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FoodMicroLecture9/10
Food Micro Midterm 2
What are the top five pathogens which contribute to foodborne illness? | Norovirus, Salmonella, C. perfringens, Campylobacter spp, S. aureus |
What are the three categories of foodborne pathogens? | Infection, intoxication, toxico-infection |
What are the oxygen requirements for S. aureus? | Facultative anaerobe |
What conditions can S. aureus grow in? | Low aw, low pH, high salt |
T or F: S. aureus are generally poor competitors in food. | True |
What are the food sources of S. aureus? | High salt foods, meats |
S. aureus disease acts via _____. | intoxication |
What is the pathway for S. aureus disease? | Toxins are stable in the GI tract and indirectly stimulate the emetic reflux center. |
_____ methods are commonly used to detect S. aureus. | ELISA |
T or F: If enterotoxins in a food are heated enough, they will be killed and will not pose a health risk. | False |
What are the oxygen requirements for Listeria? | Facultative anaerobe |
The growth of Listeria is inhibited at pH ____. | <5.5 |
What are the food sources for Listeria? | Dairy products, frozen meats, RTE meals |
How does Listeria act in the body? | Crosses the intestinal lining, internalized by phagocytes and multiplies intracellularly in the host. |
What are the oxygen requirements for streptococcus? | Microaerophile |
What is the source of streptococcus? | Foods contaminated by those with the disease. |
What are the oxygen requirements of M. bovis? | Aerobe |
M. bovis lacks a _____ _____. | cell membrane |
M. bovis has a ____-rich cell wall, making it highly resistant to disinfectants and detergents. | lipid |
What are food sources of M. bovis? | Dairy and meat products. |
T or F: M. bovis illness can last for years. | True |
M. bovis can be isolated from ____ ____. | lymph nodes |
What are the oxygen requirements of Enterococcus? | Facultative anaerobes |
What are food sources of Enterococcus? | Sausage, dairy products |
What causes Enterococcus contamination? | Processing of food/unsanitary food preparation. |
Enterococcus is often grown on ____ media. | blood |
What are the oxygen requirements for Salmonella? | Facultative anaerobe |
Over 99% of human disease causing Salmonella is due to Salmonella _____ subspecies. | enterica |
T or F: Nontyphoidal Salmonella has more severe symptoms than Typhoidal Salmonella. | False |
The presence of Salmonella indicates ____ contamination. | fecal |
What are the oxygen requirements for C. jejuni? | Microaerophile |
T or F: C. jejuni survives poorly at room temperature. | True |
What are food sources of C. jejuni? | Poultry, raw milk and cheese, contaminated water. |
C. jejuni can cause ____ syndrome, leading to paralysis. | Guillain-Barre |
What are the oxygen requirements for Yersinia? | Facultative anaerobe |
Yersinia is particularly of concern in _____ foods. | frozen |
T or F: Yersinia is more common in adults than children. | False |
____ can survive under vacuum and MAP. | Shigella |
_____ are the only host for Shigella, and are found in their feces. | Humans |
_____ do not need to grow in food to cause disease, a small contamination is enough. | Shigella |
_____ are resistant to extremely harsh conditions although not a spore. | C. burnetii |
_____ is the target organism for determining milk pasteurization conditions. | C. burnetii |
T or F: C. burnetii must be propogated with live tissue. | True |
Cronobacter can survive ____ ____ for long periods of time. | low moisture |
_____ is often associated with infant formula and infants. | Cronobacter |
____ _____ stimulates Vibrio growth. | Sodium chloride |
Vibrio is common in ____ environments. | aquatic |
What are food sources of vibrio? | seafood |
Vibrio _____ is the most serious in the US. | vulnificus |
What is the biological pathway of vibrio? | Pore-forming toxin lyses RBCs and can attack intestinal cells. |
What are the oxygen requirements for E. coli? | Facultative anaerobe |
T or F: E. coli cannot survive stomach conditions. | False |
T or F: Most strains of E.coli are harmless. | True |
What is the biological pathway of E. coli? | Cells adhere to epithelial cells, cause lesions, produce Shiga-like toxins. |
_____ E. coli is most common. | STEC |