ch 32: Waterborne and Foodborne bacterial and viral diseases

____ is the cause of Listeriosis which may lead to bacteremia and meningitis. It is psychotolerant & No food product is safe from contamination.

Listeria monocytogenes

Nonperishable foods have low moisture content and have a much _____shelf life than either perishable or semi-perishable foods.

Longer

_____cause nearly 100,000 cases of severe foodborne invasive gastroenteritis each year

Shigella spp.

______organisms are those that can gain access to the food and use the available nutrients.

Spoilage ex. Escherichia coli frequently contaminates meat products because it is found in animals' digestive tracts.

Signs. symptom of cholera

Vomiting, copious watery feces, "rice-water stool" Fluid losses of 1 liter per hour in severe cases Loss of blood volume, acidosis, potassium depletion, muscle cramps, severe thirst, flaccid skin, and sunken eyes, leading to convulsions and coma Hypotension, tachycardia, cyanosis, shock (55-70% mortality)

causes foodborne infections from contaminated meats and dairy products can lead to life-threatening enteric fever

Yersinia enterocolitica

Enteroinvasive E. coli:

bacillary dysentery, blood and mucus in the stool, more common in developing countries.

Fresh foods are spoiled by both _____and ____.

bacteria and fungi

Enteroaggregative E. coli:

causes diarrhea in young patients and AIDS patients.

ex. of prions: variant Creutzfeldt-Jakob disease (vCJD) linked to

consumption of meat from cattle suffering with bovine spongiform encephalopathy (BSE), a prion disease

Campylobacter is transmitted to humans via______ ex: -replicates in : -causes:`

contaminated -raw poultry, pork, raw shellfish, or in surface waters -small intestine -causes high fever, headache, malaise, nausea, abdominal cramps, and bloody stools

Prions: proteins that adopt novel conformations that inhibit normal protein function and cause ______ of neural tissue

degeneration

Presence of indicator organism signals potential for ____

disease

All pathogenic strains of E.coli are intestinal parasites, and a few produce potent _____.

enterotoxins

Staphylococcus aureus produces heat-stable ____

enterotoxins

signs/symptoms of legionellosis

fever, cough, aches, headaches

Legionellosis is identified by

fluorescence microscopy

Clostridium perfringens and Clostridium botulinum cause serious_____ due to endospores that mey bot be killed during cooking/canning process

food poisoning

disease that results from ingestion of foods containing preformed microbial toxins The microorganisms that produced the toxins do not have to grow in the host.

food poisoning/ intoxication

Salmonellosis is a _______ illness caused by foodborne Salmonella infection. Onset of the disease occurs eight to 48 hours after ingestion. Disease normally resolves in two to five days.

gastrointestinal

Bacillus cereus

grows in food that is cooked and left to cool slowly causes diarrhea and vomiting

Salmonella's Ability to cause disease is dependent on its ability to adhere to _____. It has a high ID50

gut mucosa.

Potable and recreational water are routinely tested for specific -______

indicator organisms ex. coliform bacteria: E.coli

L. monocytogenes is an ______pathogen. Uptake of the pathogen by phagocytes results in the growth and proliferation of the bacterium. Mortality rate:

intracellular 16%, particularly in pregnant women and fetuses.

Perishable foods typically have higher _______content and must be stored in conditions to limit microbial growth.

moisture

Botulinum toxin is a ______but is destroyed by heat

neurotoxin

____Responsible for most infections. Rotavirus, hepatitis A virus, and astrovirus are responsible for the rest

noroviruses

Treatment of cholera

oral rehydration therapy

Salmonella ingested in food or water invades _____ and grows as an intracellular pathogen.

phagocytes

Accumulation of PRPSC proteins cause ____and spongiform damage in the brain

plaques

enteroviruses such as _____,______, and _____are shed into food or water from feces.

poliovirus, norovirus, and hepatitis A

The goal of food preservation is to ___the growth of spoilage microbes.

slow

Enterotoxins of S. aureus classified as _____produce large T cell response and an inflammatory response.

superantigens

Enterotoxigenic E. coli:

traveler's diarrhea, watery diarrhea, low-grade fever, nausea, and vomiting.

t/f Enterotoxin is produced in the intestinal tract six to 15 hours after consumption.

true

t/f Treatment for Legionellosis with antibiotics is effective

true

t/f: Many common foods are preserved, produced, or enhanced by the actions of microbes.

true

t/f: Most E.coli are nonpathogenic . A few strains are foodborne pathogens

true

t/f: The chemical composition of a food determines its susceptibility to microbial spoilage.

true

S. enterica ser. (typhi) causes _______ and has been virtually eliminated in developed countries as a result of water treatment.

typhoid fever

Diffusely adherent E. coli:

typically associated with the development of urinary tract infections; may play a role in inflammatory bowel disease.

Cholera is caused by

vibrio cholerae -transmitted through contaminated water

The largest numbers of annual foodborne infections are thought to be caused by ____

viruses

Products of fermentation include

yeast bread, cheese, yogurt, buttermilk, sausage, sauerkraut, and soy sauce

Food spoilage

-any change in appearance, smell, or taste of a food product that makes it unpalatable to the consumer -Food may still be safe to eat but is regarded as unacceptable

Waterborne diseases can cause a variety of different diseases and are caused by a variety of different types of pathogens. Common sources of transmission include:

-potable water used for drinking and cooking -recreational water from public ponds, lakes, swimming pools, etc.

kill specific bacteria such as Listeria and Salmonella

Bacteriophage

Most common cause of bacterial diarrhea in the United States: more than 2 million cases of bacterial diarrhea per year

Campylobacter

Botulism is a severe and often fatal food poisoning caused by an exotoxin produced by _________ _______

Clostridium botulinum

Vibrio cholerae characteristics:

Comma-shaped rod with single polar flagellum Virulence due to enterotoxin

Proteinaceous infectious particles:

Contain no genetic material Cause transmissible spongiform encephalopathies Creutzfeldt-Jacob disease (CJD) Gerstmann-Strussler-Scheinker disease Kuru Fatal familial insomnia Scrapie in sheep and goats Bovine spongiform encephalopathy (BSE)

Removes moisture needed by microbes for growth Solar drying and commercial dehydration Not reliable: many microbes withstand _______

Desiccation

T/F : canning is always 100% effective

False (failure results in swollen cans.. dont eat)

is the anaerobic catabolism of organic compounds (generally carbohydrates).

Fermentation

microbial infection resulting from the ingestion of pathogen-contaminated food followed by growth of pathogen in the host

Food infection

food poisoning is also called_____ is often caused by toxins produced by _____

Food intoxication Staphylococcus aureus.

______allows for longer storage but isn't suitable for all foods.

Freezing

used to reduce the bacterial load (i.e., pasteurization) of a product or to actually sterilize it (i.e., canning)

Heating

Most common viral cause of food-borne disease in the United States. -fecal/oral transmission or via contamination of food and water -Profuse, watery diarrhea for 3 - 5 days, vomiting in the early stages -Low infectious dose: 1 - 20 viruses -Many outbreaks associated with cruise ships

Norovirus

Normal protein in the brain (PRPC) is transformed into a prion protein (_______).Altered protein spontaneously converts other PRPC proteins into _______proteins

PRPSC

The causative agent of Legionellosis

Pathogenic group of gram negative bacteria in the genus Legionella -common to terrestrial and aquatic habitats -resistant to heating and chlorination -common in cooling towers and evapotative condenders of large air conditioning systems *infection not spread from person to person

Enteropathogenic E. coli:

Profuse, watery diarrhea, with fever and vomiting, produce effacement of gut surfaces.

Important foodborne diseases are caused by Giardia intestinalis, Cryptosporidium parvum, and Toxoplasma gondii, which are ____ -can be spread in foods contaminated by fecal matter in water used to wash, irrigate, or spray crops. Fresh fruits are often the source of these infections.

Protist -Toxoplasma gondii can be spread by raw or undercooked meat.

slows microbial growth rate and delays spoilage

Refrigeration

Worldwide, the most important pathogenic bacteria transmitted by water are

Salmonella enterica serovar Typhi and Vibrio cholera.

______ include foods like fresh fruits and vegetables that also must be stored with care to limit microbial growth.

Semiperishable foods

How is legionella transmitted

aerosols