Shigella Flashcards Preview

Microbiology Block 3 > Shigella > Flashcards

Flashcards in Shigella Deck (20):
1

what is shigella's biology?

Gram Negative Bacilli

Non-Motile

 Non-lactose fermenter

 No H2S production

 

Oxidase (-)**

2

how many strains does shigella have? what are they?

  1. S. dysenteriae

  2. S. Flexneri            

  3. S. boydii

  4. S. sonnei

3

how does shigella spread?

Human Restricted* Fecal-oral

 

4

what is the most common strain in USA?

S. sonnei 

5

what is the most deadly strain of shigella?

S. dysenteriae

6

how does shigella move from cell-to-cell? what does it use to do this?

it rockets from cell to cell using T3SS

7

what symptom is representative of a shigella infection?

fever

8

can shigella live intracellularly?

no

9

what cell will shigella infect?

 M cells of colon via T3SS.

10

how does shigella acquire the shigella toxin?

through a bacteriophage

11

how does shiga toxin affect M cells?

cleaves 28S rRNA ceasing translation resulting in cellular apoptosis

12

why does shigella toxin cause hemorrhaging?

due to damage to blood vessels

13

what is shigellosis?

shigella dysentery

14

what are the symptoms of shigellosis?

  • Very high fever (up to 106°F)
  • Small volume bloody diarrhea containing WBC and mucus
  • **Profuse blood-liquid diarrhea if Shigella toxin-strain

15

what complications can arise with shigellosis?

  • Septic Arthritis
  • Reactive Arthritis in HLA-B27 Patients
  • HUS* –Hemolytic Uremic Syndrome

16

what agar can be used to grow shigella?

Hektoen (HE) Agar

17

what agar is this? 

what are the white spots?

what are the black spots?

Q image thumb

Hektoen (HE) Agar

shigella

salmonella

18

which is shigella?

Q image thumb

left (stab) because shigella is non-motile

19

what treatment do you give to infection with s. sonnei?

supportive only

20

what treatment do you give to other shigella infection?

TMP-SMX or fluoroquinones when it has complicated