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Berthold-Pluta A.,Zaklad Biotechnologii Mleka Katedry Biotechnologii | Pluta A.,Zaklad Biotechnologii Mleka Katedry Biotechnologii | Leszcz G.,Zaklad Biotechnologii Mleka Katedry Biotechnologii
Medycyna Weterynaryjna | Year: 2011

Bacillus cereus-mediated food poisoning of the diarrhoea! type is related to the production of the following extracellular factors by the bacteria: haemolysin BL (enterotoxin HBL), non-haemolytic toxin (NHE), and cytotoxin (CytK), as well as haemolysins IV and cereolysin O, both of which have been scarcely examined and discussed in the literature. This article reviews the literature containing current data that revise former theories on the pathogenesis of the diarrhoeal form of B. cereus-mediated food poisoning. The results of in vitro studies confirming the survival of vegetative cells in the stomach and intestine environment prove that the biological state of the examined bacteria does not have any influence on the occurrence of the diarrhoeal syndrome. After contaminated food has been ingested, B. cereus spores/vegetative cells pass the stomach and reach the small intestine. There the spores can germinate to become vegetative cells that multiply and produce enterotoxins. The enterotoxins, finally, affect the intestinal epithelium, which results in diarrhoea. So far this type of food poisoning has been attributed to enterotoxin activity, excluding any kind of interaction between the host and the microorganism. However, according to the results of the latest research, the interaction between the epithelial cells and the cells of B. cereus contributes to the occurrence of infection symptoms, and the adhesion of B. cereus to the intestinal epithelium is prerequisite for the onset of the diarrhoeal syndrome. This article illustrates different aspects of B.cereus survival inside the human gastrointestinal tract, paying special attention to its lower part, i. e. the small intestine. The effect of exposure to bile salts and other factors, as well as to the indigenous microflora of the gastrointestinal tract, on B.cereus survival has been discussed. The article also elucidates issues relating to the mechanism of bacterial-epithelial cell cross-talk (interaction), which is induced when a pathogen comes into contact with enterocytes.

Berthold-Pluta A.,Zaklad Biotechnologii Mleka Katedry Biotechnologii | Pluta A.,Zaklad Biotechnologii Mleka Katedry Biotechnologii | Zaniecka M.,Zaklad Biotechnologii Mleka Katedry Biotechnologii
Medycyna Weterynaryjna | Year: 2011

Among regional Polish dairy products, such as redykołka, bundz, and bryndza cheeses, the most popular one is oscypek cheese. Oscypek is a cheese produced in over a dozen districts of the mountainous Podhale region. It is obtained from raw sheep milk or a blend of sheep and cow milk mixed in appropriate proportions. Oscypek is a pasta filata type of cheese, smoked or unsmoked. The aim of the research was to evaluate the microbiological quality of oscypek cheeses produced in the Podhale region. In total, 32 samples of cheeses were examined: 16 samples of smoked cheeses and 16 samples unsmoked. The following parameters were measured: total bacteria count (TBC), most probable number (MPN × g-1) of coliform bacteria and Escherichia coli, MPN of Clostridium perfringens, and counts of yeasts and moulds. Coliform bacteria and E. coli, the microorganisms used as indicators of manufacturing hygiene, were present in all samples. The MPN of coliforms exceeded 10 2 per 1 g in 81% of the smoked oscypek cheese samples and in 88% of the unsmoked ones. C. perfringens spores were present in 19% of all samples, but their MPN × g-1 did not exceed 10. The presence of moulds and yeasts was established in 63% and 100% of the cheese samples, respectively. Moulds and yeasts were present in the amounts of 10-103 and 10 2-105cfu/g, respectively, in the smoked cheeses, and in the amounts of 10-104 and 103-105 cfu/g, respectively, in the unsmoked cheeses. The presence of coliforms in all the oscypek samples examined indicates deficiencies in production hygiene. This was also confirmed by the considerable percentage of cheese samples contaminated with moulds and yeasts. However, the number of these microorganisms was comparable with their presence in similar cheeses produced industrially from raw sheep milk or pasteurized cow milk. In the case of oscypek cheeses, the process of smoking may lower the TBC and the number of moulds and yeasts by approx. 1 log row compared with unsmoked oscypek cheeses. However, cheese smoking does not reduce the number of coliforms, E. coli and C. perfringens.

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