scholarly journals The Food Poisoning Toxins of Bacillus cereus

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 98 ◽  
Author(s):  
Richard Dietrich ◽  
Nadja Jessberger ◽  
Monika Ehling-Schulz ◽  
Erwin Märtlbauer ◽  
Per Einar Granum
Keyword(s):  
Bacillus Cereus ◽  
Diarrheal Disease ◽  
Current Knowledge ◽  
Food Poisoning ◽  
Toxin Production ◽  
Gastrointestinal Diseases ◽  
High Variability ◽  
Target Cells ◽  
Toxin Secretion ◽  
Hemolysin Bl

Bacillus cereus is a ubiquitous soil bacterium responsible for two types of food-associated gastrointestinal diseases. While the emetic type, a food intoxication, manifests in nausea and vomiting, food infections with enteropathogenic strains cause diarrhea and abdominal pain. Causative toxins are the cyclic dodecadepsipeptide cereulide, and the proteinaceous enterotoxins hemolysin BL (Hbl), nonhemolytic enterotoxin (Nhe) and cytotoxin K (CytK), respectively. This review covers the current knowledge on distribution and genetic organization of the toxin genes, as well as mechanisms of enterotoxin gene regulation and toxin secretion. In this context, the exceptionally high variability of toxin production between single strains is highlighted. In addition, the mode of action of the pore-forming enterotoxins and their effect on target cells is described in detail. The main focus of this review are the two tripartite enterotoxin complexes Hbl and Nhe, but the latest findings on cereulide and CytK are also presented, as well as methods for toxin detection, and the contribution of further putative virulence factors to the diarrheal disease.

scholarly journals Exposure to Bacillus cereus in Water Buffalo Mozzarella Cheese

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1899
Author(s):  
Angela Michela Immacolata Montone ◽  
Federico Capuano ◽  
Andrea Mancusi ◽  
Orlandina Di Maro ◽  
Maria Francesca Peruzy ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Water Buffalo ◽  
Diarrheal Disease ◽  
Food Poisoning ◽  
Mozzarella Cheese ◽  
Food Borne ◽  
Genes Encoding ◽  
Spoilage Bacterium ◽  
Hemolysin Bl

Bacillus cereus is a spoilage bacterium and is recognized as an agent of food poisoning. Two food-borne illnesses are caused by B. cereus: a diarrheal disease, associated with cytotoxin K, hemolysin BL, non-hemolytic enterotoxin and enterotoxin FM, and an emetic syndrome, associated with the cereulide toxin. Owing to the heat resistance of B. cereus and its ability to grow in milk, this organism should be considered potentially hazardous in dairy products. The present study assessed the risk of B. cereus poisoning due to the consumption of water buffalo mozzarella cheese. A total of 340 samples were analyzed to determine B. cereus counts (ISO 7932:2005); isolates underwent molecular characterization to detect the presence of genes encoding toxins. Eighty-nine (26.1%) samples harbored B. cereus strains, with values ranging from 2.2 × 102 to 2.6 × 106 CFU/g. Isolates showed eight different molecular profiles, and some displayed virulence characteristics. Bacterial counts and the toxin profiles of isolates were evaluated both separately and jointly to assess the risk of enteritis due to B. cereus following the consumption of buffalo mozzarella cheese. In conclusion, the results of the present study showed that the risk of poisoning by B. cereus following the consumption of this cheese was moderate.

The Use of Nisin as a Preservative in Crumpets

1994 ◽  
Vol 57 (10) ◽  
pp. 874-877 ◽  
Author(s):  
I. JENSON ◽  
L. BAIRD ◽  
J. DELVES-BROUGHTON
Keyword(s):  
Ambient Temperature ◽  
Bacillus Cereus ◽  
Shelf Life ◽  
Food Poisoning ◽  
Toxin Production ◽  
High Moisture ◽  
Naturally Occurring

Crumpets, a high moisture flour based product, have been implicated in food poisoning due to growth and toxin production by naturally occurring Bacillus cereus during 5-day storage at ambient temperature. Bacillus cereus isolates from untreated crumpets at the end of their shelf-life were shown to be sensitive to nisin. Addition of nisin to the batter at levels of 3.75 μg/g and above effectively prevented the growth to levels capable of causing food poisoning. The fate of nisin during the production and shelf-life of the crumpet was determined.

Genetic Diversity, Antimicrobial Resistance, and Toxigenic Profiles of Bacillus cereus Strains Isolated from Sunsik

2012 ◽  
Vol 75 (2) ◽  
pp. 225-230 ◽  
Author(s):  
NARI LEE ◽  
JE MIN SUN ◽  
KYUNG YOON KWON ◽  
HYUN JUNG KIM ◽  
MINSEON KOO ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Fruits And Vegetables ◽  
Food Poisoning ◽  
Pcr Analysis ◽  
Contamination Level ◽  
Detection Rates ◽  
Its Gene ◽  
Hemolysin Bl ◽  
Encoding Genes ◽  
Element Sequence

Bacillus cereus can cause emetic and diarrheal types of food poisoning, but little study has been done on the toxins and toxin-encoding genes of B. cereus strains isolated from Sunsik, a Korean ready-to-eat food prepared from grains, fruits, and vegetables. In this study, 39 unique B. cereus strains were isolated and identified from Sunsik samples, with an average contamination level of 10 to 200 CFU/g. The detection rates of the hblACD, cytK, and bceT genes among all the strains were 48.7, 66.7, and 87.1%, respectively. All 39 B. cereus strains carried nheABC and entFM genes, and 36 strains also had the ces gene, which encodes an emetic toxin. Nonhemolytic enterotoxin and hemolysin BL enterotoxin were produced by 39 and 26 strains, respectively. The strains were separated into 13 profiles based on the presence or absence of toxins and their genes, as determined by antibody tests and PCR analysis. Profile 1 was the largest group, comprising 30.7% (12 of 39) of the B. cereus strains tested; these strains harbored all toxins and their genes. The B. cereus strains were susceptible to most of the antibiotics tested but were highly resistant to β-lactam antibiotics. The repetitive element sequence polymorphism PCR fingerprints of the B. cereus strains were not influenced by the presence of toxin genes or antibiotic resistance profiles. Our results suggest that B. cereus strains from Sunsik could cause either the diarrheal or emetic types of food poisoning because all strains isolated contained at least one toxin and its gene, although the level of B. cereus contamination in Sunsik was low.

scholarly journals DETECTION OF HBLD TOXIN GENE BY BACILLUS CEREUS ISOLATED FROM MEAT CURRY FOOD SAMPLES IN MALAYSIAN RESTAURANTS

2020 ◽  
Vol 4 (2) ◽  
pp. 68-72
Author(s):  
Marwan Msarah ◽  
Ahmed Alsier ◽  
Sahilah, A.M.
Keyword(s):  
Bacillus Cereus ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Egg Yolk ◽  
Food Samples ◽  
Blood Agar ◽  
Toxin Gene ◽  
Biochemical Tests ◽  
Isolation Medium ◽  
Hemolysin Bl

Bacillus cereus is a ubiquitous foodborne pathogen, can cause food poisoning, leading to infections, have two major types of food poisoning emetic and diarrheal. Foods rich in protein such as meat are associated with foodborne outbreaks of diarrhea caused by B. cereus. The aim of this study is to isolate and identify B. cereus from ready to eat (RTE) meat curry from restaurants in Malaysia and to detect hblD pathogenic gene of B. cereus isolates. Mannitol egg yolk polymyxin agar was used as a selective isolation medium. Commercially available kits and boiling methods were used for DNA extraction, samples acquired from restaurants were examined for the presence of Hemolysin BL gene by polymerase chain reaction (PCR). Among all isolates, twenty-four of B. cereus isolates detected for HBL enterotoxin production by the discontinuous pattern on HBL sheep blood agar then confirmed by biochemical tests. More than 58.33 % of the isolate showed discontinuous hemolysis pattern on HBl blood agar and 29.16% of the samples were shown positive for hblD gene that can cause diarrhea with the size of 807bp on gel. This study demonstrated that RTE meat curry was a potential source for entero-toxigenic B. cereus and the presence of the hblD toxin genes for the HBL complex in the isolates tested were highly associated. Therefore, these meat curry isolates should be regarded as potential toxin producers.

scholarly journals Binding to The Target Cell Surface Is The Crucial Step in Pore Formation of Hemolysin BL from Bacillus cereus

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 281 ◽  
Author(s):  
Nadja Jessberger ◽  
Richard Dietrich ◽  
Stefanie Schwemmer ◽  
Franziska Tausch ◽  
Valerie Schwenk ◽  
...  
Keyword(s):  
Cell Surface ◽  
Bacillus Cereus ◽  
Target Cell ◽  
Mode Of Action ◽  
Pore Formation ◽  
Food Poisoning ◽  
Crucial Step ◽  
Sequential Binding ◽  
L1 And L2 ◽  
Hemolysin Bl

A major virulence factor involved in Bacillus cereus food poisoning is the three-component enterotoxin hemolysin BL. It consists of the binding component B and the two lytic components L1 and L2. Studying its mode of action has been challenging, as natural culture supernatants additionally contain Nhe, the second three-component enterotoxin, and purification of recombinant (r) Hbl components has been difficult. In this study, we report on pore-forming, cytotoxic, cell binding and hemolytic activity of recently generated rHbl components expressed in E. coli. It is known that all three Hbl components are necessary for cytotoxicity and pore formation. Here we show that an excess of rHbl B enhances, while an excess of rHbl L1 hinders, the velocity of pore formation. Most rapid pore formation was observed with ratios L2:L1:B = 1:1:10 and 10:1:10. It was further verified that Hbl activity is due to sequential binding of the components B - L1 - L2. Accordingly, all bioassays proved that binding of Hbl B to the cell surface is the crucial step for pore formation and cytotoxic activity. Binding of Hbl B took place within minutes, while apposition of the following L1 and L2 occurred immediately. Further on, applying toxin components simultaneously, it seemed that Hbl L1 enhanced binding of B to the target cell surface. Overall, these data contribute significantly to the elucidation of the mode of action of Hbl, and suggest that its mechanism of pore formation differs substantially from that of Nhe, although both enterotoxin complexes are sequentially highly related.

scholarly journals Characteristics of the Protein Complexes and Pores Formed by Bacillus cereus Hemolysin BL

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 672 ◽  
Author(s):  
Nadja Jessberger ◽  
Richard Dietrich ◽  
Kristina Schauer ◽  
Stefanie Schwemmer ◽  
Erwin Märtlbauer ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Lipid Bilayers ◽  
Single Channel ◽  
Protein Complexes ◽  
Food Poisoning ◽  
Cell Binding ◽  
Channel Diameter ◽  
Toxic Activity ◽  
Target Cell Membrane ◽  
Hemolysin Bl

Bacillus cereus Hemolysin BL is a tripartite toxin responsible for a diarrheal type of food poisoning. Open questions remain regarding its mode of action, including the extent to which complex formation prior to cell binding contributes to pore-forming activity, how these complexes are composed, and the properties of the pores formed in the target cell membrane. Distinct complexes of up to 600 kDa were found on native gels, whose structure and size were primarily defined by Hbl B. Hbl L1 and L2 were also identified in these complexes using Western blotting and an LC-MS approach. LC-MS also revealed that many other proteins secreted by B. cereus exist in complexes. Further, a decrease of toxic activity at temperatures ≥60 °C was shown, which was unexpectedly restored at higher temperatures. This could be attributed to a release of Hbl B monomers from tight complexation, resulting in enhanced cell binding. In contrast, Hbl L1 was rather susceptible to heat, while heat treatment of Hbl L2 seemed not to be crucial. Furthermore, Hbl-induced pores had a rather small single-channel conductance of around 200 pS and a probable channel diameter of at least 1 nm on planar lipid bilayers. These were highly instable and had a limited lifetime, and were also slightly cation-selective. Altogether, this study provides astonishing new insights into the complex mechanism of Hbl pore formation, as well as the properties of the pores.

Biocontrol of Psychrotrophic Enterotoxigenic Bacillus cereus in a Nonfat Hard Cheese by an Enterococcal Strain–Producing Enterocin AS-48

2004 ◽  
Vol 67 (7) ◽  
pp. 1517-1521 ◽  
Author(s):  
ARANTXA MUÑOZ ◽  
MERCEDES MAQUEDA ◽  
ANTONIO GÁLVEZ ◽  
MANUEL MARTÍNEZ-BUENO ◽  
ANA RODRÍGUEZ ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Lactic Acid Production ◽  
Food Poisoning ◽  
Toxin Production ◽  
Starter Cultures ◽  
Producer Strain ◽  
Toxigenic Strain ◽  
Enterococcal Strain ◽  
Efficient Control ◽  
Potential Use

Bacillus cereus is a food poisoning bacterium of great concern, especially in milk products. In this study, we describe the efficient control of the psychrotrophic and toxigenic strain B. cereus LWL1 in milk and in a nonfat hard cow's cheese by the enterocin AS-48 producer strain Enterococcus faecalis A-48-32 (Bac+). No viable B. cereus cells were detected after 72 h incubation in milk coinoculated with the AS-48–producing strain and B. cereus. Diarrheic toxin production was also markedly inhibited by the Bac+ strain to eightfold lower levels compared with control cultures of B. cereus. In cheeses manufactured by inoculation with a commercial starter (about 6.8 log CFU/ml) and B. cereus (about 4 log CFU/ml), the latter reached 6.27 log CFU/g after 5 days of maturation, and approximately 8 log CFU/g after 15 days. However, in cheeses made from milk inoculated with the starter along with a mixture of E. faecalis–B. cereus (2/1 ratio), counts of B. cereus decreased by approximately 1.0, 2.0, 4.32, and 5.6 log units with respect to control cheeses after 5, 10, 15, and 30 days of ripening, respectively. Growth of E. faecalis A-48-32 was associated with enterocin AS-48 production and persistence in cheese. Interestingly, growth of starter cultures was not affected by the Bac+ strain, and neither was lactic acid production. These results clearly indicate that E. faecalis A-48-32 produced satisfactory amounts of bacteriocin in cheese and support the potential use of AS-48–producing strains as culture adjuncts to inhibit B. cereus during cheese manufacture and ripening.

scholarly journals Gene detection and toxin production evaluation of hemolysin BL of Bacillus cereus isolated from milk and dairy products marketed in Brazil

2013 ◽  
Vol 44 (4) ◽  
pp. 1195-1198 ◽  
Author(s):  
Andre L.S. Reis ◽  
Maike T.M. Montanhini ◽  
Juliana V.M. Bittencourt ◽  
Maria T. Destro ◽  
Luciano S. Bersot
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Toxin Production ◽  
Gene Detection ◽  
Hemolysin Bl ◽  
Milk And Dairy Products

scholarly journals Further Insights into the Toxicity of Bacillus cytotoxicus Based on Toxin Gene Profiling and Vero Cell Cytotoxicity Assays

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 234
Author(s):  
Johanna Burtscher ◽  
Danai Etter ◽  
Michael Biggel ◽  
Janine Schlaepfer ◽  
Sophia Johler
Keyword(s):  
Bacillus Cereus ◽  
Vero Cell ◽  
Diarrheal Disease ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Gene Profiling ◽  
Toxin Gene ◽  
Cell Cytotoxicity ◽  
Cytotoxic Potential ◽  
Cytotoxicity Assays

Bacillus cytotoxicus belongs to the Bacillus cereus group that also comprises the foodborne pathogen Bacillus cereus sensu stricto, Bacillus anthracis causing anthrax, as well as the biopesticide Bacillus thuringiensis. The first B. cytotoxicus was isolated in the context of a severe food poisoning outbreak leading to fatal cases of diarrheal disease. Subsequent characterization of the outbreak strain led to the conclusion that this Bacillus strain was highly cytotoxic and eventually resulted in the description of a novel species, whose name reflects the observed toxicity: B. cytotoxicus. However, only a few isolates of this species have been characterized with regard to their cytotoxic potential and the role of B. cytotoxicus as a causative agent of food poisoning remains largely unclear. Hence, the aim of this study was to gain further insights into the toxicity of B. cytotoxicus. To this end, 19 isolates were obtained from mashed potato powders and characterized by toxin gene profiling and Vero cell cytotoxicity assays. All isolates harbored the cytK1 (cytotoxin K1) gene and species-specific variants of the nhe (non-hemolytic enterotoxin) gene. The isolates exhibited low or no toxicity towards Vero cells. Thus, this study indicates that the cytotoxic potential of B. cytotoxicus may be potentially lower than initially assumed.

scholarly journals Role of Hemolysin BL in the Pathogenesis of Extraintestinal Bacillus cereus Infection Assessed in an Endophthalmitis Model

1999 ◽  
Vol 67 (7) ◽  
pp. 3357-3366 ◽  
Author(s):  
Michelle C. Callegan ◽  
Bradley D. Jett ◽  
Lynn E. Hancock ◽  
Michael S. Gilmore
Keyword(s):  
Bacillus Cereus ◽  
Inflammatory Cell ◽  
Inflammatory Responses ◽  
Toxin Production ◽  
Human Infection ◽  
Dermonecrotic Toxin ◽  
Essential Contribution ◽  
Hemolysin Bl ◽  
Inflammatory Changes

ABSTRACT Bacillus cereus is a rare cause of serious human infection but, paradoxically, causes one of the most severe posttraumatic or endogenous infections of the eye, endophthalmitis, which frequently results in blindness. The virulence of B. cereus endophthalmitis historically has been attributed to toxin production. We therefore sought to examine the contribution of the dermonecrotic toxin, hemolysin BL, to the pathogenesis of B. cereus infection in an endophthalmitis system that is highly amenable to study. The pathogenesis of infection resulting from intravitreal injection of 102 CFU of either a clinical ocular isolate of B. cereus producing hemolysin BL (HBL+) or an isogenic mutant in this trait (HBL−) was assessed bacteriologically and by slit lamp biomicroscopy, electroretinography, histology, and inflammatory cell enumeration. Both HBL+ and HBL− strains evoked severe intraocular inflammatory responses as early as 12 h postinfection, with complete loss of retinal responsiveness by 12 h. The infections caused by both strains spread of the infection to adjacent tissues by 18 h. No significant differences in intraocular bacterial growth (P ≥ 0.21) or inflammatory changes (P ≥ 0.21) were observed in eyes infected with either HBL+ or HBL− strains during the course of infection. The level of retinal responsiveness was greater in HBL− infected eyes than in HBL+-infected eyes at 6 h only (P = 0.01). These results indicate that hemolysin BL makes no essential contribution to the severe and rapid course of infection in the endophthalmitis model.

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