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Charakterystyka toksyny wymiotnej Bacillus cereus

100%

Berthold A., Doroszkiewicz B.

Medycyna Weterynaryjna

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2009

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tom 65

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nr 01

15-19

Cereulide, an emetic toxin produced by specific Bacillus cereus strains, is neither able to degrade starch, nor can it ferment salicin, and shows weak haemolysis. It is a cyclic low-molecular (1.2 kDa) ring-shaped peptide. Cereulide is resistant to heat (121°C/90 minutes), digestive enzymes, trypsin and pepsin. Pathological symptoms evoked by cereulide are nausea and vomiting, which may occur 1 to 5 hours after the ingestion of a contaminated food product and continue for about 24 hours. Cereulide causes changes in hepatic cell mitochondria (vacuolation) that consequently lead to liver damage. The toxic dose for an adult is 400-500 µg of cereulide. Since it is a very widespread species in the environment, there is a high risk of Bacillus cereus-mediated food poisoning. The main cause of this type of food poisoning are products containing boiled or fried rice and foods rich in starch, such as pasta. Since the condition has a short duration, cases of emetic type food poisoning provoked by cereulide are frequently not even reported to the health service authorities and are therefore highly underestimated in official statistics. The presence of L-leucine, or L-valine aminoacids in a product markedly intensifies the process of the emetic toxin production by Bacillus cereus. Cereulide synthesis is also positively affected by the presence of oxygen. The optimal temperature for cereulide formation ranges from 15 to 20°C, whereas its production at 8-10°C or at a temperature exceeding 35°C is minimal.

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Cereulidyna i enterotoksyny Bacillus cereus sensu lato

100%

Bartoszewicz M., Swiecicka I., Buczek J.

Medycyna Weterynaryjna

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2006

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tom 62

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nr 01

28-31

Bacillus cereus sensu lato is composed of: Bacillus cereus sensu stricto, Bacillus thuringiensis, Bacillus anthracis, Bacillus mycoides, Bacillus pseudomycoides, and the recently described Bacillus weihenstephanensis. Most of these have a great impact on human activity. B. cereus and B. anthracis are well-known pathogens of mammals (including humans); B. thuringiensis is a commonly used insecticide, while B. mycoides improves plants growth. The psychotropic B. weihenstephanensis is a serious problem in food cold-storing. B. cereus s.s. produces one emetic toxin causing emesis and at least six different enterotoxins such as: hemolytic enterotoxin (HBL), non-hemolytic enterotoxin (NHE), enterotoxin T (BcET), hemolysin II, cytotoxin K (CytK), and enterotoxin FM (EntFM). HBL, NHE, and CytK have been involved in food poisoning. The other bacilli of the B. cereus group are also reported to produce enterotoxins which may lead to serious outbreaks of illness. Thus, the consequences of the above study in the area of food safety need to be seriously evaluated.

3

Czynniki patogennosci bakterii z grupy Bacillus cereus

100%

Bednarczyk A., Daczkowska-Kozon E. G.

Postępy Mikrobiologii

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2008

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tom 47

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nr 1

51-63

Ograniczanie wyników

2 Medycyna Weterynaryjna

1 Postępy Mikrobiologii

1 Bartoszewicz M.

1 Bednarczyk A.

1 Berthold A.

1 Buczek J.

1 Daczkowska-Kozon E. G.

1 Doroszkiewicz B.

1 Swiecicka I.

1 2009

1 2008

1 2006

Charakterystyka toksyny wymiotnej Bacillus cereus

Cereulidyna i enterotoksyny Bacillus cereus sensu lato

Czynniki patogennosci bakterii z grupy Bacillus cereus