Yersinia pestis

Yersinia pestis is a gram-negative, non-motile, coccobacillus bacterium without spores. It is related to pathogens Yersinia enterocolitica, and Yersinia pseudotuberculosis, from which it evolved. Yersinia pestis is responsible for the disease plague, which caused the Plague of Justinian and the Black Death, one of the deadliest pandemics in recorded history. Plague takes three main forms: pneumonic, septicemic, and bubonic. Y. pestis is a facultative anaerobic parasitic bacterium that can infect