A Microbial Biorealm page on the genus Yersinia pestis
Higher order taxa
Class: Gamma Proteobacteria
Description and significance
Yersinia pestis was discovered in Hong Kong in 1894 by a Swiss physician Alexandre Yersin, who was a student of the Pasteur school of thought. He linked Y. pestis to the bubonic plauge, an epidemic that ravaged Europe during the 1300s. The organism was isolated during a outbreak in Hong Kong, a new geographical region for the organism that has been seen in Europe and Africa.
Yersinia pestis is a rod shaped gram-negative bacteria that can also have a spherical shape. It is also covered by a slime envelope that is heat labile. When the bacteria is in a host, it is nonmotile (incapable of self-propelled movement), but when isolated it is motile.
It is very important to have the genome sequenced for Y. pestis because this organism is capable of causing very fatal diseases. Since scientists were able to sequence the genome, they now have information of how diseases caused by this pathogenic bacteria are developed and also the evolutionary history of the bacteria. Having the genome sequenced also means that they are able to determine other species that are related to yersinia pestis which can prevent future outbreaks.
Yersinia pestis has three sub species in which only two have been sequenced, strain KIM and strain CO92. Each strain consists of one chromosome. Strain KIM consists of 4,600,755 base pairs and has a circular chromosome. Strain CO92 has 4,653,728 base pairs and contains three plasmids (pMT1, pCD1 and pPCP1) of 96.2 kilobases (kb), 70.3 kb and 9.6 kb. Strain KIM also carries these plasmids. These plasmids along with a pathogenicity island called HPI, create a protein that causes the pathogenicity of the organism. These factors are important for adhesion and injection of proteins into the host cell, invasion of the bacteria and binding of iron from red blood cells. The genome has many insertion sequences and many G-C base pair differences, which means frequent recombination. Many of the genes have been acquired from other bacteria and viruses. Strain CO92 also consists of 4,012 protein-coding genes and 150 pseudogenes.
A recent study compared both these strains to show that one of these strains may have evolved from the other throughout the years.
Cell structure and metabolism
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Enter summaries of the most recent research here--at least three required
[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.
Edited by student of Rachel Larsen