Yersinia pestis Gram-negative, non-motile Non-spore-forming coccobacillus Facultative anaerobe, unencapsulated dsDNA genome size of ~ 4,380 ± 135 kb Bipolar staining (looks like safety pin) Causative agent of Black Plague LD50 ranges from 1 to 108 depending on strain Pathogenicity linked with plasmids pCD1, pPCP1, and pMT1 http://www.turbosquid.com/3d-models/3d-yersinia-pestis-bacteria-bubonic-model/682722 1-2 images General description (gram stain, DNA characteristics) Virulence facotris (invasins, adhesins, spreading factors) Antimicrobial resistance characteristics Flea http://www.wormsandgermsblog.com/tags/fleas/ Bipolar staining http://aapredbook.aappublications.org/content/1/SEC131/SEC240.figures-only Invasin, Ail, YadA, YadB, YadC, Pla, and pH 6 antigen belong to the most prominent and best-known Yersinia adhesins. They act at different times and stages of infection complementing each other by their ability to bind a variety of host molecules such as collagen, fibronectin, laminin, β1 integrins, and complement regulators. Outer cell membrane © 2013 Mikula, Kolodziejczyk and Goldman. http://en.wikipedia.org/wiki/Wayson_stain Credit: I. Miralda – F2013
Y. pestis life cycle & pathogenicity Employs an enzootic cycle using the oriental rat flea (Xenopsylla cheopis) as a vector Y. pestis prevents blood from entering flea’s stomach Blood pools in esophagus and after mixing with bacteria is regurgitated into mammalian host during feeding Bacteria can only survive when phagocytized by macrophages Unique adhesins and integrins used to block production of proinflammatory cytokines Proliferate within & travels to regional lymph nodes and colonizes other parts of body 3 Plague types, each attacks different systems with decreasing incubation time & mortality rate Bubonic (lymphatic) 2-6 days Pneumonic (respiratory) 1-7 days Septicaemic (blood) 8 hours-2 days http://hardinmd.lib.uiowa.edu/pictures22/cdc/4633_lores.jpg http://en.wikipedia.org/wiki/File:Flea_infected_with_yersinia_pestis.jpg http://www.ppdictionary.com/bacteria/gnbac/pestis.htm http://www18.homepage.villanova.edu/phoebe.lett/Plague-buboes.jpg