A case in point

A day-care center is serving stir-fried rice for lunch. The rice was cooked to the proper temperature for the proper amount of time at 1:00 P.M. The covered rice was then placed on the countertop and allowed to cool to room temperature. At 6:00 P.M., the cook placed it in the refrigerator. At 9:00 A.M. the following day, the rice was combined with the other ingredients for stir-fried rice and cooked to 165 °F (74°C) for at least fifteen seconds. The cook covered the stir-fried rice and left it on the range until she gently reheated it at noon. Within an hour of eating the stir-fried rice, however, several of the children began vomiting, and a few had diarrhea. Samples from some of the children revealed the rice as the probable cause of the outbreak.

Based on the information given, was the illness caused by bacteria, a virus, a parasite, or fungi? What is the name of the microorganism most likely to have caused the outbreak? Is this illness an infection or an intoxication?

Discussion questions

1. Why should potentially hazardous food not be left in the temperature danger zone for more than four hours? Refer to some of the phases of bacterial growth in your explanation.

2. Jams and jellies have water activity levels of about 0.75. Based on this information alone, do they provide an environment favoring bacterial growth? Explain your thinking.

3. In what ways are viruses and bacteria similar? How are they different?

4. What is the difference between a foodborne infection and foodborne intoxication?

5. Why is it important to use multiple barriers to prevent bacterial growth? What are some examples that illustrate your reasoning?

Multiple-choice study questions

1. To what does the acronym FAT TOM refer?

A. The major types of microorganisms that can cause foodborne illness

B. The conditions supporting the growth of microorganisms

C. Human health hazards associated with food high in fat and sodium

D. The federal agency responsible for monitoring food safety

2. All of the following conditions typically support the growth of microorganisms except

A. Moisture.

B. A protein or carbohydrate food source.

C. High acidity.

D. Temperatures between 4l °F and 140 °F (5 °C and 60 °C).

3. A person who has a foodborne infection most likely has eaten a food containing

A. a ciguatoxin C. a plant toxin

B. histamine D. a live pathogen

4. Which food is more likely to transmit parasites to humans?

A. Improperly cooked eggs

B. Improperly frozen sashimi

C. Improperly refrigerated milk

D. Unpasteurized apple juice

5. Which of the following is not a basic characteristic of foodborne mold?

A. It grows well in sweet, acidic food with low water activity.

B. Freezing temperatures prevent or slow its growth, but do not destroy it.

C. Its cells and spores may be killed by heating, but the toxins it produces may not be destroyed.

D. It needs a host to survive.

6. Which of the following statements regarding foodborne intoxication is true?

A. Symptoms of intoxication often appear days after exposure.

B. Medical treatment for intoxication can be painful.

C. Foodborne intoxication is more common than foodborne infection.

D. Symptoms of intoxication appear quickly, within a few hours.

7. Which of the following microorganisms is most likely to cause a foodborne infection?

A. Listeria monocytogenes

B. Staphylocoecus aureus

C. E. coli 0157: H7

D. Clostridium botulinum

8. Which of the following microorganisms is most likely to cause a foodborne intoxication?

A. Staphylococcus aureus

B. Listeria monocytogenes

C. Campylobacter jejuni

D. Salmonella

9. Which of the following foods is commonly associated with an outbreak of Bacillus cereus?

A. Cooked rice

B. Juices

C. Raw chicken

D. Shell eggs

10. Which of the following foods is commonly associated with an outbreak of Vibrio.?

A. Raw oysters

B. Unpasteurized milk

C. Apple cider

D. Sliced melons

Unit 3