Microbiology of Food (#3) Flashcards
any change in appearance, smell, or taste of a food that makes it unpalatable to the consumer; MAY be safe to eat
food spoilage
T/F: food has to have HIGH levels of pathogens to get sick from spoiled food
true
2 types of factors that cause susceptibility to microbial spoilage:
- intrinsic factors
- extrinsic factors
type of susceptibility to microbial spoilage: food composition (chemical) + structure (physical); the food itself!
intrinsic factors
type of susceptibility to microbial spoilage: environmental; what you do to the food; easier to control
extrinsic factors
which is easier to control – intrinsic or extrinsic factors of susceptibility to microbial spoilage?
extrinsic (u control the environment!)
categories of food spoilage (3):
- perishable
- semi-perishable
- nonperishable
category of food spoilage: meat
perishable
category of food spoilage: fruit and nuts
semi-perishable
category of food spoilage: pantry foods (flour, surgar)
nonperishable
the categories of food and their spoilage all have to do with their ____ composition
water
the more water in a food, the more _______ it is
perishable
types of food compositions (2):
- carbohydrates
- proteins or fats
food composition: mold predominates; degrades food by hydrolysis; little odor; ERGOTISM
carbohydrates
disease caused by Claviceps purpurea toxin; produces a HALLUCINOGENIC alkaloid that causes involuntary muscle contractions + hallucinations; grows in wet rain; problem in CARBS
ergotism
food composition: bacterial growth predominates; putrefaction occurs
proteins or fats
anaerobic breakdown of proteins; foul-smelling amine compounds
putrefaction
_______ occurs in the spoilage of carbohydrates and _____ occurs in the spoilage of proteins or fats
ergotism; putrefaction
intrinsic factors (food spoilage - 5):
- pH
- presence and availability of water
- redox potential (oxidation-reduction)
- physical structure
- antimicrobial substances
LOW pH favors ____ and ____ (ex: vinegar, pickles)
yeast + mold
in general, _____ water activity inhibits microbial growth
lower
lower redox (less oxygen) favors growth of _________ bacteria; releases oxygen
anaerobic
intrinsic factor: grinding and mixing promotes microbial growth (ex: ground beef)
physical structure
intrinsic factor: coumarins, lysozyme, allicin, etc.
antimicrobial structures
allicin, an antimicrobial, is found in _____
garlic
extrinsic factors (of food spoilage - 3):
- temperature
- relative humidity
- atmosphere
lower temperatures ____ microbial growth
retard
_____ levels of relative humidity promotes microbial growth
higher
extrinsic factor: oxygen promotes growth; modified atmospheric packaging (MAP)
atmosphere
in the atmosphere, _______ promotes growth
oxygen
use of shrink wrap and vacuum technologies to package food in controlled atmospheres
modified atmosphere packaging (MAP)
MAP =
modified atmosphere packaging
when you use shrink wrap (form of MAP), you can increase the shelf life by ___-___ times since it is impermeable to oxygen
2-3x
food preservation methods (3):
- removal of microbes
- low temp.
- high temp.
to preserve foods, you can remove microbes through ______
filtration
to preserve foods, you can refrigerate them at ≤ ____°C degrees and freeze at ≤ _____°C
≤ 5 °C
≤ -18°C
your fridge should be preferably at ____ °C
4
your freezer should be preferably at _____ °C
-20°C
high temp. food preservation methods include (3)…
- cooking and holding at high temp.
- canning
- pasteurization
DANGER ZONE temperature for microbes:
5 - 60°C
you can leave food out for ____ hours max
2
pasteurization does not kill endospores until it reaches what temperatures?
5 - 60°C (danger zone)
60°C = _____°F
140°F
you are ____ times more likely to get struck by lightning than to get botulism that was COMMERCIALLY done
100x
during canning, food is heated to what temp and for how long?
115°C for 25-100 minutes
canning kills ______ microbes
spoilage
T/F: spoilage of commercially canned foods is common
false (very rare)
endospores don’t like ______ so you don’t have to worry about botulism in fruit
acid
at what pH ensures that botulism won’t occur in cans?
< 4.6
you need a ______ canner for high pH foods
pressure
gas production in can; DEADLY; caused by endospores in an anoxic environment; swollen cans
botulism
1 teaspoon of botulism endospores can kill ______ ppl
10,000
method of high temp. food preservation; kills pathogens and substantially reduces number of spoilage organisms
pasteurization
T/F: different pasteurization procedures heat for different lengths of time
true
regarding pasteurization, SHORTER heating times result in improved _______ (have to increase temp then)
flavor
different modes of pasteurization (3):
- LTH (low temp holding)
- HTST (high temp short time)
- UHT (ultrahigh-temp processing)
mode of pasteurization: 63°C for 30 min
low temp holding (LTH)
mode of pasteurization: 72°C for 15 seconds, then rapid cooling
high temp short time (HTST)
mode of pasteurization: 138°C for 2 seconds - 20 min
ultrahigh-temperature processing (UHT)
which mode of pasteurization STERILIZES the food?
UHT (ultrahigh temp processing)
sterilization temp = greater than _____°C
> 135°C
suppose you are cleaning out your fridge and find a container of meat-loaf that you made last month. Upon opening the container, you smell a putrid odor and the meat appears to be slimy. Would you get sick if you eat the meat-loaf?
maybe – spoilage microorganisms are present which indicates that pathogens MAY be present (or have previously grown in the food)
water activity tolerated by most spoilage bacteria =
0.9
chemical agents “generally recognized as safe;” tested by FDA; could save a lot of financial loss; use acids as a method to protect food
GRAS
GRAS are a _____-based preservation
chemical
GRAS use _____ as a method to protect food
acids
GRAS =
generally recognized as safe
type of GRAS; could be mutagens and cause damage in DNA of food (not you)
propionic acid/oxides
type of GRAS that some ppl are sensitive to
parabens
type of GRAS that is a carcinogenic precursor; could be bad if there’s a lot in food
nitrite (as in sodium nitrite)
use of ionizing radiation (gamma radiation) to extend shelf life of foods; excellent penetrating power; can be used to sterilize SOME foods
radappertization
radappertization uses Cobalt-60 as a source for what process?
cold sterilization (doesn’t cook it)
radappertization (and the use of Cobalt-60 for cold sterilization) is approved by WHO for which food?
ground beef
symbol that means food was radiated; not seen in stores; only in food for lab animals right now
red dura symbol
____ in ____ ppl will get a food borne illness each year
1 in 6
about ____ ______ cases of foodborne disease occur every year in the US
48 million
____% of foodborne illnesses are attributed to known pathogens
18%
at least ______ deaths occur to to foodborne diseases (usually susceptible ppl)
3,000
types of transmission
of FOODBORNE DISEASE (3):
- breakdown in hygiene
- fecal-oral route
- fomites
type of transmission of foodborne disease: most foodborne pathogens are from HERE
fecal-oral route (FECES!)
type of transmission of foodborne disease: inanimate object that spreads disease; food is considered this (other ex: blanket, water, door knob)
fomites
2 types of foodborne illnesses:
- food intoxication (poisoning)
- food infection
type of foodborne illness: ingestion of preformed microbial toxins in foods; toxins make you sick, not microbes; growth of the pathogen host is NOT required
food intoxication (poisoning)
type of foodborne illness: results from the ingestion of pathogens in food; ingestion followed by colonization and growth in host
food infection
T/F: if you your reheat food and kill the microbes, you can still get sick from toxins
true
the onset of illness from food intoxication is usually pretty _____
rapid (basically just ate poison)
T/F: pathogens may produce toxins IN the host
true
when pathogens produce toxins in the host, they are ______-mediated infections but _____ microbes have to be there
toxin-mediated; live
when pathogens produce toxins in the host, it is a _____ infection dose level, where a ____ concentration level is needed to make you sick + outcompete microflora
high; high
________ cause most foodborne illnesss, NOT ______
viruses; NOT bacteria
recovery from viral foodborne illnesses is usually ____
rapid
5 top causes of foodborne illnesses IN ORDER:
1: norwalk-like viruses
#2: Salmonella spp.
#3: Clostridium perfringens
#4: Campylobacter jejuni
#5: Staphylococcus aureus
s. aureus has a really _____ incubation period
short (1-8 hrs)
Salmonella enterica has a really _____ incubation period
long (10-14 days)
common skin bacteria
Staphylococcus aureus
what kind of foodborne ilness does Staphylococcus aureus cause?
food intoxication (poisoning)
is Staphylococcus aureus gram-positive or negative?
gram-POS
what kind of oxygen level classification is Staphylococcus aureus?
facultative aerobe
Staphylococcus aureus can thrive in ____ salt and ____ water activity levels.
high salt; low water activity
sources of Staphylococcus aureus (3):
- human nasal cavity
- skin
- skin sores
what kind of toxins do Staphylococcus aureus produce?
enterotoxin (intestinal toxin)
what does enterotoxin mean?
intestinal toxin
what type of toxin is an enterotoxin?
exotoxin
bacteria produce this type of toxin and then RELEASE it into their environment; “super antigen;” activates a STRONGER immune response (violent symptoms) than a normal antigen; don’t even need T cells
exotoxins
toxin that is part of the bacteria; never release it until they die
endotoxin
enterotoxins made by Staphylococcus aureus are _____ _______ and resistant to what 2 things?
heat stable
- digestive protease
- stomach acid
how long does it take Staphylococcus aureus to produce enterotoxins in the danger zone?
2-4 hours
what kind of foods does Staphylococcus aureus grow in?
high-salt foods
there are around ________ staphylococcal food intoxication cases per year in the US
185,000
if you heat foods contaminated by Staphylococcus aureus, can you still get sick?
yes! (toxins are heat stable)
is Staphylococcus aureus considered a fecal-contaminate?
no (more skin)
food contaminated by Staphylococcus aureus occurs usually during food _______
preparation
contaminated foods by Staphylococcus aureus are kept for several hours in the _______
danger-zone
symptoms of Staphylococcal Food Intoxication (3):
- EXPLOSIVE vomiting
- diarrhea
- subnormal body temp (usually no fever)
onset of Staphylococcal food intoxication is ______
rapid
onset of Staphylococcal food intoxication =
1-8 hours (bc u ate poison, violent response)
duration of Staphylococcal food intoxication =
1-2 days (quick recovery)
food infection results from the ingestion of ______ _____, while food intoxication results from the ingestion of ______ ______.
foodborne pathogens; microbial toxins
is Clostridium botulinum gram-positive or negative?
gram-POS
does Clostridium botulinum form spores?
yes
what kind of oxygen level classification is Clostridium botulinum?
strict anaerobe (needs anoxic conditions)
sources of Clostridium botulinum (2):
- soil
- water
what kind of botulism implications is Clostridium botulinum involved in (3)?
wound, infant, and food BOTULISM
what specific kind of toxin does Clostridium botulinum create?
neurotoxin
what type of toxin is a neurotoxin?
exotoxin
since Clostridium botulinum produces neurotoxins, it affects ______ ______, which can cause the heart to stop, breathing to cease, and babies to be constipated
nervous tissue
neurotoxins are heat ______
labile (susceptible to heat, but not worth the risk)
Clostridium botulinum is part of the same genus that causes ______
tetanus
since Clostridium botulinum is found in soil and water, is is considered an “_______ pathogen”
accidental
neurotoxins by Clostridium botulinum are produced best in ______ protein, ______ acid foods
high protein, low acid (hi pH)
neurotoxins by Clostridium botulinum can be destroyed by high heat at what conditions (temp + how long)?
80°C for 10 min.
what kind of foods is Clostridium botulinum found in?
nonacid home-canned vegetables (corn, beans, smoked and fresh fish)
for any pH below ______, you don’t have to worry about botulism
4.6 (likes high pH)
1 teaspoon of botulism can kill _________ ppl (**correct)
100,0000
what 2 things is required for endospores involved in botulism (by Clostridium botulinum) to germinate?
- anoxic conditions
- high pH (low acid)
botulism endospores may contaminate ____ foods before harvest or slaughter
raw
most foodborne cases of botulism occur from eating foods that are not ______ after processing
cooked
home-canned foods implicated in greater than ___% of foodborne outbreaks of botulism
> 72%
less than ____% of foodborne outbreaks of botulism occur from commercially processed cans
< 10%
infant botulism usually occurs in infants up to 2 months old from what?
raw honey
in most cases of infant botulism, they are less than ____ _____ old
< 6 months
onset of botulism from Clostridium botulinum =
18-24 hours (quick)
is the onset of botulism fast or slow?
fast
symptoms of botulism (Clostridium botulinum - 3)
- heart paralysis
- difficulty swallowing, speaking, and breathing
- constipation (in babies)
duration of botulism =
1 - 10 days (BUT neurological damage could permanent - ex: stroke)
mortality % of botulism:
3-5%
while the rate of mortality from botulism is 3-5%, the first person who gets it has a mortality rate more like ___%
21% (more potent)
treatment of botulism =
antitoxin
absorbs toxins but illness has to be diagnosed quickly to be effective
antitoxin
outbreak caused by sautéed onions showed what risk about botulism?
food in bulk can be anoxic in the middle without stirring
outbreak caused by baked potatoes showed what risk about botulism?
food wrapped tightly (like in saran wrap) can be anoxic
wound botulism occurs from what?
drugs + dirty needles
3rd leading cause of foodborne illness
Clostridium perfringens
Clostridium perfringens can be food ________ but here we are talking about _________
intoxication; INFECTION
around how many cases of Clostridium perfringens food infection occur each year in the US?
1 million
in FOOD, spores from Clostridium perfringens are activated by _______ and germinate under ______ conditions
cooking; anoxic
in intestines, a ______ number of Clostridium perfringens cells must be ingested
large
infectious dose of Clostridium perfringens:
> 10^8 cells
what specific kind of toxin does Clostridium perfringens produce?
enterotoxins
enterotoxins affect the ______ and _______
stomach + intestines
what type of toxins are enterotoxins?
exotoxins
what triggers the production of enterotoxins from Clostridium perfringens ?
sporulation of vegetative cells in the intestine ***
since enterotoxins are exotoxins, when are they secreted from the bacteria, Clostridium perfringens?
when they sporulate
Clostridium perfringens produces toxins when they _______ and Clostridum botulinum produces toxins when they _________
sporulate; germinate (botulism)
cells sporulate when they are in _____ conditions
harsh
vegetative cells of Clostridium perfringens are killed by _______, extended _______, and ______
cooking, extended refrigeration, and freezing
T/F: Clostridium perfringens cells in food can be killed if brought up to a high enough temp with stirring
true
onset of Clostridium perfringens food infection =
7-15 hours (fast!)
symptoms of Clostridium perfringens food infection (2):
- diarrhea (mostly)
- cramps
*fever and vomiting are rare!!
duration of Clostridium perfringens food infection =
12 -24 hours (short lived)
since the duration of Clostridium perfringens is very short lived, it resembles what?
viral infection
what kind of food is Clostridium perfringens is found in?
foods cooked in BULK and then left out
Clostridium perfringens is commonly found in foods cooked in bulk and then left out at what temp. range + for how long?
20-40°C for short time periods
2nd leading cause of foodborne illnesses
Salmonella enterica
Salmonella serovars reacts differently to ___________ than Salmonella enterica
antibiotics
Salmonella enterica are considered all the same SPECIES, so they are all _____________
pathogens
is Salmonella enterica gram-positive or negative?
gram-NEG (bacillus)
source of Salmonella enterica =
sewage (GI of birds and other animals)
T/F: Salmonella enterica is NOT considered a fecal contaminant
false (it is)
what kind of foods/sources is Salmonella enterica found in (5):
- meat (poultry, beef, pork)
- fruits + beg
- EGGS (custards, cakes, pies, eggnog)
- dairy products
- handling ANIMALS
what type of foodborne illness is caused by Salmonella enterica?
food infection
of cases of Salmonella enterica food infection per year
1 million
less than ___% of Salmonella enterica cases are reported
< 4%
we see more Salmonella enterica cases during the _____
summertime
which Salmonella enterica cause food infection (accord. to class)?
serovars Typhimurium and Enteritidis
where do Salmonella enterica colonize in your body?
small and large intestine
what does Salmonella enterica invade and grow in after colonizing the intestines?
phagocytic cells
infectious dose range of Salmonella enterica:
10^7 - 10^9 viable cells
virulence factors of Salmonella enterica (3):
- endotoxins
- enterotoxins
- cytotoxins
virulence factor of Salmonella enterica: part of Lipid A of LPS (only in gram-neg); are absorbed and contribute to symptoms
endotoxins
virulence factor of Salmonella enterica: kill intestinal cells
cytotoxins
since Salmonella enterica cells can take over phagocytic immune cells to prevent them from being destoryed (acting like a virus), they are considered ______ pathogens
invasive pathogens
food infection from Salmonella enterica can occur from _____ ________ of food via handler, lifestock or cross-contamination in the kitchen
fecal contamination
food infection from Salmonella enterica comes from contaminated foods not _______ before consumption
heated (kills it)
onset of Salmonellosis:
8 - 48 hours
T/F: there isn’t a distinguishing symptom of Salmonellosis
true
symptoms of Salmonellosis (6)
- headache
- chills
- vomiting
- diarrhea
- fever
- enterocolitis***
are antibiotics usually given to treat Salmonellosis?
no (doesn’t rlly shorten illness)
duration of Salmonellosis:
2 - 5 days (little longer)
_____-____% of victims of Salmonellosis continues to be carriers of the bacteria for 4-8 weeks in their feces
10-20%
is Escherichia coli gram-positive or negative?
gram-NEG
what shape is Escherichia coli?
coccobacillus (short rods – NOT BACILLUS)
what oxygen level classification is Escherichia coli?
facultative aerobe
source of Escherichia coli =
sewage (GI tracts of animals)
strains of Escherichia coli (4):
- Enterotoxigenic (ETEC)
- Enteropathogenic (EPEC)
- Enteroinvasive (EIEC)
- Shiga Toxin-Producing/enterohemorrhagic (STEC or EHEC)
strain of E. coli: “traveler’s diarrhea;” common in water sources (ex: Mexico); can also produce toxins
Enterotoxigenic (ETEC)
strain of E. coli: infantile diarrhea
Enteropathogenic (EPEC)
strain of E. coli: watery diarrhea; invades phagocytes
Enteroinvasive (EIEC)
strain of E. coli: BLOODY diarrhea; extremely deadly; causes bleeding in GI tract + kidney failure
Shiga Toxin-Producing/enterohemorrhagic (STEC or EHEC)
the Shiga ______ in STEC got it;s name because it is similar to the one made by Shigella dysenteriae
toxin
food that ETEC (Enterotoxigenic) is found in
contaminated drinking water (and foods grown in it)
foods that STEC) is founded in (5):
- undercooked ground beef
- unpasteurized dairy products
- fruit juices
- spinach
- water
T/F: ppl don’t cook raw veggies like lettuce so ppl can get STEC more easily; washing it is not protective
true
Enterohemmorrhagic E. coli (O157:H7) is the leading cause of _______ ______ in CHILDREN :(
kidney failure
what type of foodborne illness is caused by Enterohemmorrhagic E. coli?
food infection
infectious dowse of Enterohemmorrhagic E. coli is unknown, but may be as low as _____ bacterial cells
10
what specific type of toxic does Enterohemmorrhagic E. coli produce?
verotoxin (the Shiga-toxin)
kidney toxin; attaches to the kidney and causes an immune response to attack your own kidneys
verotoxin
what 2 things can verotoxins cause in the human body?
- hemorrhagic colitis
- hemolytic uremic syndrome
bloody diarrhea caused by verotoxins
hemorrhagic colitis
kidney failure caused by verotxins; mortility rate is 50%
hemolytic uremic syndrome
mortality rate of hemolytic uremic syndrome = _____%
50%
Enterohemmorrhagic E. coli has an extremely _______ infectious dose
low
Enterohemmorrhagic E. coli bacteria are destroyed by proper _____ treatment
heat
onset of Enterohemmorrhagic E. coli food infection:
3-5 days (several days)
symptoms of Enterohemmorrhagic E. coli (4):
- bloody stool
- kidney failure
- brain damage
- death
*fever + vomiting are rare
duration of Enterohemmorrhagic E. coli food infection =
5-10 days
___________ cases of Enterohemmorrhagic E. coli food infection occur in the US per year, with ______ resulting in death
73,000
60
4th leading cause of foodborne illness
Campylobacter
____% of chicken and turkey carcasses are contaminated with Campylobacter
90%
are Campylobacter gram-positive or negative?
gram-NEG
what shape is Campylobacter?
spiral shaped rods*
what oxygen level classification is Campylobacter?
microaerophilic (like less than atm. oxygen)
T/F: Campylobacter is not motile
false (it is!)
source of Campylobacter:
GI track of animals (chickens, turkeys, hogs, household dogs)
how can Campylocbacter be destroyed (4)?
- pasteurization
- sensitive to air
- freezing
- gastric acid
T/F: Campylocbacter is heat-tolerant
true
Campylobacter is termed heat toleratn bc they grow at ____°C, not at _____°C
42°C (like warm temp.), not 25°C
what type of foodborne illness does Campylobacter cause?
food infection
more than ____ _______ cases of Campylobacter food infection occurs every year in the US
2 million
which two species of Campylobacter are most commonly linked to foodborne illness?
C. jejuni + C. fetus
foods involved in Campylobacter food infection (4):
- poultry
- pork
- raw clams *
- dairy
Campylobacter multiplies in the _______________ and then invades the _________
small intestine; epithelium (of the instestine)
since Campylobacter colonizes the small intestines and then invades the epithelium, it is termed “_________”
enterovasive
what kind of toxins does Campylobacter produce?
- enterotoxin
- cytotoxin
Campylobacter toxins: _________ causes intestinal distress and __________ kills epithelial cells
enterotoxin; cytotoxin
infectious dose of Campylobacter:
500 - 10^4 bacteria (pretty low)
ppl who are take _______ are more susceptible to Campylobacter food infection
anti-acids (raises pH of stomach)
onset of Campylobacter =
2-10 days
symptom of Campylobacter (2)
- *****HIGH fever (>104°F)
- ulceration of ileum (occasionally) and some bloody feces
*vomiting uncommon
duration of Campylobacter:
1-10 days (can be a long time)
is Listeria monocytogenes gram-positive or negative?
gram-POS
what shape is Listeria monocytogenes?
coccobacillus
what oxygen level classification is Listeria monocytogenes?
facultative anaerobe
what kind of tolerances is Listeria monocytogenes (3)?
- psychotolerant (grow in fridge!)
- acid-tolerant
- salt-tolerant
sources of Listeria monocytogenes (4):
- soil
- water
- vegatation
- silage (grass)
or any food tbh
foods that Listeria monocytogenes is found in:
- uncooked meat
- fruit + veg
- processed foods
- unpasteurized milk + milk products
T/F: we eat Listeria monocytogenes all the time
true (only the immunocompromised get it)
who are the most VULNERABLE to Listeriosis (4)?
- very old
- very young
- immunocompromised
- PREGNANT
will you get antibiotics for Listeria monocytogenes?
no
Listeria monocytogenes proliferates in ___________ so it is termed a ______ pathogen
phagocytes; invasive
infectious dose of Listeria monocytogenes:
<1000 in susceptible individuals** (low dose for them)
Listeria monocytogenes is known for causing what in certain individuals?
miscarriages
there are fewer than ______ cases of Listeria monocytogenes food infection per year
100
while there are few cases, Listeria monocytogenes is said to cause ____% of all the DEATHS from foodborne illnesses
20%
onset of Listeria monocytogenes:
few days - 2 months
how long does it take for gastrointestinal symptoms from Listeria monocytogenes to occur?
> 12 hours
since it could be a few days to MONTHS for Listeiosis to appear, it is said to have. a long _______ period
incubation
symptoms of Listeria monocytogenes
- bacteremia (bacteria in blood)
- meningitis
- miscarriage**
duation of Listeriosis:
usually 5-10 days
responsible for the largest meat recall in the US (2002)
Listeriosis
along with the largest meat recall, Listeriosis also called a ________ recall in 2011
cantaloupe (didn’t wash em before selling)
what should at-risk people not eat to avoid Listeriosis (4)?
- soft cheeses
- refrigerated smoked meats
- deli meats
- undercooked hot dogs
how many ppl died from the Listeriosis cantaloupe recall?
33 ppl
most foodborne infections are thought to be caused by ______
viruses
symptoms of viral food infections (3):
gastroenteritis charactertized by:
- diarrhea
- nausea
- vomiting
incubation period of viral food infections:
12-24 hours
recovery of viral food infections is _____ and _______
spontaneous + rapid (usually within 24-48 hours)
how long is recovery typically for viral food infections?
24-48 hours (quick! = 24 hr flu)
______ viruses are responsible for most mild foodborne infections in the US
Noro
Noro viruses cause ___ _______ out of the ___ ______ foodborne illnesses in the US
9 million out of 13 million
which viruses collectively cause 100,000 cases in the US (3)?
- rotavirus
- astrovirus
- hepatitis A
“diarrhea virus”
rotavirus
how are Noro viruses spread?
food + fecal contamination
Noro viruse is related to the ______ virus
polio
cell-associated __________________ are responsible for the symptoms of salmonellosis
enterotoxins + endotoxins
what 2 protozoans are known for causing foodborne diseases?
1) Giardia intestinalis
2) Cryptosporidium parvum
Giardia intestinalis + Cryptosporidium parvum are known for causing “________ / _______ diarrhea”
back-packers / wilderness
Giardia intestinalis + Cryptosporidium parvum can be spread via food (contaminated by ______ matter in untreated water that is used to wash, irrigate, or spray crops, and via drinking water (+ fruits/veg grown in water)
fecal
what kind of foods are involved in Giardia intestinalis and Cryptosporidium parvum growth?
- fresh foods such as fruit, often IMPORTED from other countries
a protozoan spread through CAT FECES or undercooked meat (espeically pork) or mice
Toxoplasma gondii
T/F: if youre not treated for Giardia intestinalis, it can REOCCUR
true
the life cycle of Toxoplasma gondii is through a _____ gut to reproduce
cat’s
Toxoplasma gondii can cause ____ like symptoms
flu
prenatal infection from Toxoplasma gondii can cause _____ and _____
blindness + stillbirth
who is most at risk for Toxoplasma gondii infection?
pregnant women
there is a hypothesis that Toxoplasma gondii causes something mentally in _____ where they are attracted to cats
mice
cryptosporidium protozoa make ______ that are resistant to ______
cysts; chlorine
in 1993, there was a outbreak of cryptosporidium protozoa in the water source in _________
Milwaukee
aside from water sources, cryptosporidium protozoa can also occur in ______
animals
infectious agent made of PROTEINS that cause disruption in neural tissue; mechanism is unclear; GENETIC link; misfolded protein that causes other proteins to misfold
prion
prions are very STRONG, where you have to put them at _____°F for several hours to denature it
900°F (no way to kill it logistically before consuming so just don’t eat it)
symptoms of prion disease (4):
- depression
- loss of motor coordination
- dementia
- death
linked to consumption of meat products (BEEF) from cattle afflicted with BSE (prion)
vCJD (Variant Creutzfeldt-Jakob disease)
vCJD =
mad cow disease
it is believed that mad cow disease came from feeding cow _____
cow (cannabolism)
if there is one “mad cow” in the herd, what do you have to do?
kill the whole herd
vCJD (mad cow disease) causes _____ in brain tissue + symptoms that resemble _____
holes; dementia
there is now a ban on feeding cattle _____ and ____ meal to stop the development of new cases of BSE in Europe
meat + bone
there have been no case of vCJD in the US, only where?
Great-Britain
food safety measures (4):
- clean (wash hands + surfaces often and fuits/veg)
- separate (don’t cross contaminate)
- cook (to proper temp)
- chill (refrigerate promptly)
ways refrigerate perishable food within ______ hours
2 hrs
if temp is above ____°F, you should refrigerate food within 1 hour
90°F
use cooked leftovers within _____ days
4
should you wash meat?
no, creates microscopic tears in meat + and aerosal in the air
does container size matter for leftovers?
yes, smaller is better (large containers can go anoxic with endospore prod. and it takes longer to get to 4°C)
