Question

The Biol 2130 students and employees of a public-school system developed diarrheal illness on April 2. The cafeteria served chicken that day. On April 1, part of the chicken was placed in water-filled pans and cooked in an oven for 2 hrs. at a temp of 177oC. The oven was turned off and the chicken was left overnight in the warm oven. Symptoms of the disease included nausea, vomiting, cramping and a fever. All the patients recovered within 24 hrs. Two “serotypes”of a Gram positive, oxidase negative, coagulase positive, cocci were isolated from 32 patients.

a. What was the probable “etiological” agent (pathogen)?

b. What is the most likely source of his infection, and how would you verify this?

c. Explain the difference in an “intoxication” and an infection.

d. Determine if the illness was due to an intoxication or an infection and give the information you based your answer on.

e. What was the probable treatment protocol for this illness? (how were they treated)

f. Explain how this outbreak could have been prevented.

Answer 1

1. Staphylococcus aureus ​​​​​, gram positive, coagulate positive and oxidase negative cocci caused food borne infections. Staphylococcus bacteria are killed by cooking but it's toxins are not destroyed and will cause illness.Staph food poisoning is characterized by a sudden start of nausea, vomiting and stomach cramps. Symptoms usually develop within 30 minutes to 8 hours after eating and last no longer than 1 day.

2. The source of Staphylococcus may be the water in which the chicken is cooked. The bacteria are present in raw water and while cooking contaminate the chicken. The presence of organism can be verified by plating the water sample by serial dilution and check for the presence of bacteria.

3. Food borne intoxication is caused by ingesting food containing toxins formed by bacteria which result from bacteria growth in the food item whereas Foodborne infection is caused by the ingesting of food containing live bacteria which grow and establish themselves in the human intestinal tract.

Salmonella, Campylobacter, E.coli, Listeria contaminate food and when ingested grow in intestines causes food borne infections. Staphylococcus aureus, Clostridium botulinum, Campylobacter jejuni releases toxin when growing in food and cause Foodborne intoxications.

4. The foodborne illness reported in this case is foodborne intoxication. The heat stable endotoxons are produced by Staphylococcus aureus that causes illness. The toxins are heat resistant and when ingested causes diarrhea and vomiting.

5. For most patients, staphlococxal food poisoning will cause a brief illness. The best treatment for these patients are rest, plenty of fluids, and medicines to calm stomach. Highly susceptible patients may require intravenous therapy and care in hospitals. Toxins is not affected by antibiotics.

6. The best way to avoid food poisoning by Staph is to prevent food from being held at unsafe temperatures (between 40°F and 140°F) for more than 2 hours. Cooked food should not be held at room temperature for long time. Store cooked food in refrigerator within 2 hours.

Wash your hands before preparing food.

For preparing food use boiled water.