Bacteria III Gram (-)

Question 1

Three Bacterial

Answer 1

Salmonella

Shigella

Eschericia

Question 2

“The usual suspects” for salmonellosis:

Answer 2

S. enterica var. enteritidis

S. enterica var. typhimurium

Question 3

Salmonellosis Transmission

Answer 3

Contaminated or poorly-cooked food

From other sick humans

From reptiles or other animals

Question 4

Salmonella Pathogenesis

Answer 4

1. Attach to small intestine
2. Type III secretion system
3. Enter host cells; replicate
4. Kill cell; release (symptoms appear)
5. (Possible) Enter bloodstream

Question 5

Salmonellosis Symptoms

Answer 5

Fever
Myalgia
Headache
Abdominal cramps
Possible blood in stool (debated whether this becomes “typhoid fever”)

Even if “healthy”, may shed bacteria for several months

Question 6

Salmonellosis Treatment

Answer 6

-Most cases resolve on their own
-Bismuth salicylate (Pepto-Bismol) and others
-Hydration therapy
-Antibiotics same as for typhoid fever
Floroquinelones, Cephalosporin

Question 7

Salmonellosis Prevention and Control

Answer 7

Food safety practices

FoodNet

Question 8

Four pathogenic species of Shigella

Answer 8

S. boydii
S. dysenteriae
S. flexneri
S. sonnei

Question 9

Shigellosis Transmission

Answer 9

Humans are only host*

Fecal-oral

The Five F’s: “Feces transferred to foods, fingers, flies, and sometimes fomites” (Talaro & Chess 2015)

Question 10

Shigella Pathogenesis

Answer 10

1. Attach to small intestine
2. Type III secretion system
3. Enter host cells; replicate
4. Make actin comets; spread to adjacent cells
5. Kill cell; release (symptoms appear)

Question 11

Shigellosis Symptoms

Answer 11

Dysentery (diarrhea with blood)

Abdominal cramps

Fever

Question 12

Shigellosis Treatment

Answer 12

Most cases resolve on their own

Bismuth salicylate (Pepto-Bismol) and others

Hydration therapy

Antibiotics: fluoroquinolones, macrolides

Question 13

Shigellosis Prevention and Control

Answer 13

Food safety practices

FoodNet

Vaccine in clinical trials

Question 14

Strains of Escherichia coli Needed to know

Answer 14

EHEC (enterohemorrhagic E. coli)
—Includes O157:H7; may cause hemorrhagic colitis or hemolytic-uremic syndrome (HUS)

ETEC (enterotoxigenic E. coli)
—Traveler’s diarrhea; infant diarrhea; multiple toxins produced

Question 15

Escherichia Transmission

Answer 15

Contaminated food and water

Infants particularly susceptible (under-developed gut)

Question 16

Escherichia Symptom Spectrum

Answer 16

“Traveler’s Diarrhea”: Cramps, bloating, Nausea, vomiting, diarrhea

Hemorrhagic Colitis: Colon splits, bleeds, Due to type III systems

Hemolytic Uremic Syndrome (HUS): Anemia, Fever, Kidney failure, Neurologic damage

Question 17

Escherichia Treatment

Answer 17

Most cases resolve on their own

Bismuth salicylate (Pepto-Bismol) and others

Hydration therapy

Antibiotics: beta-lactams, fluoroquinolones

Question 18

Escherichia Prevention and Control

Answer 18

same as Salmonella enteritidis