Multi-locus sequence typing and genetic diversity of antibiotic-resistant genes and virulence-associated genes in Burkholderia pseudomallei: Insights from whole genome sequencing of animal and environmental isolates in Thailand

Vet Microbiol. 2024 Nov:298:110236. doi: 10.1016/j.vetmic.2024.110236. Epub 2024 Aug 22.

Abstract

Burkholderia pseudomallei is a Gram-negative bacillus and the etiological agent of melioidosis in humans and animals. The disease is highly endemic in northern Australia and Southeast Asia. Comprehensive genomic data are essential for understanding the bacteria's dissemination and genetic relationships among strains from different geographical regions. In this study, we conducted antimicrobial susceptibility testing and whole-genome sequencing of 54 B. pseudomallei isolates obtained from environmental and animal sources in southern Thailand between 2011 and 2018. Their genomics were determined of antibiotic-resistant genes (ARGs), virulence-associated genes, mobile genetic elements (MGEs), sequence types (STs), and single nucleotide polymorphisms (SNPs) to evaluate their epidemiological relatedness. Remarkably, all 54 isolates displayed sensitivity to antimicrobial agents typically used for melioidosis treatment. We identified nine distinct sequence types: ST392, ST51, ST409, ST508, ST376, ST1721, ST389, ST395, and ST289. Oxacillinase genes and the resistance nodulation family of efflux pumps (RND) were identified as contributors to antimicrobial resistance. Phylogenetic analysis demonstrated close genetic relations with other strains isolated from Southeast Asia. Furthermore, 172 virulence-associated genes were identified among the isolates, suggesting variations in clinical presentations. These findings underscore the importance of ongoing molecular genetic surveillance of B. pseudomallei for effective healthcare management and reducing melioidosis mortality.

Keywords: Burkholderia pseudomallei; Melioidosis; Phylogenetic tree; Sequence type; Single nucleotide polymorphism; Virulence-associated genes.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / pharmacology
  • Burkholderia pseudomallei* / drug effects
  • Burkholderia pseudomallei* / genetics
  • Burkholderia pseudomallei* / pathogenicity
  • Drug Resistance, Bacterial / genetics
  • Genetic Variation*
  • Genome, Bacterial
  • Melioidosis* / epidemiology
  • Melioidosis* / microbiology
  • Melioidosis* / veterinary
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing*
  • Phylogeny*
  • Polymorphism, Single Nucleotide
  • Thailand / epidemiology
  • Virulence / genetics
  • Virulence Factors / genetics
  • Whole Genome Sequencing*

Substances

  • Anti-Bacterial Agents
  • Virulence Factors