Salmonella sp.

Question 1

What do most species cause?

Answer 1

Gastroenteritis

Question 2

Which species causes typhoid fever?

Answer 2

Salmonella typhi

Question 3

Salmonella transmission

Answer 3

Fecal (human or animal) to mouth

Question 4

Salmonella innoculum size

Answer 4

Large (10-100 million organisms)

Question 5

What does low pH do to Salmonella?

Answer 5

Expresses atleast 40 proteins found on pathogenicity islands on large virulence plasmids

Question 6

Salmonella invasion

Answer 6

Invades the apical surface of intestinal epithelial cells via bacterial mediated endocytosis (causes an increase in cellular Ca levels).
This induces ruffling and signal transduction activation.
Bacteria can remain in cell for several hours but will be eventually traversed to basal membrane within a vesicle and released to the lamina propria. Then taken up by lamina propria macrophages

Question 7

Which Salmonella species can replicate in the macrophages?

Answer 7

Typhoid

Question 8

Where are S. typhi found during the carrier state?

Answer 8

Small Intestines, Lymphatics, Gall Bladder,

Question 9

What hapens when S. typhi re-infects the intestines?

Answer 9

Inflammation and ulceration of Peyer’s patches, leading to diarrhea and hemorrage

Question 10

Similarities between Shigella and Salmonella

Answer 10

Both are invasive

Both are able to respond to environmental changes

Question 11

Differences between Shigella and Salmonella

Answer 11

Shigella has smaller inoculum size
Shigella is more acid resistant
Species that cause severe disease are very different