Whole genome sequencing provides an unambiguous link between Salmonella Dublin outbreak strain and a historical isolate

Epidemiol Infect. 2016 Feb;144(3):576-81. doi: 10.1017/S0950268815001636. Epub 2015 Jul 13.

Abstract

Salmonella enterica subsp. enterica serovar Dublin is an uncommon cause of human salmonellosis; however, a relatively high proportion of cases are associated with invasive disease. The serotype is associated with cattle. A geographically diffuse outbreak of S. Dublin involving nine patients occurred in Ireland in 2013. The source of infection was not identified. Typing of outbreak associated isolates by pulsed-field gel electrophoresis (PFGE) was of limited value because PFGE has limited discriminatory power for S. Dublin. Whole genome sequencing (WGS) showed conclusively that the isolates were closely related to each other, to an apparently unrelated isolate from 2011 and distinct from other isolates that were not readily distinguishable by PFGE.

Keywords: Molecular epidemiology; Salmonella typing; outbreaks; public health microbiology; surveillance.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Disease Outbreaks*
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Genome
  • Humans
  • Ireland / epidemiology
  • Male
  • Middle Aged
  • Minisatellite Repeats
  • Multilocus Sequence Typing
  • Phylogeny
  • Salmonella Infections / epidemiology*
  • Salmonella Infections / microbiology*
  • Salmonella enterica / classification
  • Salmonella enterica / genetics*
  • Sequence Analysis, DNA*