This type of bacterium is responsible for food poisoning although it has a positive effect in the form of a probiotic food additive for animals.
Bacillus cereus or B. cereus for short causes food poisoning as a result of improperly prepared and stored food. This allows these bacteria to multiply and produce ‘enterotoxins’ which are the direct cause of this illness.
The bacillus cereus bacteria
Each bacterium has a long, rod shaped appearance and is capable of causing a range of gastrointestinal illnesses which include food poisoning.
These bacteria are found in animals such as rabbits and pigs and birds such as chickens. They are found along with the salmonellaand campylobacter bacteria and can often dominate these two strains of bacteria.
There are several strains of the bacillus cereus bacteria, some of which are beneficial to animals but others are harmful to humans.
The beneficial strains are used to produce probiotic feed for animals which boosts their growth as well as reducing the number of salmonella bacteria within their digestive systems.
This also reduces the risk of salmonella food poisoning in humans.
Causes of bacillus cereus poisoning
This illness occurs via ingestion of contaminated food.
A good example of this is when food is not cooked at the correct temperature which results in it being undercooked. This situation is compounded when the undercooked food is then stored in the fridge at the wrong temperature.
This results in warm, undercooked food which is a ripe breeding ground for germs and bacteria.
These bacteria thrive in these conditions and produce spores –a series of seed like structures. These spores produce toxins (called ‘enterotoxins’) which are heat resistant and cause two types of food poisoning.
To reiterate: these bacteria cause food poisoning but this food poisoning is split into the following two versions which are:
- Diarrhoeal illness
- Emetic (vomiting) illness
Two different types of toxins cause these two forms of food poisoning.
In both cases they are caused by the consumption of infected foods due to improper cooking and storage methods. Examples of these foods include rice, chicken and red meat.
Other foods which are associated with this food poisoning include:
- Unpasteurised milk
- Cheese and cheese based products
- Starches such as rice and potatoes
Symptoms of bacillus cereus
The symptoms differ according to which of the two versions of food poisoning has been contracted.
If you have developed the diarrhoeal version then you will experience the following symptoms:
- Upset stomach
- Abdominal pain/cramps
- Watery diarrhoea
These symptoms appear 6 to 15 hours after consumption and last for 24 hours or more.
Be aware that these symptoms can mimic those of clostridium perfringens food poisoning. This can make it difficult to diagnose.
The emetic or vomiting version includes:
- Stomach cramps
Diarrhoea may occur although this tends to be rare. This type of food poisoning often develops after eating undercooked rice which is later reheated –resulting in these bacteria releasing a toxin which causes these symptoms.
This type of food poisoning occurs quickly, often within a few hours. These symptoms usually last for less than 24 hours.
This too, can mimic the symptoms of other types of food poisoning, for example staphylococcus aureus.
Treatment for bacillus cereus poisoning
This is the same as for any other type of food poisoning. It involves rest and drinking plenty of fluids especially fluids which contain electrolytes.
These electrolytes help to replace salts, e.g. sodium and minerals lost as a result of vomiting and/or diarrhoea.
Serious cases of food poisoning will require hospital treatment which includes fluids being given intravenously.
Medication such as antibiotics may be prescribed as these are effective against bacterial infections. However, some strains of bacteria have developed a resistance to them which cancels out their effectiveness.
Preventing bacillus cereus poisoning
Prevention is better than cure. This means following a few, food safety precautions which include the proper cooking and storage of food products for consumption.
- Reading instructions carefully about cooking times
- Storing food in the fridge at the correct temperature
- Avoid placing raw food on top of or next to cooked food
- Using separate chopping boards, utensils etc for raw and cooked foods.
- Wash your hands before preparing, cooking and storing food. Wash them again afterwards.
Food Poisoning Guide
- Food Poisoning
- What is food poisoning?
- Food poisoning or gastroenteritis?
- High risk for food poisoning
- Foods which are likely to cause food poisoning
- Types of food poisoning
- Chicken food poisoning
- Beef food poisoning
- Pork food poisoning
- Fish food poisoning
- Ciguatera poisoning
- Scombroid poisoning
- Bacterial food poisoning
- E coli
- Staphylococcus aureus
- Clostridium botulinum
- Campylobacter jejuni
- Vibrio parahaemolyticus
- Vibrio cholerae
- Bacillus cereus
- Clostridium perfringens
- Yersinia Enterocolitica
- Enterobacter sakazakii
- Viral food poisoning
- Entamoeba histolytica
- Mushroom toxins
- Red kidney bean toxins
- Shellfish toxins
- Causes of food poisoning
- Symptoms of food poisoning
- Diagnosing food poisoning
- Treatment for food poisoning
- Home based treatment
- Medical treatment
- Follow up treatment
- Complications of food poisoning
- Lactose intolerance
- Irritable bowel syndrome
- Kidney failure
- Haemolytic uraemic syndrome
- Reactive arthritis
- Guillain-Barre syndrome
- Reporting food poisoning
- Preventing food poisoning
- Cross contamination
- Food irradiation
- Food safety and your family
- Pregnancy and food poisoning
- Babies and food poisoning
- Children and food poisoning
- Teenagers and food poisoning
- Elderly and food poisoning
- Research into food poisoning
- Food Poisoning FAQs