cereulide and Vomiting

Topics: Animals; Bacillus cereus; Bacterial Proteins; Depsipeptides; Diarrhea; Enterotoxins; Foodborne Diseases; Gene Expression Regulation, Bacterial; Gram-Positive Bacterial Infections; Hemolysin Proteins; Host-Pathogen Interactions; Humans; Virulence; Vomiting

Bacillus cereus is the causative agent of two distinct forms of gastroenteritic disease connected to food-poisoning. It produces one emesis-causing toxin and three enterotoxins that elicit diarrhea. Due to changing lifestyles and eating habits, B. cereus is responsible for an increasing number of food-borne diseases in the industrial world. In the past, most studies concentrated on the diarrhoeal type of food-borne disease, while less attention has been given to the emetic type of the disease. The toxins involved in the diarrhoeal syndrome are well-known and detection methods are commercially available, whereas diagnostic methods for the emetic type of disease have been limited. Only recently, progress has been made in developing identification methods for emetic B. cereus and its corresponding toxin. We will summarize the data available for the emetic type of the disease and discuss some new insights in emetic strain characteristics, diagnosis, and toxin synthesis.

Topics: Bacillus cereus; Bacterial Toxins; Base Sequence; Depsipeptides; Diarrhea; DNA, Bacterial; Enterotoxins; Foodborne Diseases; Humans; Molecular Sequence Data; Vomiting

Bacillus cereus is an opportunistic foodborne agent causing food poisoning and many infectious diseases. The heat-stable emetic toxin cereulide is one of the most prevalent toxins produced by pathogenic B. cereus, resulting in symptoms such as emesis and liver failure. In the present work, the toxicity and toxicokinetics of cereulide from an emetic B. cereus isolate (CAU45) of raw milk were evaluated. The production of cereulide was tested by a cytotoxicity test and enzyme immunoassay, and confirmed by the presence of the ces (cereulide synthetase) gene and the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. All results showed that the amount and toxicity of cereulide produced by CAU45 was 7 to 15.3 folds higher than the reference emetic B. cereus DSMZ 4312. Cereulide in plasma was collected at different time points after a single intravenous injection to evaluate its toxicokinetics in rabbits. The maximum concentration of cereulide was achieved in 2.6 ± 3.4 h after administration, with the elimination half-life of 10.8 ± 9.1 h, which expands our understanding of the toxic effects of cereulide. Together, it suggests that urgent sanitary practices are needed to eliminate emetic toxins and emetic B. cereus in raw milk.

Topics: Animals; Aspartate Aminotransferases; Bacillus cereus; Bacterial Toxins; Depsipeptides; Female; Food Contamination; Male; Milk; Rabbits; Vomiting

A Bacillus cereus-related emetic outbreak was reported in a Belgian kindergarten. High levels of emetic B. cereus (>1.5E+07 colony-forming units/g) were detected in the food leftovers, and the presence of an emetic strain was confirmed in feces. Emetic toxin levels ranging up to 4.2 μg/g were also quantified in the leftovers by liquid chromatography coupled to tandem mass spectrometry (LC-MS(2)) analysis. Those levels, although moderate in comparison with earlier published intoxications, provoked profuse-vomiting episodes in 20 toddlers aged between 10 and 18 months. Few studies have focused on the levels of emetic toxin implicated in food intoxications. This publication emphasizes the importance of defining toxic doses of emetic toxin among high-risk population groups.

Topics: Bacillus cereus; Belgium; Chromatography, Liquid; Colony Count, Microbial; Depsipeptides; Disease Outbreaks; Food Contamination; Food Handling; Foodborne Diseases; Humans; Infant; Stem Cells; Tandem Mass Spectrometry; Vomiting

Bacillus cereus, the Gram-positive and spore-forming ubiquitous bacterium, may cause emesis as the result of food intoxication with cereulide, a heat-stable emetic toxin. Rapid determination of cereulide-positive B. cereus isolates is of highest importance due to consequences of this intoxication for human health and life. Here we present a 1-day pulsed-field gel electrophoresis for emetic B. cereus isolates, which allows rapid and efficient determination of their genomic relatedness and helps determining the source of intoxication in case of outbreaks caused by these bacilli.

Topics: Bacillus cereus; Depsipeptides; Electrophoresis, Gel, Pulsed-Field; Food Contamination; Foodborne Diseases; Humans; Vomiting

Cereulide, the emetic Bacillus cereus toxin, is synthesized by cereulide synthetase via a nonribosomal peptide synthetase (NRPS) mechanism. Previous studies focused on the identification, structural organization, and biochemical characterization of the ces gene locus encoding cereulide synthetase; however, detailed information about the transcriptional organization of the ces genes was lacking. The present study shows that the cesPTABCD genes are transcribed as a 23-kb polycistronic transcript, while cesH, encoding a putative hydrolase, is transcribed from its own promoter. Transcription initiation was mapped by primer extension and rapid amplification of cDNA ends (RACE). Deletion analysis of promoter elements revealed a main promoter located upstream of the cesP coding sequence, encoding a 4'-phosphopantetheinyl transferase. This promoter drives transcription of cesPTABCD. In addition, intracistronic promoter regions in proximity to the translational start sites of cesB and cesT were identified but were only weakly active under the chosen assay conditions. The identified main promoter was amplified from the emetic reference strain B. cereus F4810/72 and fused to luciferase genes in order to study promoter activity in complex environments and to establish a biomonitoring system to assess cereulide production in different types of foods. ces promoter activity was strongly influenced by the food matrix and varied by 5 orders of magnitude. The amount of cereulide toxin extracted from spiked foods correlated well with the bioluminescence data, thus illustrating the potential of the established reporter system for monitoring of ces gene expression in complex matrices.

Topics: Amino Acid Sequence; Bacillus cereus; Bacterial Toxins; Base Sequence; Depsipeptides; DNA Primers; DNA, Bacterial; Environmental Monitoring; Food Microbiology; Foodborne Diseases; Gene Expression; Genes, Bacterial; Genes, Reporter; Humans; Molecular Sequence Data; Multigene Family; Peptide Synthases; Promoter Regions, Genetic; Vomiting

Bacillus cereus can cause diarrheal and emetic types of food poisoning but little study has been done on emetic type of food poisoning in Korea. The objective of this study was to report on the emetic type of food poisoning associated with B. cereus in Korea. The toxin gene profile, toxin production, and antibiotic resistance of B. cereus isolates were investigated in this study. B. cereus was detected in three out of four samples, while the other food poisoning bacteria were not detected. All isolates (KUGH 10, 11, and 12) presented nhe A, B, and C diarrheal toxin genes (755, 743, and 683 bp), detected using NHA, NHB, and NHC primers, and ces emetic toxin gene (1271 bp), detected using CES primer, and produced nonhemolytic enterotoxin and emetic toxin (cereulide), detected using immunochemical assay and high performance liquid chromotography/mass spectrometry (HPLC/MS) analysis. All emetic-associated isolates were resistant to beta-lactam antibiotics. Most important finding in this study was that the risk of emetic-type B. cereus food poisoning has existed in Korea. This suggested that the food poisoning caused by B. cereus producing emetic and diarrheal toxins should be constantly evaluated to prevent misdiagnosis between emetic and diarrheal types of food poisoning.

Topics: Anti-Bacterial Agents; Bacillaceae Infections; Bacillus cereus; beta-Lactams; Chromatography, High Pressure Liquid; Depsipeptides; Diagnosis, Differential; Diarrhea; Disease Outbreaks; Drug Resistance, Bacterial; Enterotoxins; Foodborne Diseases; Humans; Korea; Microbial Sensitivity Tests; Oryza; Protein Isoforms; Seeds; Spectrometry, Mass, Electrospray Ionization; Vomiting

Bacillus cereus causes two types of gastrointestinal diseases: emesis and diarrhea. The emetic type of the disease is attributed to the heat-stable depsipeptide cereulide and symptoms resemble Staphylococcus aureus intoxication, but there is no rapid method available to detect B. cereus strains causing this type of disease. In this study, a polymerase chain reaction (PCR) fragment of unknown function was identified, which was shown to be specific for emetic toxin producing strains of B. cereus. The sequence of this amplicon was determined and a PCR assay was developed on this basis. One hundred B. cereus isolates obtained from different food poisoning outbreaks and diverse food sources from various geographical locations and 29 strains from other species belonging to the B. cereus group were tested by this assay. In addition, 49 non-B. cereus group strains, with special emphasis on food pathogens, were used to show that the assay is specific for emetic toxin producing B. cereus strains. The presented PCR assay is the first molecular tool for the rapid detection of emetic toxin producing B. cereus strains.

Topics: Bacillus cereus; Bacterial Toxins; Depsipeptides; DNA, Bacterial; Foodborne Diseases; Humans; Peptides, Cyclic; Polymerase Chain Reaction; Sensitivity and Specificity; Vomiting

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.

Topics: Bacillus cereus; Bacterial Toxins; Depsipeptides; Emetics; Enterotoxins; Foodborne Diseases; Humans; Hydrolysis; Peptides, Cyclic; Phenotype; Serotyping; Starch; Vomiting

The HEp-2 vacuolation factor (or cereulide) produced by Bacillus cereus isolated from vomiting-type food poisoning, which is supposed to induce emesis, was found to give mouse and suncus lethality after intravenous and intraperitoneal administration. The emetic activity of the factor was also found to be resistant to heating at 121 degrees C for 15 min, exposure to pH 2 and 11, and to digestion with proteolytic enzymes such as pepsin and trypsin. These findings suggest that the cereulide produced by B. cereus is stable in the digestive tracts, induce emesis, and show lethal activity leading to cellular damage.

Topics: Animals; Bacillus cereus; Bacterial Toxins; Depsipeptides; Dose-Response Relationship, Drug; Foodborne Diseases; Injections, Intraperitoneal; Injections, Intravenous; Male; Mice; Mice, Inbred ICR; Peptides, Cyclic; Vomiting