University:
Eastern Kentucky University
Course:
BIO 273 | Clinical Microbiology
Academic year:

2022
Views:

110

Pages:

1
Author:

rezancuk2j

Shigella (-) Features: 1. 2. 3. 4. 5. Green colonies on Hektoen Agar Immotile Facultative intracellular Acid stable Type 3 secretion system Pathogenesis: 1. Invades M cells in pyer’s patches 2. Escapes phagolysosome 3. Uses host actin filaments intracellularly to propel itself Diseases: 1. Bloody Diarrhea a. Shigella causes production of cytokines when it attacks the enterocytes i. Leads to severe inflammation of mucosa ii. Eventually leads to bloody diarrhea 2. Shigellosis (Dysentery) a. Caused by S. dysenteriae b. Shiga toxin binds to 60S subunit of ribosomes c. S. dysenteriae produces shiga toxin which can lead to hemolytic uremic syndrome (HUS) in patients of age less than 10 3. HUS a. Glomerular damage by shiga toxin i. Leads to increase in platelet aggregation ii. Diminishes circulating platelet count in the blood iii. Microthrombi formed 1. These microthrombi can cause shearing of RBCs and hence produce shistocytes