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Nadja Jessberger
Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig Maximilian University of Munich, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany

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Review
Published: 28 January 2021 in Toxins
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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.

ACS Style

Richard Dietrich; Nadja Jessberger; Monika Ehling-Schulz; Erwin Märtlbauer; Per Granum. The Food Poisoning Toxins of Bacillus cereus. Toxins 2021, 13, 98 .

AMA Style

Richard Dietrich, Nadja Jessberger, Monika Ehling-Schulz, Erwin Märtlbauer, Per Granum. The Food Poisoning Toxins of Bacillus cereus. Toxins. 2021; 13 (2):98.

Chicago/Turabian Style

Richard Dietrich; Nadja Jessberger; Monika Ehling-Schulz; Erwin Märtlbauer; Per Granum. 2021. "The Food Poisoning Toxins of Bacillus cereus." Toxins 13, no. 2: 98.

Review
Published: 05 November 2020 in Toxins
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The ubiquitous soil bacterium Bacillus cereus presents major challenges to food safety. It is responsible for two types of food poisoning, the emetic form due to food intoxication and the diarrheal form emerging from food infections with enteropathogenic strains, also known as toxico-infections, which are the subject of this review. The diarrheal type of food poisoning emerges after production of enterotoxins by viable bacteria in the human intestine. Basically, the manifestation of the disease is, however, the result of a multifactorial process, including B. cereus prevalence and survival in different foods, survival of the stomach passage, spore germination, motility, adhesion, and finally enterotoxin production in the intestine. Moreover, all of these processes are influenced by the consumed foodstuffs as well as the intestinal microbiota which have, therefore, to be considered for a reliable prediction of the hazardous potential of contaminated foods. Current knowledge regarding these single aspects is summarized in this review aiming for risk-oriented diagnostics for enteropathogenic B. cereus.

ACS Style

Nadja Jessberger; Richard Dietrich; Per Granum; Erwin Märtlbauer. The Bacillus cereus Food Infection as Multifactorial Process. Toxins 2020, 12, 701 .

AMA Style

Nadja Jessberger, Richard Dietrich, Per Granum, Erwin Märtlbauer. The Bacillus cereus Food Infection as Multifactorial Process. Toxins. 2020; 12 (11):701.

Chicago/Turabian Style

Nadja Jessberger; Richard Dietrich; Per Granum; Erwin Märtlbauer. 2020. "The Bacillus cereus Food Infection as Multifactorial Process." Toxins 12, no. 11: 701.

Journal article
Published: 24 October 2020 in Toxins
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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.

ACS Style

Nadja Jessberger; Richard Dietrich; Kristina Schauer; Stefanie Schwemmer; Erwin Märtlbauer; Roland Benz. Characteristics of the Protein Complexes and Pores Formed by Bacillus cereus Hemolysin BL. Toxins 2020, 12, 672 .

AMA Style

Nadja Jessberger, Richard Dietrich, Kristina Schauer, Stefanie Schwemmer, Erwin Märtlbauer, Roland Benz. Characteristics of the Protein Complexes and Pores Formed by Bacillus cereus Hemolysin BL. Toxins. 2020; 12 (11):672.

Chicago/Turabian Style

Nadja Jessberger; Richard Dietrich; Kristina Schauer; Stefanie Schwemmer; Erwin Märtlbauer; Roland Benz. 2020. "Characteristics of the Protein Complexes and Pores Formed by Bacillus cereus Hemolysin BL." Toxins 12, no. 11: 672.

Journal article
Published: 17 October 2020 in Foods
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Despite its benefits as biological insecticide, Bacillus thuringiensis bears enterotoxins, which can be responsible for a diarrhoeal type of food poisoning. Thus, all 24 isolates from foodstuffs, animals, soil and commercially used biopesticides tested in this study showed the genetic prerequisites necessary to provoke the disease. Moreover, though highly strain-specific, various isolates were able to germinate and also to actively move, which are further requirements for the onset of the disease. Most importantly, all isolates could grow under simulated intestinal conditions and produce significant amounts of enterotoxins. Cytotoxicity assays classified 14 isolates as highly, eight as medium and only two as low toxic. Additionally, growth inhibition by essential oils (EOs) was investigated as preventive measure against putatively enteropathogenic B. thuringiensis. Cinnamon Chinese cassia showed the highest antimicrobial activity, followed by citral, oregano and winter savory. In all tests, high strain-specific variations appeared and must be taken into account when evaluating the hazardous potential of B. thuringiensis and using EOs as antimicrobials. Altogether, the present study shows a non-negligible pathogenic potential of B. thuringiensis, independently from the origin of isolation. Generally, biopesticide strains were indistinguishable from other isolates. Thus, the use of these pesticides might indeed increase the risk for consumers’ health. Until complete information about the safety of the applied strains and formulations is available, consumers or manufacturers might benefit from the antimicrobial activity of EOs to reduce the level of contamination.

ACS Style

Valerie Schwenk; Janina Riegg; Monique Lacroix; Erwin Märtlbauer; Nadja Jessberger. Enteropathogenic Potential of Bacillus thuringiensis Isolates from Soil, Animals, Food and Biopesticides. Foods 2020, 9, 1484 .

AMA Style

Valerie Schwenk, Janina Riegg, Monique Lacroix, Erwin Märtlbauer, Nadja Jessberger. Enteropathogenic Potential of Bacillus thuringiensis Isolates from Soil, Animals, Food and Biopesticides. Foods. 2020; 9 (10):1484.

Chicago/Turabian Style

Valerie Schwenk; Janina Riegg; Monique Lacroix; Erwin Märtlbauer; Nadja Jessberger. 2020. "Enteropathogenic Potential of Bacillus thuringiensis Isolates from Soil, Animals, Food and Biopesticides." Foods 9, no. 10: 1484.

Journal article
Published: 22 July 2019 in Food Microbiology
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The diarrheal type of food poisoning caused by enteropathogenic Bacillus cereus has been linked to various exotoxins. Best described are the non-hemolytic enterotoxin (Nhe), hemolysin BL (Hbl), and cytotoxin K (CytK). Due to the ubiquitous prevalence of B. cereus in soil and crops and its ability to form highly resistant endospores, contaminations during food production and processing cannot be completely avoided. Although phylogenetically closely related, enteropathogenic B. cereus strains show a high versatility of their toxic potential. Thus, functional tools for evaluating the pathogenic potential are urgently needed in order to predict hazardous food contaminations. As the diarrheal syndrome is the result of a toxico-infection with enterotoxin production in the intestine, the entire passage of the bacteria within the host, from spore survival in the stomach, spore germination, host cell adherence, and motility, to enterotoxin production under simulated intestinal conditions was compared in a panel of 20 strains, including high pathogenic as well as apathogenic ones. This approach resulted in an overarching virulence analysis scheme. In parallel, we searched for potential toxico-specific secreted markers to discriminate low and high pathogenic strains. To this end, we targeted known exotoxins using an easy to implement immunoblotting approach as well as a caseinolytic exoprotease activity assay. Overall, Nhe component B, sphingomyelinase, and exoproteases showed good correlation with the complex virulence analysis scheme and can serve as a template for future fast and easy risk assessment tools to be implemented in routine diagnostic procedures and HACCP studies.

ACS Style

Nadja Jessberger; Markus Kranzler; Claudia Da Riol; Valerie Schwenk; Tanja Buchacher; Richard Dietrich; Monika Ehling-Schulz; Erwin Märtlbauer. Assessing the toxic potential of enteropathogenic Bacillus cereus. Food Microbiology 2019, 84, 103276 .

AMA Style

Nadja Jessberger, Markus Kranzler, Claudia Da Riol, Valerie Schwenk, Tanja Buchacher, Richard Dietrich, Monika Ehling-Schulz, Erwin Märtlbauer. Assessing the toxic potential of enteropathogenic Bacillus cereus. Food Microbiology. 2019; 84 ():103276.

Chicago/Turabian Style

Nadja Jessberger; Markus Kranzler; Claudia Da Riol; Valerie Schwenk; Tanja Buchacher; Richard Dietrich; Monika Ehling-Schulz; Erwin Märtlbauer. 2019. "Assessing the toxic potential of enteropathogenic Bacillus cereus." Food Microbiology 84, no. : 103276.

Journal article
Published: 20 May 2019 in Toxins
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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.

ACS Style

Nadja Jessberger; Richard Dietrich; Stefanie Schwemmer; Franziska Tausch; Valerie Schwenk; Andrea Didier; Erwin Märtlbauer. Binding to The Target Cell Surface Is The Crucial Step in Pore Formation of Hemolysin BL from Bacillus cereus. Toxins 2019, 11, 281 .

AMA Style

Nadja Jessberger, Richard Dietrich, Stefanie Schwemmer, Franziska Tausch, Valerie Schwenk, Andrea Didier, Erwin Märtlbauer. Binding to The Target Cell Surface Is The Crucial Step in Pore Formation of Hemolysin BL from Bacillus cereus. Toxins. 2019; 11 (5):281.

Chicago/Turabian Style

Nadja Jessberger; Richard Dietrich; Stefanie Schwemmer; Franziska Tausch; Valerie Schwenk; Andrea Didier; Erwin Märtlbauer. 2019. "Binding to The Target Cell Surface Is The Crucial Step in Pore Formation of Hemolysin BL from Bacillus cereus." Toxins 11, no. 5: 281.

Journal article
Published: 01 April 2019 in Infection and Immunity
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Enteropathogenic Bacillus cereus causes foodborne infections due to the production of pore-forming enterotoxins in the intestine. Before that, spores have to be ingested, survive the stomach passage, and germinate.

ACS Style

Nadja Jessberger; Richard Dietrich; Ann-Katrin Mohr; Claudia Da Riol; Erwin Märtlbauer. Porcine Gastric Mucin Triggers Toxin Production of Enteropathogenic Bacillus cereus. Infection and Immunity 2019, 87, 1 .

AMA Style

Nadja Jessberger, Richard Dietrich, Ann-Katrin Mohr, Claudia Da Riol, Erwin Märtlbauer. Porcine Gastric Mucin Triggers Toxin Production of Enteropathogenic Bacillus cereus. Infection and Immunity. 2019; 87 (4):1.

Chicago/Turabian Style

Nadja Jessberger; Richard Dietrich; Ann-Katrin Mohr; Claudia Da Riol; Erwin Märtlbauer. 2019. "Porcine Gastric Mucin Triggers Toxin Production of Enteropathogenic Bacillus cereus." Infection and Immunity 87, no. 4: 1.

Journal article
Published: 16 September 2017 in Toxins
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Haemolysin BL is an important virulence factor regarding the diarrheal type of food poisoning caused by Bacillus cereus. However, the pathogenic importance of this three-component enterotoxin is difficult to access, as nearly all natural B. cereus culture supernatants additionally contain the highly cytotoxic Nhe, the second three-component toxin involved in the aetiology of B. cereus-induced food-borne diseases. To better address the toxic properties of the Hbl complex, a system for overexpression and purification of functional, cytotoxic, recombinant (r)Hbl components L2, L1 and B from E. coli was established and an nheABC deletion mutant was constructed from B. cereus reference strain F837/76. Furthermore, 35 hybridoma cell lines producing monoclonal antibodies (mAbs) against Hbl L2, L1 and B were generated. While mAbs 1H9 and 1D8 neutralized Hbl toxicity and thus, represent important tools for future investigations of the mode-of-action of Hbl on the target cell surface, mAb 1D7, in contrast, even enhanced Hbl toxicity by supporting the binding of Hbl B to the cell surface. By using the specific mAbs in Dot blots, indirect and hybrid sandwich enzyme immuno assays (EIAs), complex formation between Hbl L1 and B, as well as L1 and L2 in solution could be shown for the first time. Surface plasmon resonance experiments with the rHbl components confirmed these results with KD values of 4.7 × 10−7 M and 1.5 × 10−7 M, respectively. These findings together with the newly created tools lay the foundation for the detailed elucidation of the molecular mode-of-action of the highly complex three-component Hbl toxin.

ACS Style

Franziska Tausch; Richard Dietrich; Kristina Schauer; Robert Janowski; Dierk Niessing; Erwin Märtlbauer; Nadja Jessberger. Evidence for Complex Formation of the Bacillus cereus Haemolysin BL Components in Solution. Toxins 2017, 9, 288 .

AMA Style

Franziska Tausch, Richard Dietrich, Kristina Schauer, Robert Janowski, Dierk Niessing, Erwin Märtlbauer, Nadja Jessberger. Evidence for Complex Formation of the Bacillus cereus Haemolysin BL Components in Solution. Toxins. 2017; 9 (9):288.

Chicago/Turabian Style

Franziska Tausch; Richard Dietrich; Kristina Schauer; Robert Janowski; Dierk Niessing; Erwin Märtlbauer; Nadja Jessberger. 2017. "Evidence for Complex Formation of the Bacillus cereus Haemolysin BL Components in Solution." Toxins 9, no. 9: 288.

Original research article
Published: 12 April 2017 in Frontiers in Microbiology
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Bacillus cereus is a ubiquitous bacterial pathogen increasingly reported to be the causative agent of foodborne infections and intoxications. Since the enterotoxins linked to the diarrheal form of food poising are foremost produced in the human intestine, the toxic potential of enteropathogenic B. cereus strains is difficult to predict from studies carried out under routine cultivation procedures. In this study, toxigenic properties of a panel of strains (n=19) of diverse origin were compared using cell culture medium pre-incubated with CaCo-2 cells to mimic intestinal growth conditions. Shortly after contact of the bacteria with the simulated host environment, enterotoxin gene expression was activated and total protein secretion of all strains was accelerated. Although the signal stimulating enterotoxin production still needs to be elucidated, it could be shown that it originated from the CaCo-2 cells. Overall, our study demonstrates that the currently used methods in B. cereus diagnostics, based on standard culture medium, are not allowing a conclusive prediction of the potential health risk related to a certain strain. Thus, these methods should be complemented by cultivation procedures that are simulating intestinal host conditions.

ACS Style

Nadja Jeßberger; Corinna Rademacher; Viktoria M. Krey; Richard Dietrich; Ann-Katrin Mohr; Maria-Elisabeth Böhm; Siegfried Scherer; Monika Ehling-Schulz; Erwin Märtlbauer. Simulating Intestinal Growth Conditions Enhances Toxin Production of Enteropathogenic Bacillus cereus. Frontiers in Microbiology 2017, 8, 627 .

AMA Style

Nadja Jeßberger, Corinna Rademacher, Viktoria M. Krey, Richard Dietrich, Ann-Katrin Mohr, Maria-Elisabeth Böhm, Siegfried Scherer, Monika Ehling-Schulz, Erwin Märtlbauer. Simulating Intestinal Growth Conditions Enhances Toxin Production of Enteropathogenic Bacillus cereus. Frontiers in Microbiology. 2017; 8 ():627.

Chicago/Turabian Style

Nadja Jeßberger; Corinna Rademacher; Viktoria M. Krey; Richard Dietrich; Ann-Katrin Mohr; Maria-Elisabeth Böhm; Siegfried Scherer; Monika Ehling-Schulz; Erwin Märtlbauer. 2017. "Simulating Intestinal Growth Conditions Enhances Toxin Production of Enteropathogenic Bacillus cereus." Frontiers in Microbiology 8, no. : 627.

Journal article
Published: 09 November 2015 in Toxins
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The ability of Bacillus cereus to cause foodborne toxicoinfections leads to increasing concerns regarding consumer protection. For the diarrhea-associated enterotoxins, the assessment of the non-hemolytic enterotoxin B (NheB) titer determined by a sandwich enzyme immunoassay (EIA) correlates best with in vitro cytotoxicity. In general, the regulation of enterotoxin expression of B. cereus is a coordinately-regulated process influenced by environmental, and probably also by host factors. As long as these factors are not completely understood, the currently-applied diagnostic procedures are based on indirect approaches to assess the potential virulence of an isolate. To date, sandwich EIA results serve as a surrogate marker to categorize isolates as either potentially low or highly toxic. Here, we report on a single amino acid exchange in the NheB sequence leading to an underestimation of the cytotoxic potential in a limited number of strains. During the screening of a large panel of B. cereus isolates, six showed uncommon features with low sandwich EIA titers despite high cytotoxicity. Sequence analysis revealed the point-mutation Glu151Asp in the potential binding region of the capture antibody. Application of this antibody also results in low titers in an indirect EIA format and shows variable detection intensities in Western-immunoblots. A commercially-available assay based on a lateral flow device detects all strains correctly as NheB producers in a qualitative manner. In conclusion, isolates showing low NheB titers should additionally be assayed in an indirect EIA or for their in vitro cytotoxicity to ensure a correct classification as either low or highly toxic.

ACS Style

Andrea Didier; Nadja Jeßberger; Victoria Krey; Richard Dietrich; Siegfried Scherer; Erwin Märtlbauer. The Mutation Glu151Asp in the B-Component of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) Leads to a Diverging Reactivity in Antibody-Based Detection Systems. Toxins 2015, 7, 4655 -4667.

AMA Style

Andrea Didier, Nadja Jeßberger, Victoria Krey, Richard Dietrich, Siegfried Scherer, Erwin Märtlbauer. The Mutation Glu151Asp in the B-Component of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) Leads to a Diverging Reactivity in Antibody-Based Detection Systems. Toxins. 2015; 7 (11):4655-4667.

Chicago/Turabian Style

Andrea Didier; Nadja Jeßberger; Victoria Krey; Richard Dietrich; Siegfried Scherer; Erwin Märtlbauer. 2015. "The Mutation Glu151Asp in the B-Component of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) Leads to a Diverging Reactivity in Antibody-Based Detection Systems." Toxins 7, no. 11: 4655-4667.

Original research article
Published: 10 June 2015 in Frontiers in Microbiology
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In recent years Bacillus cereus has gained increasing importance as a food poisoning pathogen. It is the eponymous member of the B. cereus sensu lato group that consists of eight closely related species showing impressive diversity of their pathogenicity. The high variability of cytotoxicity and the complex regulatory network of enterotoxin expression have complicated efforts to predict the toxic potential of new B. cereus isolates. In this study, comprehensive analyses of enterotoxin gene sequences, transcription, toxin secretion and cytotoxicity were performed. For the first time, these parameters were compared in a whole set of B. cereus strains representing isolates of different origin (food or food poisoning outbreaks) and of different toxic potential (enteropathogenic and apathogenic) to elucidate potential starting points of strain-specific differential toxicity. While toxin gene sequences were highly conserved and did not allow for differentiation between high and low toxicity strains, comparison of nheB and hblD enterotoxin gene transcription and Nhe and Hbl protein titers revealed not only strain-specific differences but also incongruence between toxin gene transcripts and toxin protein levels. With one exception all strains showed comparable capability of protein secretion and so far, no secretion patterns specific for high and low toxicity strains were identified. These results indicate that enterotoxin expression is more complex than expected, possibly involving the orchestrated interplay of different transcriptional regulator proteins, as well as posttranscriptional and posttranslational regulatory mechanisms plus additional influences of environmental conditions.

ACS Style

Nadja Jeãÿberger; Viktoria M. Krey; Corinna Rademacher; Maria-Elisabeth Bã¶hm; Ann-Katrin Mohr; Monika Ehling-Schulz; Siegfried Scherer; Erwin Märtlbauer. From genome to toxicity: a combinatory approach highlights the complexity of enterotoxin production in Bacillus cereus. Frontiers in Microbiology 2015, 6, 560 .

AMA Style

Nadja Jeãÿberger, Viktoria M. Krey, Corinna Rademacher, Maria-Elisabeth Bã¶hm, Ann-Katrin Mohr, Monika Ehling-Schulz, Siegfried Scherer, Erwin Märtlbauer. From genome to toxicity: a combinatory approach highlights the complexity of enterotoxin production in Bacillus cereus. Frontiers in Microbiology. 2015; 6 ():560.

Chicago/Turabian Style

Nadja Jeãÿberger; Viktoria M. Krey; Corinna Rademacher; Maria-Elisabeth Bã¶hm; Ann-Katrin Mohr; Monika Ehling-Schulz; Siegfried Scherer; Erwin Märtlbauer. 2015. "From genome to toxicity: a combinatory approach highlights the complexity of enterotoxin production in Bacillus cereus." Frontiers in Microbiology 6, no. : 560.

Comparative study
Published: 01 January 2014 in Toxicon
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A comparative analysis on the relevance of the Bacillus cereus enterotoxins Nhe (nonhemolytic enterotoxin), HBL (haemolysin BL) and CytK (cytotoxin K) was accomplished, concerning their toxic activity towards different target cell lines. Overall, among the components secreted by the reference strains for Nhe and HBL, the enterotoxin complexes accounted for over 90% of the total toxicity. Vero and primary endothelial cells (HUVEC) were highly susceptible to Nhe, whereas Hep-G2, Vero and A549 reacted most sensitive to Nhe plus HBL. For CytK the highest toxicity was observed on CaCo-2 cells. As HBL positive strains always produce Nhe in parallel, the specific contribution of both enterotoxin complexes to the overall observed cytotoxic effects was determined by consecutively removing their single components. While in most cell lines Nhe and HBL contributed more or less equally (40-60%) to cytotoxicity, the relative activity of Nhe was approximately 90% in HUVEC, and that of HBL 75% in A549 cells. With U937, a nearly Nhe resistant cell line was identified for the first time. This distinct susceptibility of cell lines was confirmed by investigating a set of 37 B. cereus strains. Interestingly, whereas Nhe is the enterotoxin mainly responsible for cell death as determined by WST-1 bioassays, more rapid pore formation was observed when HBL was present, pointing to a different mode of action of the two enterotoxin complexes. Furthermore, correlation was observed between cytotoxicity of solely Nhe producing strains and NheB. Cytotoxicity of Nhe/HBL producing isolates correlated with the expression of HBL L1, NheB and HBL B. In conclusion, the observed susceptibilities of target cell lines of different histological origin underline that B. cereus enterotoxins represent major virulence factors and that toxicity is not restricted to gastrointestinal infections. The varying contribution of Nhe and HBL to total cytotoxicity strongly indicates that Nhe as well as HBL specific B. cereus enterotoxin receptors exist.

ACS Style

Nadja Jeßberger; Richard Dietrich; Stefanie Bock; Andrea Didier; Erwin Märtlbauer. Bacillus cereus enterotoxins act as major virulence factors and exhibit distinct cytotoxicity to different human cell lines. Toxicon 2014, 77, 49 -57.

AMA Style

Nadja Jeßberger, Richard Dietrich, Stefanie Bock, Andrea Didier, Erwin Märtlbauer. Bacillus cereus enterotoxins act as major virulence factors and exhibit distinct cytotoxicity to different human cell lines. Toxicon. 2014; 77 ():49-57.

Chicago/Turabian Style

Nadja Jeßberger; Richard Dietrich; Stefanie Bock; Andrea Didier; Erwin Märtlbauer. 2014. "Bacillus cereus enterotoxins act as major virulence factors and exhibit distinct cytotoxicity to different human cell lines." Toxicon 77, no. : 49-57.