Salmonella Enterica

Question 1

How do you destroy Salmonella enterica?

Answer 1

Easily by cooking (can survive freezer

Question 2

What is SPI?

Answer 2

Salmonella Pathogenicity Islands

- contain virulence factors

Question 3

How does Salmonella invade?

Answer 3

acid tolerance maintains pH
flagela gets it to epithelial cells
SPI 3/4 adhesins attach to intestinal epithelium
SPI1- T3SS virulence effector proteins to host through ruffling and engulfment
SPI-5 dysbiosis
SPI2- replication and tetrathionate for terminal e (outcompete)

Question 4

Typoid vs non-typhoid

Answer 4

Typhoid - typhi, Paratyphoid = enteric fever
- fever, diarrhea, rash
Non-Typhoid- thyphimuminum, enteriditis = gastroenteritis
- ab pain, vomitng, diarrhea

Question 5

Hwo is salmonella grouped?

Answer 5

serovar, based on O antigen LPS and flagellar H

Question 6

Do most Salmonella cross the epithelium?

Answer 6

No, most have basolateral movement but it localized in the intestinal tissues

Question 7

Describe how pathogenicity island help Se survival

Answer 7

Salmonella adheres to intestinal cells, S cells attach to the intestinal epithelium by means of adhesins such as those encoded within SPI-3 and SPI-4
SPI-3 encodes MisL which binds to the fibronectin on the epithelial cells, it also encodes MgtCB which is involved in intra macrophage survival
SPI-4 contains only 6 ORFs arranged in a single operon, It encodes SiiE which mediates attachment to epithelial cells although its receptor is unknown

Question 8

What happens at the cellular level for Salmonella?

Answer 8

SP1→ T3SS → effector proteins→ drive force uptake of pathogen into non-phagocytic cells and manipulate host cell signaling
Cell actin rearrangement → ruffles→ engulf pathogen into salmonella containing vacuoles (SCVs)
Obtain nutrients from golgi
inflammation→ diarrhea
SCV can go to the basolateral side → systemic infection
T3SS
Protein appendage found in gram neg bacteria, needle like → effector proteins → escape immune response

Question 9

What is pyroptosis?

Answer 9

highly inflammatory form of programmed cell death that occurs most frequently upon infection with intracellular pathogens and is likely to form part of antimicrobial response

Question 10

What aspects lead to inflammation from Se?

Answer 10

SPI-5 encodes SopE, SopE2 and SigD → proinflammatory→ dysbiosis
Diarrhea → subcellular alterations like tight junction disruption
Increased flow of water into epithelium
AMR can occur on plasmid