Salmonella typhi, the causative agent of typhoid fever, is approximately 50,000 years old

Claire Kidgell, Ulrike Reichard, John Wain, Bodo Linz, Mia Torpdahl, Gordon Dougan, Mark Achtman

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A global collection of 26 isolates of Salmonella typhi was investigated by sequencing a total of 3336 bp in seven housekeeping genes. Only three polymorphic sites were found and the isolates fell into four sequence types. These results show that S. typhi is a recent clone whose last common ancestor existed so recently that multiple mutations have not yet accumulated. Based on molecular clock rates for the accumulation of synonymous polymorphisms, we estimate that the last common ancestor of S. typhi existed 15,000-150,000 years ago, during the human hunter-gatherer phase and prior to the development of agriculture and the domestication of animals.

Original languageEnglish
Pages (from-to)39-45
Number of pages7
JournalInfection, Genetics and Evolution
Issue number1
Publication statusPublished - 1 Oct 2002
Externally publishedYes


  • Age
  • Clone
  • Epidemic disease
  • Housekeeping gene
  • Microbial evolution
  • Multilocus sequence typing
  • Salmonella
  • Sequence diversity

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