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E. Lee F2013
Modifiedy by DYH
Yersinia pestis
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Yersinia; Gammaproteobacteria
Gram-negative bacillus
non-spore forming, non motile, facultative anaerobe
http://web.mst.edu/~microbio/BIO221
_2010/images/Yersinia-1.jpg
Infects humans in three forms: pneumonic (infection of the lungs), septicemic
(infection in the bloodstream), and bubonic (infection in the lymphnodes)
plagues
• Can cause epidemics (ex: the Black Plague and Justinianic
plague)
• Classified as category A pathogen
• Can also effect other mammals
• Fatal if not treated within 2-6 days
• Common reservoir: rodents
• Transmission by fleas (infector)
http://www.columbia.edu/itc/cerc/danoffburg/invasion_bio/inv_spp_summ/Yersinia_pestis_files/i
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E. Lee F2013
Modifiedy by DYH
Yersinia pestis virulence
• yadBC genes encode for adhesins and invasins
• Allows Y. pestis to adhere and invade epithelial cells of
host
• Virulence factors: inhibits immune response of host
• Plasminogen activator degrades blood clots
• Fraction 1 (F1) capsular and LcrV antigens
• Type III secretion system (T3SS) secretes Yersinia
Outer Proteins (Yops) into macrophages and other
immune cells
• Yop B and Yop D form pores in the host cell membrane
and Yop O, H, M, T, J, and E are injected into cytoplasm of
host via T3SS
• YopJ hinders the host cell kinase activity to inhibit
apoptosis of macrophages
• YopO also called Yersinia protein kinase A (YpkA) induces
macrophage apoptosis too
• Bacteria continues to multiply within these protective
macrophages
• Cure: F1/V antigen based vaccine
http://www.ppdictionary.com/bacteria/gnbac/pestis.htm