Yersinia pestis, the cause of plague, is a recently emerged clone of Yersinia pseudotuberculosis

✍ Scribed by Achtman, M.

• Book ID: 115546665
• Publisher: National Academy of Sciences
• Year: 1999
• Tongue: English
• Weight: 259 KB
• Volume: 96
• Category: Article
• ISSN: 0027-8424
• DOI: 10.1073/pnas.96.24.14043

✦ Synopsis

Plague, one of the most devastating diseases of human history, is caused by
Yersinia pestis
. In this study, we analyzed the population genetic structure of
Y. pestis
and the two other pathogenic
Yersinia
species,
Y. pseudotuberculosis
and
Y. enterocolitica
. Fragments of five housekeeping genes and a gene involved in the synthesis of lipopolysaccharide were sequenced from 36 strains representing the global diversity of
Y. pestis
and from 12–13 strains from each of the other species. No sequence diversity was found in any
Y. pestis
gene, and these alleles were identical or nearly identical to alleles from
Y. pseudotuberculosis
. Thus,
Y. pestis
is a clone that evolved from
Y. pseudotuberculosis
1,500–20,000 years ago, shortly before the first known pandemics of human plague. Three biovars (Antiqua, Medievalis, and Orientalis) have been distinguished by microbiologists within the
Y. pestis
clone. These biovars form distinct branches of a phylogenetic tree based on restriction fragment length polymorphisms of the locations of the IS
100
insertion element. These data are consistent with previous inferences that Antiqua caused a plague pandemic in the sixth century, Medievalis caused the Black Death and subsequent epidemics during the second pandemic wave, and Orientalis caused the current plague pandemic.