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