Shigella

Question 1

Pathogenesis
بمعني تاني…ازاي بتعمل dysentry

Answer 1

This occur by both of invasive+inflammation+toxin producing
هنقولهم بقي واحدة واحدة بالراحة
1-Shigella is swallowed through contaminated food or water.
It survives stomach acid and reaches the colon.
2. Invasion:
Shigella enters the M cells (special cells in the intestinal wall).It gets inside macrophages and causes them to die.
3. Spread in the Colon
Shigella escapes into nearby cells and spreads from one cell to another by using the host’s actin.
It damages the cells of the intestinal wall.
4. Inflammation and Ulcers
The immune system reacts with inflammation.
This leads to ulcers, bleeding, and pus in the colon.
5. Toxin Production (only in some types)
Shigella dysenteriae makes Shiga toxin.
This toxin blocks protein production in cells, leading to more damage.
*enterotoxin cause diarrhea
*Cytotoxins :cause cell lysis
*Neurotoxins:cause CNS complications

In severe cases, it can cause Hemolytic Uremic Syndrome (HUS).

Question 2

Complications

Answer 2

*HUS “Hemolytic Uremic Syndrome” due to Sh. dysenteriae type 1
* Toxic megacolon
* Protein losing enteropathy
* Post dysenteric strictures
* Post dysenteric colitis
* Post dysenteric Reiter’s (Symmetrical arthritis, Conjunctivitis, urethritis)

Question 3

Treatment

Answer 3

1st line is Cipro 500mg 1x2
* 2nd → Ceftriaxone
* Fluid replacement therapy.