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Kranzler M, Walser V, Stark TD, Ehling-Schulz M. A poisonous cocktail: interplay of cereulide toxin and its structural isomers in emetic Bacillus cereus. Front Cell Infect Microbiol 2024; 14:1337952. [PMID: 38596651 PMCID: PMC11002159 DOI: 10.3389/fcimb.2024.1337952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/11/2024] [Indexed: 04/11/2024] Open
Abstract
Food intoxications evoked by emetic Bacillus cereus strains constitute a serious threat to public health, leading to emesis and severe organ failure. The emetic peptide toxin cereulide, assembled by the non-ribosomal peptide synthetase CesNRPS, cannot be eradicated from contaminated food by usual hygienic measures due to its molecular size and structural stability. Next to cereulide, diverse chemical variants have been described recently that are produced concurrently with cereulide by CesNRPS. However, the contribution of these isocereulides to the actual toxicity of emetic B. cereus, which produces a cocktail of these toxins in a certain ratio, is still elusive. Since cereulide isoforms have already been detected in food remnants from foodborne outbreaks, we aimed to gain insights into the composition of isocereulides and their impact on the overall toxicity of emetic B. cereus. The amounts and ratios of cereulide and isocereulides were determined in B. cereus grown under standard laboratory conditions and in a contaminated sample of fried rice balls responsible for one of the most severe food outbreaks caused by emetic B. cereus in recent years. The ratios of variants were determined as robust, produced either under laboratory or natural, food-poisoning conditions. Examination of their actual toxicity in human epithelial HEp2-cells revealed that isocereulides A-N, although accounting for only 10% of the total cereulide toxins, were responsible for about 40% of the total cytotoxicity. An this despite the fact that some of the isocereulides were less cytotoxic than cereulide when tested individually for cytotoxicity. To estimate the additive, synergistic or antagonistic effects of the single variants, each cereulide variant was mixed with cereulide in a 1:9 and 1:1 binary blend, respectively, and tested on human cells. The results showed additive and synergistic impacts of single variants, highlighting the importance of including not only cereulide but also the isocereulides in routine food and clinical diagnostics to achieve a realistic toxicity evaluation of emetic B. cereus in contaminated food as well as in patient samples linked to foodborne outbreaks. Since the individual isoforms confer different cell toxicity both alone and in association with cereulide, further investigations are needed to fully understand their cocktail effect.
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Affiliation(s)
- Markus Kranzler
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Veronika Walser
- Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Freising, Germany
| | - Timo D. Stark
- Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Freising, Germany
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
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Ben Akacha B, Michalak M, Generalić Mekinić I, Kačániová M, Chaari M, Brini F, Ben Saad R, Mnif W, Garzoli S, Ben Hsouna A. Mixture design of α-pinene, α-terpineol, and 1,8-cineole: A multiobjective response followed by chemometric approaches to optimize the antibacterial effect against various bacteria and antioxidant activity. Food Sci Nutr 2024; 12:574-589. [PMID: 38268912 PMCID: PMC10804091 DOI: 10.1002/fsn3.3780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/01/2023] [Accepted: 10/07/2023] [Indexed: 01/26/2024] Open
Abstract
α-Pinene, α-terpineol, and 1,8-cineole are compounds naturally present in essential oils, although their amounts vary from oil to oil. Although several studies have reported their antibacterial and antioxidant effects, there are few reports on the synergistic or antagonistic effects of their combinations. The objective of this study was to investigate the combined antibacterial effect of these three compounds. To our knowledge, this is the first report on the prediction of their optimal combination using the mixture design approach. The experimental antibacterial activity of the α-pinene, α-terpineol, and 1,8-cineole mixtures depended on the proportion of each compound in the mixture and the target strain, with minimum inhibitory concentrations (MIC) ranging from 0.31 to 1.85 mg/mL. Using the increased simplex-centroid mixture design, the mixture containing 0.33% of each molecule proved to be the most effective against Bacillus cereus and had the lowest MIC values. In addition, α-pinene, α-terpineol, and 1,8-cineole showed significant antioxidant activity against 2,2-picryl-1-hydrazyl radical (DPPH), with IC50 values of 24.53 ± 0.05, 65.63 ± 0.71, and 63.58 ± 0.01 μg/mL, respectively. Statistical planning and the development of utility profiles of the substance mixtures can predict the optimal composition that will exhibit the highest antibacterial activity against B. cereus as well as antioxidant properties. Furthermore, the synergistic effect of the mixtures can contribute significantly to their successful use as natural preservatives in various applications.
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Affiliation(s)
- Boutheina Ben Akacha
- Laboratory of Biotechnology and Plant ImprovementCentre of Biotechnology of SfaxSfaxTunisia
| | | | - Ivana Generalić Mekinić
- Department of Food Technology and Biotechnology, Faculty of Chemistry and TechnologyUniversity of SplitSplitCroatia
| | - Miroslava Kačániová
- Faculty of Horticulture, Institute of HorticultureSlovak University of AgricultureNitraSlovakia
| | - Moufida Chaari
- Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE)Center of Biotechnology of Sfax (CBS)University of SfaxSfaxTunisia
| | - Faical Brini
- Laboratory of Biotechnology and Plant ImprovementCentre of Biotechnology of SfaxSfaxTunisia
| | - Rania Ben Saad
- Laboratory of Biotechnology and Plant ImprovementCentre of Biotechnology of SfaxSfaxTunisia
| | - Wissem Mnif
- Department of Chemistry, College of Sciences at BishaUniversity of BishaBishaSaudi Arabia
| | - Stefania Garzoli
- Department of Chemistry and Technologies of DrugSapienza UniversityRomeItaly
| | - Anis Ben Hsouna
- Laboratory of Biotechnology and Plant ImprovementCentre of Biotechnology of SfaxSfaxTunisia
- Department of Environmental Sciences and Nutrition, Higher Institute of Applied Sciences and Technology of MahdiaUniversity of MonastirMonastirTunisia
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3
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Jenull S, Bauer T, Silbermayr K, Dreer M, Stark TD, Ehling-Schulz M. The toxicological spectrum of the Bacillus cereus toxin cereulide points towards niche-specific specialisation. Environ Microbiol 2023; 25:2231-2249. [PMID: 37354053 DOI: 10.1111/1462-2920.16454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/06/2023] [Indexed: 06/26/2023]
Abstract
Most microbes share their environmental niches with very different forms of life thereby engaging in specialised relationships to enable their persistence. The bacterium Bacillus cereus occurs ubiquitously in the environment with certain strain backgrounds causing foodborne and opportunistic infections in humans. The emetic lineage of B. cereus is capable of producing the toxin cereulide, which evokes emetic illnesses. Although food products favouring the accumulation of cereulide are known, the ecological role of cereulide and the environmental niche of emetic B. cereus remain elusive. To better understand the ecology of cereulide-producing B. cereus, we systematically assayed the toxicological spectrum of cereulide on a variety of organisms belonging to different kingdoms. As cereulide is a potassium ionophore, we further tested the effect of environmental potassium levels on the action of cereulide. We found that adverse effects of cereulide exposure are species-specific, which can be exacerbated with increased environmental potassium. Additionally, we demonstrate that cereulide is produced within an insect cadaver indicating its potential ecological function for a saprophytic lifestyle. Collectively, distinct cereulide susceptibilities of other organisms may reflect its role in enabling competitive niche specialization of emetic B. cereus.
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Affiliation(s)
- Sabrina Jenull
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tobias Bauer
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Katja Silbermayr
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Maximilian Dreer
- Department of Functional and Evolutionary Ecology, Archaea Biology and Ecogenomics Unit, University of Vienna, Vienna, Austria
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
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Wang Z, Xia H, Fan F, Zhang J, Liu H, Cao J. Survival of community-acquired Bacillus cereus sepsis with venous sinus thrombosis in an immunocompetent adult man - a case report and literature review. BMC Infect Dis 2023; 23:213. [PMID: 37024789 PMCID: PMC10080751 DOI: 10.1186/s12879-023-08176-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 03/16/2023] [Indexed: 04/08/2023] Open
Abstract
BACKGROUND Bacillus cereus infections in immunocompetent patients are uncommon and mainly observed in fragile patients. It can cause lethal infections with multiple organ dysfunction syndrome (MODS). However, a patient presenting as venous sinus thrombosis and survival without sequela has not been reported. CASE PRESENTATION A 20-year-old previously healthy male developed gastroenteritis after a meal, followed by fever, convulsions, and severe disturbance of consciousness. The patient had significant leukocytosis with a mildly elevated D-dimer, creatinine level, and respiratory failure. The CT(computed tomography) revealed fatal brain edema and subarachnoid hemorrhage. Previous blood culture in a local hospital revealed B. cereus, which was confirmed by mNGS(metagenomic next-generation sequencing) using blood and urine in our hospital. Accordingly, B. cereus sepsis with MODS were considered. Later, cerebral venous sinus thrombosis was proved. After anti-infection (linezolid 0.6 g, Q12h; and meropenem 1.0 g, Q8h), anti-coagulant (enoxaparin 6000U, Q12h), and other symptomatic treatments, the patient recovered completely without sequela at the 6-month follow-up. CONCLUSIONS This case suggests that in immunocompetent adults, there is still a risk of infection with B. cereus, causing severe MODS. Special attention should be paid to venous sinus thrombosis and subarachnoid hemorrhage in such cases, while, anti-coagulant is essential therapy.
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Affiliation(s)
- Zengrong Wang
- Department of Critical Care Medicine, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China
| | - Han Xia
- Department of Scientific Affairs, Hugo Biotech Co., Ltd., No.1, East Disheng Road, Beijing, 100176, China
| | - Fangfang Fan
- Department of Respiratory and Critical Care Medicine, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China
| | - Jin Zhang
- Department of Neurology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China
| | - Hong Liu
- Department of Critical Care Medicine, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China
| | - Jing Cao
- Department of Critical Care Medicine, The First Hospital of Shanxi Medical University, Taiyuan, 030001, China.
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Yang S, Wang Y, Ren F, Li Z, Dong Q. Applying enzyme treatments in Bacillus cereus biofilm removal. Lebensm Wiss Technol 2023. [DOI: 10.1016/j.lwt.2023.114667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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6
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Yang S, Wang Y, Liu Y, Jia K, Zhang Z, Dong Q. Cereulide and Emetic Bacillus cereus: Characterizations, Impacts and Public Precautions. Foods 2023; 12:foods12040833. [PMID: 36832907 PMCID: PMC9956921 DOI: 10.3390/foods12040833] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/10/2023] [Accepted: 02/12/2023] [Indexed: 02/18/2023] Open
Abstract
Cereulide, which can be produced by Bacillus cereus, is strongly associated with emetic-type food poisoning outbreaks. It is an extremely stable emetic toxin, which is unlikely to be inactivated by food processing. Considering the high toxicity of cereulide, its related hazards raise public concerns. A better understanding of the impact of B. cereus and cereulide is urgently needed to prevent contamination and toxin production, thereby protecting public health. Over the last decade, a wide range of research has been conducted regarding B. cereus and cereulide. Despite this, summarized information highlighting precautions at the public level involving the food industry, consumers and regulators is lacking. Therefore, the aim of the current review is to summarize the available data describing the characterizations and impacts of emetic B. cereus and cereulide; based on this information, precautions at the public level are proposed.
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Regulation of Enterotoxins Associated with Bacillus cereus Sensu Lato Toxicoinfection. Appl Environ Microbiol 2022; 88:e0040522. [PMID: 35730937 PMCID: PMC9275247 DOI: 10.1128/aem.00405-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Bacillus cereus sensu lato (s.l.) includes foodborne pathogens, as well as beneficial microorganisms, such as bioinsecticides. Some of the beneficial and commercially used B. cereus s.l. strains have been shown to carry enterotoxin genes, the products of which can cause toxicoinfection in humans. Furthermore, recent epidemiological reports indicated that some bioinsecticidal strains have been linked with foodborne illness outbreaks. This demonstrates the need for improved surveillance of B. cereus s.l., which includes characterization of isolates' virulence capacity. However, the prediction of virulence capacity of B. cereus s.l. strains is challenging. Genetic screening for enterotoxin gene presence has proven to be insufficient for accurate discrimination between virulent and avirulent strains, given that nearly all B. cereus s.l. strains carry at least one enterotoxin gene. Furthermore, complex regulatory networks governing the expression of enterotoxins, and potential synergistic interactions between enterotoxins and other virulence factors make the prediction of toxicoinfection based on isolates' genome sequences challenging. In this review, we summarize and synthesize the current understanding of the regulation of enterotoxins associated with the B. cereus s.l. toxicoinfection and identify gaps in the knowledge that need to be addressed to facilitate identification of genetic markers predictive of cytotoxicity and toxicoinfection.
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Li Y, Chen N, Wu Q, Liang X, Yuan X, Zhu Z, Zheng Y, Yu S, Chen M, Zhang J, Wang J, Ding Y. A Flagella Hook Coding Gene flgE Positively Affects Biofilm Formation and Cereulide Production in Emetic Bacillus cereus. Front Microbiol 2022; 13:897836. [PMID: 35756067 PMCID: PMC9226606 DOI: 10.3389/fmicb.2022.897836] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/10/2022] [Indexed: 12/22/2022] Open
Abstract
Bacillus cereus, an important foodborne pathogen, poses a risk to food safety and quality. Robust biofilm formation ability is one of the key properties that is responsible for the food contamination and food poisoning caused by B. cereus, especially the emetic strains. To investigate the mechanism of biofilm formation in emetic B. cereus strains, we screened for the mutants that fail to form biofilms by using random mutagenesis toward B. cereus 892-1, an emetic strain with strong biofilm formation ability. When knocking out flgE, a flagellar hook encoding gene, the mutant showed disappearance of flagellar structure and swimming ability. Further analysis revealed that both pellicle and ring presented defects in the null mutant compared with the wild-type and complementary strains. Compared with the flagellar paralytic strains ΔmotA and ΔmotB, the inhibition of biofilm formation by ΔflgE is not only caused by the inhibition of motility. Interestingly, ΔflgE also decreased the synthesis of cereulide. To our knowledge, this is the first report showing that a flagellar component can both affect the biofilm formation and cereulide production in emetic B. cereus, which can be used as the target to control the biohazard of emetic B. cereus.
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Affiliation(s)
- Yangfu Li
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China.,State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Nuo Chen
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China.,State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xinmin Liang
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China.,State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaoming Yuan
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China.,State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Zhenjun Zhu
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Yin Zheng
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Shubo Yu
- State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Moutong Chen
- State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Jumei Zhang
- State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Yu Ding
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China.,State Key Laboratory of Applied Microbiology Southern China, Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
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Calvigioni M, Cara A, Celandroni F, Mazzantini D, Panattoni A, Tirloni E, Bernardi C, Pinotti L, Stella S, Ghelardi E. Characterization of a Bacillus cereus strain associated with a large feed-related outbreak of severe infection in pigs. J Appl Microbiol 2022; 133:1078-1088. [PMID: 35611609 PMCID: PMC9543730 DOI: 10.1111/jam.15636] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/12/2022] [Accepted: 05/19/2022] [Indexed: 12/03/2022]
Abstract
Aims Bacillus cereus is often responsible for foodborne diseases and both local and systemic infections in humans. Cases of infection in other mammals are rather rare. In this study, we report a B. cereus feed‐related outbreak that caused the death of 6234 pigs in Italy. Methods and Results Massive doses of a Gram‐positive, spore‐forming bacterium were recovered from the animal feed, faeces of survived pigs and intestinal content of dead ones. The B. cereus MM1 strain was identified by MALDI‐TOF MS and typified by RAPD‐PCR. The isolate was tested for the production of PC‐PLC, proteases, hemolysins and biofilm, for motility, as well as for the presence of genes encoding tissue‐degrading enzymes and toxins. Antimicrobial resistance and pathogenicity in Galleria mellonella larvae were also investigated. Our results show that the isolated B. cereus strain is swimming‐proficient, produces PC‐PLC, proteases, hemolysins, biofilm and carries many virulence genes. The strain shows high pathogenicity in G. mellonella larvae. Conclusions The isolated B. cereus strain demonstrates an aggressive profile of pathogenicity and virulence, being able to produce a wide range of determinants potentially hazardous to pigs' health. Significance and Impact of Study This study highlights the proficiency of B. cereus to behave as a devastating pathogen in swine if ingested at high doses and underlines that more stringent quality controls are needed for livestock feeds and supplements.
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Affiliation(s)
- Marco Calvigioni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Alice Cara
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Francesco Celandroni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Diletta Mazzantini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Adelaide Panattoni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Erica Tirloni
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Cristian Bernardi
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Luciano Pinotti
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Simone Stella
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Emilia Ghelardi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy.,Research Center Nutraceuticals and Food for Health-Nutrafood, University of Pisa, Italy
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10
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Detection of emetic Bacillus cereus and the emetic toxin cereulide in food matrices: Progress and perspectives. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Jovanovic J, Tretiak S, Begyn K, Rajkovic A. Detection of Enterotoxigenic Psychrotrophic Presumptive Bacillus cereus and Cereulide Producers in Food Products and Ingredients. Toxins (Basel) 2022; 14:toxins14040289. [PMID: 35448897 PMCID: PMC9030337 DOI: 10.3390/toxins14040289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/07/2022] [Accepted: 04/13/2022] [Indexed: 02/04/2023] Open
Abstract
In the last decade, foodborne outbreaks and individual cases caused by bacterial toxins showed an increasing trend. The major contributors are enterotoxins and cereulide produced by Bacillus cereus, which can cause a diarrheal and emetic form of the disease, respectively. These diseases usually induce relatively mild symptoms; however, fatal cases have been reported. With the aim to detected potential toxin producers that are able to grow at refrigerator temperatures and subsequently produce cereulide, we screened the prevalence of enterotoxin and cereulide toxin gene carriers and the psychrotrophic capacity of presumptive B. cereus obtained from 250 food products (cereal products, including rice and seeds/pulses, dairy-based products, dried vegetables, mixed food, herbs, and spices). Of tested food products, 226/250 (90.4%) contained presumptive B. cereus, which communities were further tested for the presence of nheA, hblA, cytK-1, and ces genes. Food products were mainly contaminated with the nheA B. cereus carriers (77.9%), followed by hblA (64.8%), ces (23.2%), and cytK-1 (4.4%). Toxigenic B. cereus communities were further subjected to refrigerated (4 and 7 °C) and mild abuse temperatures (10 °C). Overall, 77% (94/121), 86% (104/121), and 100% (121/121) were able to grow at 4, 7, and 10 °C, respectively. Enterotoxin and cereulide potential producers were detected in 81% of psychrotrophic presumptive B. cereus. Toxin encoding genes nheA, hblA, and ces gene were found in 77.2, 55, and 11.7% of tested samples, respectively. None of the psychrotrophic presumptive B. cereus were carriers of the cytotoxin K-1 encoding gene (cytK-1). Nearly half of emetic psychrotrophic B. cereus were able to produce cereulide in optimal conditions. At 4 °C none of the examined psychrotrophs produced cereulide. The results of this research highlight the high prevalence of B. cereus and the omnipresence of toxin gene harboring presumptive B. cereus that can grow at refrigerator temperatures, with a focus on cereulide producers.
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Affiliation(s)
- Jelena Jovanovic
- Department of Food Technology, Safety, and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (J.J.); (K.B.)
| | - Svitlana Tretiak
- Department of Pathobiology, Pharmacology and Zoological Medicine, Ghent University, Salisburylaan 133, D5 Ingang 78, 9820 Merelbeke, Belgium;
- Impextraco nv, Wiekevorstsesteenweg 38, 2220 Heist-op-den-Berg, Belgium
| | - Katrien Begyn
- Department of Food Technology, Safety, and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (J.J.); (K.B.)
| | - Andreja Rajkovic
- Department of Food Technology, Safety, and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (J.J.); (K.B.)
- Correspondence:
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Cereulide and Deoxynivalenol Increase LC3 Protein Levels in HepG2 Liver Cells. Toxins (Basel) 2022; 14:toxins14020151. [PMID: 35202179 PMCID: PMC8880806 DOI: 10.3390/toxins14020151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 02/14/2022] [Indexed: 02/05/2023] Open
Abstract
Food contaminants of bacterial or fungal origin frequently contaminate staple foods to various extents. Among others, the bacterial toxin cereulide (CER) and the mycotoxin deoxynivalenol (DON) co-occur in a mixed diet and are absorbed by the human body. Both toxins exert dis-tinctive mitotoxic potential. As damaged mitochondria are removed via autophagy, mitochondrial and lysosomal toxicity were assessed by applying low doses of single and combined toxins (CER 0.1-50 ng/mL; DON 0.01-5 µg/mL) to HepG2 liver cells. In addition to cytotoxicity assays, RT-qPCR was performed to investigate genes involved in lysosomal biogenesis and autophagy. CER and DON caused significant cytotoxicity on HepG2 cells after 5 and 24 h over a broad concentration range. CER, alone and in combination with DON, increased the transcription of the autophagy related genes coding for the microtubule associated protein 1A/1B light chain 3 (LC3) and sequestome 1 (SQSTM1) as well as LC3 protein expression which was determined using immunocytochemistry. DON increased LC3 protein expression without induction of gene transcription, hence it seems plausible that CER and DON act on different pathways. The results support the hypothesis that CER induces autophagy via the LC3 pathway and damaged mitochondria are therefore eliminated.
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13
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Bacillus cereus Toxin Repertoire: Diversity of (Iso)cereulide(s). MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030872. [PMID: 35164132 PMCID: PMC8840689 DOI: 10.3390/molecules27030872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/14/2022] [Accepted: 01/19/2022] [Indexed: 11/17/2022]
Abstract
The emetic Bacillus cereus toxin cereulide (1) poses a significant safety risk in the food industry, causing emesis and nausea after consumption of contaminated foods. Analogously to cereulide, the structures of various isocereulides, namely, isocereulides A–G, have been recently reported and could also be identified in B. cereus-contaminated food samples. The HPLC fractionation of B. cereus extracts allows us to isolate additional isocereulides. By applying MSn sequencing, post-hydrolytic dipeptide, amino acid and α-hydroxy acid analyses using UPLC-ESI-TOF-MS to purify the analytes, seven new isocereulides H–N (2–8) could be elucidated in their chemical structures. The structure elucidation was supported by one-dimensional and two-dimensional NMR spectra of the isocereulides H (2), K (5), L and N (6 + 8) and M (7). The toxicity of 2–8 was investigated in a HEp-2 cell assay to determine their respective 50% effective concentration (EC50). Thus, 2–8 exhibited EC50 values ranging from a 0.4- to 1.4-fold value compared to cereulide (1). Missing structure-activity correlations indicate the necessity to determine the toxic potential of all naturally present isocereulides as single compounds to be able to perform a thorough toxicity evaluation of B. cereus-contaminated foods in the future.
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Acute Liver Failure after Ingestion of Fried Rice Balls: A Case Series of Bacillus cereus Food Poisonings. Toxins (Basel) 2021; 14:toxins14010012. [PMID: 35050989 PMCID: PMC8779543 DOI: 10.3390/toxins14010012] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 12/19/2021] [Accepted: 12/22/2021] [Indexed: 12/30/2022] Open
Abstract
Bacillus cereus foodborne intoxications and toxicoinfections are on a rise. Usually, symptoms are self-limiting but occasionally hospitalization is necessary. Severe intoxications with the emetic Bacillus cereus toxin cereulide, which is notably resistant heat and acid during cooking, can cause acute liver failure and encephalopathy. We here present a case series of food poisonings in five immunocompetent adults after ingestion of fried rice balls, which were massively contaminated with Bacillus cereus. The patients developed a broad clinical spectrum, ranging from emesis and diarrhoea to life-threatening acute liver failure and acute tubular necrosis of the kidney in the index patient. In the left-over rice ball, we detected 8 × 106Bacillus cereus colony-forming units/g foodstuff, and cereulide in a concentration of 37 μg/g foodstuff, which is one of the highest cereulide toxin contaminations reported so far from foodborne outbreaks. This report emphasizes the potential biological hazard of contaminated rice meals that are not freshly prepared. It exemplifies the necessity of a multidisciplinary approach in cases of Bacillus cereus associated food poisonings to rapidly establish the diagnosis, to closely monitor critically ill patients, and to provide supportive measures for acute liver failure and—whenever necessary—urgent liver transplantation.
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Lin R, Li D, Xu Y, Wei M, Chen Q, Deng Y, Wen J. Chronic cereulide exposure causes intestinal inflammation and gut microbiota dysbiosis in mice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117814. [PMID: 34329069 DOI: 10.1016/j.envpol.2021.117814] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/21/2021] [Accepted: 07/18/2021] [Indexed: 06/13/2023]
Abstract
Known as a cause of food poisoning, Bacillus cereus (B. cereus) is widespread in nature. Cereulide, the heat-stable and acid-resistant emetic toxin which is produced by some B. cereus strains, is often associated with foodborne outbreaks, and causes acute emetic toxicity at high dosage exposure. However, the toxicological effect and underlying mechanism caused by chronic low-dose cereulide exposure require to be further addressed. In the study, based on mouse model, cereulide exposure (50 μg/kg body weight) for 28 days induced intestinal inflammation, gut microbiota dysbiosis and food intake reduction. According to the cell models, low dose cereulide exposure disrupted the intestinal barrier function and caused intestinal inflammation, which were resulted from endoplasmic reticulum (ER) stress IRE1/XBP1/CHOP pathway activation to induce cell apoptosis and inflammatory cytokines production. For gut microbiota, cereulide decreased the abundances of Lactobacillus and Oscillospira. Furthermore, cereulide disordered the metabolisms of gut microbiota, which exhibited the inhibitions of butyrate and tryptophan. Interestingly, cereulide exposure also inhibited the tryptophan hydroxylase to produce the serotonin in the gut and brain, which might lead to depression-like food intake reduction. Butyrate supplementation (100 mg/kg body weight) significantly reduced intestinal inflammation and serotonin biosynthesis suppression caused by cereulide in mice. In conclusion, chronic cereulide exposure induced ER stress to cause intestinal inflammation, gut microbiota dysbiosis and serotonin biosynthesis suppression. IRE1 could be the therapeutic target and butyrate supplementation is the potential prevention strategy.
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Affiliation(s)
- Ruqin Lin
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China
| | - Danyang Li
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China
| | - Yangyang Xu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China
| | - Mengyao Wei
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China
| | - Qingmei Chen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China
| | - Yiqun Deng
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China
| | - Jikai Wen
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Key Laboratory of Zoonosis of Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China; Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, 510642, PR China.
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Cereulide Exposure Caused Cytopathogenic Damages of Liver and Kidney in Mice. Int J Mol Sci 2021; 22:ijms22179148. [PMID: 34502057 PMCID: PMC8431326 DOI: 10.3390/ijms22179148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/20/2021] [Accepted: 08/20/2021] [Indexed: 12/18/2022] Open
Abstract
Cereulide is one of the main food-borne toxins for vomiting synthesized by Bacillus cereus, and it widely contaminates meat, eggs, milk, and starchy foods. However, the toxicological effects and mechanisms of the long-time exposure of cereulide in vivo remain unknown. In this study, oral administration of 50 and 200 μg/kg body weight cereulide in the mice for 28 days caused oxidative stress in liver and kidney tissues and induce abnormal expression of inflammatory factors. In pathogenesis, cereulide exposure activated endoplasmic reticulum stress (ER stress) via the pathways of inositol-requiring enzyme 1α (IRE1α)/Xbox binding protein (XBP1) and PRKR-like ER kinase (PERK)/eukaryotic translation initiation factor 2α (eIF2α), and consequently led to the apoptosis and tissue damages in mouse liver and kidney. In vitro, we confirmed that the accumulation of reactive oxygen species (ROS) caused by cereulide is the main factor leading to ER stress in HepaRG and HEK293T cells. Supplementation of sodium butyrate (NaB) inhibited the activations of IRE1α/XBP1 and PERK/eIF2α pathways caused by cereulide exposure in mice, and reduced the cell apoptosis in liver and kidney. In conclusion, this study provides a new insight in understanding the toxicological mechanism and prevention of cereulide exposure.
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Walser V, Kranzler M, Dawid C, Ehling-Schulz M, Stark TD, Hofmann TF. Distribution of the Emetic Toxin Cereulide in Cow Milk. Toxins (Basel) 2021; 13:toxins13080528. [PMID: 34437398 PMCID: PMC8402402 DOI: 10.3390/toxins13080528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 12/21/2022] Open
Abstract
Bacillus cereus is frequently associated with food-borne intoxications, and its emetic toxin cereulide causes emesis and nausea after consumption of contaminated foods. The major source for contamination is found within contaminated raw materials containing the highly chemically resistant cereulide, independent of vegetative bacteria cells. Up to date, non-existing removal strategies for cereulide evoke the question of how the toxin is distributed within a food sample, especially cow milk. Milk samples with different milk fat contents were incubated with purified cereulide, separated by centrifugation into a lipid and an aqueous phase, and cereulide was quantified in both fractions by SIDA-LC-MS/MS. By artificially increasing the milk fat content from 0.5% to 50%, the amount of cereulide recovered in the lipid phase and could be augmented from 13.3 to 78.6%. Further, the ratio of cereulide increased in the lipid phase of milk with additional plant-based lipid (sunflower oil) to 47.8%. This demonstrated a clear affinity of cereulide towards the hydrophobic, lipid phase, aligning with cereulide's naturally strong hydrophobic properties. Therefore, an intensified cereulide analysis of lipid enriched dairy products to prevent severe cereulide intoxications or cross-contamination in processed foods is suggested.
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Affiliation(s)
- Veronika Walser
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
| | - Markus Kranzler
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.K.); (M.E.-S.)
| | - Corinna Dawid
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.K.); (M.E.-S.)
| | - Timo D. Stark
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
- Correspondence: ; Tel.: +49-8161-71-2911
| | - Thomas F. Hofmann
- Food Chemistry and Molecular Sensory Science, Department of Molecular Life Sciences, School of Life Sciences, Technical University of Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany; (V.W.); (C.D.); (T.F.H.)
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18
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Jovanovic J, Ornelis VFM, Madder A, Rajkovic A. Bacillus cereus food intoxication and toxicoinfection. Compr Rev Food Sci Food Saf 2021; 20:3719-3761. [PMID: 34160120 DOI: 10.1111/1541-4337.12785] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/13/2021] [Accepted: 05/15/2021] [Indexed: 12/12/2022]
Abstract
Bacillus cereus is one of the leading etiological agents of toxin-induced foodborne diseases. Its omnipresence in different environments, spore formation, and its ability to adapt to varying conditions and produce harmful toxins make this pathogen a health hazard that should not be underestimated. Food poisoning by B. cereus can manifest itself as an emetic or diarrheal syndrome. The former is caused by the release of the potent peptide toxin cereulide, whereas the latter is the result of proteinaceous enterotoxins (e.g., hemolysin BL, nonhemolytic enterotoxin, and cytotoxin K). The final harmful effect is not only toxin and strain dependent, but is also affected by the stress responses, accessory virulence factors, and phenotypic properties under extrinsic, intrinsic, and explicit food conditions and host-related environment. Infamous portrait of B. cereus as a foodborne pathogen, as well as a causative agent of nongastrointestinal infections and even nosocomial complications, has inspired vast volumes of multidisciplinary research in food and clinical domains. As a result, extensive original data became available asking for a new, both broad and deep, multifaceted look into the current state-of-the art regarding the role of B. cereus in food safety. In this review, we first provide an overview of the latest knowledge on B. cereus toxins and accessory virulence factors. Second, we describe the novel taxonomy and some of the most pertinent phenotypic characteristics of B. cereus related to food safety. We link these aspects to toxin production, overall pathogenesis, and interactions with its human host. Then we reflect on the prevalence of different toxinotypes in foods opening the scene for epidemiological aspects of B. cereus foodborne diseases and methods available to prevent food poisoning including overview of the different available methods to detect B. cereus and its toxins.
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Affiliation(s)
- Jelena Jovanovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Vincent F M Ornelis
- Department of Organic and Macromolecular Chemistry, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Annemieke Madder
- Department of Organic and Macromolecular Chemistry, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Andreja Rajkovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Zhong W, Shahbaz O, Teskey G, Beever A, Kachour N, Venketaraman V, Darmani NA. Mechanisms of Nausea and Vomiting: Current Knowledge and Recent Advances in Intracellular Emetic Signaling Systems. Int J Mol Sci 2021; 22:5797. [PMID: 34071460 PMCID: PMC8198651 DOI: 10.3390/ijms22115797] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 02/07/2023] Open
Abstract
Nausea and vomiting are common gastrointestinal complaints that can be triggered by diverse emetic stimuli through central and/or peripheral nervous systems. Both nausea and vomiting are considered as defense mechanisms when threatening toxins/drugs/bacteria/viruses/fungi enter the body either via the enteral (e.g., the gastrointestinal tract) or parenteral routes, including the blood, skin, and respiratory systems. While vomiting is the act of forceful removal of gastrointestinal contents, nausea is believed to be a subjective sensation that is more difficult to study in nonhuman species. In this review, the authors discuss the anatomical structures, neurotransmitters/mediators, and corresponding receptors, as well as intracellular emetic signaling pathways involved in the processes of nausea and vomiting in diverse animal models as well as humans. While blockade of emetic receptors in the prevention of vomiting is fairly well understood, the potential of new classes of antiemetics altering postreceptor signal transduction mechanisms is currently evolving, which is also reviewed. Finally, future directions within the field will be discussed in terms of important questions that remain to be resolved and advances in technology that may help provide potential answers.
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Affiliation(s)
- Weixia Zhong
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA 91766, USA; (W.Z.); (G.T.); (V.V.)
| | - Omar Shahbaz
- School of Medicine, Universidad Iberoamericana, Av. Francia 129, Santo Domingo 10203, Dominican Republic;
| | - Garrett Teskey
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA 91766, USA; (W.Z.); (G.T.); (V.V.)
| | - Abrianna Beever
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (A.B.); (N.K.)
| | - Nala Kachour
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (A.B.); (N.K.)
| | - Vishwanath Venketaraman
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA 91766, USA; (W.Z.); (G.T.); (V.V.)
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (A.B.); (N.K.)
| | - Nissar A. Darmani
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 309 East Second Street, Pomona, CA 91766, USA; (W.Z.); (G.T.); (V.V.)
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20
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Assessing Mixture Effects of Cereulide and Deoxynivalenol on Intestinal Barrier Integrity and Uptake in Differentiated Human Caco-2 Cells. Toxins (Basel) 2021; 13:toxins13030189. [PMID: 33806705 PMCID: PMC7998855 DOI: 10.3390/toxins13030189] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/16/2022] Open
Abstract
The human intestine is regularly exposed to ingested food contaminants, such as fungal and bacterial toxins, which have been described to co-occur in a mixed diet. Thus, it is of utmost importance to understand possible interactions between contaminants of different origin. Hence, we investigated the single and combined effects of one of the most abundant mycotoxins, deoxynivalenol (DON; 0.1 to 10 µg/mL), and the bacterial toxin cereulide (CER; 1 to 100 ng/mL) on differentiated human Caco-2 (C2BBe1) cells cultured in a transwell system. We tested the capacity of the two toxins to alter the intestinal integrity and further investigated the uptake of both compounds and the formation of selected DON metabolites. CER alone (10 and 100 ng/mL) and in combination with DON (10 ng/mL CER with 1 µg/mL DON) was found to alter the barrier function by increasing the transepithelial electrical resistance and the expression of the tight junction protein claudin-4. For the first time, DON-3-sulfate was identified as a metabolite of human intestinal cells in vitro. Moreover, co-incubation of CER and DON led to an altered ratio between DON and DON-3-sulfate. Hence, we conclude that co-exposure to CER and DON may alter the intestinal barrier function and biotransformation of intestinal cells.
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21
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Kalbhenn EM, Bauer T, Stark TD, Knüpfer M, Grass G, Ehling-Schulz M. Detection and Isolation of Emetic Bacillus cereus Toxin Cereulide by Reversed Phase Chromatography. Toxins (Basel) 2021; 13:toxins13020115. [PMID: 33557428 PMCID: PMC7915282 DOI: 10.3390/toxins13020115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/30/2021] [Accepted: 02/01/2021] [Indexed: 12/17/2022] Open
Abstract
The emetic toxin cereulide is a 1.2 kDa dodecadepsipeptide produced by the food pathogen Bacillus cereus. As cereulide poses a serious health risk to humans, sensitive and specific detection, as well as toxin purification and quantification, methods are of utmost importance. Recently, a stable isotope dilution assay tandem mass spectrometry (SIDA–MS/MS)-based method has been described, and an method for the quantitation of cereulide in foods was established by the International Organization for Standardization (ISO). However, although this SIDA–MS/MS method is highly accurate, the sophisticated high-end MS equipment required for such measurements limits the method’s suitability for microbiological and molecular research. Thus, we aimed to develop a method for cereulide toxin detection and isolation using equipment commonly available in microbiological and biochemical research laboratories. Reproducible detection and relative quantification of cereulide was achieved, employing reversed phase chromatography (RPC). Chromatographic signals were cross validated by ultraperformance liquid chromatography–mass spectrometry (UPLC–MS/MS). The specificity of the RPC method was tested using a test panel of strains that included non-emetic representatives of the B. cereus group, emetic B. cereus strains, and cereulide-deficient isogenic mutants. In summary, the new method represents a robust, economical, and easily accessible research tool that complements existing diagnostics for the detection and quantification of cereulide.
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Affiliation(s)
- Eva Maria Kalbhenn
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.M.K.); (T.B.)
| | - Tobias Bauer
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.M.K.); (T.B.)
| | - Timo D. Stark
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, 85354 Freising, Germany;
| | - Mandy Knüpfer
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937 Munich, Germany; (M.K.); (G.G.)
| | - Gregor Grass
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937 Munich, Germany; (M.K.); (G.G.)
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.M.K.); (T.B.)
- Correspondence:
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22
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The Food Poisoning Toxins of Bacillus cereus. Toxins (Basel) 2021; 13:toxins13020098. [PMID: 33525722 PMCID: PMC7911051 DOI: 10.3390/toxins13020098] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/14/2021] [Accepted: 01/25/2021] [Indexed: 12/13/2022] Open
Abstract
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.
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Doellinger J, Schneider A, Stark TD, Ehling-Schulz M, Lasch P. Evaluation of MALDI-ToF Mass Spectrometry for Rapid Detection of Cereulide From Bacillus cereus Cultures. Front Microbiol 2020; 11:511674. [PMID: 33329410 PMCID: PMC7709880 DOI: 10.3389/fmicb.2020.511674] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 09/16/2020] [Indexed: 12/20/2022] Open
Abstract
Bacillus cereus plays an often unrecognized role in food borne diseases. Food poisoning caused by this pathogen is manifested by either diarrhea or emesis. Due to the relatively high prevalence of emetic toxin cereulide associated food poisoning, methods for simple and reliable detection of cereulide producing strains are of utmost importance. Recently, two different studies reported on the application of MALDI-ToF MS for either the differentiation of emetic and non-emetic strains of B. cereus or for direct detection of cereulide from bacterial colony smears. However, for implementation of cereulide detection using MALDI-ToF MS in routine microbiological diagnostics additional investigations on the sensitivity and specificity as well as on the fitting into common workflows for bacterial identification are needed. These aspects prompted us to investigate open issues and to test sample preparation methods, commonly used for microbial identification for their suitability to detect the emetic toxin from bacteria. Based on our experimental findings we propose a workflow that allows identification of B. cereus and sensitive detection of cereulide in parallel, using linear-mode MALDI-ToF MS equipment. The protocol was validated in a blinded study and is based on the well-established ethanol/formic acid extraction method. Cereulide is detected in the ethanol wash solution of samples identified as B. cereus as peaks at m/z 1175 and 1191. Peak position difference of 16 Th (Thomson) indicates detection of the sodium and potassium adducts of cereulide. This sample treatment offers possibilities for further characterization by more sophisticated LC-MS-based methods. In summary, the ease of use and the achieved level of analytical sensitivity as well as the wide-spread availability of MALDI-ToF MS equipment in clinical microbiological laboratories provides a promising tool to improve and to facilitate routine diagnostics of B. cereus associated food intoxications.
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Affiliation(s)
- Joerg Doellinger
- Proteomics and Spectroscopy Unit (ZBS 6), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany
| | - Andy Schneider
- Proteomics and Spectroscopy Unit (ZBS 6), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany
| | - Timo D Stark
- Food Chemistry and Molecular Sensory Science, Technical University of Munich, Munich, Germany
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Peter Lasch
- Proteomics and Spectroscopy Unit (ZBS 6), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany
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Bacillus cereus: Epidemiology, Virulence Factors, and Host-Pathogen Interactions. Trends Microbiol 2020; 29:458-471. [PMID: 33004259 DOI: 10.1016/j.tim.2020.09.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/30/2022]
Abstract
The toxin-producing bacterium Bacillus cereus is an important and neglected human pathogen and a common cause of food poisoning. Several toxins have been implicated in disease, including the pore-forming toxins hemolysin BL (HBL) and nonhemolytic enterotoxin (NHE). Recent work revealed that HBL binds to the mammalian surface receptors LITAF and CDIP1 and that both HBL and NHE induce potassium efflux and activate the NLRP3 inflammasome, leading to pyroptosis. These mammalian receptors, in part, contribute to inflammation and pathology. Other putative virulence factors of B. cereus include cytotoxin K, cereulide, metalloproteases, sphingomyelinase, and phospholipases. In this review, we highlight the latest progress in our understanding of B. cereus biology, epidemiology, and pathogenesis, and discuss potential new directions for research in this field.
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25
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Liu XY, Hu Q, Xu F, Ding SY, Zhu K. Characterization of Bacillus cereus in Dairy Products in China. Toxins (Basel) 2020; 12:E454. [PMID: 32674390 PMCID: PMC7405013 DOI: 10.3390/toxins12070454] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023] Open
Abstract
Bacillus cereus is a common and ubiquitous foodborne pathogen with an increasing prevalence rate in dairy products in China. High and unmet demands for such products, particularly milk, raise the risk of B. cereus associated contamination. The presence of B. cereus and its virulence factors in dairy products may cause food poisoning and other illnesses. Thus, this review first summarizes the epidemiological characteristics and analytical assays of B. cereus from dairy products in China, providing insights into the implementation of intervention strategies. In addition, the recent achievements on the cytotoxicity and mechanisms of B. cereus are also presented to shed light on the therapeutic options for B. cereus associated infections.
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Affiliation(s)
- Xiao-Ye Liu
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.-Y.L.); (Q.H.)
- Department of Mechanics and Engineering Science, College of Engineering, Academy for Advanced Interdisciplinary Studies, and Beijing Advanced Innovation Center for Engineering Science and Emerging Technology, College of Engineering, Peking University, Beijing 100871, China
| | - Qiao Hu
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.-Y.L.); (Q.H.)
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
| | - Fei Xu
- National Feed Drug Reference Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
| | - Shuang-Yang Ding
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
| | - Kui Zhu
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.-Y.L.); (Q.H.)
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
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Vidic J, Chaix C, Manzano M, Heyndrickx M. Food Sensing: Detection of Bacillus cereus Spores in Dairy Products. BIOSENSORS 2020; 10:E15. [PMID: 32106440 PMCID: PMC7146628 DOI: 10.3390/bios10030015] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/14/2020] [Accepted: 02/22/2020] [Indexed: 12/21/2022]
Abstract
Milk is a source of essential nutrients for infants and adults, and its production has increased worldwide over the past years. Despite developments in the dairy industry, premature spoilage of milk due to the contamination by Bacillus cereus continues to be a problem and causes considerable economic losses. B. cereus is ubiquitously present in nature and can contaminate milk through a variety of means from the farm to the processing plant, during transport or distribution. There is a need to detect and quantify spores directly in food samples, because B. cereus might be present in food only in the sporulated form. Traditional microbiological detection methods used in dairy industries to detect spores show limits of time (they are time consuming), efficiency and sensitivity. The low level of B. cereus spores in milk implies that highly sensitive detection methods should be applied for dairy products screening for spore contamination. This review describes the advantages and disadvantages of classical microbiological methods used to detect B. cereus spores in milk and milk products, related to novel methods based on molecular biology, biosensors and nanotechnology.
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Affiliation(s)
- Jasmina Vidic
- INRAE, AgroParisTech, Micalis Institute, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Carole Chaix
- Institut des Sciences Analytiques, UMR 5280 CNRS, Université de Lyon, Université Claude Bernard Lyon 1, F-69100 Villeurbanne, France;
| | - Marisa Manzano
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, via Sondrio 2/A, 33100 Udine, Italy;
| | - Marc Heyndrickx
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Brusselsesteenweg 370, B-9090 Melle, Belgium;
- Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
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27
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Combinatory effects of cereulide and deoxynivalenol on in vitro cell viability and inflammation of human Caco-2 cells. Arch Toxicol 2020; 94:833-844. [PMID: 32065293 DOI: 10.1007/s00204-020-02658-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/03/2020] [Indexed: 02/06/2023]
Abstract
Deoxynivalenol (DON), one of the most abundant mycotoxins in cereal products, was recently detected with other mycotoxins and the emetic bacterial toxin cereulide (CER) in maize porridge. Within a cereal-based diet, co-exposure to these toxins is likely, hence raising the question of combinatory toxicological effects. While the toxicological evaluation of DON has quite progressed, consequences of chronic, low-dose CER exposure are still insufficiently explored. Information about the combinatory toxicological effects of these toxins is lacking. In the present study, we investigated how CER (0.1-100 ng/mL) and DON (0.01-10 µg/mL) alone and in a constant ratio of 1:100 (CER:DON) affect the cytotoxicity and immune response of differentiated human intestinal Caco-2 cells. While DON alone reduced cell viability only in the highest concentration (10 µg/mL), CER caused severe cytotoxicity upon prolonged incubation (starting from 10 ng/mL after 24 h and 48 h, 2.5 ng/mL and higher after 72 h). After 72 h, synergistic effects were observed at 2.5 ng/mL CER and 0.25 µg/mL DON. Different endpoints of inflammation were investigated in interleukin-1β-stimulated Caco-2 cells. Notably, DON-induced interleukin-8 transcription and secretion were diminished by the presence of 10 and 25 ng/mL CER after short-term (5 h) incubation, indicating immunosuppressive properties. We hypothesise that habitual consumption of cereal-based foods co-contaminated with CER and DON may cause synergistic cytotoxic effects and an altered immune response in the human intestine. Therefore, further research concerning effects of co-occurring bacterial toxins and mycotoxins on the impairment of intestinal barrier integrity, intestinal inflammation and the promotion of malnutrition is needed.
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Moist and Mold Exposure is Associated With High Prevalence of Neurological Symptoms and MCS in a Finnish Hospital Workers Cohort. Saf Health Work 2020; 11:173-177. [PMID: 32596012 PMCID: PMC7303478 DOI: 10.1016/j.shaw.2020.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 12/18/2022] Open
Abstract
Background Indoor air dampness microbiota (DM) is a big health hazard. Sufficient evidence exists that exposure to DM causes new asthma or exacerbation, dyspnea, infections of upper airways and allergic alveolitis. Less convincing evidence has yet been published for extrapulmonary manifestations of dampness and mold hypersensitivity syndrome ). Methods We investigated the prevalence of extrapulmonary in addition to respiratory symptoms with a questionnaire in a cohort of nurses and midwives (n = 90) exposed to DM in a Helsinki Obstetric Hospital. The corresponding prevalence was compared with an unexposed cohort (n = 45). Particular interest was put on neurological symptoms and multiple chemical sensitivity. Results The results show that respiratory symptoms were more common among participants of the study vs. control cohort, that is, 80 vs 29%, respectively (risk ratio [RR]: 2.56, p < 0.001). Symptoms of the central or peripheral nervous system were also more common in study vs. control cohort: 81 vs 11% (RR: 6.63, p < 0.001). Fatigue was reported in 77 vs. 24%, (RR: 3.05, p < 0.001) and multiple chemical sensitivity in 40 vs. 9%, (RR: 3.44, p = 0.01), the so-called “brain fog”, was prevalent in 62 vs 11% (RR: 4.94, p < 0.001), arrhythmias were reported in 57 vs. 2.4% (RR: 19.75, p < 0.001) and musculoskeletal pain in 51 vs 22% (RR: 2.02, p = 0.02) among participants of the study vs. control cohort, respectively. Conclusion The results indicate that the exposure to DM is associated with a plethora of extrapulmonary symptoms. Presented data corroborate our recent reports on the health effects of moist and mold exposure in a workplace.
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29
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Rouzeau-Szynalski K, Stollewerk K, Messelhäusser U, Ehling-Schulz M. Why be serious about emetic Bacillus cereus: Cereulide production and industrial challenges. Food Microbiol 2019; 85:103279. [PMID: 31500702 DOI: 10.1016/j.fm.2019.103279] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 07/18/2019] [Accepted: 07/25/2019] [Indexed: 01/06/2023]
Abstract
Cereulide, a potent toxin produced by Bacillus cereus, is a small, highly heat- and acid-resistant depsipeptide toxin, which confronts food industry with several challenges. Due to the ubiquitous presence of B. cereus in the environment, this opportunistic pathogen can enter food production and processing at almost any stage. Although the bacteria itself might be removed during food processing, the cereulide toxin will most likely not be destroyed or inactivated by these processes. Because of the high toxicity of cereulide and the high incidence rates often observed in connection with foodborne outbreaks, the understanding of the mechanisms of toxin production as well as accurate data on contamination sources and factors promoting toxin formation are urgently needed to prevent contamination and toxin production in food production processes. Over the last decade, considerable progress had been made on the understanding of cereulide toxin biosynthesis in emetic B. cereus, but an overview of current knowledge on this toxin with regards to food industry perspective is lacking. Thus, we aim in this work to summarize data available on extrinsic parameters acting on cereulide toxin synthesis in emetic B. cereus and to discuss the food industry specific challenges related to this toxin. Furthermore, we emphasize how identification of the cardinals in food production processes can lead to novel effective strategies for prevention of toxin formation in the food processing chain and could contribute to the improvement of existing HACCP studies.
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Affiliation(s)
| | - Katharina Stollewerk
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Austria
| | - Ute Messelhäusser
- Bavarian Health and Food Safety Authority, Veterinaerstr. 2, 85764, Oberschleissheim, Germany
| | - Monika Ehling-Schulz
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Austria.
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30
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Sipos W. Shifts in porcine PBMC populations from adolescence to adulthood. Vet Immunol Immunopathol 2019; 211:35-37. [PMID: 31084891 DOI: 10.1016/j.vetimm.2019.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/12/2019] [Accepted: 04/14/2019] [Indexed: 01/06/2023]
Abstract
In mammals, the immune system is undergoing significant changes during development, which has many impacts on the individual's capacity to cope with infectious diseases or other pathologic conditions, where the immune system is involved. Especially in livestock, it is important to know in detail about these changes, including shifts in the composition of systemic leukocyte populations, as this knowledge may help to focus on relevant cell populations when developing novel vaccines for use in juvenile versus adult animals. In this mini-review, a synoptic comparison of published PBMC populations, which were analysed in healthy weaned piglets as well as multiparous non-gestating sows, shows remarkable shifts within leukocyte populations. γδ T cells increase by factor 1.5, plasmacytoid dendritic cells and T helper cells more than double, and cytotoxic T cells as well as regulatory T cells increase more than four fold, whereas NK cells as well as B cells in adult sows comprise only 40% and monocytes 70% of the relative population sizes in weaned piglets. In summary, these insights into age-dependent shifts of porcine leukocyte populations indicate a principal increase of acquired immunity-associated leukocyte populations, whereas primarily innate immunity-associated cell types (NK cells, monocytes) are diminished.
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Affiliation(s)
- Wolfgang Sipos
- Clinical Department for Farm Animals, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
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31
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Ducrest PJ, Pfammatter S, Stephan D, Vogel G, Thibault P, Schnyder B. Rapid detection of Bacillus ionophore cereulide in food products. Sci Rep 2019; 9:5814. [PMID: 30967595 PMCID: PMC6456620 DOI: 10.1038/s41598-019-42167-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 03/22/2019] [Indexed: 12/17/2022] Open
Abstract
Cereulide is a toxic cyclic depsipeptide produced by certain strains of Bacillus cereus found in soil and food products. While some harmless strains of Bacillus are used as probiotic, others can cause nausea and vomiting, and represent an important food safety concern. Current detection methods are time consuming and do not necessarily detect toxic cereulide. Here, we developed a rapid protocol using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry that detects the toxin originating from a colony smear of B. cereus. The distinct molecular feature of the toxin peak at m/z 1,191 was clearly identified from bacterial extracts with a limit of detection (LOD) of 30 ng/mL. Final optimisation of the sample preparation was based on cereulide chelating cations to produce the alkali adduct [M + K]+ without the use of a MALDI matrix, and provided a 1,000-fold improvement of LOD with 30 pg/mL of cereulide. We evaluated the application of this method for the detection of cereulide in rice, milk, and different ready-to-eat meals. The proposed protocol is quick, easy and provides an improvement over conventional methods for the detection of B. cereus toxin.
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Affiliation(s)
- P J Ducrest
- University of Applied Sciences, HES-SO Valais//Wallis, Institute of Life Technologies, Sion, Switzerland
| | - S Pfammatter
- University of Montreal, Institute for Research in Immunology and Cancer, Montreal, Quebec, Canada
| | - D Stephan
- University of Applied Sciences, HES-SO Valais//Wallis, Institute of Life Technologies, Sion, Switzerland
| | - G Vogel
- Mabritec AG, Riehen, Switzerland
| | - P Thibault
- University of Montreal, Institute for Research in Immunology and Cancer, Montreal, Quebec, Canada
| | - B Schnyder
- University of Applied Sciences, HES-SO Valais//Wallis, Institute of Life Technologies, Sion, Switzerland.
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