Yersinia pestis ttp www turbosquid com3 dmodels3 dyersiniapestisbacteriabubonicmodel682722
Yersinia pestis ttp: //www. turbosquid. com/3 d-models/3 d-yersinia-pestisbacteria-bubonic-model/682722 • Gram-negative, non-motile • Non-spore-forming coccobacillus • Facultative anaerobe, unencapsulated • ds. DNA genome size of ~ 4, 380 ± 135 kb • Bipolar staining (looks like safety pin) • Causative agent of Black Plague • LD 50 ranges from 1 to 108 depending on strain • Pathogenicity linked with plasmids p. CD 1, p. PCP 1, and p. MT 1 http: //en. wikipedia. org/wiki/Wayson_stain Credit: I. Miralda – F 2013
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 http: //hardinmd. lib. uiowa. edu/pictures 22/cdc/4633_lores. jpg http: //en. wikipedia. org/wiki/File: Flea_infected_with_yersinia_pestis. jpg • 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: //www. ppdictionary. com/bacteria/gnbac/pestis. htm http: //www 18. homepage. villanova. edu/phoebe. lett/Plaguebuboes. jpg
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