1. Yersinia pestis Yersinia; Gammaproteobacteria Gram-negative bacillus
E. Lee F2013
Modifiedy by DYH
Yersinia pestis
Yersinia; Gammaproteobacteria
Gram-negative bacillus
non-spore forming, non motile, facultative anaerobe
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)

2. Yersinia pestis virulence
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