Food borne pathogens Flashcards
What is the difference between intoxication and infection?
Intoxication-> in food there is toxin , and you get sick from it (happens very quick)
Infection->you get sick from proliferating bacteria from food
Do S.aureus and C.botulinum cause intoxication or infection
intoxication
General characteristics of a foodborne intoxication
- Toxin is produced by a pathogen while growing in the food
- The toxin can be heat liable or heat stable
- Ingestion of a food containing active toxin, not viable cells, is necessary for poisoning
- Symptoms generally occur quickly, as early as 30 minutes after ingestion
- Febrile symptoms are not present
S.aureus and C.botulinum: which toxin is heat stable, which toxin is heat liable
S.aureus- heat stable
c.botulinum-heat liable (can be destroyed as long as you cook it)
What type of toxin S.aureus has
Enterotoxin- acts on GI
Staph. intoxication summary of symptoms+diarrhea
How Staph.aureus intoxication is usually caused
•Most contamination is traced to humans during food preparation
Do you need assistance from S.aureus recovery?
•Self-limiting and recovery in 24-48 hours
Red flags for S.aureus infection
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
What should be done to prevent food form S.aureus intoxication
- Keep your food cold or hot
- Wear the mask and gloves
The difference between adult and infant ingestion of C.botulinum
•Infant Botulism – Ingestion and intestinal proliferation of the organism, internal production of the toxin (infection)
Adults→toxin
What food product is an issue for children
Honey due to potential of C.botulinum infection
What is the principle of borulinum toxin
- 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!
salmonella enterica: symptoms infection
What subspecies of Salmonella enterica is causing illness in humans
Enterica
Serovars are subclasses of subspecies, what is it based on
•serovars based on the presence of somatic, flagellar, and capsular antigens
Serovars of S.enterica that is common to cause illness
Typhimurium and Enteritidis
Salmonella: in what products it can be found
Most often in meats, eggs and dairy, but sometimes in baked goods as well
Are symptoms of salmonella bad? should you get treated?
- 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
L.monocytogenes should you worry about the infection?
If your immune system is working properly, you might not even notice it, but if immunocompromised or pregnant (can kill fetus)
Will listeria grow in the fridge?
•Lowering the temperature doesn’t stop the Lm growth but it does slow it
Listeria: what can kill it in products
•It is sensitive to pasteurization temperature
Salt related conditions for Lysteria
it can grow in pH as low as 4.4 and as salts up to 10%
Why milk should be pasterurized even fro making cheese?
- 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
Why cold meats and listeria can be a good match?
- 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
Campylobacter jejuni: clinical manifestations
Diarrhea (can be bloody), fever, headache
The difference between C.jejuni and C.coli infections
Almost no distinguish
How C.jejuni acts on the body and what diseases can happen
•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
Key take out about e.coli species
It can be good for your gut, can be neutral, can be so so, and can be very bad, great diversity
Where e.coli death are really a problem
Where people do not have access to clean water
E.coli how it can act on your gut
- 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
Where e.coli are coming from
Food, animals, humans, drinking water
How e.coli can be cathegorized
•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)
chronobacter is usually associated with what type of food
Powdered milk formulas
Who is susceptible to chronobacter
- Immunocompromised children, not full term, etc.
Are all vibrios bad?
40-60% of seafood is contaminated with vibrios but not all of them are bad
Why there can be vibrio season?
Waters higher than 17 degrees
Infections of vibrio parahaemolyticus are associated with what food
raw seafood like oysters
Scary cases of Vibrio vulnificus (really things to worry about when you skin gets off) are associated with what
Consumption of raw oysters and some hepatic malfuction
Cholerae toxin does what
- 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
The difference between vibrio (parahaemolyticus, vulnificus and cholerea), “seriosness”, symptoms, and one toxin for cholerea
