Toxin producing spore-formers
34 important questions on Toxin producing spore-formers
What are the two main spore forming toxin producing pathogens and why are they and emerging risk in our food chain?
- Bacillus cereus
- Clostridium perfringens
They are an emerging risk in our food chain because of more minimal processing techniques become popular.
What makes Bacillus cereus and Clostridium perfringens special from other bacteria?
What is the transmission cycle of Bacillus cereus?
The mammals can also contaminate the food and the food can contaminate the humans.
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How do spores work?
How can you kill spores?
More usefull is to wake them up and then kill them.
What are the two types off food pron diseases caused by Bacillus cereus and by what toxins are they caused?
- Diarrhea: enterotoxin
- Vometing: emetic toxin
Why is the number of B. cereus lower in the USA so much lower then in Scandinavia?
What is the hard thing about determining if a product is infected with B. cereus?
That doe the bacteria in the bacilli group have incommen?
- gram positive
- spore forming
- motile
- (an)airobic growth
What is the main difference between the bacilli bacteria?
Why don't we have more outbreaks with Bacillus lichniformis?
What are the 3 groups in which you can subdivide B. cereus?
- mesophilic (can grow up to 50 degrees)
- phychrotophic (can grow up to 40 degrees)
- termophilic (can grow up to 60 degrees)
What can you say about the heat resistance of the different subgroups of B. cereus?
- phychrotrophic is not heat resistant
- mesophilic is heat resistant
- thermophilic is very heat resistant.
What are the infection dose, incubation time, symptomes and duration for B. cereus enterotoxins?
Incubation time: 6-12 h
Symptomes: Abdominal pain, diarrhea
Duration: 12 to 24 hours.
How do the enterotoxin of B. cereus make you sick?
The toxin is simelair to known toxins for staphilococcus for instance.
The toxin damages the epeterial layer of your intestines by making protein holes in the membrane causing free flux of compounds (ions) and because of this you get diarrhea.
What is the role of PlcR in B. cerus?
On the other hand is also causes the production of the toxins.
What is the incubation time, symptoms and duration of food-borne intoxication with emetic toxin of B. cereus?
symptoms: vometing, nausea
How is the emetic toxin of B. cereus called?
What are the stability properties of cereulide?
- Heat resistant up to 121°C
- Stable at pH range 2-11
- Not degraded by pepsin and trypsin
- Not antigenic
Why does cereulide make you sick?
What are the genes involved in producing cerreulide?
Multiple factors control production of cereulide. They can influence its production.
What is the ecological niche and transmission of emetic Bacillus cereus?
- Emetic strains of B. cereus are likely to colonize roots and tubers of plants
- Contamination of plants/raw food upon harvest or by small animals/invertebrates
- When used as fodder, contamination of cow udder and milk
- Emetic strains spores are more thermoresistant than other B. cereus strains spores
- Cooked food enriched in emetic strains which could produce cereulide and cause disease
For what can they use the building in of fluorecence in the toxin producing part of the gens?
What is the highest risk for bacilluc cereus growth production process?
What kind of bacteria is Clostrida perfringens?
Toxins are produced in the GI track.
Spores are resistant to processing and preservation treatments.
What are the toxins produced by Clostridium perfringens that is related with food poisening?
Only 1 to 5% of the Clostridium perfringens produces the CPE toxins.
There are also types present in your GI track. Of course they don't produce the toxins.
What is the appropriate holding temperature, storage temperature and reheating temperature of C. perfringens and what is the growth range and optimal temperature for growth?
storage temperature: <4-12 degrees
reheating temperature: >72 degrees
Growth range is between 15 and 50 degrees
Optimal temperature between 43 and 46 degrees.
What is an important step in your production procedure to prevent C. perfringens growth?
Storage at low temperatures is also important!
What are the USDA-FSIS guidlenes for growth of C. perfringen and C. botulinum?
C. botulinum: no multiplication at all
What is different form the C. Perfringens producing CPE with the other C. Perfringens?
What are the 2 different ways of CPE production?
C-cpe: chromosomal CPE produces
P-cpe: plasmid CPE produces.
What is the difference between the C-cpe and P-cpe?
- enzymes that can metabolis sugars
- 75% cases
- Producing bacteria are more heat resistant
- Producing bacteria grow out during the cooling
P-cpe:
- adaptation to GI track. They produce biotin and entanolamine and by this they can consume lipids of the membranes.
- 25% cases
- Producing bacteria are less heat resistant but grow better at low temperatures
- Producing bacteria can grow out at low temperatures so temperature abuse with insufficient heating is dangerous.
What are the transmition routes of C-cpe and P-cpe producing Clostridium perfringuns?
P-cpe grows inside the body.
What are the control points of Clostridium perfringus?
Training and hygiene food handlers.
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