Yersinia pestis

species of bacteria, cause of plague

Yersinia pestis is a bacillus. It is a bacterium.[1] It has been identified as the infectious agent of bubonic plague. This bacterium also causes other forms of plague- Septicemic plague and pneumonic plague.[2] These three forms of the plague have been responsible for a high death toll in many epidemics throughout human history. These diseases are believed to be the cause of the Black Death. Because of the Black Death, about one third (one of three) people in Europe died. This was between 1347 and 1353.

Yersinia pestis
Scientific classification
Gamma Proteobacteria
Y. pestis
Binomial name
Yersinia pestis
(Lehmann & Neumann, 1896)
van Loghem 1944

The bacillus was discovered by the physician Alexandre Yersin during an epidemic of the plague in Hong Kong, in 1894.[3] Yersin worked for the Pasteur Institute at the time. Originally, the microoganism was named Pasteurella pestis. It was renamed in 1967.

Currently, three varieties of Y. pestis are known.

Historians are currently divided about the role of Y. pestis in the Black Death. Some historians said that the Black Death spread far too fast. Therefore, Y. pestis could not have caused it. DNA from Y. pestis has been found in the teeth of some of the victims of the Black Death.[4][5] For this reason, Y. pestis must have been at least a factor in some (but not necessarily all) European plague epidemics.


These references are probably not in Simple English.

  1. Collins FM (1996). Pasteurella, Yersinia, and Francisella. In: Baron's Medical Microbiology (Baron S et al., eds.) (4th ed. ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1. |edition= has extra text (help)
  2. Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. pp. pp. 484-8. ISBN 0-8385-8529-9. |pages= has extra text (help); |edition= has extra text (help)CS1 maint: multiple names: authors list (link) CS1 maint: extra text: authors list (link)
  3. Bockemühl J (1994). "[100 years after the discovery of the plague-causing agent--importance and veneration of Alexandre Yersin in Vietnam today]". Immun Infekt. 22 (2): 72–5. PMID 7959865.
  4. Drancourt M, Aboudharam G, Signolidagger M, Dutourdagger O, Raoult D. (1998). "Detection of 400-year-old Yersinia pestis DNA in human dental pulp: An approach to the diagnosis of ancient septicemia". PNAS. 95 (21): 12637–12640. PMID 9770538.CS1 maint: multiple names: authors list (link)
  5. Drancourt M; Raoult D. (2002). "Molecular insights into the history of plague". Microbes Infect. 4: 105–9. PMID 11825781.CS1 maint: multiple names: authors list (link)

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