1
|
Xu B, Huang X, Qin H, Lei Y, Zhao S, Liu S, Liu G, Zhao J. Evaluating the Safety of Bacillus cereus GW-01 Obtained from Sheep Rumen Chyme. Microorganisms 2024; 12:1457. [PMID: 39065225 PMCID: PMC11278751 DOI: 10.3390/microorganisms12071457] [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: 06/08/2024] [Revised: 06/26/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Bacillus cereus is responsible for 1.4-12% food poisoning outbreaks worldwide. The safety concerns associated with the applications of B. cereus in health and medicine have been controversial due to its dual role as a pathogen for foodborne diseases and a probiotic in humans and animals. In this study, the pathogenicity of B. cereus GW-01 was assessed by comparative genomic, and transcriptome analysis. Phylogenetic analysis based on a single-copy gene showed clustering of the strain GW-01, and 54 B. cereus strains from the NCBI were classified into six major groups (I-VI), which were then associated with the source region and sequence types (STs). Transcriptome results indicated that the expression of most genes related with toxins secretion in GW-01 was downregulated compared to that in the lag phase. Overall, these findings suggest that GW-01 is not directly associated with pathogenic Bacillus cereus and highlight an insightful strategy for assessing the safety of novel B. cereus strains.
Collapse
Affiliation(s)
- Bowen Xu
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Xinyi Huang
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Haixiong Qin
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Ying Lei
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
| | - Sijia Zhao
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Shan Liu
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Gang Liu
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| | - Jiayuan Zhao
- Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610101, China; (B.X.); (X.H.); (H.Q.); (Y.L.); (S.Z.); (S.L.); (G.L.)
- College of Life Science, Sichuan Normal University, Chengdu 610101, China
| |
Collapse
|
2
|
Li PR, Wang ZX, Xu ZK, Wang J, Li B, Shen X, Xu ZL. An RPA-Assisted CRISPR/Cas12a Assay Combining Fluorescence and Lateral Flow Strips for the Rapid Detection of Enterotoxigenic Bacillus cereus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 38857358 DOI: 10.1021/acs.jafc.4c03601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
Bacillus cereus (B. cereus) is a foodborne pathogen that can produce tripartite enterotoxins, which can cause a variety of diseases after infection. It is critical to rapidly and accurately detect strains with enteropathogenic potential to safeguard human health. In this study, a dual-signal visualized detection platform with fluorescence assay and paper-based lateral flow assay (LFA) based on recombinase polymerase amplification (RPA), CRISPR/Cas12a system, and self-developed CRISPR nucleic acid test strips was constructed for enterotoxigenic B. cereus. The genes that encode two tripartite enterotoxins─nheA, nheB, and nheC for nonhemolytic enterotoxin and hblA, hblC, and hblD for hemolysin BL─were utilized as detection targets. The platform was capable of detecting six enterotoxin genes at the same genomic DNA level. The limits of detection for each gene were 10-3 ng/μL in fluorescence assay and 10-4 ng/μL in LFA. Furthermore, 101-102 CFU/mL of B. cereus in pure culture was detected. Additionally, a smartphone miniprogram could assist in evaluating the results in LFA. The platform demonstrated good utility by detecting B. cereus in food samples, including milk and rice. The results indicate that our RPA-CRISPR/Cas12a dual-signal visualized detection platform can quickly and easily detect B. cereus with three-component enterotoxin-producing potentials. The whole analytic process took less than 60 min without complex operation or expensive equipment.
Collapse
Affiliation(s)
- Peng-Ru Li
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Zi-Xuan Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Ze-Ke Xu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Juan Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Bin Li
- Guangzhou Wanlian Biotechnology Co., Ltd., Guangzhou 510670, China
| | - Xing Shen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Zhen-Lin Xu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China
| |
Collapse
|
3
|
Frentzel H, Kraemer M, Kelner-Burgos Y, Uelze L, Bodi D. Cereulide production capacities and genetic properties of 31 emetic Bacillus cereus group strains. Int J Food Microbiol 2024; 417:110694. [PMID: 38614024 DOI: 10.1016/j.ijfoodmicro.2024.110694] [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: 11/28/2023] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/15/2024]
Abstract
The highly potent toxin cereulide is a frequent cause of foodborne intoxications. This extremely resistant toxin is produced by Bacillus cereus group strains carrying the plasmid encoded cesHPTABCD gene cluster. It is known that the capacities to produce cereulide vary greatly between different strains but the genetic background of these variations is not clear. In this study, cereulide production capacities were associated with genetic characteristics. For this, cereulide levels in cultures of 31 strains were determined after incubation in tryptic soy broth for 24 h at 24 °C, 30 °C and 37 °C. Whole genome sequencing based data were used for an in-depth characterization of gene sequences related to cereulide production. The taxonomy, population structure and phylogenetic relationships of the strains were evaluated based on average nucleotide identity, multi-locus sequence typing (MLST), core genome MLST and single nucleotide polymorphism analyses. Despite a limited strain number, the approach of a genome wide association study (GWAS) was tested to link genetic variation with cereulide quantities. Our study confirms strain-dependent differences in cereulide production. For most strains, these differences were not explainable by sequence variations in the cesHPTABCD gene cluster or the regulatory genes abrB, spo0A, codY and pagRBc. Likewise, the population structure and phylogeny of the tested strains did not comprehensively reflect the cereulide production capacities. GWAS yielded first hints for associated proteins, while their possible effect on cereulide synthesis remains to be further investigated.
Collapse
Affiliation(s)
- Hendrik Frentzel
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| | - Marco Kraemer
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Ylanna Kelner-Burgos
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Laura Uelze
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Sequencing and Genotyping Service Unit, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Dorina Bodi
- German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| |
Collapse
|
4
|
Sarkar D, Hunt I, Macdonald C, Wang B, Bowman JP, Tamplin ML. Modelling growth of Bacillus cereus in paneer by one-step parameter estimation. Food Microbiol 2023; 112:104231. [PMID: 36906319 DOI: 10.1016/j.fm.2023.104231] [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: 10/25/2022] [Revised: 01/08/2023] [Accepted: 01/22/2023] [Indexed: 02/07/2023]
Abstract
Bacillus cereus phylogenetic group III and IV strains are commonly associated with food products and cause toxin mediated foodborne diseases. These pathogenic strains have been identified from milk and dairy products, such as reconstituted infant formula and several cheeses. Paneer is a fresh, soft cheese originating from India that is prone to foodborne pathogen contamination, such as by Bacillus cereus. However, there are no reported studies of B. cereus toxin formation in paneer or predictive models quantifying growth of the pathogen in paneer under different environmental conditions. This study assessed enterotoxin-producing potential of B. cereus group III and IV strains, isolated from dairy farm environments, in fresh paneer. Growth of a four-strain cocktail of toxin-producing B. cereus strains was measured in freshly prepared paneer incubated at 5-55 °C and modelled using a one-step parameter estimation combined with bootstrap re-sampling to generate confidence intervals for model parameters. The pathogen grew in paneer between 10 and 50 °C and the developed model fit the observed data well (R2 = 0.972, RMSE = 0.321 log10 CFU/g). The cardinal parameters for B. cereus growth in paneer along with the 95% confidence intervals were: μopt 0.812 log10 CFU/g/h (0.742, 0.917); Topt is 44.177 °C (43.16, 45.49); Tmin is 4.405 °C (3.973, 4.829); Tmax is 50.676 °C (50.367, 51.144). The model developed can be used in food safety management plans and risk assessments to improve safety of paneer while also adding to limited information on B. cereus growth kinetics in dairy products.
Collapse
Affiliation(s)
- Dipon Sarkar
- Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
| | - Ian Hunt
- Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
| | - Cameron Macdonald
- Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
| | - Bing Wang
- Department of Food Science and Technology, University of Nebraska-Lincoln, 1901 N 21st St, Lincoln, NE, 68588, United States.
| | - John P Bowman
- Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
| | - Mark L Tamplin
- Centre of Food Safety & Innovation, University of Tasmania, Private Bag 54, Sandy Bay, Tasmania, 7005, Australia.
| |
Collapse
|
5
|
Frentzel H, Kelner-Burgos Y, Fischer J, Heise J, Göhler A, Wichmann-Schauer H. Occurrence of selected bacterial pathogens in insect-based food products and in-depth characterisation of detected Bacillus cereus group isolates. Int J Food Microbiol 2022; 379:109860. [DOI: 10.1016/j.ijfoodmicro.2022.109860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/06/2022] [Accepted: 07/26/2022] [Indexed: 10/16/2022]
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Ramm F, Stech M, Zemella A, Frentzel H, Kubick S. The Pore-Forming Hemolysin BL Enterotoxin from Bacillus cereus: Subunit Interactions in Cell-Free Systems. Toxins (Basel) 2021; 13:toxins13110807. [PMID: 34822591 PMCID: PMC8623112 DOI: 10.3390/toxins13110807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/05/2021] [Accepted: 11/12/2021] [Indexed: 11/16/2022] Open
Abstract
The tripartite enterotoxin Hemolysin BL (Hbl) has been widely characterized as a hemolytic and cytotoxic virulence factor involved in foodborne diarrheal illness caused by Bacillus cereus. Previous studies have described the formation of the Hbl complex and aimed to identify the toxin’s mode of action. In this study, we analyzed the assembly of Hbl out of its three individual subunits L1, L2 and B in a soluble as well as a putative membrane bound composition using a Chinese hamster ovary (CHO) cell-free system. Subunits were either coexpressed or synthesized individually in separate cell-free reactions and mixed together afterwards. Hemolytic activity of cell-free synthesized subunits was demonstrated on 5% sheep blood agar and identified both synthesis procedures, coexpression as well as individual synthesis of each subunit, as functional for the synthesis of an active Hbl complex. Hbl’s ability to perforate cell membranes was evaluated using a propidium iodide uptake assay. These data suggested that coexpressed Hbl subunits augmented cytotoxic activity with increasing concentrations. Further, a pre-pore-complex of L1-L2 showed cytotoxic effects suggesting the possibility of an interaction between the cell membrane and the pre-pore-complex. Overall, this study shows that cell-free protein synthesis is a fast and efficient way to study the assembly of multiple protein subunits in soluble as well as vesicular fractions.
Collapse
Affiliation(s)
- Franziska Ramm
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany; (F.R.); (M.S.); (A.Z.)
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Marlitt Stech
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany; (F.R.); (M.S.); (A.Z.)
| | - Anne Zemella
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany; (F.R.); (M.S.); (A.Z.)
| | - Hendrik Frentzel
- Department of Biological Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany;
| | - Stefan Kubick
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476 Potsdam, Germany; (F.R.); (M.S.); (A.Z.)
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
- Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus–Senftenberg, Brandenburg Medical School Theodor Fontane and the University of Potsdam, 14476 Potsdam, Germany
- Correspondence: ; Tel.: +49-331-58-187-306; Fax: +49-331-58-187-199
| |
Collapse
|
8
|
Butcher M, Puiu D, Romagnoli M, Carroll KC, Salzberg SL, Nauen DW. Rapidly fatal infection with Bacillus cereus/thuringiensis: genome assembly of the responsible pathogen and consideration of possibly contributing toxins. Diagn Microbiol Infect Dis 2021; 101:115534. [PMID: 34601446 PMCID: PMC9716716 DOI: 10.1016/j.diagmicrobio.2021.115534] [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: 05/06/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 10/20/2022]
Abstract
Bloodstream infection with Bacillus cereus/thuringiensis can be life threatening, particularly in patients who are severely immunocompromised. In this report we describe a case that progressed from asymptomatic to fatal over approximately 5 hours despite extensive resuscitation efforts. We identify the pathogen and assemble its genome, in which we find genes for toxins that may have contributed to the precipitous demise. In the context of this and other cases we discuss the possible indication for rapid appropriate antibiotic administration and potentially antitoxin treatment or toxin removal in fulminant illness in immunocompromised patients.
Collapse
Affiliation(s)
- Monica Butcher
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Daniela Puiu
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Mark Romagnoli
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Karen C Carroll
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Steven L Salzberg
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA
| | - David W Nauen
- Department of Pathology and Center for Computational Biology, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Abraha HB, Kim K, Sbhatu DB. Bacteriophages for detection and control of foodborne bacterial pathogens—The case of
Bacillus cereus
and their phages. J Food Saf 2021. [DOI: 10.1111/jfs.12906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Haftom Baraki Abraha
- Department of Food Science and Technology Jeonbuk National University Jeonju Republic of Korea
| | - Kwang‐Pyo Kim
- Department of Food Science and Technology Jeonbuk National University Jeonju Republic of Korea
- Department of Agricultural Convergence Technology Collage of Agriculture and Life Sciences, Jeonbuk National University Jeonju Republic of Korea
| | - Desta Berhe Sbhatu
- Department of Biological and Chemical Engineering Mekelle Institute of Technology, Mekelle University Mekelle Ethiopia
| |
Collapse
|
11
|
Sánchez-Chica J, Correa MM, Aceves-Diez AE, Castañeda-Sandoval LM. Enterotoxin Gene Distribution and Genotypes of Bacillus cereussensu lato Isolated from Cassava Starch. Toxins (Basel) 2021; 13:131. [PMID: 33578634 PMCID: PMC7916381 DOI: 10.3390/toxins13020131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/24/2022] Open
Abstract
Bacillus cereus is a human pathogenic bacterium found in foods with the potential to cause emesis and diarrhea. This study estimated the presence, toxigenic and genomic diversity of B. cereus s.l. obtained from cassava starch samples collected in bakeries and powdered food companies in Medellín (Colombia). Bacillus cereuss.l. was found in 43 of 75 (57%) cassava starch samples and 98 isolates were obtained. The nheABC, hblCDAB, cytK2, entFM and cesB toxin genes were detected by multiplex PCR and the most frequent operon was nheABC, whereas cesB gene was not found. Twelve toxigenic profiles were determined by the detection of toxin genes, and the most frequent profiles harbored all enterotoxin genes. A broad genomic diversity was detected according to GTG5-PCR fingerprinting results with 76 B. cereus s.l. grouped in sixteen clusters and the 22 isolates clustering separately. No relationship was observed between genomic background and toxigenic profiles. In general, the results showed a high genomic and enterotoxigenic diversity in B. cereus s.l. found in cassava starch. These results should incentive future studies to understand the distribution of B. cereus s.l. isolated on raw materials in comparison with finished products.
Collapse
Affiliation(s)
- Jennifer Sánchez-Chica
- Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín 050010, Colombia; (J.S.-C.); (M.M.C.)
| | - Margarita M. Correa
- Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín 050010, Colombia; (J.S.-C.); (M.M.C.)
| | - Angel E. Aceves-Diez
- Research and Development Department, Minkab Laboratories, Av. 18 de Marzo No. 546, Col. La Nogalera, Guadalajara P.O. Box 44470, Jalisco, Mexico;
| | - Laura M. Castañeda-Sandoval
- Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín 050010, Colombia; (J.S.-C.); (M.M.C.)
| |
Collapse
|
12
|
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.
Collapse
|
13
|
Deng F, Chen Y, Sun T, Wu Y, Su Y, Liu C, Zhou J, Deng Y, Wen J. Antimicrobial resistance, virulence characteristics and genotypes of Bacillus spp. from probiotic products of diverse origins. Food Res Int 2020; 139:109949. [PMID: 33509502 DOI: 10.1016/j.foodres.2020.109949] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/10/2020] [Accepted: 11/29/2020] [Indexed: 12/16/2022]
Abstract
Spore-forming probiotic Bacillus spp. have received extensively increasing scientific and commercial interest, but raised the concerns in the potential risks and pathogenesis. In this study, 50 commercial probiotic products were collected from all over the country and Bacillus spp. isolated from products were evaluated for the safety on the aspects of hemolytic activity, contamination profiles, toxin genes, cytotoxicity, antimicrobial resistance, and genotyping. 34 probiotic products (68%) exhibited hemolysis, including 19 human probiotics, 9 animal probiotics, and 6 plant probiotics. 28 products (56%) contained other bacteria not labeled in the ingredients. 48 strains in Bacillus spp. including 17 B. subtilis group isolates, 28 B. cereus, and 3 other Bacillus spp. were isolated from human, food animal, and plant probiotic products. Detection rates of enterotoxin genes, nheABC and hblCDA, and cytotoxin cytK2 in 48 Bacillus spp. isolates were 58%, 31%, and 46%, respectively. Also, one isolate B. cereus 34b from an animal probiotic product was positive for ces, encoding cereulide. 28 of 48 Bacillus spp. isolates were cytotoxic. 19 of 28 B. cereus isolates maintained to exhibit hemolysis after heat treatment. All 48 Bacillus spp. isolates exhibited resistance to lincomycin, and 5 were resistant to tetracycline. The genotyping of commercial probiotic Bacillus spp. reported in this study showed that ces existed in B. cereus 34b with the specific sequence type (ST1066). These findings support the hypothesis that probiotic products were frequently contaminated and that some commercial probiotics consisted of Bacillus spp. may possess toxicity and antimicrobial resistance genes. Thus, the further efforts are needed in regarding the surveillance of virulence factors, toxins, and antibiotic resistance determinants in probiotic Bacillus spp.
Collapse
Affiliation(s)
- Fengru 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
| | - Yunsheng 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
| | - Tianyu Sun
- 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
| | - Yuting Wu
- 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
| | - Yiting Su
- 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
| | - Changyue Liu
- 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
| | - Junyu Zhou
- 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
| | - 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.
| | - 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.
| |
Collapse
|
14
|
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.
Collapse
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.)
| |
Collapse
|
15
|
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.
Collapse
|
16
|
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.
Collapse
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:
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Sánchez-Chica J, Correa MM, Aceves-Diez AE, Castañeda-Sandoval LM. Genetic and toxigenic diversity of Bacillus cereus group isolated from powdered foods. Journal of Food Science and Technology 2020; 58:1892-1899. [PMID: 33897025 DOI: 10.1007/s13197-020-04700-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/13/2020] [Accepted: 08/06/2020] [Indexed: 11/27/2022]
Abstract
Bacillus cereus is a human pathogenic bacterium that produces emetic and diarrheal foodborne diseases. This study evaluated the genetic and toxigenic diversity in B. cereus group isolates from powdered foods collected in public educational institutions, bakeries and powdered food companies located in Medellín, Colombia. B. cereus was detected in 35 of 305 (11%) powdered food samples and 52 B. cereus were isolated. The presence of ten toxin genes, hblCDAB, nheABC, cytK2, entFM and cesB, was evaluated in the isolates by multiplex PCR. The nheABC operon was found in all isolates (100%), hblCDAB in 22 (42%), hblCDA in 8 (15%) and hblCD in 3 (6%); the cytK2 gene was detected in 32 isolates (62%) and entFM in 32 (62%). Notably, the cesB gene was not detected. According to the presence of toxin genes, fifteen profiles were identified. The predominant toxigenic profile contained all toxin genes but cesB. A large genetic diversity was observed by GTG5 fingerprinting with 46 isolates grouped in seven clusters and the remaining six clustering individually. There was no relationship between toxigenic profiles and genetic clusters, but some genetic clusters seemed to be related to particular powdered food types. In general, the results evidenced high genetic and enterotoxigenic diversity among the B. cereus group isolates.
Collapse
Affiliation(s)
- Jennifer Sánchez-Chica
- Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia-UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Margarita M Correa
- Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia-UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Angel E Aceves-Diez
- Research and Development Department, Minkab Laboratories, P.O. Box 44470, Av. 18 de Marzo No. 546, Col. La Nogalera, Guadalajara, Jalisco Mexico
| | | |
Collapse
|
19
|
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.
Collapse
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;
| |
Collapse
|
20
|
Rajkovic A, Jovanovic J, Monteiro S, Decleer M, Andjelkovic M, Foubert A, Beloglazova N, Tsilla V, Sas B, Madder A, De Saeger S, Uyttendaele M. Detection of toxins involved in foodborne diseases caused by Gram‐positive bacteria. Compr Rev Food Sci Food Saf 2020; 19:1605-1657. [DOI: 10.1111/1541-4337.12571] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Andreja Rajkovic
- Laboratory of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience EngineeringGhent University Ghent Belgium
| | - Jelena Jovanovic
- Laboratory of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience EngineeringGhent University Ghent Belgium
| | - Silvia Monteiro
- Laboratorio Analises, Instituto Superior TecnicoUniversidade de Lisboa Lisbon Portugal
| | - Marlies Decleer
- Laboratory of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience EngineeringGhent University Ghent Belgium
- Laboratory of Food Analysis, Department of Bioanalysis, Faculty of Pharmaceutical SciencesGhent University Ghent Belgium
| | - Mirjana Andjelkovic
- Operational Directorate Food, Medicines and Consumer SafetyService for Chemical Residues and Contaminants Brussels Belgium
| | - Astrid Foubert
- Laboratory of Food Analysis, Department of Bioanalysis, Faculty of Pharmaceutical SciencesGhent University Ghent Belgium
| | - Natalia Beloglazova
- Laboratory of Food Analysis, Department of Bioanalysis, Faculty of Pharmaceutical SciencesGhent University Ghent Belgium
- Nanotechnology Education and Research CenterSouth Ural State University Chelyabinsk Russia
| | - Varvara Tsilla
- Laboratory of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience EngineeringGhent University Ghent Belgium
| | - Benedikt Sas
- Laboratory of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience EngineeringGhent University Ghent Belgium
| | - Annemieke Madder
- Laboratorium for Organic and Biomimetic Chemistry, Department of Organic and Macromolecular ChemistryGhent University Ghent Belgium
| | - Sarah De Saeger
- Laboratory of Food Analysis, Department of Bioanalysis, Faculty of Pharmaceutical SciencesGhent University Ghent Belgium
| | - Mieke Uyttendaele
- Laboratory of Food Microbiology and Food Preservation, Department of Food Technology, Safety and Health, Faculty of Bioscience EngineeringGhent University Ghent Belgium
| |
Collapse
|
21
|
Ramarao N, Tran SL, Marin M, Vidic J. Advanced Methods for Detection of Bacillus cereus and Its Pathogenic Factors. SENSORS (BASEL, SWITZERLAND) 2020; 20:E2667. [PMID: 32392794 PMCID: PMC7273213 DOI: 10.3390/s20092667] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/02/2020] [Accepted: 05/05/2020] [Indexed: 12/21/2022]
Abstract
Bacillus cereus is an opportunistic foodborne pathogen causing food intoxication and infectious diseases. Different toxins and pathogenic factors are responsible for diarrheal syndrome, like nonhemolytic enterotoxin Nhe, hemolytic enterotoxin Hbl, enterotoxin FM and cytotoxin K, while emetic syndrome is caused by the depsipeptide cereulide toxin. The traditional method of B. cereus detection is based on the bacterial culturing onto selective agars and cells enumeration. In addition, molecular and chemical methods are proposed for toxin gene profiling, toxin quantification and strain screening for defined virulence factors. Finally, some advanced biosensors such as phage-based, cell-based, immunosensors and DNA biosensors have been elaborated to enable affordable, sensitive, user-friendly and rapid detection of specific B. cereus strains. This review intends to both illustrate the state of the B. cereus diagnostic field and to highlight additional research that is still at the development level.
Collapse
Affiliation(s)
- Nalini Ramarao
- INRAE, AgroParisTech, Micalis Institute, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (M.M.)
| | | | | | - Jasmina Vidic
- INRAE, AgroParisTech, Micalis Institute, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (M.M.)
| |
Collapse
|
22
|
Frentzel H, Juraschek K, Pauly N, Kelner-Burgos Y, Wichmann-Schauer H. Indications of biopesticidal Bacillus thuringiensis strains in bell pepper and tomato. Int J Food Microbiol 2020; 321:108542. [DOI: 10.1016/j.ijfoodmicro.2020.108542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 09/27/2019] [Accepted: 01/26/2020] [Indexed: 12/20/2022]
|
23
|
Ramm F, Dondapati SK, Thoring L, Zemella A, Wüstenhagen DA, Frentzel H, Stech M, Kubick S. Mammalian cell-free protein expression promotes the functional characterization of the tripartite non-hemolytic enterotoxin from Bacillus cereus. Sci Rep 2020; 10:2887. [PMID: 32076011 PMCID: PMC7031377 DOI: 10.1038/s41598-020-59634-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 01/23/2020] [Indexed: 11/29/2022] Open
Abstract
Bacillus cereus is increasingly recognized as an opportunistic pathogen causing local and systemic infections. The causative strains typically produce three pore-forming enterotoxins. This study focusses on the tripartite non-hemolytic enterotoxin (Nhe). Until today, studies have tried to elucidate the structure, complex formation and cell binding mechanisms of the tripartite Nhe toxin. Here, we demonstrate the synthesis of the functional tripartite Nhe toxin using eukaryotic cell-free systems. Single subunits, combinations of two Nhe subunits as well as the complete tripartite toxin were tested. Functional activity was determined by hemolytic activity on sheep blood agar plates, planar lipid bilayer measurements as well as cell viability assessment using the MTT assay. Our results demonstrate that cell-free protein synthesis based on translationally active eukaryotic lysates is a platform technology for the fast and efficient synthesis of functionally active, multicomponent toxins.
Collapse
Affiliation(s)
- Franziska Ramm
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany.,Freie Universität Berlin, Institute of Chemistry and Biochemistry - Biochemistry, Takustr. 6, 14195, Berlin, Germany
| | - Srujan Kumar Dondapati
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
| | - Lena Thoring
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
| | - Anne Zemella
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
| | - Doreen Anja Wüstenhagen
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
| | - Hendrik Frentzel
- German Federal Institute for Risk Assessment, Department of Biological Safety, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Marlitt Stech
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany
| | - Stefan Kubick
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam, Germany. .,Faculty of Health Sciences, joint Faculty of the Brandenburg University of Technology Cottbus - Senftenberg, the Brandenburg Medical School Theodor Fontane and the University of Potsdam, Potsdam, Germany.
| |
Collapse
|
24
|
Cui Y, Wang S, Ding S, Shen J, Zhu K. Toxins and mobile antimicrobial resistance genes in Bacillus probiotics constitute a potential risk for One Health. JOURNAL OF HAZARDOUS MATERIALS 2020; 382:121266. [PMID: 31563808 DOI: 10.1016/j.jhazmat.2019.121266] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/12/2019] [Accepted: 09/19/2019] [Indexed: 06/10/2023]
Abstract
Probiotic microbes conferring health benefits to the hosts have attracted great attention. However, the safety of probiotics is not guaranteed, although the increasing widespread use of probiotics with excellent overall safety records. Here, we performed a systematic evaluation of the safety of commercial Bacillus probiotics intended for usage in humans, animals, plants, aquaculture and environment in China. Nearly half of the 65 isolated Bacillus spp. strains from these commercial probiotic products were capable of producing hazardous toxins. Infections with the representative isolates could cause sepsis, intestinal inflammation and liver injury in different mouse models. Additionally, these isolates harbor multiple antimicrobial resistance genes coupled with mobile genetic elements. Collectively, the capability for producing various toxins and harboring mobile antimicrobial resistance genes in Bacillus probiotics indicates a potential risk for One Health.
Collapse
Affiliation(s)
- Yifang Cui
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Shaolin Wang
- Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety and Beijing Laboratory for Food Quality and Safety, Beijing 100193, China
| | - Shuangyang Ding
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jianzhong Shen
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety and Beijing Laboratory for Food Quality and Safety, Beijing 100193, China
| | - Kui Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| |
Collapse
|
25
|
SYBR Green Real-Time PCR Assay for Detection of the Indicator Bacillus cereus to Validate Thermal Processing of Tender Coconut Water. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2019. [DOI: 10.22207/jpam.13.3.04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
26
|
Gdoura-Ben Amor M, Jan S, Baron F, Grosset N, Culot A, Gdoura R, Gautier M, Techer C. Toxigenic potential and antimicrobial susceptibility of Bacillus cereus group bacteria isolated from Tunisian foodstuffs. BMC Microbiol 2019; 19:196. [PMID: 31445510 PMCID: PMC6708205 DOI: 10.1186/s12866-019-1571-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 08/14/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Despite the importance of the B. cereus group as major foodborne pathogens that may cause diarrheal and/or emetic syndrome(s), no study in Tunisia has been conducted in order to characterize the pathogenic potential of the B. cereus group. The aim of this study was to assess the sanitary potential risks of 174 B. cereus group strains isolated from different foodstuffs by detecting and profiling virulence genes (hblA, hblB, hblC, hblD, nheA, nheB, nheC, cytK, bceT and ces), testing the isolates cytotoxic activity on Caco-2 cells and antimicrobial susceptibility towards 11 antibiotics. RESULTS The entertoxin genes detected among B. cereus isolates were, in decreasing order, nheA (98.9%), nheC (97.7%) and nheB (86.8%) versus hblC (54.6%), hblD (54.6%), hblA (29.9%) and hblB (14.9%), respectively encoding for Non-hemolytic enterotoxin (NHE) and Hemolysin BL (HBL). The isolates are multi-toxigenic, harbouring at least one gene of each NHE and HBL complexes associated or not to bceT, cytK-2 and ces genes. Based on the incidence of virulence genes, the strains were separated into 12 toxigenic groups. Isolates positive for cytK (37,9%) harbored the cytK-2 variant. The detection rates of bceT and ces genes were 50.6 and 4%, respectively. When bacteria were incubated in BHI-YE at 30 °C for 18 h and for 5 d, 70.7 and 35% of the strains were shown to be cytotoxic to Caco-2 cells, respectively. The cytotoxicity of B. cereus strains depended on the food source of isolation. The presence of virulence factors is not always consistent with cytotoxicity. However, different combinations of enterotoxin genetic determinants are significantly associated to the cytotoxic potential of the bacteria. All strains were fully sensitive to rifampicin, chloramphenicol, ciprofloxacin, and gentamycin. The majority of the isolates were susceptible to streptomycin, kanamycin, erythromycin, vancomycin and tetracycline but showed resistance to ampicillin and novobiocin. CONCLUSION Our results contribute data that are primary to facilitate risk assessments in order to prevent food poisoning due to B. cereus group.
Collapse
Affiliation(s)
- Maroua Gdoura-Ben Amor
- Laboratory Research of Toxicology-Microbiology Environmental and Health LR17ES06, Sciences Faculty of Sfax, University of Sfax, Sfax, Tunisia.
- Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, Rennes, France.
| | - Sophie Jan
- Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, Rennes, France
| | - Florence Baron
- Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, Rennes, France
| | - Noël Grosset
- Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, Rennes, France
| | - Antoine Culot
- Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, Rennes, France
- Mixscience, Rue des Courtillons, ZAC Cissé Blossac, 35712, Bruz, France
| | - Radhouane Gdoura
- Laboratory Research of Toxicology-Microbiology Environmental and Health LR17ES06, Sciences Faculty of Sfax, University of Sfax, Sfax, Tunisia
| | - Michel Gautier
- Equipe Microbiologie, Agrocampus Ouest, INRA, UMR1253 Science et Technologie du Lait et de l'Œuf, Rennes, France
| | - Clarisse Techer
- Mixscience, Rue des Courtillons, ZAC Cissé Blossac, 35712, Bruz, France
| |
Collapse
|
27
|
Cui Y, Märtlbauer E, Dietrich R, Luo H, Ding S, Zhu K. Multifaceted toxin profile, an approach toward a better understanding of probiotic Bacillus cereus. Crit Rev Toxicol 2019; 49:342-356. [PMID: 31116061 DOI: 10.1080/10408444.2019.1609410] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Strains of the Bacillus cereus group have been widely used as probiotics for human beings, food animals, plants, and environmental remediation. Paradoxically, B. cereus is responsible for both gastrointestinal and nongastrointestinal syndromes and represents an important opportunistic food-borne pathogen. Toxicity assessment is a fundamental issue to evaluate safety of probiotics. Here, we summarize the state of our current knowledge about the toxins of B. cereus sensu lato to be considered for safety assessment of probiotic candidates. Surfactin-like emetic toxin (cereulide) and various enterotoxins including nonhemolytic enterotoxin, hemolysin BL, and cytotoxin K are responsible for food poisoning outbreaks characterized by emesis and diarrhea. In addition, other factors, such as hemolysin II, Certhrax, immune inhibitor A1, and sphingomyelinase, contribute to toxicity and overall virulence of B. cereus.
Collapse
Affiliation(s)
- Yifang Cui
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University , Beijing , China.,State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University , Beijing , China
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Ludwig-Maximilians-University Munich , Oberschleißheim , Germany
| | - Richard Dietrich
- Department of Veterinary Sciences, Ludwig-Maximilians-University Munich , Oberschleißheim , Germany
| | - Hailing Luo
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University , Beijing , China
| | - Shuangyang Ding
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University , Beijing , China
| | - Kui Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University , Beijing , China.,National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University , Beijing , China
| |
Collapse
|
28
|
Binding to The Target Cell Surface Is The Crucial Step in Pore Formation of Hemolysin BL from Bacillus cereus. Toxins (Basel) 2019; 11:toxins11050281. [PMID: 31137585 PMCID: PMC6563250 DOI: 10.3390/toxins11050281] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/13/2019] [Accepted: 05/16/2019] [Indexed: 12/19/2022] Open
Abstract
A major virulence factor involved in Bacillus cereus food poisoning is the three-component enterotoxin hemolysin BL. It consists of the binding component B and the two lytic components L1 and L2. Studying its mode of action has been challenging, as natural culture supernatants additionally contain Nhe, the second three-component enterotoxin, and purification of recombinant (r) Hbl components has been difficult. In this study, we report on pore-forming, cytotoxic, cell binding and hemolytic activity of recently generated rHbl components expressed in E. coli. It is known that all three Hbl components are necessary for cytotoxicity and pore formation. Here we show that an excess of rHbl B enhances, while an excess of rHbl L1 hinders, the velocity of pore formation. Most rapid pore formation was observed with ratios L2:L1:B = 1:1:10 and 10:1:10. It was further verified that Hbl activity is due to sequential binding of the components B - L1 - L2. Accordingly, all bioassays proved that binding of Hbl B to the cell surface is the crucial step for pore formation and cytotoxic activity. Binding of Hbl B took place within minutes, while apposition of the following L1 and L2 occurred immediately. Further on, applying toxin components simultaneously, it seemed that Hbl L1 enhanced binding of B to the target cell surface. Overall, these data contribute significantly to the elucidation of the mode of action of Hbl, and suggest that its mechanism of pore formation differs substantially from that of Nhe, although both enterotoxin complexes are sequentially highly related.
Collapse
|
29
|
Ulrich S, Gottschalk C, Dietrich R, Märtlbauer E, Gareis M. Identification of cereulide producing Bacillus cereus by MALDI-TOF MS. Food Microbiol 2019; 82:75-81. [PMID: 31027822 DOI: 10.1016/j.fm.2019.01.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 01/11/2019] [Accepted: 01/21/2019] [Indexed: 12/23/2022]
Abstract
The Bacillus (B.) cereus group consists of nine recognized species which are present worldwide. B. cereus play an important role in food-borne diseases by producing different toxins. Yet, only a small percentage of B. cereus strains are able to produce the heat stable cereulide, the causative agent of emetic food poisoning. To minimize the entry of emetic B. cereus into the food chain, food business operators are dependent on efficient and reliable methods enabling the differentiation between emetic and non-emetic strains. Currently, only time-consuming cell bioassays, molecular methods and tandem mass spectrometry are available for this purpose. Thus, the aim of the present study was to establish a fast and reliable method for the differentiation between emetic/non-emetic strains by MALDI-TOF MS. Selected strains/isolates of the B. cereus group as well as other Bacillus spp. (total n = 121) were cultured on sheep blood agar for 48 h before analysis. Subsequently, the cultures were directly analyzed by MALDI-TOF MS without prior extraction steps. The samples were measured in the mass range of m/z 800-1800 Da. Using ClinProTools 3.0 statistical software and Flex analysis software (Bruker Daltonics GmbH, Bremen, Germany), a differentiation between emetic/non-emetic isolates was possible with a rate of correct identification of 99.1% by means of the evaluation of two specific biomarkers (m/z 1171 and 1187 Da).
Collapse
Affiliation(s)
- Sebastian Ulrich
- Food Safety, Veterinary Faculty, Ludwig-Maximilians-University Munich, Schoenleutnerstr. 8, 85764, Oberschleissheim, Germany.
| | - Christoph Gottschalk
- Food Safety, Veterinary Faculty, Ludwig-Maximilians-University Munich, Schoenleutnerstr. 8, 85764, Oberschleissheim, Germany
| | - Richard Dietrich
- Hygiene and Technology of Milk, Veterinary Faculty, Ludwig-Maximilians-University Munich, Schoenleutnerstr. 8, 85764, Oberschleissheim, Germany
| | - Erwin Märtlbauer
- Hygiene and Technology of Milk, Veterinary Faculty, Ludwig-Maximilians-University Munich, Schoenleutnerstr. 8, 85764, Oberschleissheim, Germany
| | - Manfred Gareis
- Food Safety, Veterinary Faculty, Ludwig-Maximilians-University Munich, Schoenleutnerstr. 8, 85764, Oberschleissheim, Germany
| |
Collapse
|
30
|
Cadirci O, Gucukoglu A, Terzi Gulel G, Uyanik T. Enterotoxigenic structures of Bacillus cereusstrains isolated from ice creams. J Food Saf 2018. [DOI: 10.1111/jfs.12537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ozgur Cadirci
- Ondokuz Mayıs University, Faculty of Veterinary MedicineDepartment of Food Hygiene and Technology Samsun Turkey
| | - Ali Gucukoglu
- Ondokuz Mayıs University, Faculty of Veterinary MedicineDepartment of Food Hygiene and Technology Samsun Turkey
| | - Goknur Terzi Gulel
- Ondokuz Mayıs University, Faculty of Veterinary MedicineDepartment of Food Hygiene and Technology Samsun Turkey
| | - Tolga Uyanik
- Ondokuz Mayıs University, Faculty of Veterinary MedicineDepartment of Food Hygiene and Technology Samsun Turkey
| |
Collapse
|
31
|
Bursová Š, Necidová L, Haruštiaková D. Growth and toxin production of Bacillus cereus strains in reconstituted initial infant milk formula. Food Control 2018. [DOI: 10.1016/j.foodcont.2017.05.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
32
|
Mesophilic Sporeformers Identified in Whey Powder by Using Shotgun Metagenomic Sequencing. Appl Environ Microbiol 2018; 84:AEM.01305-18. [PMID: 30076196 DOI: 10.1128/aem.01305-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/31/2018] [Indexed: 01/19/2023] Open
Abstract
Spoilage and pathogenic spore-forming bacteria are a major cause of concern for producers of dairy products. Traditional agar-based detection methods employed by the dairy industry have limitations with respect to their sensitivity and specificity. The aim of this study was to identify low-abundance sporeformers in samples of a powdered dairy product, whey powder, produced monthly over 1 year, using novel culture-independent shotgun metagenomics-based approaches. Although mesophilic sporeformers were the main target of this study, in one instance thermophilic sporeformers were also targeted using this culture-independent approach. For comparative purposes, mesophilic and thermophilic sporeformers were also tested for within the same sample using culture-based approaches. Ultimately, the approaches taken highlighted differences in the taxa identified due to treatment and isolation methods. Despite this, low levels of transient, mesophilic, and in some cases potentially pathogenic sporeformers were consistently detected in powder samples. Although the specific sporeformers changed from one month to the next, it was apparent that 3 groups of mesophilic sporeformers, namely, Bacillus cereus, Bacillus licheniformis/Bacillus paralicheniformis, and a third, more heterogeneous group containing Brevibacillus brevis, dominated across the 12 samples. Total thermophilic sporeformer taxonomy was considerably different from mesophilic taxonomy, as well as from the culturable thermophilic taxonomy, in the one sample analyzed by all four approaches. Ultimately, through the application of shotgun metagenomic sequencing to dairy powders, the potential for this technology to facilitate the detection of undesirable bacteria present in these food ingredients is highlighted.IMPORTANCE The ability of sporeformers to remain dormant in a desiccated state is of concern from a safety and spoilage perspective in dairy powder. Traditional culturing techniques are slow and provide little information without further investigation. We describe the identification of mesophilic sporeformers present in powders produced over 1 year, using novel shotgun metagenomic sequencing. This method allows detection and identification of possible pathogens and spoilage bacteria in parallel. Strain-level analysis and functional gene analysis, such as identification of toxin genes, were also performed. This approach has the potential to be of great value with respect to the detection of spore-forming bacteria and could allow a processor to make an informed decision surrounding process changes to reduce the risk of spore contamination.
Collapse
|
33
|
Talebi S, Makhdoumi A, Bahreini M, Matin M, Moradi H. Three novelBacillusstrains from a traditional lacto-fermented pickle as potential probiotics. J Appl Microbiol 2018; 125:888-896. [DOI: 10.1111/jam.13901] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/25/2018] [Accepted: 04/25/2018] [Indexed: 12/20/2022]
Affiliation(s)
- S. Talebi
- Department of Biology; Faculty of Science; Ferdowsi University of Mashhad; Mashhad Iran
| | - A. Makhdoumi
- Department of Biology; Faculty of Science; Ferdowsi University of Mashhad; Mashhad Iran
| | - M. Bahreini
- Department of Biology; Faculty of Science; Ferdowsi University of Mashhad; Mashhad Iran
| | - M.M. Matin
- Department of Biology; Faculty of Science; Ferdowsi University of Mashhad; Mashhad Iran
- Cell and Molecular Biotechnology Research Group; Institute of Biotechnology; Ferdowsi University of Mashhad; Mashhad Iran
| | - H.S. Moradi
- Department of Biology; Faculty of Science; Ferdowsi University of Mashhad; Mashhad Iran
| |
Collapse
|
34
|
Soni A, Oey I, Silcock P, Bremer PJ. Impact of temperature, nutrients, pH and cold storage on the germination, growth and resistance of Bacillus cereus spores in egg white. Food Res Int 2018; 106:394-403. [DOI: 10.1016/j.foodres.2018.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/10/2017] [Accepted: 01/06/2018] [Indexed: 12/11/2022]
|
35
|
Dong L, Liu H, Meng L, Xing M, Wang J, Wang C, Chen H, Zheng N. Quantitative PCR coupled with sodium dodecyl sulfate and propidium monoazide for detection of viable Staphylococcus aureus in milk. J Dairy Sci 2018; 101:4936-4943. [PMID: 29605335 DOI: 10.3168/jds.2017-14087] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/04/2018] [Indexed: 11/19/2022]
Abstract
Conventional quantitative PCR (qPCR) are unable to differentiate DNA of viable Staphylococcus aureus cells from dead ones. The aim of this study was to use sodium dodecyl sulfate (SDS) and propidium monoazide (PMA) coupled with lysostaphin to detect viable Staph. aureus. The cell suspensions were treated with SDS and PMA before DNA extraction. The SDS is an anionic surfactant, which can increase the permeability of dead cells to PMA without compromising the viability of live cells. The lysostaphin was applied to improve the effectiveness of DNA extraction. The reliability and specificity of this method were further determined by the detection of Staph. aureus in spiked milk. The results showed that there were significant differences between the SDS-PMA-qPCR and qPCR when a final concentration of 200 μg/mL of lysostaphin was added in DNA extraction. The viable Staph. aureus could be effectively detected when SDS and PMA concentrations were 100 µg/mL and 40 μM, respectively. Compared with conventional qPCR, the SDS-PMA-qPCR assay coupled with lysostaphin was more specific and sensitive. Therefore, this method could accurately detect the number of viable Staph. aureus cells.
Collapse
Affiliation(s)
- Lei Dong
- Ministry of Agriculture Laboratory of Quality and Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Ministry of Agriculture-Milk and Dairy Product Inspection Center (Beijing), Beijing 100193, P. R. China; College of Food Science and Engineer, Qingdao Agricultural University, Qingdao 266109, P. R. China
| | - Huimin Liu
- Ministry of Agriculture Laboratory of Quality and Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Ministry of Agriculture-Milk and Dairy Product Inspection Center (Beijing), Beijing 100193, P. R. China; Institute of Quality Standard and Testing Technology, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, P. R. China
| | - Lu Meng
- Ministry of Agriculture Laboratory of Quality and Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Ministry of Agriculture-Milk and Dairy Product Inspection Center (Beijing), Beijing 100193, P. R. China
| | - Mengru Xing
- Ministry of Agriculture Laboratory of Quality and Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Ministry of Agriculture-Milk and Dairy Product Inspection Center (Beijing), Beijing 100193, P. R. China; College of Food Science and Engineer, Qingdao Agricultural University, Qingdao 266109, P. R. China
| | - Jiaqi Wang
- Ministry of Agriculture Laboratory of Quality and Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Ministry of Agriculture-Milk and Dairy Product Inspection Center (Beijing), Beijing 100193, P. R. China
| | - Cheng Wang
- Institute of Quality Standard and Testing Technology, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, P. R. China
| | - He Chen
- Institute of Quality Standard and Testing Technology, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, P. R. China
| | - Nan Zheng
- Ministry of Agriculture Laboratory of Quality and Safety Risk Assessment for Dairy Products (Beijing), Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Ministry of Agriculture-Milk and Dairy Product Inspection Center (Beijing), Beijing 100193, P. R. China.
| |
Collapse
|
36
|
Soleimani M, Hosseini H, Pilevar Z, Mehdizadeh M, Carlin F. Prevalence, molecular identification and characterization of
Bacillus cereus
isolated from beef burgers. J Food Saf 2017. [DOI: 10.1111/jfs.12414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maryam Soleimani
- Department of Food Science and TechnologyNational Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical SciencesTehran Iran
| | - Hedayat Hosseini
- Department of Food Science and TechnologyNational Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical SciencesTehran Iran
| | - Zahra Pilevar
- Department of Food Science and TechnologyNational Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical SciencesTehran Iran
| | | | - Frédéric Carlin
- INRA, UMR408, Securite et Qualite des Produits d'Origine Vegetale Avignon France
| |
Collapse
|
37
|
Evidence for Complex Formation of the Bacillus cereus Haemolysin BL Components in Solution. Toxins (Basel) 2017; 9:toxins9090288. [PMID: 28926954 PMCID: PMC5618221 DOI: 10.3390/toxins9090288] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 09/11/2017] [Accepted: 09/12/2017] [Indexed: 02/08/2023] Open
Abstract
Haemolysin BL is an important virulence factor regarding the diarrheal type of food poisoning caused by Bacillus cereus. However, the pathogenic importance of this three-component enterotoxin is difficult to access, as nearly all natural B. cereus culture supernatants additionally contain the highly cytotoxic Nhe, the second three-component toxin involved in the aetiology of B. cereus-induced food-borne diseases. To better address the toxic properties of the Hbl complex, a system for overexpression and purification of functional, cytotoxic, recombinant (r)Hbl components L2, L1 and B from E. coli was established and an nheABC deletion mutant was constructed from B. cereus reference strain F837/76. Furthermore, 35 hybridoma cell lines producing monoclonal antibodies (mAbs) against Hbl L2, L1 and B were generated. While mAbs 1H9 and 1D8 neutralized Hbl toxicity and thus, represent important tools for future investigations of the mode-of-action of Hbl on the target cell surface, mAb 1D7, in contrast, even enhanced Hbl toxicity by supporting the binding of Hbl B to the cell surface. By using the specific mAbs in Dot blots, indirect and hybrid sandwich enzyme immuno assays (EIAs), complex formation between Hbl L1 and B, as well as L1 and L2 in solution could be shown for the first time. Surface plasmon resonance experiments with the rHbl components confirmed these results with KD values of 4.7 × 10−7 M and 1.5 × 10−7 M, respectively. These findings together with the newly created tools lay the foundation for the detailed elucidation of the molecular mode-of-action of the highly complex three-component Hbl toxin.
Collapse
|
38
|
Chelliah R, Wei S, Park BJ, Kim SH, Park DS, Kim SH, Hwan KS, Oh DH. Novel motB as a potential predictive tool for identification of B. cereus, B. thuringiensis and differentiation from other Bacillus species by triplex real-time PCR. Microb Pathog 2017; 111:22-27. [PMID: 28778821 DOI: 10.1016/j.micpath.2017.07.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 06/28/2017] [Accepted: 07/31/2017] [Indexed: 10/19/2022]
Abstract
Quantitative triplex real-time PCR (qPCR) offers an alternative method for detection of bacterial contamination. It provides quantitation of the number of gene copies. In our study, we established a qPCR assay to detect and quantify the specificity towards Bacillus cereus and B. thuringiensis. The assay was designed to detect a 280 bp fragment of motB gene encoding the flagellar motor protein, specific for detection of B. cereus and B. thuringiensis, excluding other group species B. pseudomycoides, B. mycoides and B. weihenstephanensis. Specificity of the assay was confirmed with 111 strains belonging to Bacillus cereus group and performed against 58 B. cereus, 50 B. thuringiensis, 3 other Bacillus bacteria and 9 non-Bacillus bacteria. Detection limit was determined for each assay. Direct analysis of samples revealed the specificity towards identification and characterization of B. cereus group cultured in nutrient media. Based on results, it was observed that motB showed 97% specificity towards B. cereus strains, 98% for B. thuringiensis but other B. cereus group showed less sensitivity (0%), thus, provides an efficient tool to identify B. cereus and B. thuringiensis. Further, environmental and food samples do not require band isolation, re-amplification or sequence identification. Thus, reducing the time and cost of analysis.
Collapse
Affiliation(s)
- Ramachandran Chelliah
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Shuai Wei
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Byung-Jae Park
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Se-Hun Kim
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Dong-Suk Park
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, 54874, Republic of Korea
| | - Soon Han Kim
- Food Microbiology Division, National Institute of Food and Drug Safety Evaluation, 187, Osongsaengmyeong 2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28159, Republic of Korea
| | - Kim Seok Hwan
- Food Microbiology Division, National Institute of Food and Drug Safety Evaluation, 187, Osongsaengmyeong 2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 28159, Republic of Korea
| | - Deog-Hwan Oh
- Department of Food Science and Biotechnology, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| |
Collapse
|
39
|
Genetic and genomic diversity of NheABC locus from Bacillus strains. Arch Microbiol 2017; 199:775-785. [PMID: 28283680 PMCID: PMC5486940 DOI: 10.1007/s00203-017-1350-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/13/2017] [Accepted: 01/27/2017] [Indexed: 12/17/2022]
Abstract
Non-hemolytic enterotoxin (NHE), a tri-partite, proteinaceous toxin encoded by contiguous nheA, nheB and nheC genes of Bacillus cereus sensu lato (B. cereus s.l.), is considered to be associated with the foodborne diarrheic syndrome. However, B. cereus s.l. includes a number of closely related strains, and the occurrence of NHE among them, and other members of Bacillus is unclear. Consequently, we aimed to determine the distribution and evolution of NHE within Bacillus by confirming the presence of the nheA, B and C sequences and variation within them using published data, and to analyze the genomic and genetic diversity. The phylogenetic tree of NHE proteins (NheA, NheB and NheC) from 81 different B. cereus s.l. strains was constructed. And on the genetic determinants of the NHE toxin did not bring any obvious link between the nheABC genes sequence of a strain and its virulence in the diarrhoeal pathogenesis. Analysis of the genomic diversity of the nheA, B and C loci revealed that their upstream regions were more conserved than the downstream sequences. Multilocus sequence typing schemes (MLST) based on seven concatenated housekeeping genes and nheA, B and C genes of the 75 strains were developed. The neighbor joining phylogenetic tree based on seven housekeeping genes together with nheA, B and C genes was similiar to published Bacillus phylogenetic trees. And on the genetic determinants of the NHE toxin did not bring any obvious link between the nheABC genes sequence of a strain and its virulence in the diarrhoeal pathogenesis.The results indicate that nheA, B and C genes do not affect the diversity of housekeeping genes, and this specific NHE protein does not participate in the diarrheic syndrome.
Collapse
|
40
|
McHugh AJ, Feehily C, Hill C, Cotter PD. Detection and Enumeration of Spore-Forming Bacteria in Powdered Dairy Products. Front Microbiol 2017; 8:109. [PMID: 28197144 PMCID: PMC5281614 DOI: 10.3389/fmicb.2017.00109] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 01/16/2017] [Indexed: 01/28/2023] Open
Abstract
With the abolition of milk quotas in the European Union in 2015, several member states including Ireland, Luxembourg, and Belgium have seen year on year bi-monthly milk deliveries to dairies increase by up to 35%. Milk production has also increased outside of Europe in the past number of years. Unsurprisingly, there has been a corresponding increased focus on the production of dried milk products for improved shelf life. These powders are used in a wide variety of products, including confectionery, infant formula, sports dietary supplements and supplements for health recovery. To ensure quality and safety standards in the dairy sector, strict controls are in place with respect to the acceptable quantity and species of microorganisms present in these products. A particular emphasis on spore-forming bacteria is necessary due to their inherent ability to survive extreme processing conditions. Traditional microbiological detection methods used in industry have limitations in terms of time, efficiency, accuracy, and sensitivity. The following review will explore the common spore-forming bacterial contaminants of milk powders, will review the guidelines with respect to the acceptable limits of these microorganisms and will provide an insight into recent advances in methods for detecting these microbes. The various advantages and limitations with respect to the application of these diagnostics approaches for dairy food will be provided. It is anticipated that the optimization and application of these methods in appropriate ways can ensure that the enhanced pressures associated with increased production will not result in any lessening of safety and quality standards.
Collapse
Affiliation(s)
- Aoife J McHugh
- Food Bioscience Department, Teagasc Food Research CentreCork, Ireland; School of Microbiology, University College CorkCork, Ireland
| | - Conor Feehily
- Food Bioscience Department, Teagasc Food Research CentreCork, Ireland; APC Microbiome InstituteCork, Ireland
| | - Colin Hill
- School of Microbiology, University College CorkCork, Ireland; APC Microbiome InstituteCork, Ireland
| | - Paul D Cotter
- Food Bioscience Department, Teagasc Food Research CentreCork, Ireland; APC Microbiome InstituteCork, Ireland
| |
Collapse
|
41
|
Didier A, Dietrich R, Märtlbauer E. Antibody Binding Studies Reveal Conformational Flexibility of the Bacillus cereus Non-Hemolytic Enterotoxin (Nhe) A-Component. PLoS One 2016; 11:e0165135. [PMID: 27768742 PMCID: PMC5074587 DOI: 10.1371/journal.pone.0165135] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/06/2016] [Indexed: 11/18/2022] Open
Abstract
The non-hemolytic enterotoxin complex (Nhe) is supposed to be the main virulence factor of B. cereus causing a diarrheal outcome of food poisoning. This tripartite toxin consists of the single components NheA, -B and -C all of them being necessary for maximum toxicity. In the past, research activities aiming to elucidate the mode-of-action of Nhe were mostly focused on the B- and C-component. In this study the generation of novel monoclonal antibodies (mAb) and their thorough characterization enabled the determination of key features for NheA. By the means of immunoaffinity chromatography it could be shown that NheA does not interact with -B and -C in solution. Additionally, the establishment of a highly sensitive sandwich-EIA now enables the detection of NheA in B. cereus supernatants down to 20 pg ml-1.Peptide-based epitope mapping in combination with partially deleted recombinant NheA fragments allowed the allocation of the binding regions for the three mAbs under study. Furthermore, by different EIA set-ups the conformational flexibility of NheA could be shown. For two of the antibodies under study different mechanisms of NheA neutralization were proven. Due to prevention of complete pore formation by one of the antibodies, NheA could be detected in an intermediate stage of the tripartite complex on the cell surface. Taken together, the results obtained in the present study allow a refinement of the mode-of-action for the Nhe toxin-complex.
Collapse
Affiliation(s)
- A. Didier
- Department of Veterinary Science, Ludwig-Maximilians Universität München, Oberschleißheim, Germany
- * E-mail:
| | - R. Dietrich
- Department of Veterinary Science, Ludwig-Maximilians Universität München, Oberschleißheim, Germany
| | - E. Märtlbauer
- Department of Veterinary Science, Ludwig-Maximilians Universität München, Oberschleißheim, Germany
| |
Collapse
|
42
|
Cui Y, Liu Y, Liu X, Xia X, Ding S, Zhu K. Evaluation of the Toxicity and Toxicokinetics of Cereulide from an Emetic Bacillus cereus Strain of Milk Origin. Toxins (Basel) 2016; 8:toxins8060156. [PMID: 27275834 PMCID: PMC4926125 DOI: 10.3390/toxins8060156] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 05/06/2016] [Accepted: 05/11/2016] [Indexed: 02/07/2023] Open
Abstract
Bacillus cereus is an opportunistic foodborne agent causing food poisoning and many infectious diseases. The heat-stable emetic toxin cereulide is one of the most prevalent toxins produced by pathogenic B. cereus, resulting in symptoms such as emesis and liver failure. In the present work, the toxicity and toxicokinetics of cereulide from an emetic B. cereus isolate (CAU45) of raw milk were evaluated. The production of cereulide was tested by a cytotoxicity test and enzyme immunoassay, and confirmed by the presence of the ces (cereulide synthetase) gene and the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. All results showed that the amount and toxicity of cereulide produced by CAU45 was 7 to 15.3 folds higher than the reference emetic B. cereus DSMZ 4312. Cereulide in plasma was collected at different time points after a single intravenous injection to evaluate its toxicokinetics in rabbits. The maximum concentration of cereulide was achieved in 2.6 ± 3.4 h after administration, with the elimination half-life of 10.8 ± 9.1 h, which expands our understanding of the toxic effects of cereulide. Together, it suggests that urgent sanitary practices are needed to eliminate emetic toxins and emetic B. cereus in raw milk.
Collapse
Affiliation(s)
- Yifang Cui
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Yuan Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Xiaoye Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Xi Xia
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Shuangyang Ding
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Kui Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
| |
Collapse
|
43
|
Zhu K, Hölzel CS, Cui Y, Mayer R, Wang Y, Dietrich R, Didier A, Bassitta R, Märtlbauer E, Ding S. Probiotic Bacillus cereus Strains, a Potential Risk for Public Health in China. Front Microbiol 2016; 7:718. [PMID: 27242738 PMCID: PMC4876114 DOI: 10.3389/fmicb.2016.00718] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 04/29/2016] [Indexed: 12/14/2022] Open
Abstract
Bacillus cereus is an important cause of foodborne infectious disease and food poisoning. However, B. cereus has also been used as a probiotic in human medicine and livestock production, with low standards of safety assessment. In this study, we evaluated the safety of 15 commercial probiotic B. cereus preparations from China in terms of mislabeling, toxin production, and transferable antimicrobial resistance. Most preparations were incorrectly labeled, as they contained additional bacterial species; one product did not contain viable B. cereus at all. In total, 18 B. cereus group strains-specifically B. cereus and Bacillus thuringiensis-were isolated. Enterotoxin genes nhe, hbl, and cytK1, as well as the ces-gene were assessed by PCR. Enterotoxin production and cytotoxicity were confirmed by ELISA and cell culture assays, respectively. All isolated B. cereus group strains produced the enterotoxin Nhe; 15 strains additionally produced Hbl. Antimicrobial resistance was assessed by microdilution; resistance genes were detected by PCR and further characterized by sequencing, transformation and conjugation assays. Nearly half of the strains harbored the antimicrobial resistance gene tet(45). In one strain, tet(45) was situated on a mobile genetic element-encoding a site-specific recombination mechanism-and was transferable to Staphylococcus aureus and Bacillus subtilis by electro-transformation. In view of the wide and uncontrolled use of these products, stricter regulations for safety assessment, including determination of virulence factors and transferable antimicrobial resistance genes, are urgently needed.
Collapse
Affiliation(s)
- Kui Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural UniversityBeijing, China; Department of Veterinary Sciences, Ludwig Maximilian University of MunichOberschleißheim, Germany
| | - Christina S Hölzel
- Department of Veterinary Sciences, Ludwig Maximilian University of Munich Oberschleißheim, Germany
| | - Yifang Cui
- National Center for Veterinary Drug Safety Evaluation, China Agricultural University Beijing, China
| | - Ricarda Mayer
- Department of Veterinary Sciences, Ludwig Maximilian University of Munich Oberschleißheim, Germany
| | - Yang Wang
- National Center for Veterinary Drug Safety Evaluation, China Agricultural University Beijing, China
| | - Richard Dietrich
- Department of Veterinary Sciences, Ludwig Maximilian University of Munich Oberschleißheim, Germany
| | - Andrea Didier
- Department of Veterinary Sciences, Ludwig Maximilian University of Munich Oberschleißheim, Germany
| | - Rupert Bassitta
- Department of Veterinary Sciences, Ludwig Maximilian University of Munich Oberschleißheim, Germany
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Ludwig Maximilian University of Munich Oberschleißheim, Germany
| | - Shuangyang Ding
- National Center for Veterinary Drug Safety Evaluation, China Agricultural University Beijing, China
| |
Collapse
|
44
|
Sánchez J, Correa M, Castañeda-Sandoval LM. Bacillus cereus un patógeno importante en el control microbiológico de los alimentos. REVISTA FACULTAD NACIONAL DE SALUD PÚBLICA 2016. [DOI: 10.17533/udea.rfnsp.v34n2a12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
45
|
Cui Y, Liu X, Dietrich R, Märtlbauer E, Cao J, Ding S, Zhu K. Characterization ofBacillus cereusisolates from local dairy farms in China. FEMS Microbiol Lett 2016; 363:fnw096. [DOI: 10.1093/femsle/fnw096] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2016] [Indexed: 12/11/2022] Open
|
46
|
Formation of small transmembrane pores: An intermediate stage on the way to Bacillus cereus non-hemolytic enterotoxin (Nhe) full pores in the absence of NheA. Biochem Biophys Res Commun 2015; 469:613-8. [PMID: 26654951 DOI: 10.1016/j.bbrc.2015.11.126] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 11/27/2015] [Indexed: 02/03/2023]
Abstract
The non-hemolytic enterotoxin (Nhe) of Bacillus cereus is a three-partite toxin formed of the components NheA, -B and -C. Pore formation and subsequent lysis of target cells caused by Nhe is an orchestrated process comprising three steps: (i) formation of NheB/C oligomers in solution, (ii) attachment of the oligomers to the cell membrane, (iii) binding of NheA to the oligomers. The present study aimed to characterize the properties of the NheB/C complex and the fate of the target cell upon binding. An enzyme immunoassay allowing kinetic measurements and surface plasmon resonance revealed the fast and high affinity formation of the NheB/C oligomers. The benefit of these complexes is a more stable cell binding as well as stronger and earlier cytotoxic effect. High molecular mass hetero-oligomers (620 kDa) probably consisting of one NheC and up to 15 NheB were detected by size-exclusion chromatography and on native PAGE immunoblots. Due to the NheBC application the morphology and membrane permeability of Vero cells is partly disturbed. Formation of stable transmembrane channels with a conductance of about 870 pS and a diameter of about 2 nm due to the application of NheBC could be demonstrated in lipid bilayer experiments. Thus, the NheBC complex itself has a tendency to increase the membrane permeability prior to the emergence of full pores containing also NheA.
Collapse
|
47
|
Didier A, Jeßberger N, Krey V, Dietrich R, Scherer S, Märtlbauer E. The mutation Glu151Asp in the B-component of the Bacillus cereus non-hemolytic enterotoxin (Nhe) leads to a diverging reactivity in antibody-based detection systems. Toxins (Basel) 2015; 7:4655-67. [PMID: 26569304 PMCID: PMC4663526 DOI: 10.3390/toxins7114655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 10/29/2015] [Accepted: 11/02/2015] [Indexed: 11/17/2022] Open
Abstract
The ability of Bacillus cereus to cause foodborne toxicoinfections leads to increasing concerns regarding consumer protection. For the diarrhea-associated enterotoxins, the assessment of the non-hemolytic enterotoxin B (NheB) titer determined by a sandwich enzyme immunoassay (EIA) correlates best with in vitro cytotoxicity. In general, the regulation of enterotoxin expression of B. cereus is a coordinately-regulated process influenced by environmental, and probably also by host factors. As long as these factors are not completely understood, the currently-applied diagnostic procedures are based on indirect approaches to assess the potential virulence of an isolate. To date, sandwich EIA results serve as a surrogate marker to categorize isolates as either potentially low or highly toxic. Here, we report on a single amino acid exchange in the NheB sequence leading to an underestimation of the cytotoxic potential in a limited number of strains. During the screening of a large panel of B. cereus isolates, six showed uncommon features with low sandwich EIA titers despite high cytotoxicity. Sequence analysis revealed the point-mutation (Glu)151(Asp) in the potential binding region of the capture antibody. Application of this antibody also results in low titers in an indirect EIA format and shows variable detection intensities in Western-immunoblots. A commercially-available assay based on a lateral flow device detects all strains correctly as NheB producers in a qualitative manner. In conclusion, isolates showing low NheB titers should additionally be assayed in an indirect EIA or for their in vitro cytotoxicity to ensure a correct classification as either low or highly toxic.
Collapse
Affiliation(s)
- Andrea Didier
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig-Maximilians Universität München, 85763 Oberschleißheim, Germany.
| | - Nadja Jeßberger
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig-Maximilians Universität München, 85763 Oberschleißheim, Germany.
| | - Victoria Krey
- Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs-und Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität München, 85354 Freising, Germany.
| | - Richard Dietrich
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig-Maximilians Universität München, 85763 Oberschleißheim, Germany.
| | - Siegfried Scherer
- Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs-und Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität München, 85354 Freising, Germany.
| | - Erwin Märtlbauer
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig-Maximilians Universität München, 85763 Oberschleißheim, Germany.
| |
Collapse
|
48
|
Jeßberger N, Krey VM, Rademacher C, Böhm ME, Mohr AK, Ehling-Schulz M, Scherer S, Märtlbauer E. From genome to toxicity: a combinatory approach highlights the complexity of enterotoxin production in Bacillus cereus. Front Microbiol 2015; 6:560. [PMID: 26113843 PMCID: PMC4462024 DOI: 10.3389/fmicb.2015.00560] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 05/21/2015] [Indexed: 01/30/2023] Open
Abstract
In recent years Bacillus cereus has gained increasing importance as a food poisoning pathogen. It is the eponymous member of the B. cereus sensu lato group that consists of eight closely related species showing impressive diversity of their pathogenicity. The high variability of cytotoxicity and the complex regulatory network of enterotoxin expression have complicated efforts to predict the toxic potential of new B. cereus isolates. In this study, comprehensive analyses of enterotoxin gene sequences, transcription, toxin secretion and cytotoxicity were performed. For the first time, these parameters were compared in a whole set of B. cereus strains representing isolates of different origin (food or food poisoning outbreaks) and of different toxic potential (enteropathogenic and apathogenic) to elucidate potential starting points of strain-specific differential toxicity. While toxin gene sequences were highly conserved and did not allow for differentiation between high and low toxicity strains, comparison of nheB and hblD enterotoxin gene transcription and Nhe and Hbl protein titers revealed not only strain-specific differences but also incongruence between toxin gene transcripts and toxin protein levels. With one exception all strains showed comparable capability of protein secretion and so far, no secretion patterns specific for high and low toxicity strains were identified. These results indicate that enterotoxin expression is more complex than expected, possibly involving the orchestrated interplay of different transcriptional regulator proteins, as well as posttranscriptional and posttranslational regulatory mechanisms plus additional influences of environmental conditions.
Collapse
Affiliation(s)
- Nadja Jeßberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München Oberschleißheim, Germany
| | - Viktoria M Krey
- Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität München Freising, Germany
| | - Corinna Rademacher
- Functional Microbiology, Department of Pathobiology, Institute of Microbiology, University of Veterinary Medicine Vienna Vienna, Austria
| | - Maria-Elisabeth Böhm
- Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität München Freising, Germany
| | - Ann-Katrin Mohr
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München Oberschleißheim, Germany
| | - Monika Ehling-Schulz
- Functional Microbiology, Department of Pathobiology, Institute of Microbiology, University of Veterinary Medicine Vienna Vienna, Austria
| | - Siegfried Scherer
- Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität München Freising, Germany
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München Oberschleißheim, Germany
| |
Collapse
|
49
|
Rasooly R, Hernlem B, He X, Friedman M. Plant compounds enhance the assay sensitivity for detection of active Bacillus cereus toxin. Toxins (Basel) 2015; 7:835-45. [PMID: 25767986 PMCID: PMC4379528 DOI: 10.3390/toxins7030835] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 03/06/2015] [Indexed: 12/28/2022] Open
Abstract
Bacillus cereus is an important food pathogen, producing emetic and diarrheal syndromes, the latter mediated by enterotoxins. The ability to sensitively trace and identify this active toxin is important for food safety. This study evaluated a nonradioactive, sensitive, in vitro cell-based assay, based on B. cereus toxin inhibition of green fluorescent protein (GFP) synthesis in transduced monkey kidney Vero cells, combined with plant extracts or plant compounds that reduce viable count of B. cereus in food. The assay exhibited a dose dependent GFP inhibition response with ~25% inhibition at 50 ng/mL toxin evaluated in culture media or soy milk, rice milk or infant formula, products associated with food poisonings outbreak. The plant extracts of green tea or bitter almond and the plant compounds epicatechin or carvacrol were found to amplify the assay response to ~90% inhibition at the 50 ng/mL toxin concentration greatly increasing the sensitivity of this assay. Additional studies showed that the test formulations also inhibited the growth of the B. cereus bacteria, likely through cell membrane disruption. The results suggest that the improved highly sensitive assay for the toxin and the rapid inactivation of the pathogen producing the toxin have the potential to enhance food safety.
Collapse
Affiliation(s)
- Reuven Rasooly
- Foodborne Contaminants Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
| | - Bradley Hernlem
- Foodborne Contaminants Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
| | - Xiaohua He
- Foodborne Contaminants Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
| | - Mendel Friedman
- Healthy Processed Foods Research Unit, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
| |
Collapse
|
50
|
Singh AK, Sun X, Bai X, Kim H, Abdalhaseib MU, Bae E, Bhunia AK. Label-free, non-invasive light scattering sensor for rapid screening of Bacillus colonies. J Microbiol Methods 2015; 109:56-66. [DOI: 10.1016/j.mimet.2014.12.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/17/2014] [Accepted: 12/18/2014] [Indexed: 11/26/2022]
|