent for melioidosis, has become a public health problem in India and across the world. Melioidosis can be difficult to diagnose because of the inconsistent clinical presentations of the disease. This study aims to determine the genetic diversity among the clinical isolates of B. pseudomaelli from India in order to establish a molecular epidemiology and elucidate the Southeast Asian association.

Methods: Molecular typing using multi locus sequence typing was performed on thirty one archived B. pseudomallei clinical isolates, previously characterised from specimens obtained from patients admitted to the Christian Medical College & Hospital, Vellore from 2015 to 2016. Further investigations into the genetic heterogeneity and evolution at a regional and global level were performed using insilico tools.

Results: Multi locus sequence typing (MLST) of the isolates from systemic and localized forms of melioidosis, including blood, pus, tissue, and urine specimens, revealed twenty isolates with novel sequence types and eleven with previously reported sequence types. High genetic diversity was observed using MLST with a strong association within the Southeast Asian region.

Conclusions: Molecular typing of B. pseudomallei clinical isolates using MLST revealed high genetic diversity and provided a baseline molecular epidemiology of the disease in India with a strong Southeast Asian association of the strains. Future studies should focus on whole genome based Single-Nucleotide-Polymorphism (SNP) which has the advantage of a high discriminatory power, to further understand the novel sequence types reported in this study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Typing Techniques
  • Burkholderia pseudomallei / genetics*
  • Burkholderia pseudomallei / isolation & purification
  • Genetic Variation*
  • Genotype
  • Geography
  • Humans
  • India / epidemiology
  • Melioidosis / epidemiology
  • Melioidosis / microbiology*
  • Molecular Epidemiology
  • Multilocus Sequence Typing
  • Sequence Analysis, DNA

Grants and funding

This study was funded by the Fluid Research grant (IRB MIN 16044) Christian Medical College, Vellore, India and the Indian Council of Medical Research, India. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.