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Pediatrics in Review Apr 2013
Review
Topics: Bacillaceae Infections; Bacillus cereus; Humans
PubMed: 23547067
DOI: 10.1542/pir.34-4-196 -
FEMS Microbiology Reviews Jul 2008Bacillus cereus is widespread in nature and frequently isolated from soil and growing plants, but it is also well adapted for growth in the intestinal tract of insects... (Review)
Review
Bacillus cereus is widespread in nature and frequently isolated from soil and growing plants, but it is also well adapted for growth in the intestinal tract of insects and mammals. From these habitats it is easily spread to foods, where it may cause an emetic or a diarrhoeal type of food-associated illness that is becoming increasingly important in the industrialized world. The emetic disease is a food intoxication caused by cereulide, a small ring-formed dodecadepsipeptide. Similar to the virulence determinants that distinguish Bacillus thuringiensis and Bacillus anthracis from B. cereus, the genetic determinants of cereulide are plasmid-borne. The diarrhoeal syndrome of B. cereus is an infection caused by vegetative cells, ingested as viable cells or spores, thought to produce protein enterotoxins in the small intestine. Three pore-forming cytotoxins have been associated with diarrhoeal disease: haemolysin BL (Hbl), nonhaemolytic enterotoxin (Nhe) and cytotoxin K. Hbl and Nhe are homologous three-component toxins, which appear to be related to the monooligomeric toxin cytolysin A found in Escherichia coli. This review will focus on the toxins associated with foodborne diseases frequently caused by B. cereus. The disease characteristics are described, and recent findings regarding the associated toxins are discussed, as well as the present knowledge on virulence regulation.
Topics: Animals; Bacillus cereus; Diarrhea; Enterotoxins; Food Microbiology; Foodborne Diseases; Gastrointestinal Tract; Gene Expression Regulation, Bacterial; Humans; Pore Forming Cytotoxic Proteins; Soil Microbiology; Vomiting
PubMed: 18422617
DOI: 10.1111/j.1574-6976.2008.00112.x -
Biological & Pharmaceutical Bulletin 2020Bacillus cereus is well known as a causative agent of food poisoning but it also causes bacteremia and endophthalmitis in nosocomial infections. However, as an... (Review)
Review
Bacillus cereus is well known as a causative agent of food poisoning but it also causes bacteremia and endophthalmitis in nosocomial infections. However, as an environmental bacterium that lives in soil, it is often treated as simple contamination by hospitals. In recent years, highly pathogenic B. cereus strains that are similar to Bacillus anthracis have been detected in hospitals. The B. cereus sphingomyelinase contributes to its pathogenicity, as do sphingomyelinases produced by Staphylococcus aureus, Pseudomonas aeruginosa, Helicobacter pylori, and B. anthracis. Highly pathogenic B. cereus produces a large amount of sphingomyelinase. In this review, we describe the regulation of sphingomyelinase expression through the PlcR-PapR system, the pathogenicity of bacterial sphingomyelinases, and their potential as therapeutic drug targets.
Topics: Bacillus cereus; Humans; Sphingomyelin Phosphodiesterase
PubMed: 32009113
DOI: 10.1248/bpb.b19-00762 -
International Journal of Cosmetic... Apr 2015Bacillus cereus is ubiquitous in nature and thus occurs naturally in a wide range of raw materials and foodstuffs. B. cereus spores are resistant to desiccation and heat... (Review)
Review
Bacillus cereus is ubiquitous in nature and thus occurs naturally in a wide range of raw materials and foodstuffs. B. cereus spores are resistant to desiccation and heat and able to survive dry storage and cooking. Vegetative cells produce several toxins which on ingestion in sufficient numbers can cause vomiting and/or diarrhoea depending on the toxins produced. Gastrointestinal disease is commonly associated with reheated or inadequately cooked foods. In addition to being a rare cause of several acute infections (e.g. pneumonia and septicaemia), B. cereus can also cause localized infection of post-surgical or trauma wounds and is a rare but significant pathogen of the eye where it may result in severe endophthalmitis often leading to loss of vision. Key risk factors in such cases are trauma to the eye and retained contaminated intraocular foreign bodies. In addition, rare cases of B. cereus-associated keratitis (inflammation of the cornea) have been linked to contact lens use. Bacillus cereus is therefore a microbial contaminant that could adversely affect product safety of cosmetic and facial toiletries and pose a threat to the user if other key risk factors are also present. The infective dose in the human eye is unknown, but as few as 100 cfu has been reported to initiate infection in a susceptible animal model. However, we are not aware of any reports in the literature of B. cereus infections in any body site linked with use of personal care products. Low levels of B. cereus spores may on occasion be present in near-eye cosmetics, and these products have been used by consumers for many years. In addition, exposure to B. cereus is more likely to occur through other routes (e.g. dustborne contamination) due to its ubiquity and resistance properties of spores. The organism has been recovered from the eyes of healthy individuals. Therefore, although there may be a perceived hazard, the risk of severe eye infections as a consequence of exposure through contaminated near-eye cosmetics is judged to be vanishingly small. It is unlikely that more stringent microbiological standards for near-eye cosmetics will have any impact on the risk of severe eye infections caused by B. cereus, as these are not linked to use of personal care products.
Topics: Bacillus cereus; Cosmetics; Environmental Exposure; Gram-Positive Bacterial Infections; Humans
PubMed: 25482451
DOI: 10.1111/ics.12191 -
Journal of Food Protection Mar 2005The genus Bacillus includes members that demonstrate a wide range of diversity from physiology and ecological niche to DNA sequence and gene regulation. The species of... (Review)
Review
The genus Bacillus includes members that demonstrate a wide range of diversity from physiology and ecological niche to DNA sequence and gene regulation. The species of most interest tend to be known for their pathogenicity and are closely linked genetically. Bacillus anthracis causes anthrax, and Bacillus thuringiensis is widely used for its insecticidal properties but has also been associated with foodborne disease. Bacillus cereus causes two types of food poisoning, the emetic and diarrheal syndromes, and a variety of local and systemic infections. Although in this review we provide information on the genus and a variety of species, the primary focus is on the B. cereus strains and toxins that are involved in foodborne illness. B. cereus produces a large number of potential virulence factors, but for the majority of these factors their roles in specific infections have not been established. To date, only cereulide and the tripartite hemolysin BL have been identified specifically as emetic and diarrheal toxins, respectively. Nonhemolytic enterotoxin, a homolog of hemolysin BL, also has been associated with the diarrheal syndrome. Recent findings regarding these and other putative enterotoxins are discussed.
Topics: Bacillus cereus; Bacterial Typing Techniques; Enterotoxins; Foodborne Diseases; Humans; Phylogeny; Species Specificity
PubMed: 15771198
DOI: 10.4315/0362-028x-68.3.636 -
International Journal of Food... Sep 1994Dried milk products and infant food are known to be frequently contaminated with Bacillus cereus. Sources of the organism and its behaviour in the product and in the... (Review)
Review
Dried milk products and infant food are known to be frequently contaminated with Bacillus cereus. Sources of the organism and its behaviour in the product and in the equipment during processing are discussed. With regard to the incidence of B. cereus in infant food, 261 samples distributed in 17 countries were collected and examined for its B. cereus content. Fifty-four percent of the samples were contaminated with B. cereus reaching levels from 0.3 to 600/g. Counts higher than 10/g were found in only 27 samples (10%). Most of the positive samples (44%) contained 0.3 to 10 B. cereus/g. Four samples (1.5%) were contaminated with more than 100 organisms/g reaching a maximum level of 600 B. cereus/g. When classified into different types of products about 50% of the infant formulae based on milk, the follow-on formulae and the weaning foods were contaminated with B. cereus as well as 69% of those based on soy protein and 92% of the special dietetic foods. Compared to our earlier studies from 1982/83, the percentage of contaminated samples from Germany increased from 31% to 70% in the case of infant formulae, from 28% to 55% in the case of follow-on formulae, and from 40% to 100% in the case of special dietetic food. The percentage of weaning food contaminated with B. cereus remained nearly unchanged. It should be stressed, however, that the numbers of B. cereus were almost the same in both studies with the highest count in 1982/83 being 460 and in 1992 600/g. Samples naturally contaminated with counts of about 100 B. cereus/g were reconstituted and incubated at a room temperature of 27 degrees C. Levels of 10(5) B. cereus/g were reached after 7-9 h. Toxigenicity of B. cereus in dried milk products and infant food as well as food poisoning outbreaks attributed to B. cereus are discussed.
Topics: Animals; Bacillus cereus; Disease Outbreaks; Enterotoxins; Equipment Contamination; Foodborne Diseases; Humans; Incidence; Infant Food; Infant, Newborn; Milk
PubMed: 7811567
DOI: 10.1016/0168-1605(94)90218-6 -
Environmental Microbiology Aug 2003Bacillus cereus sensu lato, the species group comprising Bacillus anthracis, Bacillus thuringiensis and B. cereus (sensu stricto), has previously been scrutinized... (Review)
Review
Bacillus cereus sensu lato, the species group comprising Bacillus anthracis, Bacillus thuringiensis and B. cereus (sensu stricto), has previously been scrutinized regarding interspecies genetic correlation and pathogenic characteristics. So far, little attention has been paid to analysing the biological and ecological properties of the three species in their natural environments. In this review, we describe the B. cereus sensu lato living in a world on its own; all B. cereus sensu lato can grow saprophytically under nutrient-rich conditions, which are only occasionally found in the environment, except where nutrients are actively collected. As such, members of the B. cereus group have recently been discovered as common inhabitants of the invertebrate gut. We speculate that all members disclose symbiotic relationships with appropriate invertebrate hosts and only occasionally enter a pathogenic life cycle in which the individual species infects suitable hosts and multiplies almost unrestrained.
Topics: Animals; Bacillus anthracis; Bacillus cereus; Bacillus thuringiensis; Digestive System; Ecosystem; Gene Transfer, Horizontal; Humans; Invertebrates; Spores, Bacterial; Symbiosis
PubMed: 12871230
DOI: 10.1046/j.1462-2920.2003.00461.x -
MSphere Nov 2020Gram-positive, spore-forming members of the group species complex are widespread in natural environments and display various degrees of pathogenicity. Recently, group...
Gram-positive, spore-forming members of the group species complex are widespread in natural environments and display various degrees of pathogenicity. Recently, group strain Flugge ATCC 21929 was found to represent a novel lineage within the species complex, sharing a relatively low degree of genomic similarity with all group genomes (average nucleotide identity [ANI] < 88). ATCC 21929 has been previously associated with the production of a patented antibiotic, antibiotic 60-6 (i.e., cerexin A); however, the virulence potential and growth characteristics of this lineage have never been assessed. Here, we provide an extensive genomic and phenotypic characterization of ATCC 21929, and we assess its pathogenic potential ATCC 21929 most closely resembles NH24A2 (ANI and DNA-DNA hybridization values of 86.70 and 34.10%, respectively). Phenotypically, ATCC 21929 does not possess cytochrome oxidase activity and is able to grow at a range of temperatures between 15 and 43°C and a range of pH between 6 and 9. At 32°C, ATCC 21929 shows weak production of diarrheal enterotoxin hemolysin BL (Hbl) but no production of nonhemolytic enterotoxin (Nhe); at 37°C, neither Hbl nor Nhe is produced. Additionally, at 37°C, ATCC 21929 does not exhibit cytotoxic effects toward HeLa cells. With regard to fatty acid composition, ATCC 21929 has iso-C17:0 present in highest abundance. Based on the characterization provided here, ATCC 21929 (= PS00077A = PS00077B = PSU-0922 = BHP) represents a novel effective group species, which we propose as effective species "" The group comprises numerous closely related lineages with various degrees of pathogenic potential and industrial relevance. Species-level taxonomic classification of group strains is important for risk evaluation and communication but remains challenging. Biochemical and phenotypic assays are often used to assign group strains to species but are insufficient for accurate taxonomic classification on a genomic scale. Here, we show that antibiotic-producing ATCC 21929 represents a novel lineage within the group that, by all metrics used to delineate prokaryotic species, exemplifies a novel effective species. Furthermore, we show that ATCC 21929 is incapable of producing enterotoxins Hbl and Nhe or exhibiting cytotoxic effects on HeLa cells at human body temperature These results provide greater insight into the genomic and phenotypic diversity of the group and may be leveraged to inform future public health and food safety efforts.
Topics: Anti-Bacterial Agents; Bacillus cereus; Genome, Bacterial; HeLa Cells; Humans; Phylogeny; Soil Microbiology
PubMed: 33148822
DOI: 10.1128/mSphere.00882-20 -
Research in Microbiology Nov 2010When propagated on solid surfaces, Bacillus cereus can produce differentiated swarm cells under a wide range of growth conditions. This behavioural versatility is... (Review)
Review
When propagated on solid surfaces, Bacillus cereus can produce differentiated swarm cells under a wide range of growth conditions. This behavioural versatility is ecologically relevant, since it allows this bacterium to adapt swarming to environmental changes. Swarming by B. cereus is medically important: swarm cells are more virulent and particularly prone to invade host tissues. Characterisation of swarming-deficient mutants highlights that flagellar genes as well as genes governing different metabolic pathways are involved in swarm-cell differentiation. In this review, the environmental and genetic requirements for swarming and the role played by swarm cells in the virulence this pathogen exerts will be outlined.
Topics: Animals; Bacillus cereus; Gram-Positive Bacterial Infections; Humans; Virulence
PubMed: 21035546
DOI: 10.1016/j.resmic.2010.10.007 -
Food Microbiology Sep 2021B. cereus is a human pathogen associated with food poisoning leading to gastrointestinal disorders, as well as local and severe systemic infections. The pathogenic...
B. cereus is a human pathogen associated with food poisoning leading to gastrointestinal disorders, as well as local and severe systemic infections. The pathogenic spectrum of B. cereus ranges from strains used as probiotics in humans to lethal highly toxic strains. In this study, we gathered a collection of 100 strains representative of the pathological diversity of B. cereus in humans, and characterized these strains for their cytotoxic potential towards human cells. We analyzed the correlation between cytotoxicity to epithelial and macrophage cells and the combination of 10 genes suspected to play a role during B. cereus virulence. We highlight genetic differences among isolates and studied correlations between genetic signature, cytotoxicity and strain pathological status. We hope that our findings will improve our understanding of the pathogenicity of B. cereus, thereby making it possible to improve both clinical diagnosis and food safety.
Topics: Animals; Bacillus cereus; Cell Line; Epithelial Cells; Food Contamination; Food Microbiology; Foodborne Diseases; Gram-Positive Bacterial Infections; Humans; Macrophages; Phylogeny; Virulence
PubMed: 33875199
DOI: 10.1016/j.fm.2021.103759