Salmonella

Question 1

Describe the genus Salmonella

Answer 1

Gram- rods, facultative anaerob; Ferments glucose not lactose, oxidase negative. Produces H2S.

Question 2

Understand the pathogenic differences between S. typhi and S. enteritidis

Answer 2

Chart pg 235

Question 3

What are the salmonella virulence factors?

Answer 3

LPS, invasins, ability to survive in macrophages, Vi antigen (capsule), and complex regulatory cascade.

Question 4

Understand the differences between salmonellosis and Typhoid fever.

Answer 4

Chart pg 236

Question 5

Describe the pathogenesis of salmonella

Answer 5

Infects through M cells in mucosa of large intestine. M cells are killed and peyer’s patches are damaged; Bacteria are ingested by macrophages in the lamina propria.

Question 6

What does salmonella do once its inside a phagocyte?

Answer 6

It survives and proliferates within a vacuole; Carried to lymphatics, spleen and liver by macrophages

Question 7

Once the bacteria is in the spleen and liver, what happens?

Answer 7

Multiplication, LPS released in bloodstream, continues on to gall bladder (can persist there).

Question 8

What are the symptoms once its in the spleen/liver?

Answer 8

Fever, flushed appearance, and anorexia; Chills or convulsions also.