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55 Cards in this Set
- Front
- Back
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What are the microorganisms that are of concern in food microbiology? |
Bacteria and Fungi (yeast and mold) |
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Describe how bacteria looks like. Shape? Size? |
Spherical, rod-shaped or spiral 1-4 micrometers |
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What's the dehydrated state of bacteria? Describe how it works. |
Spores (endospores). They can survive even under heat, without nutrients, difficult to destroy. When favorable environment comes again, they reactivate. |
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What's the size and shape of the yeasts? |
~20 micrometers, more complex organism, spherical or ellipsoidal |
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What are yeast's positive function? |
Leavening of dough, fermentation of alcohol |
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What are mold's appearance like? |
Larger and more complex than yeasts. The structure is a multicellular filament called hyphae |
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When can mold be functional? |
Mold-ripened cheese production |
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What does microorganisms do to food? Describe in detail |
Microorganisms are essentially an enzyme factory: they degrade food systems enzymatically, some even specialize in a substrate they attack: CHO, protein, lipid. |
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What's the result of the degradation of microorganism on food? |
Change in texture, Off-flavor Gases, acids, polysaccharide, or alcohol production. |
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Does microbials prefer high or low moistured environment? |
High. At low moisture, they are less able to grow. |
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Which of the three microorganisms has the least affinity to moisture? (Though they all really love moisture) |
Molds |
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What are the four categories of microbial according to affinity for temperature? What's their favored growing temperature? |
mesophilic 20-45 thermophilic >45, some up to 82 psychrophilic <10 psychrotrophic 4: fridge T |
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What are the two categories of microbial according to need for oxygen? |
obligate: strictly aerobic or anaerobic facultative: survive in either one |
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What are the two categories of foodborne illnesses? Describe them. |
Food infection: Microorganism established itself in intestine and caused the infection Food intoxication: The toxin produced by the microorganism than causes illnesses. Some combine both. |
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Salmonellosis caused by?
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Salmonella genus bacteria |
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Listeriosis caused by? |
Listeria monocytogenes |
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Campylobacteriosis caused by? |
Campylobacter genus, primarily C.jejuni |
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How fast is the onset of food infection and foot intoxication? |
Minutes to hours Days to weeks |
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What are the three major food-borne infections? |
Salmonellosis Listeriosis Campulobacteriosis |
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What's the oxygen requirement state for Clostridium botulinum? |
Obligate anaerobe. |
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What's the acidity affinity for Clostridium botulinum? What's the line differentiating low-acid and high-acid food? |
Likes low acid (more basic) more concern in low-acid canned food. pH 4.6: Below 4.6, Clostridium cannot reproduce in vegetative state. |
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What's the reason for botulism to happen? |
Clostridium botulinum, producer of botulinum toxin, botox. |
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What's the occurrence of botulism? How dangerous? |
Very rare Usually lethal |
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What's the main vehicle of transmission of Staphylococcal enterotoxins? |
Food handlers. |
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How serious is the intoxication of Staphylococcal enterotoxins? |
Not so serious, since only act on intestines. |
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Where are mycotoxins produced from? |
From molds. |
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What's a hepatotoxin? Name one |
Toxin that damages the liver Aflatoxin, from Aspergillus flavus. Liver carcinogens. |
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What's the most-know enterohemorrhagic toxin- producing strain of the enteral coliform bacteria? |
Escherichia coli O157:H7 |
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What are the examples of food intoxication? |
Aflatoxin (mycotoxins), Aspergiullus flavus Staphylococcal enterotoxin, Staphylococcus Botulinum toxin, Clostridium botulinum |
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What causes combined infection and intoxication |
Escherichia coli O157:H7 (shiga-toxin-producing E.coli: STEC) |
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What are the risky foods f E.coli O157:H7? |
Unpasteurized milk, raw milk cheese, raw meat, etc. |
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What's the possible outcome disease of STEC infection? Occurrence? Symptoms? |
5-10%, hemolytic uremic syndrome. Lysis of RBC, Kidney failure, permanent kidney damage, death. |
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How prevalent is STEC? |
90 annual death in US. 250,000 illnesses. |
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How prevalent is norovirus? |
Almost half of the outbreak of foodborne illness. |
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How is norovirus transmitted? |
Very easily from person to person. Through food or water |
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How serious is the norovirus infection? |
Not so serious. |
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Which viruses can be transmitted in food or water? |
Hepatitis A, poliovirus, etc. |
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How prevalent is protozoan parasites diseases? |
Death of toxoplasmosis is the second leading cause of death. From Toxiplasma gondii |
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What is the surviving environment for T.gondii? |
Can survive outside a host in dormant form cysts or in eggs: oocysts.
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How is T.gondii transmitted? |
In contaminated food or water. In warm-blooded animal, esp. cats In uncooked meat. |
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How serious is toxoplasmosis? |
Serious for weakened immuned people and infants, and transmitted easily in pregnancy. |
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What are the disease caused by Protozoan parasites? |
toxoplasmosis amoebic dysentery. |
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What is dysentery? |
inflammation of the intestine, causing diarrhea with blood. |
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Salmonella main source of carrier? |
Poultry |
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How prevalent is salmonellosis? |
380 death in US/yr 1 million cases. Leading cause of death from foodborne illness |
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Carrier of Listeria? |
Chilled food, so "refrigerator disease" Raw-milk cheese, ready-to-eat meat |
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How prevalent of Listeriosis? |
3rd most prevalent cause of death from food poisoning. |
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How prevalent is Campylobacteriosis? How serious? |
Most foodborne infections worldwide Usually not so serious, but long-term effects. for eg. 40% Guillain-Barre caused by campylobacteriosisC |
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Carrier of Campylobacter? |
Poultry |
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How many E.coli serotypes? Are they all harmful? What's the one noted harmful E.coli strain? What does it do? |
700 and more no. microflora in intestines beneficial, but little produce toxins. shiga-toxin-producing E.coli (STEC), toxin producing, causing RBC lysis |
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What's the first three most prevalent foodbornecause of death in ? |
Salmonellosis Toxoplasmosis (parasite) Listeriosis |
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What's the cause of biggest number of foodborne illness outbreak? |
Norovirus |
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Which pathogenic microorganisms travel in contaminated food and water? |
Toxoplasma gondii. Norovirus |
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Which pathogenic microorganisms travel in poultry? |
Salmonella Campytobacter |
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Which pathogenic microorganisms travel in raw milk and raw meat? |
Listeriosis E.coli O157:H7 |
