1. Yersinia pestis
B. Clark F2013
Modified by DYH
Bacteria responsible for the Black Death, which killed over 1/3 of European population from
Gram negative, rod shaped coccobacillus
Unique morphology between cocci and bacilli
Obligate intracellular pathogen
Facultative anaerobe
Primary carriers are the Oriental rat flea and infected rodents
Produce antiphagocytic slime layer in its path
Genome size of strain CO92 is 4.65 Mbp and strain KIM is 4.6 Mbp
4,198 total ORFs

2. Yersinia pestis Can produce loose capsule in some cases
B. Clark F2013
Modified by DYH
Can produce loose capsule in some cases
Lacks O-side chain due to disrupted O-anitgen gene cluster
Called a “rough mutant”
Infection takes three main forms: pneumonic, septicemic, & bubonic plagues
All pathogenic species contain pCD1 virulence plasmid
Uses a Type 3 Secretion System to inject bacterial proteins into host immune cells
LPS chains mediate antibody resistance
Expression of yadBC gene is similar to adhesin function
Adherence and invasion of epithelial cells
Proliferates in lymph nodes where is can avoid destruction by immune system