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Madouri R, Ziane M, Benaceur F, Cufaoglu G. Characterization of toxigenic genes of Bacillus cereus strains isolated from different spices sold in Algeria. Braz J Microbiol 2024:10.1007/s42770-024-01514-8. [PMID: 39269638 DOI: 10.1007/s42770-024-01514-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 09/03/2024] [Indexed: 09/15/2024] Open
Abstract
Many cooked foods are prepared with spices and dried herbs; these can be contaminated by several types of microorganisms, including aerobic spore-forming bacteria. The Bacillus cereus group is very widespread in nature and is known among the common food contaminants. They are involved in food poisoning, causing two types of syndromes, diarrheal and emetic. The aims of the present work were to determine the prevalence of toxigenic Bacillus cereus spores in spices and herbs marketed in the Laghouat area and to identify their toxigenic genes via PCR. Among the 191 samples, 14.13% were determined to be B. cereus, with concentrations ranging from 2.52 to 5.82 log cfu/g, where the highest level of contamination was observed in allspice and ginger. Moreover, entFM (100%), nhe (88.23%) and cytK (70.58%) were the most frequently identified toxin genes, whereas hbl (23.52%) was less common, and no emetic toxin-encoding gene (cesB) was found in any of the samples. Considering the results of the present study, the B. cereus microbial load and toxin gene profiles of spices show that spices have potential for public health in Algeria. In this context, it is crucial to guarantee the microbiological safety of spices by respecting good hygiene practices, eliminating bacterial spores and toxin production via sterilization and using appropriate packaging for these products.
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Affiliation(s)
- Redhwane Madouri
- Laboratory of Biological and Agronomic Sciences, Université Amar Telidji de Laghouat, BP 37G, Route de Ghardaïa, Laghouat, 03000, Algeria
| | - Mohammed Ziane
- Département de Biologie, Facultés des sciences et Technologie, Université de Ain Témouchent, route de Sidi bel abbès, N101, Ain Temouchent, 46000, Algérie.
| | - Farouk Benaceur
- Laboratory of Biological and Agronomic Sciences, Université Amar Telidji de Laghouat, BP 37G, Route de Ghardaïa, Laghouat, 03000, Algeria
| | - Gizem Cufaoglu
- Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, Kirikkale University, Yahsihan,, 71450, Turkey
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2
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Kain T, Albahri M, Plötz M, Jessberger N. Growth, persistence and toxin production of pathogenic bacteria in plant-based drinking milk alternatives. J Food Sci 2024; 89:5799-5811. [PMID: 39169550 DOI: 10.1111/1750-3841.17309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Revised: 07/23/2024] [Accepted: 07/28/2024] [Indexed: 08/23/2024]
Abstract
The present study investigated the microbiological safety of the increasingly popular plant-based milk alternatives. No (10/27) or only very low microbial counts (17/27) were detected in the tested products. These were mainly identified as spore formers via MALDI-ToF-MS. Three products contained Bacillus cereus group isolates, which were able to form considerable amounts of enterotoxins and exhibited cytotoxicity towards CaCo-2 cells. Preliminary tests showed good growth of B. cereus, Listeria monocytogenes, and Salmonella enterica in all tested products (maximum bacterial counts: 5 × 1012 cfu/mL). These experiments also revealed strain-, time-, and temperature-, but especially product-specific enterotoxin production of B. cereus. In propagation and persistence tests according to DIN EN ISO 20976-1:2019-09, rapid bacterial proliferation was also detected in all products. B. cereus generally showed lower bacterial counts (106-107 cfu/mL) compared to L. monocytogenes and S. enterica (108-109 cfu/mL), but was detectable in a larger number of products over the test period of 6 weeks. pH values decreased (20/27) over time and visual and/or olfactory alterations (24/27) were observed. The present study provides information on the occurrence, growth and persistence of pathogenic bacteria in plant-based drinking milk alternatives. It also points out that the accompanying changes in pH, odor, and appearance are not necessarily recognizable to the consumer. PRACTICAL APPLICATION: The present study contributes to the understanding of the microbial risk related to plant-based drinking milk alternatives. It is crucial that the manufacturer ensures that particularly spore formers have been effectively eliminated from the products. Among them, especially toxin-producing bacteria can pose a risk to the consumer, as these products promote proliferation and persistence of the bacteria.
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Affiliation(s)
- Theresa Kain
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Manar Albahri
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Madeleine Plötz
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Nadja Jessberger
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Hanover, Germany
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3
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Dos Santos Mascarenhas LR, Vivoni AM, Caetano RG, Rusak LA, Alvarenga VO, Lacerda ICA. Molecular characterization and toxigenic profiles of Bacillus cereus isolates from foodstuff and food poisoning outbreaks in Brazil. Braz J Microbiol 2024; 55:1693-1701. [PMID: 38446406 PMCID: PMC11153380 DOI: 10.1007/s42770-024-01283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 02/07/2024] [Indexed: 03/07/2024] Open
Abstract
Bacillus cereus sensu stricto (s.s.) is a well-known foodborne pathogen that produces a range of enterotoxins and is able to cause two different types of foodborne illnesses-the emetic and the diarrheal syndromes. In this study, 54 B. cereus s.s. strains isolated from foodstuff and foods involved in food poisoning outbreaks were characterized according to the presence of toxin-encoding genes, virulence-encoding genes, and panC typing. Most isolates were assigned to panC groups IV (61.1%) and III (25.9%), but members of groups II and V could also be found. Investigation of specific alleles revealed high numbers of isolates carrying toxin and other virulence genes including nheA (100%), nheB (100%), hblA (79.6%), hblC (79.6%), hblD (74.1%), cytK-2 (61.1%), clo (100%), pc-plc (75.9%), sph (68.5%), pi-plc (66.6%), hlyIII (62.9%), and hlyII (24.1%). All isolates were negative for ces and cytK-1. In summary, we detected various enterotoxin and other virulence factor genes associated with diarrheal syndrome in strains analyzed, implicated or not with food poisoning. Furthermore, the most isolates analyzed belong to high-risk phylogenetic groups' panC types III and IV. Our study provides a convenient molecular scheme for characterization of B. cereus s.s. strains responsible for food poisoning outbreaks in order to improve the monitoring and investigation and assess emerging clusters and diversity of strains.
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Affiliation(s)
- Luís Renato Dos Santos Mascarenhas
- Food Microbiology Laboratory, Ezequiel Dias Foundation, Belo Horizonte/MG, Brazil.
- Department of Food, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte/MG, Brazil.
| | | | - Renata Gomes Caetano
- Department of Food, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte/MG, Brazil
| | - Leonardo Alves Rusak
- Bacterial Physiology Laboratory, Oswaldo Cruz Foundation, Rio de Janeiro/RJ, Brazil
| | - Verônica Ortiz Alvarenga
- Department of Food, Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte/MG, Brazil
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Fichant A, Lanceleur R, Hachfi S, Brun-Barale A, Blier AL, Firmesse O, Gallet A, Fessard V, Bonis M. New Approach Methods to Assess the Enteropathogenic Potential of Strains of the Bacillus cereus Group, including Bacillus thuringiensis. Foods 2024; 13:1140. [PMID: 38672813 PMCID: PMC11048917 DOI: 10.3390/foods13081140] [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: 02/14/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Bacillus cereus (Bc) is a wide group of Gram-positive and spore-forming bacteria, known to be the etiological agents of various human infections, primarily food poisoning. The Bc group includes enteropathogenic strains able to germinate in the digestive tract and to produce enterotoxins such as Nhe, Hbl, and CytK. One species of the group, Bacillus thuringiensis (Bt), has the unique feature of producing insecticidal crystals during sporulation, making it an important alternative to chemical pesticides to protect crops from insect pest larvae. Nevertheless, several studies have suggested a link between the ingestion of pesticide strains and human cases of food poisoning, calling their safety into question. Consequently, reliable tools for virulence assessment are worth developing to aid decision making in pesticide regulation. Here, we propose complementary approaches based on two biological models, the human intestinal Caco-2 cell line and the insect Drosophila melanogaster, to assess and rank the enteric virulence potency of Bt strains in comparison with other Bc group members. Using a dataset of 48 Bacillus spp. strains, we showed that some Bc group strains, including Bt, were able to induce cytotoxicity in Caco-2 cells with concomitant release of IL-8 cytokine, a landmark of pro-inflammatory response. In the D. melanogaster model, we were able to sort a panel of 39 strains into four different classes of virulence, ranging from no virulence to strong virulence. Importantly, for the most virulent strains, mortality was associated with a loss of intestinal barrier integrity. Interestingly, although strains can share a common toxinotype, they display different degrees of virulence, suggesting the existence of specific mechanisms of virulence expression in vivo in the intestine.
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Affiliation(s)
- Arnaud Fichant
- Laboratory for Food Safety, University Paris-Est, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 94700 Maisons-Alfort, France; (A.F.); (O.F.)
- Université Côte d’Azur, CNRS, INRAE, ISA, 06903 Sophia-Antipolis, France; (S.H.); (A.B.-B.); (A.G.)
| | - Rachelle Lanceleur
- Fougères Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 35306 Fougères, France; (R.L.); (A.-L.B.); (V.F.)
| | - Salma Hachfi
- Université Côte d’Azur, CNRS, INRAE, ISA, 06903 Sophia-Antipolis, France; (S.H.); (A.B.-B.); (A.G.)
| | - Alexandra Brun-Barale
- Université Côte d’Azur, CNRS, INRAE, ISA, 06903 Sophia-Antipolis, France; (S.H.); (A.B.-B.); (A.G.)
| | - Anne-Louise Blier
- Fougères Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 35306 Fougères, France; (R.L.); (A.-L.B.); (V.F.)
| | - Olivier Firmesse
- Laboratory for Food Safety, University Paris-Est, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 94700 Maisons-Alfort, France; (A.F.); (O.F.)
| | - Armel Gallet
- Université Côte d’Azur, CNRS, INRAE, ISA, 06903 Sophia-Antipolis, France; (S.H.); (A.B.-B.); (A.G.)
| | - Valérie Fessard
- Fougères Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 35306 Fougères, France; (R.L.); (A.-L.B.); (V.F.)
| | - Mathilde Bonis
- Laboratory for Food Safety, University Paris-Est, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 94700 Maisons-Alfort, France; (A.F.); (O.F.)
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Huang Z, Yuan X, Zhu Z, Feng Y, Li N, Yu S, Li C, Chen B, Wu S, Gu Q, Zhang J, Wang J, Wu Q, Ding Y. Isolation and characterization of Bacillus cereus bacteriophage DZ1 and its application in foods. Food Chem 2024; 431:137128. [PMID: 37591138 DOI: 10.1016/j.foodchem.2023.137128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/25/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023]
Abstract
Bacillus cereus is a pathogenic bacterium that causes food contamination, resulting in food poisoning such as diarrhea and emesis. Therefore, it is crucial to develop effective strategies to control this bacterium. In this study, we isolated and characterized a novel B. cereus phage, named DZ1. Morphological and genomic analyses revealed that phage DZ1 is a new species belonging to the Andromedavirus genus. Phage DZ1 was tolerant to a wide range of pH values (5-9), temperatures (4-55 ℃), and high concentrations of NaCl solution (1000 mM). B. cereus with 21 different sequence types (STs) can be lysed by phage DZ1. Importantly, phage DZ1 inhibited B. cereus growth in spiked rice substrates or milk up to 36 and 72 h, respectively, with suppression of 3 log. Therefore, phage DZ1 is a useful biocontrol agent for the control of B. cereus in the food industry.
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Affiliation(s)
- Zhichao Huang
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Xiaoming Yuan
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Zhenjun Zhu
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China
| | - Ying Feng
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China
| | - Na Li
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Shubo Yu
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Chun Li
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Bo Chen
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Shi Wu
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Qihui Gu
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Jumei Zhang
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Qingping Wu
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Yu Ding
- Department of Food Science & Engineering, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China.
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Jugert CS, Didier A, Plötz M, Jessberger N. Strain-specific Antimicrobial Activity of Lactoferrin-based Food Supplements. J Food Prot 2023; 86:100153. [PMID: 37640158 DOI: 10.1016/j.jfp.2023.100153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 08/31/2023]
Abstract
The iron-binding glycoprotein lactoferrin is well known for its wide range of antibacterial effects. However, the aim of this study was to show that its antibacterial activity is not generally applicable to a bacterial species as a whole. In disk diffusion assays performed with 112 isolates from 13 bacterial species (including the foodborne pathogens Bacillus cereus and Staphylococcus aureus), a lactoferrin-based food supplement showed no inhibition of growth on 24%, moderate inhibition on 31%, and strong inhibition on 45% of all tested isolates. Minimal inhibitory concentrations against B. cereus and Bacillus thuringiensis strain-specifically ranged from 0.31 mg/mL to no impairment at all. Further 11 commercially available lactoferrin-based food supplements and purified bovine lactoferrin showed strain- as well as product-specific growth inhibition. In comparison to bovine lactoferrin, human lactoferrin showed no inhibitory effects. In summary, purified lactoferrin and lactoferrin-based food supplements inhibit bacterial growth in a dose-, strain-, and product-dependent manner. Thus, a general antimicrobial effect of lactoferrin against a specific bacterial species cannot be assumed.
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Affiliation(s)
- Clara-Sophie Jugert
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany
| | - Andrea Didier
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany
| | - Madeleine Plötz
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany
| | - Nadja Jessberger
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
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Buchacher T, Digruber A, Kranzler M, Del Favero G, Ehling-Schulz M. Bacillus cereus extracellular vesicles act as shuttles for biologically active multicomponent enterotoxins. Cell Commun Signal 2023; 21:112. [PMID: 37189133 PMCID: PMC10184354 DOI: 10.1186/s12964-023-01132-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/19/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND Extracellular vesicles (EVs) from Gram-positive bacteria have gained considerable importance as a novel transport system of virulence factors in host-pathogen interactions. Bacillus cereus is a Gram-positive human pathogen, causing gastrointestinal toxemia as well as local and systemic infections. The pathogenicity of enteropathogenic B. cereus has been linked to a collection of virulence factors and exotoxins. Nevertheless, the exact mechanism of virulence factor secretion and delivery to target cells is poorly understood. RESULTS Here, we investigate the production and characterization of enterotoxin-associated EVs from the enteropathogenic B. cereus strain NVH0075-95 by using a proteomics approach and studied their interaction with human host cells in vitro. For the first time, comprehensive analyses of B. cereus EV proteins revealed virulence-associated factors, such as sphingomyelinase, phospholipase C, and the three-component enterotoxin Nhe. The detection of Nhe subunits was confirmed by immunoblotting, showing that the low abundant subunit NheC was exclusively detected in EVs as compared to vesicle-free supernatant. Cholesterol-dependent fusion and predominantly dynamin-mediated endocytosis of B. cereus EVs with the plasma membrane of intestinal epithelial Caco2 cells represent entry routes for delivery of Nhe components to host cells, which was assessed by confocal microscopy and finally led to delayed cytotoxicity. Furthermore, we could show that B. cereus EVs elicit an inflammatory response in human monocytes and contribute to erythrocyte lysis via a cooperative interaction of enterotoxin Nhe and sphingomyelinase. CONCLUSION Our results provide insights into the interaction of EVs from B. cereus with human host cells and add a new layer of complexity to our understanding of multicomponent enterotoxin assembly, offering new opportunities to decipher molecular processes involved in disease development. Video Abstract.
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Affiliation(s)
- Tanja Buchacher
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Astrid Digruber
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Markus Kranzler
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
| | - Giorgia Del Favero
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Vienna, Austria
- Core Facility Multimodal Imaging, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria.
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8
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Biggel M, Jessberger N, Kovac J, Johler S. Recent paradigm shifts in the perception of the role of Bacillus thuringiensis in foodborne disease. Food Microbiol 2022; 105:104025. [DOI: 10.1016/j.fm.2022.104025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 12/16/2022]
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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: 5] [Impact Index Per Article: 2.5] [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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10
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Schwenk V, Dietrich R, Klingl A, Märtlbauer E, Jessberger N. Characterization of strain-specific Bacillus cereus swimming motility and flagella by means of specific antibodies. PLoS One 2022; 17:e0265425. [PMID: 35298545 PMCID: PMC8929632 DOI: 10.1371/journal.pone.0265425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/01/2022] [Indexed: 11/18/2022] Open
Abstract
One of the multiple factors determining the onset of the diarrhoeal disease caused by enteropathogenic Bacillus cereus is the ability of the bacteria to actively move towards the site of infection. This ability depends on flagella, but it also varies widely between different strains. To gain more insights into these strain-specific variations, polyclonal rabbit antisera as well as monoclonal antibodies (mAbs) were generated in this study, which detected recombinant and natural B. cereus flagellin proteins in Western blots as well as in enzyme immunoassays (EIAs). Based on mAb 1A11 and HRP-labelled rabbit serum, a highly specific sandwich EIA was developed. Overall, it could be shown that strain-specific swimming motility correlates with the presence of flagella/flagellin titres obtained in EIAs. Interestingly, mAb 1A11, recognizing an epitope in the N-terminal region of the flagellin protein, proved to inhibit bacterial swimming motility, while the rabbit serum rather decreased growth of selected B. cereus strains. Altogether, powerful tools enabling the in-depth characterization of the strain-specific variations in B. cereus swimming motility were developed.
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Affiliation(s)
- Valerie Schwenk
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
| | - Richard Dietrich
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
| | - Andreas Klingl
- Department of Biology I, Plant Development and Electron Microscopy, Biocenter Ludwig-Maximilians Universität München, Planegg-Martinsried, München, Germany
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
| | - Nadja Jessberger
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Hannover, Germany
- * E-mail:
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11
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Jessberger N, Diedrich R, Janowski R, Niessing D, Märtlbauer E. Presence and function of Hbl B', the fourth protein component encoded by the hbl operon in Bacillus cereus. Virulence 2022; 13:483-501. [PMID: 35291913 PMCID: PMC8932913 DOI: 10.1080/21505594.2022.2046951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The genes hblC, hblD and hblA encode the components Hbl L2, L1 and B of the pore forming enterotoxin haemolysin BL of Bacillus cereus. Two variants of the operon existand the more common one additionally contains hblB downstream of hblCDA. Up to now, it was completely unclear whether the corresponding protein, Hbl B', is widely expressed among B. cereus strains and if it has a distinct function. In the present study, it was shown that the hblB gene is indeed expressed and the Hbl B' protein is secreted by nearly all analysed B. cereus strains. For the latter, a detection system was developed based on monoclonal antibody 11A5. Further, a distinct reduction of cytotoxic and haemolytic activity was observed when recombinant (r)Hbl B' was applied simultaneously with L2, L1 and B. This effect was due to direct interaction of rHbl B' with L1. D-6B. cereusAltogether, we present the first simple tool for the detection of Hbl B' in B. cereus culture supernatants. Moreover, an important regulatory function of Hbl B' in the mechanism of Hbl was determined, which is best described as an additional control of complex formation, balancing the amounts of Hbl B-L1 complexes and the corresponding free subunits.
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Affiliation(s)
- Nadja Jessberger
- Institute for Food Quality and Food Safety, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Richard Diedrich
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
| | - Robert Janowski
- Institute of Structural Biology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany
| | - Dierk Niessing
- Institute of Structural Biology, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
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12
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Zheng H, Sheng R, Li H, Ahmad W, Chen Q. Rapid and selective detection of Bacillus cereus in food using cDNA-based up-conversion fluorescence spectrum copy and aptamer modified magnetic separation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120618. [PMID: 34802926 DOI: 10.1016/j.saa.2021.120618] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/06/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
A sensitive luminescent bioassay for the detection of Bacillus cereus (B. cereus), a common bacterium, harmful to human health, was established based on up-conversion fluorescence and magnetic separation technology. Herein, aptamers (Apt) are modified on the surface of magnetic nanoparticles (MNPs) to form Apt-MNPs capture probes. The aptamer complementary strands (cDNA) are connected to upconversion nanoparticles (UCNPs) to form UCNPs-cDNA signal probes. In the absence of analyte, the UCNPs-cDNA-Apt-MNPs complex will be formed due to the specific binding between the aptamer and the complementary strand. In the presence of B. cereus, the amount of free UCNPs-cDNA increased in the system, which ultimately increased the fluorescence intensity of the solution. Hence, when the UCNPs-cDNA-Apt-MNPs system was excited by a 980 nm near-infrared light, a decrease in the fluorescence of the complex was observed at 548 nm due to the detachment of UCNPs-cDNA. Therefore, based on this principle, the calibration curve is constructed between the concentration of the analyte (B. cereus) and the fluorescence intensity. The results show that the method has a good quantitative ability for B. cereus in the range of 49-49 × 106 cfu/mL under the optimal conditions with a detection limit of 22 cfu/mL. Moreover, the proposed detection method also exhibits a high degree of specificity. The spiked recovery rate of the actual sample was in the range of 90.54%-111.28%, with good relative standard deviation values (2.12%-3.13%), indicating that the method has good reproducibility and stability. This study demonstrates that the constructed method can be used successfully for the rapid detection of B. cereus in food.
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Affiliation(s)
- Hanyu Zheng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Ren Sheng
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Huanhuan Li
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
| | - Waqas Ahmad
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China
| | - Quansheng Chen
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China; College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, PR China.
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13
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Pathogenic potential of bacteria isolated from commercial biostimulants. Arch Microbiol 2022; 204:162. [PMID: 35119529 PMCID: PMC8816496 DOI: 10.1007/s00203-022-02769-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 11/08/2022]
Abstract
Microbial-based products are a promising alternative to agrochemicals in sustainable agriculture. However, little is known about their impact on human health even if some of them, i.e., Bacillus and Paenibacillus species, have been increasingly implicated in different human diseases. In this study, 18 bacteria were isolated from 2 commercial biostimulants, and they were genotypically and phenotypically characterized to highlight specific virulence properties. Some isolated bacteria were identified as belonging to the genus Bacillus by BLAST and RDP analyses, a genus in-depth studied for plant growth-promoting ability. Moreover, 16S rRNA phylogenetic analysis showed that seven isolates grouped with Bacillus species while two and four clustered, respectively, with Neobacillus and Peribacillus. Unusually, bacterial strains belonging to Franconibacter and Stenotrophomonas were isolated from biostimulants. Although Bacillus species are generally considered nonpathogenic, most of the species have shown to swim, swarm, and produced biofilms, that can be related to bacterial virulence. The evaluation of toxins encoding genes revealed that five isolates had the potential ability to produce the enterotoxin T. In conclusion, the pathogenic potential of microorganisms included in commercial products should be deeply verified, in our opinion. The approach proposed in this study could help in this crucial step.
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14
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Qu Y, Wei C, Dai X, Bai Y, Zhao X, Lan Q, Wang W, Wu Y, Gao M, Tang W, Zhou C, Suo Y. The Possible Transmission and Potential Enterotoxicity of Bacillus cereus on Lettuce Farms in Five Chinese Provinces. Front Microbiol 2021; 12:746632. [PMID: 34659182 PMCID: PMC8517410 DOI: 10.3389/fmicb.2021.746632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 09/13/2021] [Indexed: 11/26/2022] Open
Abstract
Bacillus cereus is a well-characterized human pathogen that produces toxins associated with diarrheal and emetic foodborne diseases. To investigate the possible transmission of B. cereus on lettuce farms in China and determine its enterotoxicity, (I) a total of 524 samples (lettuce: 332, soil: 69, water: 57, manure: 57, pesticide: 9) were collected from 46 lettuce farms in five Chinese provinces, (II) multilocus sequence typing (MLST) was used to classify B. cereus isolates and for trace analysis, and (III) the presence of toxin genes and enterotoxins (Hbl and Nhe) was detected in 68 strains. The results showed that one hundred and sixty-one lettuce samples (48.5%) tested positive for B. cereus at levels ranging from 10 to 5.3 × 104 CFU/g. Among the environmental sample categories surveyed, the highest positive rate was that of the pesticide samples at 55.6%, followed by soil samples at 52.2% and manure samples at 12.3%. Moreover, one hundred isolates of B. cereus yielded 68 different sequence types (STs) and were classified into five phylogenetic clades. Furthermore, Nhe toxin genes (nheA, nheB, nheC) were broadly distributed and identified in all 68 strains (100%), while Hbl toxin genes (hblA, hblC, hblD) were present in 61 strains (89.7%), entFM was detected in 62 strains (91.2%), and cytK was found in 29 strains (42.6%). All strains were negative for ces. As for the enterotoxin, Nhe was observed in all 68 isolates carrying nheB, while Hbl was present in 76.5% (52/68) of the strains harboring hblC. This study is the first report of possible B. cereus transmission and of its potential enterotoxicity on lettuce farms in China. The results showed that soil and pesticides are the main sources of B. cereus on lettuce farms in China, and the possible transmission routes are as follows: soil-lettuce, manure-lettuce, pesticide-lettuce, manure-soil-lettuce, and water-manure-soil-lettuce. Furthermore, the B. cereus isolates, whether from lettuce or the environment, pose a potential risk to health.
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Affiliation(s)
- Yang Qu
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute for Agro-Food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, China.,Shanghai Co-Elite Agro-Food Testing Service Co., Ltd., Shanghai, China
| | - Chao Wei
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute of Quality Standard and Testing Technology for Agro-Products of Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Xiaohang Dai
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute of Quality Standard and Testing Technology for Agro-Products of Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Yalong Bai
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute for Agro-Food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Xin Zhao
- Institute of Germplasm Resources and Biotechnology, Tianjin Academy of Agricultural Sciences, Tianjin, China
| | - Qingkuo Lan
- Institute of Germplasm Resources and Biotechnology, Tianjin Academy of Agricultural Sciences, Tianjin, China
| | - Wenbo Wang
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute of Agricultural Standards and Testing Technology for Agri-Products, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Yuanjuan Wu
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute of Agricultural Standards and Testing Technology for Agri-Products, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Min Gao
- Laboratory of Quality and Safety Risk Assessment for Agro-Products Processing of Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | - Weihao Tang
- Laboratory of Quality and Safety Risk Assessment for Agro-Products Processing of Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | - Changyan Zhou
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute for Agro-Food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, China.,Shanghai Co-Elite Agro-Food Testing Service Co., Ltd., Shanghai, China
| | - Yujuan Suo
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of Ministry of Agriculture and Rural Affairs, Institute for Agro-Food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, China.,Shanghai Co-Elite Agro-Food Testing Service Co., Ltd., Shanghai, China
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15
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Impact of Phytochemicals on Viability and Cereulide Toxin Synthesis in Bacillus cereus Revealed by a Novel High-Throughput Method, Coupling an AlamarBlue-Based Assay with UPLC-MS/MS. Toxins (Basel) 2021; 13:toxins13090672. [PMID: 34564676 PMCID: PMC8470179 DOI: 10.3390/toxins13090672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 11/17/2022] Open
Abstract
Due to its food-poisoning potential, Bacillus cereus has attracted the attention of the food industry. The cereulide-toxin-producing subgroup is of particular concern, as cereulide toxin is implicated in broadscale food-borne outbreaks and occasionally causes fatalities. The health risks associated with long-term cereulide exposure at low doses remain largely unexplored. Natural substances, such as plant-based secondary metabolites, are widely known for their effective antibacterial potential, which makes them promising as ingredients in food and also as a surrogate for antibiotics. In this work, we tested a range of structurally related phytochemicals, including benzene derivatives, monoterpenes, hydroxycinnamic acid derivatives and vitamins, for their inhibitory effects on the growth of B. cereus and the production of cereulide toxin. For this purpose, we developed a high-throughput, small-scale method which allowed us to analyze B. cereus survival and cereulide production simultaneously in one workflow by coupling an AlamarBlue-based viability assay with ultraperformance liquid chromatography–mass spectrometry (UPLC-MS/MS). This combinatory method allowed us to identify not only phytochemicals with high antibacterial potential, but also ones specifically eradicating cereulide biosynthesis already at very low concentrations, such as gingerol and curcumin.
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16
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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: 55] [Impact Index Per Article: 18.3] [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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17
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Further Insights into the Toxicity of Bacillus cytotoxicus Based on Toxin Gene Profiling and Vero Cell Cytotoxicity Assays. Toxins (Basel) 2021; 13:toxins13040234. [PMID: 33805220 PMCID: PMC8064374 DOI: 10.3390/toxins13040234] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022] Open
Abstract
Bacillus cytotoxicus belongs to the Bacillus cereus group that also comprises the foodborne pathogen Bacillus cereus sensu stricto, Bacillus anthracis causing anthrax, as well as the biopesticide Bacillus thuringiensis. The first B. cytotoxicus was isolated in the context of a severe food poisoning outbreak leading to fatal cases of diarrheal disease. Subsequent characterization of the outbreak strain led to the conclusion that this Bacillus strain was highly cytotoxic and eventually resulted in the description of a novel species, whose name reflects the observed toxicity: B. cytotoxicus. However, only a few isolates of this species have been characterized with regard to their cytotoxic potential and the role of B. cytotoxicus as a causative agent of food poisoning remains largely unclear. Hence, the aim of this study was to gain further insights into the toxicity of B. cytotoxicus. To this end, 19 isolates were obtained from mashed potato powders and characterized by toxin gene profiling and Vero cell cytotoxicity assays. All isolates harbored the cytK1 (cytotoxin K1) gene and species-specific variants of the nhe (non-hemolytic enterotoxin) gene. The isolates exhibited low or no toxicity towards Vero cells. Thus, this study indicates that the cytotoxic potential of B. cytotoxicus may be potentially lower than initially assumed.
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18
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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: 113] [Impact Index Per Article: 37.7] [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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19
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Zhang Z, Jin M, Wang K, Zhang N, Zhang Q, Tao X, Wei H. Short-term intake of Lactiplantibacillus plantarum ZDY2013 fermented milk promotes homoeostasis of gut microbiota under enterotoxigenic Bacillus cereus challenge. Food Funct 2021; 12:5118-5129. [PMID: 33973610 DOI: 10.1039/d1fo00162k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Probiotics have long been used as functional starter cultures for fermented foods and are associated with numerous health benefits. Lactiplantibacillus (L.) plantarum ZDY2013 is an acid-tolerant probiotic candidate owning antagonistic properties against the food-borne pathogen Bacillus (B.) cereus and serves as a potent regulator of the gut microbiota. However, whether it retains these properties when used as dietary supplements in functional foods remains unknown. Accordingly, we investigated the ameliorating effects of L. plantarum fermented milk on disease phenotypes triggered by enterotoxigenic B. cereus in mice. The results revealed that administration of 3.0 × 108 cfu pathogenic B. cereus for one week induced damage to intestinal structures and bowel function, accompanied by an imbalance of gut microbiota. However, before or after B. cereus infection, oral administration of L. plantarum fermented milk mitigated losses of body weight and damage in the histological structure of the gastrointestinal tract, restored serum levels of IL-1β and IL-10, and contributed to significant decreases in platelet counts and uric acid levels. Most importantly, it restored the dissimilarity of gut microbiota and the abundance of bacterial taxa (i.e., reduced the abundance of Deferribacteres and Bacilli and increased the abundance of Lactobacillus and Bifidobacterium) without impacting the taxonomic composition. Combining these results, we speculate that enterotoxigenic B. cereus damages the intestinal epithelium and weakens its adherence capacity for the microbe, which is rescued by the supplementation of L. plantarum fermented milk. Overall, our findings revealed that L. plantarum ZDY2013 has the potential to be a fermented starter in functional foods and retains its antagonism against B. cereus pathogenesis.
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Affiliation(s)
- Zhihong Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 30047, China.
| | - Mingliang Jin
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Kaiming Wang
- Department of Physiology, CEGIIR, University of Alberta, Edmonton T6G 2E1, Canada
| | - Na Zhang
- Sino-German Joint Research Institute, Nanchang University, Nanchang 30047, China
| | - Qimeng Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 30047, China.
| | - Xueying Tao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 30047, China.
| | - Hua Wei
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 30047, China. and Sino-German Joint Research Institute, Nanchang University, Nanchang 30047, China
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20
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Montone AMI, Capuano F, Mancusi A, Di Maro O, Peruzy MF, Proroga YTR, Cristiano D. Exposure to Bacillus cereus in Water Buffalo Mozzarella Cheese. Foods 2020; 9:E1899. [PMID: 33352642 PMCID: PMC7766095 DOI: 10.3390/foods9121899] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/18/2020] [Accepted: 12/17/2020] [Indexed: 01/04/2023] Open
Abstract
Bacillus cereus is a spoilage bacterium and is recognized as an agent of food poisoning. Two food-borne illnesses are caused by B. cereus: a diarrheal disease, associated with cytotoxin K, hemolysin BL, non-hemolytic enterotoxin and enterotoxin FM, and an emetic syndrome, associated with the cereulide toxin. Owing to the heat resistance of B. cereus and its ability to grow in milk, this organism should be considered potentially hazardous in dairy products. The present study assessed the risk of B. cereus poisoning due to the consumption of water buffalo mozzarella cheese. A total of 340 samples were analyzed to determine B. cereus counts (ISO 7932:2005); isolates underwent molecular characterization to detect the presence of genes encoding toxins. Eighty-nine (26.1%) samples harbored B. cereus strains, with values ranging from 2.2 × 102 to 2.6 × 106 CFU/g. Isolates showed eight different molecular profiles, and some displayed virulence characteristics. Bacterial counts and the toxin profiles of isolates were evaluated both separately and jointly to assess the risk of enteritis due to B. cereus following the consumption of buffalo mozzarella cheese. In conclusion, the results of the present study showed that the risk of poisoning by B. cereus following the consumption of this cheese was moderate.
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Affiliation(s)
- Angela Michela Immacolata Montone
- Department of Food Microbiology, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055 Portici (NA), Italy; (A.M.I.M.); (F.C.); (A.M.); (O.D.M.); (D.C.)
| | - Federico Capuano
- Department of Food Microbiology, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055 Portici (NA), Italy; (A.M.I.M.); (F.C.); (A.M.); (O.D.M.); (D.C.)
| | - Andrea Mancusi
- Department of Food Microbiology, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055 Portici (NA), Italy; (A.M.I.M.); (F.C.); (A.M.); (O.D.M.); (D.C.)
| | - Orlandina Di Maro
- Department of Food Microbiology, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055 Portici (NA), Italy; (A.M.I.M.); (F.C.); (A.M.); (O.D.M.); (D.C.)
| | - Maria Francesca Peruzy
- Department of Veterinary Medicine and Animal Production, University of Naples “Federico II”, Via Delpino 1, 80137 Naples, Italy;
| | - Yolande Thérèse Rose Proroga
- Department of Food Microbiology, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055 Portici (NA), Italy; (A.M.I.M.); (F.C.); (A.M.); (O.D.M.); (D.C.)
| | - Daniela Cristiano
- Department of Food Microbiology, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055 Portici (NA), Italy; (A.M.I.M.); (F.C.); (A.M.); (O.D.M.); (D.C.)
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21
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Li Q, Xie G, Wang Y, Aguilar ZP, Xu H. Vancomycin-modified poly-l-lysine magnetic separation combined with multiplex polymerase chain reaction assay for efficient detection of Bacillus cereus in milk. J Dairy Sci 2020; 104:1465-1473. [PMID: 33272582 DOI: 10.3168/jds.2020-18962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022]
Abstract
In this study, a new vancomycin (Van)-modified poly-l-lysine (PLL) magnetic bead (MB) technique was developed for isolation of gram-positive bacteria. The method combines magnetic separation with a multiplex PCR (mPCR) assay and gel electrophoresis for easy and rapid detection of Bacillus cereus. Vancomycin was used as a molecular ligand between the MB and the d-alanyl-d-alanine moieties on the cell wall surface of B. cereus. The PLL served as a flexible molecular tether between the MB and Van that reduced steric hindrance maintaining the biological activity of Van. The MB-PLL-Van capture nanoprobes exhibited excellent capture and isolation efficiency for B. cereus in spiked milk matrix samples without interference from the complex food matrix. The subsequent mPCR assay showed high specificity for the 4 target genes in B. cereus, the entFM, cesB, cer, and 16S rRNA genes, that were used to achieve efficient genotyping and detection. Under optimum conditions, the limit of detection reached 103 cfu/mL, with a dynamic range of detection at 103 to 107 cfu/mL in pure culture. Application of the MB-PLL-Van mediated mPCR assay for B. cereus in milk matrix samples achieved results similar to those of the pure culture. In addition, with a 6-h pre-enrichment of B. cereus that was spiked in milk matrix samples, the limit of detection reached 101 cfu/mL. The MB-PLL-Van mediated mPCR assay developed in this study could be used as a universal technology platform for the efficient enrichment and genotyping of gram-positive bacteria.
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Affiliation(s)
- Qianying Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Guoyang Xie
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | - Yutong Wang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China
| | | | - Hengyi Xu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, PR China.
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22
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Liu S, Brul S, Zaat SAJ. Bacterial Persister-Cells and Spores in the Food Chain: Their Potential Inactivation by Antimicrobial Peptides (AMPs). Int J Mol Sci 2020; 21:E8967. [PMID: 33260797 PMCID: PMC7731242 DOI: 10.3390/ijms21238967] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/15/2022] Open
Abstract
The occurrence of bacterial pathogens in the food chain has caused a severe impact on public health and welfare in both developing and developed countries. Moreover, the existence of antimicrobial-tolerant persisting morphotypes of these pathogens including both persister-cells as well as bacterial spores contributes to difficulty in elimination and in recurrent infection. Therefore, comprehensive understanding of the behavior of these persisting bacterial forms in their environmental niche and upon infection of humans is necessary. Since traditional antimicrobials fail to kill persisters and spores due to their (extremely) low metabolic activities, antimicrobial peptides (AMPs) have been intensively investigated as one of the most promising strategies against these persisting bacterial forms, showing high efficacy of inactivation. In addition, AMP-based foodborne pathogen detection and prevention of infection has made significant progress. This review focuses on recent research on common bacterial pathogens in the food chain, their persisting morphotypes, and on AMP-based solutions. Challenges in research and application of AMPs are described.
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Affiliation(s)
- Shiqi Liu
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Stanley Brul
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Sebastian A. J. Zaat
- Department of Medical Microbiology, Centre for Infection and Immunity Amsterdam (CINIMA), Academic Medical Centre, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
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23
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Li C, Yuan X, Li N, Wang J, Yu S, Zeng H, Zhang J, Wu Q, Ding Y. Isolation and Characterization of Bacillus cereus Phage vB_BceP-DLc1 Reveals the Largest Member of the Φ29-Like Phages. Microorganisms 2020; 8:E1750. [PMID: 33171789 PMCID: PMC7695010 DOI: 10.3390/microorganisms8111750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 10/31/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023] Open
Abstract
Bacillus phage φ29 and its relatives have been considered as one of the most important model organisms for DNA replication, transcription, morphogenesis, DNA packaging studies, and nanotechnology applications. Here, we isolated and characterized a new member of the φ29-like phage, named Bacillus cereus phage vB_BceP-DLc1. This phage, with a unique inserted gene cluster, has the largest genome among known φ29-like phages. DLc1 can use the surface carbohydrate structures of the host cell as receptors and only infects the most related B. cereus strains, showing high host-specificity. The adsorption rate constant and life cycle of DLc1 under experimental conditions were also determined. Not only stable under temperatures below 55 °C and pH range from 5 to 11, the new phage also showed tolerance to high concentrations of NaCl, 75% ethanol, chloroform, and mechanical vortex, which is preferable for practical use in the food and pharmaceutical industries.
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Affiliation(s)
- Chun Li
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, College of Science & Engineering, Jinan University, Guangzhou 510632, China; (C.L.); (X.Y.); (N.L.)
| | - Xiaoming Yuan
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, College of Science & Engineering, Jinan University, Guangzhou 510632, China; (C.L.); (X.Y.); (N.L.)
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Na Li
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, College of Science & Engineering, Jinan University, Guangzhou 510632, China; (C.L.); (X.Y.); (N.L.)
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou 510642, China;
| | - Shubo Yu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Haiyan Zeng
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Jumei Zhang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Yu Ding
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, College of Science & Engineering, Jinan University, Guangzhou 510632, China; (C.L.); (X.Y.); (N.L.)
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China; (S.Y.); (H.Z.); (J.Z.); (Q.W.)
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
- Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China
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Jessberger N, Dietrich R, Granum PE, Märtlbauer E. The Bacillus cereus Food Infection as Multifactorial Process. Toxins (Basel) 2020; 12:E701. [PMID: 33167492 PMCID: PMC7694497 DOI: 10.3390/toxins12110701] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
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.
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Affiliation(s)
- Nadja Jessberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Richard Dietrich
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Per Einar Granum
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, P.O. Box 5003 NMBU, 1432 Ås, Norway;
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
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Characteristics of the Protein Complexes and Pores Formed by Bacillus cereus Hemolysin BL. Toxins (Basel) 2020; 12:toxins12110672. [PMID: 33114414 PMCID: PMC7694065 DOI: 10.3390/toxins12110672] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/13/2020] [Accepted: 10/21/2020] [Indexed: 11/25/2022] Open
Abstract
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.
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Schwenk V, Riegg J, Lacroix M, Märtlbauer E, Jessberger N. Enteropathogenic Potential of Bacillus thuringiensis Isolates from Soil, Animals, Food and Biopesticides. Foods 2020; 9:foods9101484. [PMID: 33080854 PMCID: PMC7603059 DOI: 10.3390/foods9101484] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 12/14/2022] Open
Abstract
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.
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Affiliation(s)
- Valerie Schwenk
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (V.S.); (J.R.); (E.M.)
| | - Janina Riegg
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (V.S.); (J.R.); (E.M.)
| | - Monique Lacroix
- Centre Armand-Frappier Santé Biotechnologie, 531, boul. des Prairies, Laval, QC H7V 1B7, Canada;
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (V.S.); (J.R.); (E.M.)
| | - Nadja Jessberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (V.S.); (J.R.); (E.M.)
- Correspondence:
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Rasooly R, Do P, Hernlem B. Quantitative bioluminescence assay for measuring Bacillus cereus nonhemolytic enterotoxin complex. PLoS One 2020; 15:e0238153. [PMID: 32998160 PMCID: PMC7527251 DOI: 10.1371/journal.pone.0238153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/10/2020] [Indexed: 11/19/2022] Open
Abstract
Bacillus cereus is a foodborne pathogen causing emesis and diarrhea in those affected. It is assumed that the non-hemolytic enterotoxin (Nhe) plays a key role in B. cereus induced diarrhea. The ability to trace Nhe activity is important for food safety. While assays such as PCR and ELISA exist to detect Nhe, those methods cannot differentiate between active and inactive forms of Nhe. The existing rabbit ileal loop bioassay used to detect Nhe activity is ethically disfavored because it uses live experimental animals. Here we present a custom built low-cost CCD based luminometer and applied it in conjunction with a cell-based assay using Vero cells transduced to express the luciferase enzyme. The activity of Nhe was measured as its ability to inhibit synthesis of luciferase as quantified by reduction of light emission by the luciferase reaction. Emitted light intensity was observed to be inversely proportional to Nhe concentration over a range of 7 ng/ml to 125 ng/ml, with a limit of detection of 7 ng/ml Nhe.
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Affiliation(s)
- Reuven Rasooly
- Western Regional Research Center, Foodborne Toxin Detection & Prevention Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA, United States of America
| | - Paula Do
- Western Regional Research Center, Foodborne Toxin Detection & Prevention Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA, United States of America
| | - Bradley Hernlem
- Western Regional Research Center, Foodborne Toxin Detection & Prevention Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA, United States of America
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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: 33] [Impact Index Per Article: 8.3] [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: 52] [Impact Index Per Article: 13.0] [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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Onyebuchi C, Kavaz D. Chitosan And N, N, N-Trimethyl Chitosan Nanoparticle Encapsulation Of Ocimum Gratissimum Essential Oil: Optimised Synthesis, In Vitro Release And Bioactivity. Int J Nanomedicine 2019; 14:7707-7727. [PMID: 31571873 PMCID: PMC6759822 DOI: 10.2147/ijn.s220202] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022] Open
Abstract
Background The encapsulation of plant essential oils (EOs) with polymeric materials (e.g. chitosan (CS) and N, N, N-trimethyl chitosan (TMC)) and the further reduction of the polymers into their nano sizes are gaining research interest in nanotechnology due to potential applications in medical drug delivery systems as well as the food and pharmaceutical industry. The present study reports a novel approach for the synthesis of Ocimum gratissimum essential oil (OGEO)-loaded CS and TMC nanoparticles with distinct bioactive and physiochemical properties. Methods The OGEO-loaded CS and TMC nanoparticles were characterised using various microscopic and spectroscopic techniques. The bioactive compounds in Ocimum gratissimum methanolic extract (OG-MeOH) and EOs was evinced with gas chromatography-mass spectrometry (GC-MS). Total phenolic content (TPC) of OGEO and OG-MeOH was determined using the Folin-Ciocalteu method. The in vitro drug release kinetic pattern was ascertained by membrane dialysis, while antioxidant activity was determined by the 2,2-diphenyl-1picrylhydrozyl (DPPH) free radical scavenging method. The disc diffusion method was used for antibacterial activity evaluation, while MTT and a trypan blue dye exclusion assay were used to assess cytotoxic activity on MDA-MB-231 breast cancer cells. Results GC-MS analysis revealed components that have not been previously reported for Ocimum gratissimum. The maximum OGEO cumulative drug release percentage in vitro was observed at pH 3 for both OGEO-loaded chitosan nanoparticles (OGEO-CSNPs) and OGEO-loaded N, N, N-trimethyl chitosan nanoparticles (OGEO-TMCNPs). The antioxidant activity of OGEO-CSNPs and OGEO-TMCNPs never reached a steady state after 75 h. OGEO-TMCNPs exhibited antibacterial activity at a lower concentration for both Gram-negative and Gram-positive food pathogens. In vitro cytotoxicity revealed the increased toxicity of OGEO-TMCNPs on MDA-MB-231 breast cancer cell lines. Conclusion OGEO-loaded CS and TMC nanoparticles were synthesised using a novel material optimisation approach. The synthesised nanoparticles have shown a promising application in the pharmaceutical and food industries.
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Affiliation(s)
- Confidence Onyebuchi
- Bioengineering Department, Faculty of Engineering, Cyprus International University, Haspolat- Lefkoşa 98258, Northern Cyprus via Mersin 10 Turkey
| | - Doğa Kavaz
- Bioengineering Department, Faculty of Engineering, Cyprus International University, Haspolat- Lefkoşa 98258, Northern Cyprus via Mersin 10 Turkey.,Biotechnology Research Centre, Cyprus International University, Haspolat- Lefkoşa 99258, Northern Cyprus via Mersin 10 Turkey
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