Bacillus cereus Infection: Causes, Symptoms and Control
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Ελληνικά (Greek)
Bacillus cereus is a facultative anaerobic type of bacteria that can produce harmful toxins (endospores). This bacterium is resistant to high temperatures and can lead to food poisoning. Most individuals affected by food poisoning caused by Bacillus cereus recover within 12 to 24 hours of the onset of symptoms. Usually, symptoms disappear in 6 to 24 hours.
Types of Bacillus Cereus Bacteria
Bacillus cereus bacteria can cause two types of foodborne illness. The first type (emetic syndrome) produces toxins in food before it is consumed, and the symptoms of food poisoning caused by this type usually appear within 1 to 6 hours after eating the contaminated food. The temperature for emetic toxin production ranges from 77ºF (25ºC) to 86ºF (30ºF). Usually, symptoms disappear in 6 to 24 hours.
The second type (diarrhoeal syndrome) produces toxins inside the intestines, and the symptoms of food poisoning caused by this type usually appear within 6 to 15 hours after consuming contaminated food. Usually, symptoms disappear in 12 to 24 hours after consumption.
Sources of Bacillus cereus Bacteria
Bacillus cereus can be found in various environmental or food sources such as soil, dust, cereals, rice, spices, and dried foods.
Where is Bacillus cereus most commonly found?
Certain foods serve as vehicles for B. cereus, such as fish, dairy, meat, sauces, soups, stews, and sushi, as well as dishes made with improperly cooked pasta, pastry, potatoes, rice, and vegetables, can cause illness. The emetic form of illness (vomiting) is most frequently associated with improperly refrigerated starch dishes, such as fried rice; whereas the diarrheal form of illness is associated with foods containing meat and vegetables.
To prevent contamination by Bacillus cereus bacteria, it is important to follow these guidelines:
- Cook food thoroughly at a temperature of 75 degrees Celsius or above.
- Prevent cross-contamination, make sure to use separate utensils and surfaces for raw and cooked foods.
- After cooking, cool the food rapidly to 41ºF (5ºC) or below and store it at the correct temperature to avoid bacterial growth.
- When preserving food, ensure that it is maintained at the proper temperature.
- When reheating food, make sure to heat it to 75 degrees Celsius or above. Heating (i.e., cooking) to ≥ 145ºF (63ºC) and reheating to 165ºF (74ºC) for 15 seconds will destroy the vegetative (actively growing) cells.
- Heat resistance increases with increasing salinity (presence of salt) and decreases with increasing acidity.
- Hot foods be maintained at a temperature of 135ºF (57ºC) or above and cold foods be maintained at a temperature of 41ºF (5ºC) or below.
- Since foods containing the emetic toxin need to be heated to 249ºF (121ºC) for more than 80 minutes, reheating foods until they are steaming is not enough to inactivate the emetic toxin and efforts should be devoted to prevention.
