Production of an Emetic Toxin, Cereulide, Is Associated with a Specific Class of Bacillus cereus
Nagoya University, Nagoya, Aichi, Japan Current Microbiology
(Impact Factor: 1.42).
06/1996; 33(1):67-69. DOI: 10.1007/s002849900076
The emetic toxin (cereulide) of Bacillus cereus was quantified in several isolates of B. cereus and in various food sources. When the emetic toxin was produced, vomiting-type food poisoning was observed in humans. We
also found that the H-1 serovar phenotype was strongly associated with the production of cereulide and that none of the isolates
that hydrolyzed starch or expressed diarrheal enterotoxin activity produced cereulide.
Available from: hal.archives-ouvertes.fr
- "Interestingly, in the present study, 37% of the isolates were amylase negative. According to previous reports (Agata et al. 1996; Valero et al. 2002), the inability to hydrolyze starch has been indicative of emetic subtype. This indicates high prevalence of emetic subtype in dairy products analyzed in the present study. "
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ABSTRACT: Bacillus cereus group, associated with foodborne outbreaks and dairy defects such as sweet curdling and bitterness of milk, is an indicator of poor hygiene, and high numbers are unacceptable. In the present study, the prevalence of B. cereus group was investigated in a total of 230 samples belonging to eight different types of dairy products marketed in India. The prevalence of B. cereus group in cheese, ice cream, milk powder, and milk was high (33%-55%), whereas it was low in butter and paneer samples (20% and 4%, respectively). None of the curd and khoa samples were found contaminated. The level of contamination in the various dairy products was up to 10(8) cfu.g(-1) or mL(-1). An antibiogram of 144 isolates of B. cereus group was obtained using 14 different antibiotics commonly used against foodborne diseases. All the 144 isolates were multidrug (at least five antibiotics) resistant. Ninety-three percent of them exhibited beta-hemolysis. Of the 144 isolates, 97%, 96%, and 63% were capable of producing protease, lipase, and amylase, respectively, indicating spoilage potentiality of the isolates. Seventy-one percent of the isolates formed biofilm at 4 A degrees C. The principal component analysis allowed classifying different correlated variables into two types of risks (spoilage and food poisoning). Hierarchical cluster analysis classified isolates into four main groups on the basis of the studied characters. The present study will help to better assess the health and spoilage risk associated with B. cereus group in dairy environment and to incorporate adequate preventive measures.
Available from: Siele Ceuppens
- "Consumption of food contaminated with B. cereus can lead to two types of food-borne gastrointestinal illnesses, namely the emetic and diarrheal syndrome. The former illness is caused by the extremely stable emetic toxin cereulide, produced during bacterial outgrowth in the food, which remains functional after most food processing and digestive activities (Agata et al., 1996; Rajkovic et al., 2008; Shinagawa et al., 1996). The diarrheal type of food-borne disease is caused by multiple enterotoxins, such as haemolysin BL (Hbl), nonhemolytic enterotoxin (Nhe) and cytotoxin K (CytK) (Al-Khatib et al., 2007; Beecher et al., 1995; Lund et al., 2000; Lund and Granum, 1996; Midura et al., 1970). "
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ABSTRACT: There is an interest to understand the fate and behaviour of the food-borne pathogen Bacillus cereus in the gut, a challenging environment with a high bacterial background. We evaluated the current detection methods to select an appropriate strategy for B. cereus monitoring during gastrointestinal experiments. Application of quantitative real-time PCR (qPCR) in a gastrointestinal matrix required careful selection of the qPCR reaction and elaborate optimization of the DNA extraction protocol. Primer competition and depletion problems associated with qPCR reactions targeting general 16S rRNA gene can be avoided by the selection of a target sequence that is unique for and widespread among the target bacteria, such as the toxin gene nheB in the case of pathogenic B. cereus. Enumeration of B. cereus during the ileum phase was impossible by plating due to overgrowth by intestinal bacteria, while a carefully optimized qPCR enabled specific detection and quantification of B. cereus. On the other hand, plating allowed the distinction of viable, injured and dead bacteria and the germination of spores, which was not possible with qPCR. In conclusion, both plating and qPCR were necessary to yield the maximal information regarding the viability and physiology of the B. cereus population in various gastrointestinal compartments.
Available from: Andreja Rajkovic
- "xins , respectively . The cereulide production has been tested using the bio - assay , employing the known inhibitory effect of the toxin to the boar spermatozoa motility ( Andersson et al . , 1998 ) . Only strains that were found negative on HBL production and that gave negative starch hydro - lyses reaction were tested for cereulide production ( Agata et al . , 1996 ; Pirttijarvi et al . , 2000 ) ."
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ABSTRACT: Refrigerated processed foods of extended durability (REPFED) potato puree was analysed for Bacillus cereus contamination along the production line and during the product shelf-life. Isolated B. cereus strains were tested for their psychrotrophic character and the ability to produce enterotoxins. Bacillus cereus contamination during four subsequent productions was in the range of 2.3–4.0 log cfu g)1 . Productions five and six were significantly less contaminated with B. cereus (£1 log cfu g)1). All B. cereus isolates from the first four productions were able to grow at 7 ° and 10 °C, whereas the majority of the isolates from productions five and six did not. No B. cereus isolates grew at 4 °C. randomly amplified polymorphic DNA (RAPD) fingerprinting showed that the most of B. cereus contamination originated from one source. In total, 30.4% of isolates expressed enterotoxic character. The present study points out the necessity to prevent an 'in house' colonisation and contamination during food processing in order to accomplish the safety of REPFED throughout the shelf-life. It also indicates the most critical steps in the production line of ready-to-eat potato puree and impact of failures regarding the food safety. The data provided can be used for risk assessment studies regarding B. cereus in REPFED.
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