Redox proteomic study of Bacillus cereus thiol proteome during fermentative anaerobic growth

Abstract Background Bacillus cereus is a notorious foodborne pathogen, which can grow under anoxic conditions. Anoxic growth is supported by endogenous redox metabolism, for which the thiol redox proteome serves as an interface. Here, we studied the cysteine (Cys) proteome dynamics of B. cereus ATCC 14579 cells grown under fermentative anoxic conditions. We used a quantitative thiol trapping method combined with proteomics profiling. Results In total, we identified 153 reactive Cys residues in 117 proteins participating in various cellular processes and metabolic pathways, including translation, carbohydrate metabolism, and stress response. Of these reactive Cys, 72 were detected as reduced Cys. The B. cereus Cys proteome evolved during growth both in terms of the number of reduced Cys and the Cys-containing proteins identified, reflecting its growth-phase-dependence. Interestingly, the reduced status of the B. cereus thiol proteome increased during growth, concomitantly to the decrease of extracellular oxidoreduction potential. Conclusions Taken together, our data show that the B. cereus Cys proteome during unstressed fermentative anaerobic growth is a dynamic entity and provide an important foundation for future redox proteomic studies in B. cereus and other organisms.

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Outbreaks, Germination, and Inactivation of Bacillus cereus in Food Products: A Review

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-429 ◽

2020 ◽

Vol 83 (9) ◽

pp. 1480-1487

Author(s):

WON CHOI ◽

SANG-SOON KIM

Keyword(s):

Food Safety ◽

Bacillus Cereus ◽

Food Processing ◽

Rapid Detection ◽

Foodborne Pathogen ◽

Present Review ◽

Detection Methods ◽

Processing Technologies ◽

Foodborne Outbreaks ◽

Food Commodity

ABSTRACT Bacillus cereus has been reported as a foodborne pathogen worldwide. Although food processing technologies to inactivate the pathogen have been developed for decades, foodborne outbreaks related to B. cereus have occurred. In the present review, foodborne outbreaks, germination, inactivation, and detection of B. cereus are discussed, along with inactivation mechanisms. B. cereus outbreaks from 2003 to 2016 are reported based on food commodity, number of cases, and consequent illnesses. Germination before sporicidal treatments is highlighted as an effective way to inactivate B. cereus, because the resistance of the pathogen increases significantly following sporulation. Several germinants used for B. cereus are listed, and their efficacies are compared. Finally, recently used interventions with sporicidal mechanisms are identified, and rapid detection methods that have been developed are discussed. Combining two or more interventions, known as the hurdle technology concept, is suggested to maximize the sporicidal effect. Further study is needed to ensure food safety and to understand germination mechanisms and sporicidal resistance of B. cereus. HIGHLIGHTS

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Characterization of Bacillus cereus in Dairy Products in China

Toxins ◽

10.3390/toxins12070454 ◽

2020 ◽

Vol 12 (7) ◽

pp. 454 ◽

Cited By ~ 1

Author(s):

Xiao-Ye Liu ◽

Qiao Hu ◽

Fei Xu ◽

Shuang-Yang Ding ◽

Kui Zhu

Keyword(s):

Bacillus Cereus ◽

Virulence Factors ◽

Prevalence Rate ◽

Dairy Products ◽

Foodborne Pathogen ◽

Food Poisoning ◽

Intervention Strategies ◽

Epidemiological Characteristics ◽

Shed Light

Bacillus cereus is a common and ubiquitous foodborne pathogen with an increasing prevalence rate in dairy products in China. High and unmet demands for such products, particularly milk, raise the risk of B. cereus associated contamination. The presence of B. cereus and its virulence factors in dairy products may cause food poisoning and other illnesses. Thus, this review first summarizes the epidemiological characteristics and analytical assays of B. cereus from dairy products in China, providing insights into the implementation of intervention strategies. In addition, the recent achievements on the cytotoxicity and mechanisms of B. cereus are also presented to shed light on the therapeutic options for B. cereus associated infections.

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Cereulide synthetase acquisition and loss events within the evolutionary history of Group III Bacillus cereus sensu lato facilitate the transition between emetic and diarrheal foodborne pathogen

10.1101/2020.05.12.090951 ◽

2020 ◽

Cited By ~ 1

Author(s):

Laura M. Carroll ◽

Martin Wiedmann

Keyword(s):

Bacillus Cereus ◽

Evolutionary History ◽

Common Ancestor ◽

Reference Genome ◽

Foodborne Pathogen ◽

Genomic Diversity ◽

Whole Genome ◽

Group Iii ◽

History Of ◽

Bacillus Cereus Sensu Lato

AbstractCereulide-producing members of Bacillus cereus sensu lato (B. cereus s.l.) Group III, also known as “emetic B. cereus”, possess cereulide synthetase, a plasmid-encoded, non-ribosomal peptide synthetase encoded by the ces gene cluster. Despite the documented risks that cereulide-producing strains pose to public health, the level of genomic diversity encompassed by “emetic B. cereus” has never been evaluated at a whole-genome scale. Here, we employ a phylogenomic approach to characterize Group III B. cereus s.l. genomes which possess ces (ces-positive) alongside their closely related ces-negative counterparts to (i) assess the genomic diversity encompassed by “emetic B. cereus”, and (ii) identify potential ces loss and/or gain events within the evolutionary history of the high-risk and medically relevant sequence type (ST) 26 lineage often associated with emetic foodborne illness. Using all publicly available ces-positive Group III B. cereus s.l. genomes and the ces-negative genomes interspersed among them (n = 150), we show that “emetic B. cereus” is not clonal; rather, multiple lineages within Group III harbor cereulide-producing strains, all of which share a common ancestor incapable of producing cereulide (posterior probability [PP] 0.86-0.89). The ST 26 common ancestor was predicted to have emerged as ces-negative (PP 0.60-0.93) circa 1904 (95% highest posterior density [HPD] interval 1837.1-1957.8) and first acquired the ability to produce cereulide before 1931 (95% HPD 1893.2-1959.0). Three subsequent ces loss events within ST 26 were observed, including among isolates responsible for B. cereus s.l. toxicoinfection (i.e., “diarrheal” illness).Importance“B. cereus” is responsible for thousands of cases of foodborne disease each year worldwide, causing two distinct forms of illness: (i) intoxication via cereulide (i.e., “emetic” syndrome) or (ii) toxicoinfection via multiple enterotoxins (i.e., “diarrheal” syndrome). Here, we show that “emetic B. cereus” is not a clonal, homogenous unit that resulted from a single cereulide synthetase gain event followed by subsequent proliferation; rather, cereulide synthetase acquisition and loss is a dynamic, ongoing process that occurs across lineages, allowing some Group III B. cereus s.l. populations to oscillate between diarrheal and emetic foodborne pathogen over the course of their evolutionary histories. We also highlight the care that must be taken when selecting a reference genome for whole-genome sequencing-based investigation of emetic B. cereus s.l. outbreaks, as some reference genome selections can lead to a confounding loss of resolution and potentially hinder epidemiological investigations.

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Prevalence of Bacillus cereus s.l. in ultra-high temperature chocolate milk from selected milk manufacturers in Malaysia

Food Research ◽

10.26656/fr.2017.4(4).417 ◽

2020 ◽

Vol 4 (4) ◽

pp. 982-990

Author(s):

Ubong Anyi ◽

C.Y. New ◽

L.C. Chai ◽

Y.Y. Loo ◽

Nor Khaizura M.A.R. ◽

...

Keyword(s):

Bacillus Cereus ◽

Foodborne Pathogen ◽

Most Probable Number ◽

Contamination Level ◽

Chocolate Milk ◽

Probable Number ◽

Potential Source ◽

Milk Contamination ◽

Bacillus Spp ◽

Polymerase Chain

Bacillus cereus is a major foodborne pathogen of great concern to the dairy industry owing to its resilient spores as well as the adverse effect of its toxins. At present, there is no informational study available to solve or pinpoint the UHT chocolate milk contamination issue in Malaysia. This work aimed to investigate the prevalence and contamination level of B. cereus s.l. in UHT chocolate milk and to suggest the appropriate solution for the issue. In the present study, B. cereus s.l. prevalence and contamination level in individually packed UHT chocolate milk from processing factories was evaluated. The prevalence and concentration of B. cereus s.l. were determined via MPN-PCR (Most Probable Number-Polymerase Chain Reaction) assay. Results showed that 31.11% from 220 of UHT chocolate milk tested contained Bacillus spp.; of this Bacillus spp. positive samples, 24.30% were also positive for B. cereus s.l. with concentration ranging from less than 3 to more than 1100 MPN/mL. Findings from this study highlighted the possibility of UHT chocolate milk as a potential source of B. cereus s.l. infection. Therefore, findings emphasized the needs to revise, monitor and improve UHT sterilization process to reduce infection risk. Furthermore, it is also essential to maintain the hygiene to minimize initial microbial load and contamination of UHT chocolate milk, beginning from production to retail.

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

Environment & Ecosystem science ◽

10.26480/ees.02.2020.68.72 ◽

2020 ◽

Vol 4 (2) ◽

pp. 68-72

Author(s):

Marwan Msarah ◽

Ahmed Alsier ◽

Sahilah, A.M.

Keyword(s):

Bacillus Cereus ◽

Foodborne Pathogen ◽

Food Poisoning ◽

Egg Yolk ◽

Food Samples ◽

Blood Agar ◽

Toxin Gene ◽

Biochemical Tests ◽

Isolation Medium ◽

Hemolysin Bl

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

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Characterization of aerobic and anaerobic vegetative growth of the food-borne pathogen Bacillus cereus F4430/73 strain

Canadian Journal of Microbiology ◽

10.1139/w04-132 ◽

2005 ◽

Vol 51 (2) ◽

pp. 149-158 ◽

Cited By ~ 51

Author(s):

Eric Rosenfeld ◽

Catherine Duport ◽

Assia Zigha ◽

Philippe Schmitt

Keyword(s):

Bacillus Cereus ◽

Vegetative Growth ◽

Carbon Sources ◽

Complex Iii ◽

Anaerobic Growth ◽

Defined Media ◽

Food Borne ◽

High Amino Acid ◽

Bacterium Bacillus ◽

By Products

The Gram-positive bacterium Bacillus cereus is a facultative anaerobe that is still poorly characterized metabolically. In this study, the aerobic vegetative growth and anaerobic vegetative growth of the food-borne pathogen B. cereus F4430/73 strain were compared with those of the genome-sequenced ATCC14579 strain using glucose and glycerol as fermentative and nonfermentative carbon sources, respectively. Uncontrolled batch cultures on several defined media showed that B. cereus strains had high amino acid or pyruvate requirements for anaerobic fermentative growth. In addition, growth performance was considerably improved by maintaining the pH of the culture medium near neutrality. Spectra of fermentation by-products were typically (per mole of glucose) 0.2–0.4 acetate, 1.1–1.4 L-lactate, 0.3–0.4 formate, and 0.05–0.2 ethanol with only traces of succinate, pyruvate, and 2,3-butanediol. These spectra were drastically changed in the presence of 20 mmol nitrate·L–1, which stimulated anaerobic growth. During anaerobic and aerobic respiration, the persistent production of acetate and other by-products indicated overflow metabolisms. This was especially true in glucose-grown cells for which respiratory complex III made only a minor contribution to growth. Surprisingly, oxygen uptake rates linked to the cytochrome c and quinol branches of the respiratory chain were maintained at high levels in anaerobic, respiring, or fermenting cells. Growth and metabolic features of B. cereus F4430/73 are discussed using biochemical and genomic data.Key words: Bacillus cereus, growth, defined media, fermentation, respiration.

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Proposal of a Taxonomic Nomenclature for the Bacillus cereus Group Which Reconciles Genomic Definitions of Bacterial Species with Clinical and Industrial Phenotypes

mBio ◽

10.1128/mbio.00034-20 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 17

Author(s):

Laura M. Carroll ◽

Martin Wiedmann ◽

Jasna Kovac

Keyword(s):

Bacillus Cereus ◽

Bacterial Species ◽

Foodborne Pathogen ◽

Bacterial Taxonomy ◽

Closely Related Species ◽

Important Species ◽

Content Type ◽

Bioterrorism Agent ◽

Current Species ◽

Species Definitions

ABSTRACT The Bacillus cereus group comprises numerous closely related species, including bioterrorism agent B. anthracis, foodborne pathogen B. cereus, and biopesticide B. thuringiensis. Differentiating organisms capable of causing illness or death from those used in industry is essential for risk assessment and outbreak preparedness. However, current species definitions facilitate species-phenotype incongruences, particularly when horizontally acquired genes are responsible for a phenotype. Using all publicly available B. cereus group genomes (n = 2,231), we show that current species definitions lead to overlapping genomospecies clusters, in which 66.2% of genomes belong to multiple genomospecies at a conventional 95 average nucleotide identity (ANI) genomospecies threshold. A genomospecies threshold of ≈92.5 ANI is shown to reflect a natural gap in genome similarity for the B. cereus group, and medoid genomes identified at this threshold are shown to yield resolvable genomospecies clusters with minimal overlap (six of 2,231 genomes assigned to multiple genomospecies; 0.269%). We thus propose a nomenclatural framework for the B. cereus group which accounts for (i) genomospecies using resolvable genomospecies clusters obtained at ≈92.5 ANI, (ii) established lineages of medical importance using a formal collection of subspecies names, and (iii) heterogeneity of clinically and industrially important phenotypes using a formalized and extended collection of biovar terms. We anticipate that the proposed nomenclature will remain interpretable to clinicians, without sacrificing genomic species definitions, which can in turn aid in pathogen surveillance; early detection of emerging, high-risk genotypes; and outbreak preparedness. IMPORTANCE Historical species definitions for many prokaryotes, including pathogens, have relied on phenotypic characteristics that are inconsistent with genome evolution. This scenario forces microbiologists and clinicians to face a tradeoff between taxonomic rigor and clinical interpretability. Using the Bacillus cereus group as a model, a conceptual framework for the taxonomic delineation of prokaryotes which reconciles genomic definitions of species with clinically and industrially relevant phenotypes is presented. The nomenclatural framework outlined here serves as a model for genomics-based bacterial taxonomy that moves beyond arbitrarily set genomospecies thresholds while maintaining congruence with phenotypes and historically important species names.

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Prevalence of ces and cytk Genes of Bacillus cereus Isolated From Raw Milk in Tabriz, Iran

International Journal of Enteric Pathogens ◽

10.34172/ijep.2020.17 ◽

2020 ◽

Vol 8 (3) ◽

pp. 76-79

Author(s):

Mahtab Hamidpour ◽

Saman Mahdavi

Keyword(s):

Bacillus Cereus ◽

Bacterial Contamination ◽

Dairy Product ◽

Foodborne Pathogen ◽

Food Poisoning ◽

Raw Milk ◽

Specific Primers ◽

Different Types ◽

Pcr Method ◽

Polymerase Chain

Background: Bacillus cereus is a gram-positive and spore-forming bacterium which is widespread in nature. It also has been known as a major foodborne pathogen that often plays a role in the contamination of ready-to-eat and dairy products. It causes two different types of food poisoning in human: the diarrheal type and the emetic type. Objective: The current study was planned to determine the prevalence of ces and cytk genes of Bacillus cereus isolated from raw milk in Tabriz, Iran. Materials and Methods: In this study, 40 B. cereus strains isolated from cow raw milk, that had already been identified phenotypically, were assessed for molecular confirmation by polymerase chain reaction (PCR) method. Then, they were evaluated for presence of ces and cytK genes by specific primers. Results: Of 40 B. cereus strains, 39 strains were confirmed molecularly. The frequency of cytK and ces genes was reported 38 (97.43%) and 0 (0%), respectively. Conclusion: The results of present study showed that B. cereus strains isolated from raw milk had high potential in causing diarrhea poisoning. Therefore, using procedures to reduce the bacterial contamination during the processing of dairy product is essential.

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Anaerobic Growth of Listeria monocytogenes on Rhamnose Is Stimulated by Vitamin B 12 and Bacterial Microcompartment-Dependent 1,2-Propanediol Utilization

mSphere ◽

10.1128/msphere.00434-21 ◽

2021 ◽

Author(s):

Zhe Zeng ◽

Siming Li ◽

Sjef Boeren ◽

Eddy J. Smid ◽

Richard A. Notebaart ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Molecular Mechanisms ◽

Foodborne Pathogen ◽

Anaerobic Growth ◽

Severe Illness ◽

Vitamin B ◽

Anaerobic Conditions ◽

Content Type ◽

Bacterial Microcompartment ◽

Vitamin B 12

Listeria monocytogenes is a foodborne pathogen causing severe illness and, as such, it is crucial to understand the molecular mechanisms contributing to its survival strategy and pathogenicity. Rhamnose is a deoxyhexose sugar abundant in a range of environments, including the human intestine, and can be degraded in anaerobic conditions into 1,2-propanediol.

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Effects of Nitrogen Dioxide and Anoxia on Global Gene and Protein Expression in Long-Term Continuous Cultures of Nitrosomonas eutropha C91

Applied and Environmental Microbiology ◽

10.1128/aem.00668-12 ◽

2012 ◽

Vol 78 (14) ◽

pp. 4788-4794 ◽

Cited By ~ 11

Author(s):

Boran Kartal ◽

Hans J. C. T. Wessels ◽

Erwin van der Biezen ◽

Kees-Jan Francoijs ◽

Mike S. M. Jetten ◽

...

Keyword(s):

Nitric Oxide ◽

Protein Expression ◽

Wastewater Treatment Plants ◽

Batch Cultivation ◽

Culture Conditions ◽

Anaerobic Growth ◽

Nitric Oxide Reductase ◽

Content Type ◽

Anoxic Conditions ◽

Gene And Protein Expression

ABSTRACTNitrosomonas eutrophais an ammonia-oxidizing betaproteobacterium found in environments with high ammonium levels, such as wastewater treatment plants. The effects of NO2on gene and protein expression under oxic and anoxic conditions were determined by maintainingN. eutrophastrain C91 in a chemostat fed with ammonium under oxic, oxic-plus-NO2, and anoxic-plus-NO2culture conditions. Cells remained viable but ceased growing under anoxia; hence, the chemostat was switched from continuous to batch cultivation to retain biomass. After several weeks under each condition, biomass was harvested for total mRNA and protein isolation. Exposure ofN. eutrophaC91 to NO2under either oxic or anoxic conditions led to a decrease in proteins involved in N and C assimilation and storage and an increase in proteins involved in energy conservation, including ammonia monooxygenase (AmoCAB). Exposure to anoxia plus NO2resulted in increased representation of proteins and transcripts reflective of an energy-deprived state. Several proteins implicated in N-oxide metabolism were expressed and remained unchanged throughout the experiment, except for NorCB nitric oxide reductase, which was not detected in the proteome. Rather, NorY nitric oxide reductase was expressed under oxic-plus-NO2and anoxic-plus-NO2conditions. The results indicate that exposure to NO2results in an energy-deprived state ofN. eutrophaC91 and that anaerobic growth could not be supported with NO2as an oxidant.

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