Food borne pathogens

Question 1

What is the difference between intoxication and infection?

Answer 1

Intoxication-> in food there is toxin , and you get sick from it (happens very quick)

Infection->you get sick from proliferating bacteria from food

Question 2

Do S.aureus and C.botulinum cause intoxication or infection

Answer 2

intoxication

Question 3

General characteristics of a foodborne intoxication

Answer 3

1. Toxin is produced by a pathogen while growing in the food
2. The toxin can be heat liable or heat stable
3. Ingestion of a food containing active toxin, not viable cells, is necessary for poisoning
4. Symptoms generally occur quickly, as early as 30 minutes after ingestion
5. Febrile symptoms are not present

Question 4

S.aureus and C.botulinum: which toxin is heat stable, which toxin is heat liable

Answer 4

S.aureus- heat stable

c.botulinum-heat liable (can be destroyed as long as you cook it)

Question 5

What type of toxin S.aureus has

Answer 5

Enterotoxin- acts on GI

Question 6

Staph. intoxication summary of symptoms+diarrhea

Answer 6

Question 7

How Staph.aureus intoxication is usually caused

Answer 7

•Most contamination is traced to humans during food preparation

Question 8

Do you need assistance from S.aureus recovery?

Answer 8

•Self-limiting and recovery in 24-48 hours

Question 9

Red flags for S.aureus infection

Answer 9

Room temperature and some kind of scar or injury (some people have it on skin or in the nose) of the person who prepares it without proper protection

Question 10

What should be done to prevent food form S.aureus intoxication

Answer 10

1. Keep your food cold or hot
2. Wear the mask and gloves

Question 11

The difference between adult and infant ingestion of C.botulinum

Answer 11

•Infant Botulism – Ingestion and intestinal proliferation of the organism, internal production of the toxin (infection)

Adults→toxin

Question 12

What food product is an issue for children

Answer 12

Honey due to potential of C.botulinum infection

Question 13

What is the principle of borulinum toxin

Answer 13

• Following ingestion/production the toxin molecules are absorbed by the gut and are spread via the blood to peripheral nerves
• Normally the axon terminal of the neuron connects with muscle tissues through SNARE proteins and releases acetylcholine into the muscle cells which causes the contraction
• BoNT acts as a protease cleaving the SNARE proteins
• This deprives the muscle of the acetylcholine signal and results in flaccid paralysis
• This becomes a major issue when it comes to lung or heart muscles!

Question 14

salmonella enterica: symptoms infection

Answer 14

Question 15

What subspecies of Salmonella enterica is causing illness in humans

Answer 15

Enterica

Question 16

Serovars are subclasses of subspecies, what is it based on

Answer 16

•serovars based on the presence of somatic, flagellar, and capsular antigens

Question 17

Serovars of S.enterica that is common to cause illness

Answer 17

Typhimurium and Enteritidis

Question 18

Salmonella: in what products it can be found

Answer 18

Most often in meats, eggs and dairy, but sometimes in baked goods as well

Question 19

Are symptoms of salmonella bad? should you get treated?

Answer 19

• Illness is self-limiting, non-bloody diarrhea, and abdominal pain
• Symptoms generally resolve within 5 days
• Therefore, uncomplicated cases only require supportive therapy, such as fluid and electrolyte replacement
• Antibiotics prolong carrier state and increase AMR so they generally are not used!

Immunocompromised patients might have an issue

Question 20

L.monocytogenes should you worry about the infection?

Answer 20

If your immune system is working properly, you might not even notice it, but if immunocompromised or pregnant (can kill fetus)

Question 21

Will listeria grow in the fridge?

Answer 21

•Lowering the temperature doesn’t stop the Lm growth but it does slow it

Question 22

Listeria: what can kill it in products

Answer 22

•It is sensitive to pasteurization temperature

Question 23

Salt related conditions for Lysteria

Answer 23

it can grow in pH as low as 4.4 and as salts up to 10%

Question 24

Why milk should be pasterurized even fro making cheese?

Answer 24

• Pasteurization reduces the number of Lm cells in milk to levels that don’t pose a risk to human health
• Raw milk cheeses are unpasteurized
• Lm survives well during cheese manufacturing due to both the temperature (cold) as well as the salt content (high)
• While many of it’s competitors die

Pregnant do not eat raw cheeses and raw milk, and cold meats products

Question 25

Why cold meats and listeria can be a good match?

Answer 25

• Ready-to-eat meats that are heated and then cooled in brine are especially good for Lm because competing bacteria are reduced
• If Listeria contamination can happen after heating there will be a major problem

Question 26

Campylobacter jejuni: clinical manifestations

Answer 26

Diarrhea (can be bloody), fever, headache

Question 27

The difference between C.jejuni and C.coli infections

Answer 27

Almost no distinguish

Question 28

How C.jejuni acts on the body and what diseases can happen

Answer 28

•Patients who are infected with C. jejuni are thought to develop antibodies against certain antigens in the bacteria LPS that cross react with peripheral nerve cell surface gangliosides.

acts on myelin sheets on neurons

Guillain-Barre syndrome (GBS)and Miller Fisher Syndrome

Question 29

Key take out about e.coli species

Answer 29

It can be good for your gut, can be neutral, can be so so, and can be very bad, great diversity

Question 30

Where e.coli death are really a problem

Answer 30

Where people do not have access to clean water

Question 31

E.coli how it can act on your gut

Answer 31

• they can cause the water to come out of your gut enterocytes and result in diarrhea
• Toxins for enterocytes
• Microvilli killing e,coli → not absorbing water→ diarrhea
• Other can go inside the enterocytes and blood. Produce toxin that shrink your RBC and deactivate kidneys

Question 32

Where e.coli are coming from

Answer 32

Food, animals, humans, drinking water

Question 33

How e.coli can be cathegorized

Answer 33

•E. coli can be categorized into different pathotypes based on their ability to produce toxins, ability to adhere to epithelial cells, and ability to invade epithelial cells (the pathogenic traits have mostly been acquired through horizontal gene transfer)

Question 34

chronobacter is usually associated with what type of food

Answer 34

Powdered milk formulas

Question 35

Who is susceptible to chronobacter

Answer 35

• Immunocompromised children, not full term, etc.

Question 36

Are all vibrios bad?

Answer 36

40-60% of seafood is contaminated with vibrios but not all of them are bad

Question 37

Why there can be vibrio season?

Answer 37

Waters higher than 17 degrees

Question 38

Infections of vibrio parahaemolyticus are associated with what food

Answer 38

raw seafood like oysters

Question 39

Scary cases of Vibrio vulnificus (really things to worry about when you skin gets off) are associated with what

Answer 39

Consumption of raw oysters and some hepatic malfuction

Question 40

Cholerae toxin does what

Answer 40

• The build up of ions in the intestinal lumen draws water from cells and tissues via osmosis – causing acute diarrhea
• As water is being removed from body tissues, dehydration will result if left untreated

Question 41

The difference between vibrio (parahaemolyticus, vulnificus and cholerea), “seriosness”, symptoms, and one toxin for cholerea

Answer 41