Week 4- Food and Water Safety f2011student

8/3/2019 Week 4- Food and Water Safety f2011student

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Food and Water Safety

Definitions

Food borne Infections

- Ingestion of ________ microorganisms

- __________ incubation times

Food borne Microbial Intoxication

- Food contains the active toxin

- Incubation time 24 to 48 hours


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Water Contaminants

Physical contaminants

Presence of particulate matter

Chemical contaminants

Industrial activities or agricultural runoff


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Biological contaminants

Overabundance of organisms or presence

of non-native microorganisms


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CDC Risk- The Top Five

Shigella dysenteriae

Escherichia coliO157:H7 (E. coli)

Salmonella species Vibrio cholerae

Cryptosporidium parvum (C. parvum)


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Other,

- Norwalk virus, Hepatitis A and hepatitis E

- Helmiths or worms such as tapeworms,

flukes and round worms

- Fungi and molds


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Shigella dysenteriae

One of four types of __________ bacteria that

produces a diarrhea inducing, disease causing

enterotoxin

All four strains cause dysentery (shigellosis)

S. dysenteriae, S. flexneri, S. boydii, S. sonnei

200 cells could cause infection as little affected by

stomach acids


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S. Dysenteriae

Secretes an exotoxin, Shiga toxin, stops protein

synthesis in its hosts cells

Pathophysiology


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E. Coli 0157:H7

Gram negative rod shaped bacteria with

_____ virulence (as few as 10 organisms)

First described as a cause of human illness

in 1982

E. coli is the most common type of

pathogenic infection ___________


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Sources

Animal and Other Sources

- improperly composted manure- contaminated water*

- spread animal to person and person to

person, _______________


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Food Sources

- undercooked beef- Non pasteurized milk and cheese

- spinach and other fruits and/or vegetables

contaminated with feces


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Pathophysiology ofE.coli0157:H7

Introduces two types of cells into intestinal

cells

Proteins of one type disrupt cell

metabolism

Proteins of another type lodge in cell

cytoplasm and enables this strain to

displace others


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Produces _________ inhibits protein

synthesis, attaches to neutrophil surfaces

and is spread in body widespread

death of host cells and tissue

Antimicrobial drugs __________

production ofShiga-like toxin


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S/S

Some show minimal, or no illness, and

become carriers

bloody or watery diarrhea, cramping,

nausea and vomiting


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Some may develop hemolytic uremic syndrome

(HUS)

Destruction of red blood cells and kidney failure

3-5% mortality

http://www.idph.state.il.us/Bioterrorism/factsheets/food_water_b
http://www.idph.state.il.us/Bioterrorism/factsheets/food_water_borne.htmhttp://www.idph.state.il.us/Bioterrorism/factsheets/food_water_borne.htm


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Vibrio cholerae

The only cholerae species that can survive

in fresh water

Strain 01 El Tor has caused pandemics

Strain 0139 Bengal arose in India in 1992

May be destroyed by stomach acid so size

of infectious dose 108 cells


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Pathophysiology

Cholera toxin enters epithelial cells liningintestine causing loss of sodium andchloride with water following the

electrolytes causing __________


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Oral Rehydration Therapy

Developed by WHO

Fluid/electrolyte replacement with sodium

______________________________________

dissolved in water (similar to Pedialyte)


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Clostridium Botulism

Spore forming anaerobe in water and soil

and, occasionally, animal intestinal tract

Human and animal distinctly different

types

Botulin is the most potent microbial toxin

known to mankind


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Food Sources of Botulism

Spores are present on vegetables or meat at

time of gathering

Reasons for Spread

________ cooking does not reach

sufficient pressure or temperature to kill


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Processing removes oxygen encouraging

growth

Room temperature storage favors spore

germination and growth


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Pathophysiology and S/S

Botulin prevents the uptake of theneurotransmitter substance acetylcholineat the neuromuscular junction

Muscles of head- double vision, difficulty inswallowing but no cognitive lapse

Causes descending muscular paralysis andrespiratory compromise with death fromrespiratory failure


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Norwalk Virus (Norwalk, Ohio)

Cup-shaped enteric virus transferred

orofecally from human to human

Reservoir is _______

camps, day care, cruise ship, nursing home

Gastroenteritis- acute onset with N/V,

cramps, diarrhea, and chills recovery


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Hepatitis

Viral infections of liver necrosis of

hepatocytes and liver inflammation

S/S may include jaundice, malaise, fever,

chills, diarrhea, abdominal pain, and

blood abnormalities

Outcome is recovery to risk of,..


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Food Safety Handling Tipshttp://www.dukehealth.org/health_library/care_guides/cancer/tre

Buy refrigerated foods that are cold and frozen

food that is solid. Shop for these last and get

them home quickly ___________________________________

Place raw meat and poultry in separate plastic

bags to prevent dripping on other foods

Wash your hands with soap and running water

before and after preparing foods
http://www.dukehealth.org/health_library/care_guides/cancer/treatment_instructions/preventing_food_and_water_borne_illnesshttp://www.dukehealth.org/health_library/care_guides/cancer/treatment_instructions/preventing_food_and_water_borne_illness


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Cook meat and poultry to > 165F and eggs untilfirm

Put cooked meat and poultry on a clean platter

Separate raw and cooked foods to avoid crosscontamination

Be careful not to use the same cutting board formeats and vegetables

Wash all surfaces and supplies thoroughly Refrigerate leftovers promptly with maximum of

two hours


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Reheat leftovers to > ________

Bring soups, sauces and gravies to a rolling boil

and then simmer for ten minutes

Avoid preparing food for others if you are ill


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Prevention of Food Spoilage

[Thompson, Manore, Sheeshka)

Salting and sugaring

Drying

Smoking

Cooling

Industrial canning

Pasteurization

Addition of preservatives


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Water Contaminants

Previously done,

Vibro cholerae Shigella spp.

Salmonella spp. E. coli Norwalk Clostridium Botulism

Giardia intestinalis (lamblia)


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Giardia intestinalis

Pathogenic flagellate with________

Infection from flagellate ______ which cansurvive for __________ months in the

environment


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Reservoir

intestinal tracts of humans and animals

(beaver, coyotoes, cats,) world-wide

Water- mountain stream clean and

municipal as chlorine amounts insufficient

[ozone, iodine, boiling]

soil, feces-contaminated surfaces


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Pathophysiology and S/S

Cysts enter duodenum, __________ and

travel to jejunum damage to epithelium

[reversible]

Diarrhea, abdominal pain and flatulence


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Steps in Water Treatment

[Burton text]

Filtration- removal of large debris ie. Branches

Sedimentation- water rests in holding tank

allowing debris to settle to the bottom

Coagulation- Aluminum potassium sulfate added

to resting water to clump the debris


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Filtration- water passes through sand, earth filters,charcoal filters or membrane filters to removeremaining bacteria, protozoas, and others suchas C. Parvum

Chlorination- 0.2 to 1 ppm chlorine gas or othersubstance. In some facilities ozone or ultraviolet

light may be used instead

Multiple places for errors so need to check water

Documents

Week 4- Food and Water Safety f2011student