Transcript Yersinia pestis - University of Louisville

Yersinia pestis
http://www.turbosquid.com/3d-models/3d-yersinia-pestisbacteria-bubonic-model/682722
• 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://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
http://hardinmd.lib.uiowa.edu/pictures22/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://www18.homepage.villanova.edu/phoebe.lett/Plaguebuboes.jpg