Y. pestis (Yersinia pestis), the Gram-negative Coccobacillus belonging to the Enterobacteriaceae is the causative agent of Plague and is arguably the deadliest pathogen in history. It is one of several agents likely to be used as a biological weapon in a bioterrorism event. Yersinia sp. is responsible for disease syndromes ranging from Gastroenteritis to Plague. Y. pestis is actually categorized into three subtypes or biovars; Antiqua, Medievalis, and Orientalis, each associated with a major pandemic. Y. pestis strand CO92 is in the biovar Orientalis. The biovar Orientalis bacteria are responsible for the modern Plague. Y. pestis CO92 has a circular chromosome that is 4.65Mb in size. Strain CO92 has one less rRNA operon than strain KIM (Ref.1). Y. pestis is [...]