Foodborne Ilnesses

Question 1

How many cases are food borne illnesses per year?

Answer 1

48,000,000
15% of americans

Question 2

How does food poisoning occur?

Answer 2

Ingestion of pre-existing enterotoxins

Question 3

The pathogen may no longer _____

Answer 3

Be present

Question 4

2 examples of non present pathogens

Answer 4

Botulism and staphylococcus aureus

Question 5

Types of Foodborne pathogens (3)

Answer 5

1. Salmonella enteriditis (eggs, poultry, produce, pets)
2. Salmonella typhi (typhoid fever, 4–500 cases annually in USA, mainly from travelers)
3. Campylobacter jejuni (poultry, cattle, drinking water, sexual activity, causes more diarrhea than salmonella and shigella)

Question 6

How can Listeria occur?

Answer 6

Bacteria could be in packaged food

Question 7

Shigellosis is a _____ bacterium

Answer 7

Gram-negative

Question 8

Shigellosis symptoms

Answer 8

Usual gastroenteritis symptoms, plus dysentery

Question 9

What can you contract Shigellosis from?

Answer 9

Eggs, shellfish, dairy, vegetables, water

Question 10

What are the two types of shiga toxins?

Answer 10

Active (A) and Binding (B)

Question 11

What is Active Subnit?

Answer 11

An N-glycosides which cleaves a single adenine residue from 28S rRNA, halting protein synthesis

Question 12

What do shiga toxins lead to?

Answer 12

Death of vascular endothelial cells, causing bloody diarrhea

Question 13

Where are shiga toxins most effective?

Answer 13

In small blood vessels, such as the gut and kidney

Question 14

Where are many of the genes that are needed for Shigella virulence?

Answer 14

On the invasion plasmid

Question 15

What does the virulence plasmid contain?

Answer 15

Many pathogenicity island clusters
- toxin genes stxA and stxB are NOT on this
-contained in a viral prophage embedded in the bacteria genome

Question 16

Two ways of transfer for genes

Answer 16

Vertical and horizontal

Question 17

Lateral gene transfer types

Answer 17

Transformation, phase transduction, bacterial conjugation, transposition
- all can occur within or between species and strains

Question 18

E.coli is a _______

Answer 18

Natural gut bacterium

Question 19

T/F many strains exist, most are harmless or even beneficial

Answer 19

True

Question 20

Which strains of Ecoli are highly toxic?

Answer 20

EHEC strains and O157:H7

Question 21

What can E.coli cause?

Answer 21

Hemolytic uremic syndrome

Question 22

What are the symptoms of hemolytic uremic syndrome?

Answer 22

Initial symptoms are bloody diarrhea
Later symptoms are pallor bruising, lethargy, and anemia
Finally, hematuria (blood in the urine) and acute renal failure develop)
Disease is fatal in 3-5 % cases

Question 23

What does the O antigen stand for in E.Coli?

Answer 23

Bacterial cell wall lipopolysaccharide variation

Question 24

What does the H antigen stand for in E.Coli?

Answer 24

Bacterial flagella variation

Question 25

How did E.coli acquire Shiga toxins?

Answer 25

EHEC manufactures Shiga toxins such as Stx5, STx5 binding to receptor molecule gb3 in kidney glomerular cells inactivates an enzyme

Question 26

What increased when E.coli acquired shiga toxins?

Answer 26

Increase in von willebrand Factor, resulting in increased clotting

Question 27

What does micro-clots do?

Answer 27

Accumulate within blood vessels, damaging red cells and restricting blood flow

Question 28

What was the most famous case of E.Coli outbreak?

Answer 28

1993 jack in the box burger undercooked

Question 29

Where was food supply contamination an issue?

Answer 29

Washington state, healthy beef cattle Ontario Canada , healthy slaughterhouse England, implicated slaughterhouse

Question 30

Food inspection issue with dance instructor

Answer 30

Contaminated burger patty caused paralyzation

Question 31

Where were the components of the burger patties from that paralyzed the dance teacher?

Answer 31

Meats from three different areas prepared in a slaughterhouse

Question 32

When do suppliers check for contamination?

Answer 32

Cargill tests after it is ground together Costco does test

Question 33

Other types of E.coli

Answer 33

Enterohemorrhagic e.coli causes 62,000 infections and 50 deaths in the US

Question 34

How sterile is food study?

Answer 34

Study carried out in Minneapolis/St. Paul examining ExPEC contamination of foods - 9% of prevalence in misc. foods -69% in beef and pork - 92% in poultry

Question 35

ESBL-producing E.coli in human-derived and food chain-derived samples

Answer 35

11% of fecal samples contained ESBL -frequent in sewage and retail meat

Question 36

Cholera and copepods

Answer 36

Vibrios are often attached to the chitinous shells of planktonic copepods - simple filtration of drinking water through sari cloth can remove the copepods and lower the risk of infection

Question 37

What does Biofilm do?

Answer 37

Allows bacteria to survive in nutrient poor and stressful environments

Question 38

What does the cholera toxin do?

Answer 38

Releases in to intestinal epithelial cells Increases Cl- ion excretion Increased luminal ion concentration Watery diarrhea

Question 39

How is V. Cholerae killed?

Answer 39

Stomach acids

Question 40

What does surviving bacteria do?

Answer 40

Enter small intestine and swim into the mucus layer -detach the flagellum, losing ability to swim -begin secreting the toxins that cause disease

Question 41

Symptoms of Cholera

Answer 41

Rapid onset of severe rice water diarrhea, plus vomiting Fluid loss can be 3-5 gallons per day

Question 42

When does cholera develop?

Answer 42

Disease commonly develops from diarrhea to shock within 4-12 hours, with death following from 18 hours onwards

Question 43

What is the cholera toxin CTx?

Answer 43

- toxin activates adenylate cyclase increase in cAMP -activates the CFTR protein, resulting in enhanced flow of chloride ions and water from the cell -V. Cholerae also inhabits the gut of copepods, and CTx may be important in their osmoregulation

Question 44

Pandemics of cholera

Answer 44

Seven cholera pandemics have been in recent history - horizontal transfer

Question 45

Where was the 2010 cholera outbreak?

Answer 45

Haiti

Question 46

Cholera ecology slide