Exam 2 Flashcards
Parasites are split into 2 groups: ___ and ___
Protozoans (single cell)
Heminths (worms)
Parasites, viruses, and prions Can/Can Not grow in food. They enter food by infected handler, infected harvester, contaminated irrigation water/rinse water
Can NOT
Name the 5 protozoans
- Cryptosporidium (GI)
- Cyclospora (GI)
- Toxoplasma
- Giardia (GI)
- Entamoeba histolitica (GI)
Cryptosporidium (GI)
Transmission: RTE foods, salads, fruits, unpasteurized apple cider
Symptoms: severe diarrhea (25-50 stools/day) for 2-3 weeks
Tx: control diarrhea replace electrolytes (fluids), antibiotics may work
Additional facts: caused largest waterborne outbreak in US hx, resistant to chlorine, immunocompromised are high risk
Cyclospora (GI)
Transmission: grapes, berries, raw vegetables, leafy greens
Onset: contaminated irrigation/rinse water
Symptoms: severe diarrhea (1 month), cramps, loss of appetite, nausea (CAN)
Tx: antibiotics may work
Additional facts: commonly found in Guatemala and Chile, 20,000 cases/yr
Toxoplasma
Transmission: consuming infected undercooked meat, cat sheds organism in feces –> litter box emptied
Symptoms: acute) chills, fever, headache, and fatigue. chronic) hepatitis, heart damage, brain inflammation. Disease often chronic
Tx: antibiotics
Additional facts: brain, heart, skeletal muscle and eye affected. Immunocompromised are high risk - cancer/transplant pts, aids, elderly, fatal in fetuses but if not fatal can cause mental retardation and blindness due to serious toxoplasma infections
Giardia (GI)
Transmission: contaminated water, RTE foods, salads, fresh vegetables, fruits
Onset: contaminated food handler/water
Symptoms: foul diarrhea, mostly affects diapered children in daycare
Tx: anti-parasiticals
Additional facts: most common parasite in US, flagellate comes in 2 forms: 1) in GI tract –> trophozoite (active form) attaches to wall of small intestine 2) in stool –> cyst form (resting stage) very resistant to environment
Entamoeba histolitica (GI)
Transmission: RTE foods, salads, contaminated water
Symptoms: chronic diarrhea lasting months
Tx: anti-parasiticals
Additional facts: very common in developing countries, attaches to wall of large intestine (mucosa), commonly seen in nursing homes and prisons, in stool –> forms cyst –> resistant to environment, left untreated will form amoebic dissentary
Name the 3 types of helminths
- Nematodes (roundworms)
- Trichinella and Ascaris
- Cestodes (tapeworms)
- Trematodes (flute worms)
Nematodes (roundworms)
- Trichinella
Transmission: meat of polar bears, seals, and walruses (Alaska), used to be common w/ undercooked pork in southern US
Morphology: Adult form –> worms, Immature form –> larvae, larvae hatches in stomach and enters muscle an organ tissue
Symptoms: small amount = painful but will survive, large amount (>5000) = fatal, can experience severe allergic rx
Prevention: freezing meat for 1 month, cooking meat properly
Additional facts: brain and heart affected
Nematodes (roundworms)
- Ascaris
Transmission: fecal/oral, dogs
Morphology: adult female lays eggs –> eggs hatch and larvae enter lungs –. coughing sends them to GI tract (feces)
Symptoms: low # = asymptomatic, high # = may plug GI tract, can cause allergic rx
Additional facts: 1 mil cases (pigs) in north america
Cestodes (tapeworms)
Transmission: undercooked pork, beef, fish
Onset: fecal/oral
Morphology: segmented worm –> head (scalix), tail (proglottid). Absorbs nutrients from intestine, can grow between 25 - 30 ft long
Symptoms: low # = asymptomatic, high # = malnutrition, abdominal discomfort, and vitamin deficiencies
Tx: anti-parasiticals
Trematodes (flute worms)
Affects GI and urinary tract
Name the 4 types of viruses
- Hepatitis A
- Hepatitis E
- Hepatitis B
- Norovirus
Hepatitis A
Transmission: fecal/oral from infected food handlers
Symptoms: Liver inflammation, often with jaundice lasting 2-4 weeks
Prevention: vaccine
Additional facts: Long incubation period of 10-50 days, no carrier state
Hepatitis E
Transmission: fecal/oral from contaminated water, raw foods
Symptoms: Liver inflammation
Prevention: proper cooking, no vaccine
Additional facts: very common in developing countries, Long incubation period of 10-50 days, no carrier state, 20% fatality rate of pregnant mothers and fetus
Hepatitis B
Transmission: bodily fluids, mother to child
Symptoms: similar to Hep A/E
Prevention: vaccine
Additional facts: 20% fatality rate in pregnant women, common in developing countries
Norovirus “barf bug”
Transmission: fecal/oral from food handler, Infects mucosal cells of the small intestine, kills them and spreads through GI tract
Symptoms: Vomiting and diarrhea lasting 1-2 days
Additional facts: Common in schools and residential institutions, stays viable in environment for long periods, No long-lasting immunity, Low infectious dose (1 viruses)
Prions
- Infectious proteins
- Highly resistant to disinfectants and heat and aren’t
destroyed by cooking - Converts normal proteins into beta-pleated sheets
Name the 5 types of prion diseases
- Scrapie
- Kuru
- Mad cow disease
- CJ disease
- Chronic wasting disease
Scrapie
- Disease of sheep
- Unusual activity, lose balance and death
Kuru
- In New Guinea natives that were cannibals
- Mainly women and children affected
- Causes holes in brain
Mad cow disease
- Appeared in adult cattle in the 1980’s
- AKA bovine spongiform encephalopathy
- Fatal
variant CJ disease
- Infections in humans appeared in the 1990’s
- Transmitted during a transplant or from eating contaminated meat
- Same symptoms and outcome (death) as mad cow disease
Chronic wasting disease
- Transmissible spongiform encephalopathy (TSE)
- Primarily affects deer, elk, and moose
Lactic Acid Bacteria (LAB)
- A large group of bacteria that ferment sugars to form lactic acid
- Often used to make fermented dairy products (yogurt, cheeses,
etc. ) - LAB starter cultures are added to pasteurized milk
- The acid produced reduces the pH to reduce spoilage
Foods using LAB
● Yogurt ● Buttermilk ● Sour cream ● Cheeses ● Sauerkraut – from cabbage ● Pickles – from cucumbers ● Sausages
Yeast-based fermentation
- Yeasts break down sugars to ethanol and CO2
- Carbon dioxide production is used to make bread rise
- Ethanol production is used in making various alcoholic beverages
but also commercial alcohol – gasoline additives, etc.
Yeast-based products
● Breads ● Beer ● Wine ● Vinegar ● Cocoa ● Coffee ● Soy sauce
Spoilage organisms
- Spoilage: any unacceptable change n a food’s color, texture, taste,
or smell - Meat, poultry, and fish: spoilage usually by Pseudomonas and
related bacteria - Spoilage of bread, fruits, and vegetables: usually molds
Molds
- Many mold species, in addition to spoilage, produce dangerous
toxins in improperly stored foods - Some of these toxins are highly poisonous at the part per BILLION
level!
Aflatoxins
- From Aspergillus flavus growth in improperly stored grains
- Produces liver damage and death after acute exposure to high levels and liver cancer after long-term chronic exposure to low levels
- Animal feed may kill cow, etc. Humans: milk can lead to liver cancer, Peanuts < 10 pph
Ochratoxins
- From other Aspergillus and Penicillium species
- Causes severe kidney damage from both acute and chronic exposure to contaminated barley, wheat, and bread from these grains
Trichothecenes
- From Fusarium species in contaminated wheat, corn, barley, and foods from these grains
- It is suspected that numerous countries have produced
trichothecenes as biological weapons
Ergot
- From Claviceps purpurea on rye
- Two separate toxin types are produced:
- Gangrenous – causing severe vasoconstriction and
potential loss of limbs due to inadequate circulation
- Convulsive – causing bizarre behavior, coma, and death in extreme cases (LSD) - Now rare, but occurred sporadically in the Middle Ages
What are the 2 types of Antimicrobial Preservatives?
Chemical and natural
Antimicrobial Preservatives
● Action: Inhibition of growth rather than killing
● Examples: organic acids – acetic, benzoic, lactic, propionic, and sorbic. Used in wide variety of foods
● Nitrites: Used in cured meats (bacon, hot dogs, bologna)
● Phosphates
● Sodium chloride: Used for centuries; reduces the water activity of a food
● Sulfites: Used mostly for preserving fruits and vegetables
● Chlorine: For sanitizing water and equipment surfaces and treating meat and poultry surfaces
● Quat’s
● Peroxides: Used for equipment surfaces
● Ozone: Water for food processing
Natural Preservatives
● Lysozyme – a natural enzyme from various sources, used in some countries
● Lactoferrin – can be used in milk
● Avidin – an egg protein
● Spices and oils – cloves, cinnamon, oregano, thyme, and sage
● Onion and garlic
● Phenolics – in wood smoke. For meats, fish, and poultry
Probiotics
- Bacteria, usually certain lactic acid bacteria, whose
consumption promotes a “good” flora of the intestinal tract
-
Organic Food
- Food produced using methods that do not involve use of synthetic pesticides and fertilizers, do not contain GMOs, and are not processed using irradiation, industrial solvents, or chemical food additives
- Products must be produced by suppliers with organic certification by the federal government
- Organic certification: Animal manure limited to crops harvested >60 days after application
Problems with organic food
- Enforcement
- Price
- Quality
- Yield
- Use of animal manures presents a possible exposure to
disease microbes - Note: in organic production, sick animals can be treated with abx, but supposedly cannot, after recovery, be returned to ORGANIC use (but can be used for regular products)
Physical methods - Food preservation
● Have not been proven to be more nutritious
● Dehydration – reduces the water activity; product may be shelf-stable
● Refrigeration/Freezing – long used for extended food storage but does not KILL microbes, only prevent their growth
● Heat treatment
● Pasteurization – mild heat treatment to kill nonsporeforming pathogens
● Canning – usually steam under pressure for a time to assure killing of Cl. Botulinum spores
● UHT/HTST: Ultrahigh temp tx usually allow shelf storage of product but may affect taste. HTST tx of milk provides a longer refrigerated shelf life
● Cooking – reduces the microbial content of a food but doesn’t necessarily kill all bacteria, especially sporeformers, so subsequent refrigeration is required if food is not consumed immediately
● Radiation – a relatively new method to extend shelf life but consumer fears require “treated by irradiation” label
Hazard analysis critical control points and good manufacturing practices
- Defect action levels – allow federal regulators to take actions to remove a product from the market if exceeded
- Examples: four or more rodent hairs per 100 gram of apple butter!!!! Mammalian excreta of 100mg or more per pound of cocoa beans!!
HACCP
A food manufacturing program that takes preventative steps at each potentially hazardous step in production of a food product and keeps accurate records of these steps
Food Recall
A voluntary action by a company to protect consumers
from potentially adverse effects of a contaminated, adulterated, or misbranded product. If a company refuses a recall, the appropriate government agency can step in to detain the product and stop production if there is a danger to public health.
Responsible Regulatory Agencies
- Dept. of Agriculture: meat and poultry
- Food and Drug Admin: other foods including fruits, vegetables, fish, and shellfish
- USDA: regulate pasteurized eggs; FDA regulates other egg products
What are the 5 controls used for milk to avoid milk spoilage and food posing.
- good dairy farm sanitation
- safe milk tanker transport from farm to plant
- good milk plant processing
- safe transport from plant to store
- adequate storage/shelf life monitoring in store
what technique is the major control for commercial milk. In use in US for over 100 years
pasteurization
Describe 2 reason for why pasteurization is good control for commercial milk?
- the heat process destroys all pathogen in the milk products
- it extends shelf life by reducing spoilage bacteria
Describe the most common pasteurization process for milk
- 165F for 15 seconds
- Requires refrigeration - shelf life typically 16 to 21 days
Describe the Ultra high temperature pasteurization process for milk
- 282 for 2 seconds
- Plus aseptic packaging - allow long term storage at room temp
describe the ultrapasteurization process for milk
similar to ultra high temp pasteurization, but storage at refrigeration temp -typical shelf life 70 days
Why do organic milk last longer than non organic milk?
many organic producers use ultrapasterization
This organic brand milk uses pasteurization techniques
organic valley brand milk
What are two food poisoning agents that use to be common in milk, but are now rare in the U.S.?
- bovine tuberculosis
2. brucellosis
What are the 6 current food poisoning agents in milk?
- salmonella
- Shigella
- campylobacter
- yersina
- toxin producing e.coli
- listeria
Can pasteurization eliminate all of the current food poisoning agents in milk?
yes
t/f) some health-conscious groups believe that raw milk contains some major substances essential to health that are destroyed by pasteurization.
true
(t/f) current federal regulations require milk sold over state lines to be pasteurized
true
Despite over 100 hundred year of scientific evidence proving that pasteurization of milk is beneficial, what do people who support raw milk claim?
They argue that a hundred years ago, before pasteurization,people drank raw milk without ill effects
Why can’t we just let the people that want raw milk suffer the consequences
they want consumption of raw milk not just for themselves, but for their small children, & infections with milk pathogens often affect children, especially babies, much more seriously than adults–sometimes with fatal outcomes
In Miller’s Organic farm case study, what food was infected (1) and what was disease agent that caused it (2)?
- raw chocolate milk
2. listeria monocytogenes
In the Miller’s Organic farm case study, what linked the listeria strains to the 2 ill elderly people in 2014 (1 in cali and 1 in flordia) (1)? how many people died (2)?
- genetic fingerprinting
2. 1 (the guy from Florida)
What law was broken Miller’s Organic farm case study?
the sale of raw milk over state lines
Which agency regulates milk production (1) and who enforces these regulations (2)
- FDA
2. each state
(t/f) each state has at least 1 FDA-certified & inspected milk testing lab
true
What lab is the FDA-certified & inspected milk testing lab in Mississippi
State Public Health Lab
How often are raw milk from dairy farms tested?
monthly
How often are pasteurized milk (all sizes 1/2 pints to gallon; all levels of butterfat content, & all brands sold in state) tested
at least every 3 months
What are the 3 test done to test microbiolgic quality in Raw milk?
- somatic cell count
- standard plate count
- antibiotic screening
What is the somatic cell count test for raw milk
an indirect test that checks for the number of cow leukocytes (white blood cells) present.
What is a recurring problem in dairy cows due to udder infections. This infection causes the cow’s immune system to produce white blood cells
mastitis
What is the standard plate count test for raw milk
it determines the total number of bacteria present
Describe the antibiotic screening for raw milk.
Sick cows require treatment, but some people are highly allergic to small quantities of certain antibiotics. Each tanker of raw milk is checked for presence of PENICILLIN-class antibiotics, & there are monthly random screes for other antibiotics.
(t/f) Positive tankers in the antibiotic screening of raw milk cannot be processed, & 1000’s of gallons of milk must be disposed of.
true
(t/f) The coliform count test is done raw milk?
false
-it is only done on pasteurized milk, all raw milk contains coliforms
t/f) coliforms are usually harmless, however there has been indication of recent fecal contamination in milk?
true
t/f) it is easier to test for coliforms than all the possible milk pathogens?
true
What is the purpose of the coliform count in pasteurized milk?
it serves as an indirect measure of adequate pasteurization
Regulation of coliform allows howmay coliform/ml in a product?
<10 coliforms/ml
(t/f) milk is one of the most highly regulated & tested food product
true
(t/f) it is not possible to guarantee 100%, but raw milk is one of the safest food products available
false
-it is not possible to guarantee 100%, but raw milk is one of the safest food products available
