Food Poisoning BActeria CIEH Level 3.4
Facultative anaerobes
cause of illness – large numbers of the bacteria living in food (infective dose >100,000 organisms/gram of food)
control measures: – separation of raw and high-risk foods and work area – thorough cleaning and disinfection – thorough thawing and cooking of poultry and meat – good personal hygiene – effective pest control
Clostridium perfringens
Anaerobic bacterium/forms spores and an endotoxin
cause of illness – an endotoxin – bacteria multiply rapidly, usually in meat that is cooked – slowly or stored at ambient temperature – spores form in adverse conditions – spores regenerate into bacteria – toxins released when bacteria die in host’s intestines – infective dose 1,000,000 organisms/gram of food
control measures: – strict temperature control – separation of raw and cooked foods – regular removal of all dirt from food areas – careful washing of vegetables
Staphylococcus aureus
Facultative anaerobe/salt tolerant/produces an exotoxin
cause of illness – heat resistant exotoxin produced by bacteria as they multiply on food
control measures: good personal hygiene and especially – hand-washing – storage under refrigeration – effective food hygiene
Bacillus cereus
sources – cereals, soil, dust, vegetation and spices
Emetic illness – caused by exotoxin (associated with cooked rice)
symptoms – nausea and vomiting
onset time – 1–5 hours
Diarrhoeal illness – caused by endotoxin (associated with meat, milk, fish)
symptoms – diarrhoea and abdominal pain
onset time – 8–16 hrs
Bacillus cereus
Aerobic spore-forming bacterium that produces a toxin
cause of illness – one of two types of toxin: exotoxin that is released in the food before it is consumed – causes nausea and vomiting
cause of illness – one of two types of toxin: endotoxin that is released in the intestinal tract – causes diarrhoea and abdominal pain
control measures: thorough cooking and rapid cooling of food – storage under refrigeration – avoidance of reheating – preventing cross contamination
Clostridium botulinum
Anaerobic spore-forming bacterium / produces a heat-sensitive neurotoxin
cause of illness – neurotoxin produced by the bacteria as it multiplies in the food
control measures: high standards in preservation of food e.g. canning (‘botulinum cook’), bottling, vacuum packing - inspecting cans and contents before use – avoiding eating raw and fermented fish in certain parts of world
Credits:
Created with images by skeeze - "salmonella bacteria macro" • NIAID - "Methicillin-Resistant Staphylococcus aureus (MRSA)"