Editing Bacillus cereus

{{Short description|Species of bacterium}}
{{Use dmy dates|date=February 2020}}
{{Speciesbox
| image = Bacillus_cereus_01.png
| image_alt = "B. cereus" colonies on a sheep-blood agar plate
| image_caption = ''B.&nbsp;cereus'' colonies on a sheep-blood [[agar plate]]
| genus = Bacillus
| species = cereus
| authority = Frankland & Frankland 1887
| subdivision_ranks = Biovars
| subdivision = * [[Bacillus cereus biovar anthracis|''Bacillus cereus'' bv. ''anthracis'']]
}}
[[File:Bacillus cereus SEM-cr.jpg|thumb|Electron micrograph of ''Bacillus cereus'']]

'''''Bacillus cereus''''' is a [[Gram-positive bacteria|Gram-positive]] [[Bacillus|rod-shaped]] bacterium commonly found in [[soil]], food, and marine sponges.<ref name="Paul-2021">{{Cite journal | vauthors = Paul SI, Rahman MM, Salam MA, Khan MA, Islam MT |date=2021-12-15 |title=Identification of marine sponge-associated bacteria of the Saint Martin's island of the Bay of Bengal emphasizing on the prevention of motile Aeromonas septicemia in Labeo rohita  |journal=Aquaculture |volume=545 |pages=737156 |doi=10.1016/j.aquaculture.2021.737156 }}</ref> The specific name, ''cereus'', meaning "waxy" in [[Latin]], refers to the appearance of colonies grown on [[blood agar]]. Some strains are harmful to humans and cause [[foodborne illness]] due to their spore-forming nature, while other strains can be beneficial as [[probiotics]] for animals, and even exhibit mutualism with certain plants.<ref>{{cite book |title=Sherris Medical Microbiology |publisher=McGraw Hill |year=2004 |isbn=978-0-8385-8529-0 | veditors = Ryan KJ, Ray CG |edition=4th }}{{page needed|date=September 2020}}</ref><ref name="CharalampopoulosRastall20092">{{cite book | vauthors = Felis GE, Dellaglio F, Torriani S |chapter=Taxonomy of probiotic microorganisms | veditors = Charalampopoulos D, Rastall RA |title=Prebiotics and Probiotics Science and Technology |publisher= Springer Science & Business Media |year=2009 |isbn=978-0-387-79057-2 |pages=627  |chapter-url=https://books.google.com/books?id=nIn8EIS2iE8C&pg=PA627}}</ref><ref name="Azcón-2010" /> ''B.&nbsp;cereus'' bacteria may be [[Aerobic organism|aerobes]] or [[facultative anaerobe]]s, and like other members of the genus ''[[Bacillus]]'', can produce protective [[endospore]]s. They have a wide range of [[virulence factor]]s, including [[phospholipase C]], [[cereulide]], [[Metalloproteinase|sphingomyelinase, metalloproteases]], and [[cytotoxin K]], many of which are regulated via [[quorum sensing]].<ref>{{cite journal | vauthors = Enosi Tuipulotu D, Mathur A, Ngo C, Man SM | title = Bacillus cereus: Epidemiology, Virulence Factors, and Host-Pathogen Interactions | language = English | journal = Trends in Microbiology | volume = 29 | issue = 5 | pages = 458–471 | date = May 2021 | pmid = 33004259 | doi = 10.1016/j.tim.2020.09.003 | hdl = 1885/219768 | s2cid = 222156441 | hdl-access = free }}</ref><ref name="Yossa-2022">{{cite journal | vauthors = Yossa N, Bell R, Tallent S, Brown E, Binet R, Hammack T | title = Genomic characterization of Bacillus cereus sensu stricto 3A ES isolated from eye shadow cosmetic products | journal = BMC Microbiology | volume = 22 | issue = 1 | pages = 240 | date = October 2022 | pmid = 36199032 | pmc = 9533521 | doi = 10.1186/s12866-022-02652-5 | doi-access = free }}</ref> ''B. cereus'' strains exhibit [[Flagellum|flagellar]] [[motility]].<ref name="Involvement of motility and flagell">{{cite journal | vauthors = Houry A, Briandet R, Aymerich S, Gohar M | title = Involvement of motility and flagella in Bacillus cereus biofilm formation | journal = Microbiology | volume = 156 | issue = Pt 4 | pages = 1009–1018 | date = April 2010 | pmid = 20035003 | doi = 10.1099/mic.0.034827-0 | doi-access = free }}</ref>

The ''Bacillus cereus'' group comprises seven closely related species: ''B.&nbsp;cereus'' ''sensu stricto'' (referred to herein as ''B.&nbsp;cereus''), ''[[Bacillus anthracis|B.&nbsp;anthracis]]'', ''[[Bacillus thuringiensis|B.&nbsp;thuringiensis]]'', ''[[Bacillus mycoides|B. mycoides]]'', ''[[Bacillus pseudomycoides|B. pseudomycoides]]'', and ''[[Bacillus cytotoxicus|B.&nbsp;cytotoxicus]]'';<ref>{{cite journal | vauthors = Guinebretière MH, Auger S, Galleron N, Contzen M, De Sarrau B, De Buyser ML, Lamberet G, Fagerlund A, Granum PE, Lereclus D, De Vos P, Nguyen-The C, Sorokin A | display-authors = 6 | title = Bacillus cytotoxicus sp. nov. is a novel thermotolerant species of the Bacillus cereus group occasionally associated with food poisoning | journal = International Journal of Systematic and Evolutionary Microbiology | volume = 63 | issue = Pt 1 | pages = 31–40 | date = January 2013 | pmid = 22328607 | doi = 10.1099/ijs.0.030627-0 | s2cid = 2407509 }}</ref> or as six species in a ''Bacillus cereus'' sensu lato: ''[[Bacillus weihenstephanensis|B. weihenstephanensis]]'', ''B. mycoides'', ''B. pseudomycoides'', ''B. cereus'', ''B. thuringiensis'', and ''B. anthracis''.<ref name="Kolsto-et-al-2009">{{cite journal | vauthors = Kolstø AB, Tourasse NJ, Økstad OA | title = What sets Bacillus anthracis apart from other Bacillus species? | journal = Annual Review of Microbiology | volume = 63 | issue = 1 | pages = 451–476 | year = 2009 | pmid = 19514852 | doi = 10.1146/annurev.micro.091208.073255 | publisher = [[Annual Reviews (publisher)|Annual Reviews]] | author1-link = Anne-Brit Kolstø }}</ref> A phylogenomic analysis combined with average nucleotide identity (ANI) analysis revealed that the ''B. anthracis'' species also includes strains annotated as ''B. cereus'' and ''B. thuringiensis.''<ref>{{cite journal | vauthors = Nikolaidis M, Hesketh A, Mossialos D, Iliopoulos I, Oliver SG, Amoutzias GD | title = A Comparative Analysis of the Core Proteomes within and among the ''Bacillus subtilis'' and ''Bacillus cereus'' Evolutionary Groups Reveals the Patterns of Lineage- and Species-Specific Adaptations | journal = Microorganisms | volume = 10 | issue = 9 | pages = 1720 | date = August 2022 | pmid = 36144322 | pmc = 9505155 | doi = 10.3390/microorganisms10091720 | doi-access = free }}</ref>

==History==
Colonies of ''B.&nbsp;cereus'' were originally isolated by [[Percy F. Frankland]] from a [[gelatine]] plate left exposed to the air in a cow shed in 1887.<ref>{{cite journal | vauthors = Frankland GC, Frankland PF |date=1 January 1887 |title=Studies on some new micro-organisms obtained from air |journal=[[Philosophical Transactions of the Royal Society B: Biological Sciences]] |volume=178 |pages=257–287 |bibcode=1887RSPTB.178..257F |doi=10.1098/rstb.1887.0011 |jstor=91702 |doi-access=free}}</ref> In the 2010s, examination of [[FDA Warning Letter|warning letters]] issued by the [[Food and Drug Administration|US Food and Drug Administration]] issued to [[pharmaceutical manufacturing]] facilities addressing facility microbial contamination revealed that the most common contaminant was ''B.&nbsp;cereus''.<ref>{{Cite journal | vauthors = Sandle T |date=28 November 2014 |title=The risk of ''Bacillus cereus'' to pharmaceutical manufacturing |url=https://www.americanpharmaceuticalreview.com/Featured-Articles/169507-The-Risk-of-em-Bacillus-cereus-em-to-Pharmaceutical-Manufacturing/ |url-status=live |journal=American Pharmaceutical Review |type=Paper |volume=17 |issue=6 |page=56 |archive-url=https://web.archive.org/web/20150425154058/http://www.americanpharmaceuticalreview.com/Featured-Articles/169507-The-Risk-of-em-Bacillus-cereus-em-to-Pharmaceutical-Manufacturing/ |archive-date=25 April 2015}}</ref>

Several new enzymes have been discovered in ''B.&nbsp;cereus'', such as [[AlkC]] and [[AlkD]], both of which are involved in [[DNA repair]].<ref>
{{cite journal | vauthors = Alseth I, Rognes T, Lindbäck T, Solberg I, Robertsen K, Kristiansen KI, Mainieri D, Lillehagen L, Kolstø AB, Bjørås M | display-authors = 6 | title = A new protein superfamily includes two novel 3-methyladenine DNA glycosylases from Bacillus cereus, AlkC and AlkD | journal = Molecular Microbiology | volume = 59 | issue = 5 | pages = 1602–1609 | date = March 2006 | pmid = 16468998 | pmc = 1413580 | doi = 10.1111/j.1365-2958.2006.05044.x | author9-link = Anne-Brit Kolstø }}</ref>

== Microbiology ==
[[File:Bacillus cereus endospore stain.jpg|thumb|''Bacillus cereus'' endospore stain]]
''B. cereus'' is a [[Bacillus (shape)|rod-shaped]] bacterium with a [[Gram-positive bacteria|Gram-positive]] cell envelope. Depending on the strain, it may be [[Aerobic organism|aerobic]] or [[Facultative anaerobic organism|facultatively anaerobic.]] Most strains are [[Mesophile|mesophilic]], having an optimal temperature between 25&nbsp;°C and 37&nbsp;°C, and neutralophilic, preferring neutral pH, but some have been found to grow in environments with much more extreme conditions.<ref name="Drobniewski-1993">{{Cite journal | vauthors = Drobniewski F |date=October 1993 |title=Bacillus cereus and Related Species | doi = 10.1128/CMR.6.4.324 |journal=American Society for Microbiology |volume=6 |issue=4 |pages=324–338|pmid=8269390 |pmc=358292 }}</ref>

These bacteria are both [[Bacterial spore|spore-forming]] and [[biofilm]]-forming, presenting a large challenge to the food industry due to their contamination capability. Biofilms of ''B. cereus'' most commonly form on air-liquid interfaces or on hard surfaces such as glass. ''B. cereus'' display flagellar motility, which has been shown to aid in biofilm formation via an increased ability to reach surfaces suitable for biofilm formation, to spread the biofilm over a larger surface area, and to recruit planktonic, or single, free-living bacteria.<ref name="Involvement of motility and flagell"/> Biofilm formation may also occur while in spore form due to varying adhesion ability of spores.<ref name="Biology and taxonomy of Bacillus ce">{{cite journal | vauthors = Vilas-Bôas GT, Peruca AP, Arantes OM | title = Biology and taxonomy of Bacillus cereus, Bacillus anthracis, and Bacillus thuringiensis | journal = Canadian Journal of Microbiology | volume = 53 | issue = 6 | pages = 673–687 | date = June 2007 | pmid = 17668027 | doi = 10.1139/W07-029 }}</ref>

Their flagella are [[peritrichous]], meaning there are many flagella located all around the cell body that can bundle together at a single location on the cell to propel it. This flagellar property also allows the cell to change directions of movement depending on where on the cell the flagellum filaments come together to generate movement.<ref name="Biology and taxonomy of Bacillus ce"/><ref>{{cite journal | vauthors = Riley EE, Das D, Lauga E | title = Swimming of peritrichous bacteria is enabled by an elastohydrodynamic instability | journal = Scientific Reports | volume = 8 | issue = 1 | pages = 10728 | date = July 2018 | pmid = 30013040 | doi = 10.1038/s41598-018-28319-8 | pmc = 6048115 | arxiv = 1806.01902 | bibcode = 2018NatSR...810728R }}</ref>

Some studies and observations have shown that silica particles the size of a few nanometers have been deposited in a spore coat layer in the extracytoplasmic region of the ''Bacillus cereus'' spore. The layer was first discovered by the use of scanning transmission electron microscopy (STEM), however the images taken did not have resolution high enough to determine the precise location of the silica. Some investigators hypothesize that the layer helps different spores from sticking together. It has also been shown to provide some resistance to acidic environments. The silica coat is related to the permeability of the spore's inner membrane. Strong mineral acids are able to break down spore permeability barriers and kill the spore. However, when the spore has a silica coating, it may reduce the permeability of the membrane and provide resistance to many acids.<ref>{{Cite journal |last1=Hirota |first1=Ryuichi |last2=Hata |first2=Yumehiro |last3=Ikeda |first3=Takeshi |last4=Ishida |first4=Takenori |last5=Kuroda |first5=Akio |date=January 2010 |title=The Silicon Layer Supports Acid Resistance of Bacillus cereus Spores |journal=Journal of Bacteriology |volume=192 |issue=1 |pages=111–116 |doi=10.1128/JB.00954-09 |issn=0021-9193 |pmc=2798246 |pmid=19880606}}</ref>

=== Metabolism ===
''Bacillus cereus'' has mechanisms for both aerobic and anaerobic respiration, making it a [[Facultative anaerobic organism|facultative anaerobe]].<ref name="microbewiki.kenyon.edu">{{Cite web |title=Bacillus cereus - microbewiki |url=https://microbewiki.kenyon.edu/index.php/Bacillus_cereus#:~:text=substrate%20level%20phosphorylation.-,B.,acids%20for%20growth%20and%20energy. |access-date=2022-11-16 |website=microbewiki.kenyon.edu |language=en}}</ref> Its aerobic pathway consists of three terminal oxidases: cytochrome aa3, cytochrome caa3, and cytochrome bd, the use of each dependent on the amount of oxygen present in the environment.<ref>{{Cite journal |last1=Chateau |first1=Alice |last2=Alpha-Bazin |first2=Béatrice |last3=Armengaud |first3=Jean |last4=Duport |first4=Catherine |date=18 Jan 2022 |title=Heme A Synthase Deficiency Affects the Ability of Bacillus cereus to Adapt to a Nutrient-Limited Environment |journal=International Journal of Molecular Sciences |language=en |volume=23 |issue=3 |pages=1033 |doi=10.3390/ijms23031033 |pmid=35162964 |pmc=8835132 |issn=1422-0067|doi-access=free }}</ref> The ''B. cereus'' genome encodes genes for metabolic enzymes including NADH dehydrogenases, succinate dehydrogenase, complex III, and cytochrome c oxidase, as well as others. ''Bacillus cereus'' can metabolize several different compounds to create energy, including carbohydrates, proteins, peptides, and amino acids.<ref name="microbewiki.kenyon.edu" />

The Embden-Meyerhof pathway is the predominant pathway used by ''Bacillus cereus'' to catabolize glucose at every stage of the cell's development, according to estimates of a radiorespirometric method of glucose catabolism. This is true at times of germinative phases, as well as sporogenic phases. At the filamentous, granular, forespore, and transitional stages, the Embden-Meyerhof pathway was responsible for the catabolism of 98% of the cell's glucose. The remainder of the glucose was catabolized by the hexose monophosphate oxidative pathway.<ref>{{Cite journal |last1=Goldman |first1=Manuel |last2=Blumenthal |first2=Harold J. |title=Pathways of Glucose Catabolism in Bacillus Cereus |date=February 1964 |journal=Journal of Bacteriology |volume=87 |issue=2 |pages=377–386 |doi=10.1128/jb.87.2.377-386.1964 |issn=0021-9193 |pmid=14151060|pmc=277019 }}</ref>

Analysis of the core genome of ''B. cereus'' reveals a limited presence of enzymes meant for breakdown of [[polysaccharide]]s and a prevalence of [[protease]]s and amino acid degradation and transport pathways, indicating that their preferred diet consists of proteins and their breakdown products.<ref>{{cite journal |display-authors=6 |vauthors=Ivanova N, Sorokin A, Anderson I, Galleron N, Candelon B, Kapatral V, Bhattacharyya A, Reznik G, Mikhailova N, Lapidus A, Chu L, Mazur M, Goltsman E, Larsen N, D'Souza M, Walunas T, Grechkin Y, Pusch G, Haselkorn R, Fonstein M, Ehrlich SD, Overbeek R, Kyrpides N |date=May 2003 |title=Genome sequence of Bacillus cereus and comparative analysis with Bacillus anthracis |journal=Nature |volume=423 |issue=6935 |pages=87–91 |doi=10.1038/nature01582 |pmid=12721630|bibcode=2003Natur.423...87I |s2cid=4361366 |doi-access=free }}</ref>

An isolate of a bacterium found to produce [[Polyhydroxybutyrate|PHBs]] was identified as ''B. cereus'' through analysis of 16S rRNA sequences as well as similarity of morphological and biochemical characteristics. PHBs may be produced when there is excess carbon or limited essential nutrients present in the environment, and they are later broken down by the microbe as a fuel source under starvation conditions. This indicates the potential role of ''B. cereus'' in producing biodegradable plastic substitutes. PHB production was highest when provided with glucose as a carbon source.<ref>{{cite journal | vauthors = Hamdy SM, Danial AW, Gad El-Rab SM, Shoreit AA, Hesham AE | title = Production and optimization of bioplastic (Polyhydroxybutyrate) from Bacillus cereus strain SH-02 using response surface methodology | journal = BMC Microbiology | volume = 22 | issue = 1 | pages = 183 | date = July 2022 | pmid = 35869433 | pmc = 9306189 | doi = 10.1186/s12866-022-02593-z | doi-access = free }}</ref>

== Genomics ==
The genome of ''B. cereus'' has been characterized and shown to contain over 5 million bp of DNA. Out of these, more than 5500 protein-encoding genes have been identified, of which the top categories of genes with known functions include: metabolic processes, processing of proteins, virulence factors, response to stress, and defense mechanisms. Many of the genes categorized as virulence factors, stress responses, and defense mechanisms encode factors in antibiotic resistance.<ref name="Yossa-2022"/> There are approximately 600 genes which are common in 99% of the taxa of ''B. cereus'' sensu lato, which constitutes around 1% of all genes in the [[pan-genome]]. Due to the prevalence of horizontal gene transfer among bacteria, the pan-genome of ''B. cereus'' is continually expanding.<ref>{{cite journal | vauthors = Bazinet AL | title = Pan-genome and phylogeny of Bacillus cereus sensu lato | journal = BMC Evolutionary Biology | volume = 17 | issue = 1 | pages = 176 | date = August 2017 | pmid = 28768476 | pmc = 5541404 | doi = 10.1186/s12862-017-1020-1 | doi-access = free }}</ref> The GC content of its DNA across all strains is approximately 35%.<ref name="Whole-Genome Characterization of Ba">{{cite journal | vauthors = Chang T, Rosch JW, Gu Z, Hakim H, Hewitt C, Gaur A, Wu G, Hayden RT | display-authors = 6 | title = Whole-Genome Characterization of Bacillus cereus Associated with Specific Disease Manifestations | journal = Infection and Immunity | volume = 86 | issue = 2 | pages = e00574–17 | date = February 2018 | pmid = 29158433 | pmc = 5778371 | doi = 10.1128/IAI.00574-17 | veditors = Freitag NE }}</ref>

Following exposure to non-lethal acid shock at pH 5.4-5.5, the [[arginine deiminase]] gene in ''B. cereus'', ''arcA,'' shows substantial up-regulation. This gene is part of the ''arcABC'' operon which is induced by low-pH environments in ''Listeria monocytogenes'', and is associated with growth and survival in acidic environments. This suggests that this gene is also important for survival of ''B. cereus'' in acidic environments.<ref>{{cite journal |vauthors=Duport C, Jobin M, Schmitt P |date=2016-10-04 |title=Adaptation in ''Bacillus cereus'': From Stress to Disease |journal=Frontiers in Microbiology |volume=7 |pages=1550 |doi=10.3389/fmicb.2016.01550 |pmc=5047918 |pmid=27757102|doi-access=free }}</ref>

The activation of virulence factors has been shown to be transcriptionally regulated via [[Quorum sensing|quorum-sensing]] in ''B. cereus.'' The activation of many virulence factors secreted is dependent on the activity of the Phospholipase C regulator (PlcR), a transcriptional regulator which is most active at the beginning of the [[Stationary phase (biology)|stationary phase]] of growth. A small peptide called PapR acts as the effector in the quorum-sensing pathway, and when reimported into the cell, it interacts with PlcR to activate transcription of these virulence genes.<ref name="Yossa-2022"/> When point mutations were introduced into the plcR gene using the CRISPR/Cas9 system, it was observed that the mutated bacteria lost their hemolytic and phospholipase activity.<ref>{{cite journal | vauthors = Wang Y, Wang D, Wang X, Tao H, Feng E, Zhu L, Pan C, Wang B, Liu C, Liu X, Wang H | display-authors = 6 | title = Highly Efficient Genome Engineering in ''Bacillus anthracis'' and ''Bacillus cereus'' Using the CRISPR/Cas9 System | journal = Frontiers in Microbiology | volume = 10 | pages = 1932 | date = 2019 | pmid = 31551942 | doi = 10.3389/fmicb.2019.01932 | pmc = 6736576 | doi-access = free }}</ref>

The flagella of ''B. cereus'' are encoded by 2 to 5 ''fla'' genes, depending on the strain.<ref name="Involvement of motility and flagell"/>

== Identification ==
[[File:Bacillus cereus colonies on the indicator media.jpg|thumb|Bacillus cereus colonies on the indicator media Brilliance Bacillus cereus agar]]
For the isolation and enumeration of ''B.&nbsp;cereus'', there are two standardized methods by [[International Organization for Standardization]] (ISO): ISO 7932 and ISO 21871. Because of ''B.&nbsp;cereus''{{'}} ability to produce [[lecithinase]] and its inability to ferment [[mannitol]], there are some proper [[Selective medium|selective media]] for its isolation and identification such as mannitol-egg yolk-polymyxin (MYP) and polymyxin-pyruvate-egg yolk-mannitol-bromothymol blue agar (PEMBA). ''B.&nbsp;cereus'' colonies on MYP have a violet-red background and are surrounded by a zone of egg-yolk precipitate.<ref name="Foodborne Diseases">{{cite book | vauthors = Griffiths D, Schraft H |chapter=''Bacillus cereus'' food poisoning | veditors = Dodd CE, Aldsworth T, Stein RA, Cliver DO, Riemann HP |title=Foodborne Diseases |date=2017 |publisher=Elsevier |isbn=978-0-12-385007-2 |edition=3rd |pages=395–405  |doi=10.1016/b978-0-12-385007-2.00020-6  }}</ref>

Below is a list of differential techniques and results that can help to identify ''B.&nbsp;cereus'' from other bacteria and ''Bacillus'' species.<ref>{{Cite book |title=Bacillus |publisher=Springer Science |year=1989 |isbn=978-1-4899-3502-1 |veditors=Harwood CR |oclc=913804139 |pages=44–46}}</ref>
* [[Anaerobic organism|Anaerobic growth]]: Positive
* [[Voges–Proskauer test|Voges Proskauer test]]: Positive
* Acid produced from
** {{sc|D}}-glucose: Positive
** {{sc|L}}-arabinose: Negative
** {{sc|D}}-xylose: Negative
** {{sc|D}}-mannitol: Negative
* Starch&nbsp;[[hydrolysis]]: Positive
* [[Nitrogen fixation|Nitrate reduction]]: Positive
* Degradation of&nbsp;[[tyrosine]]: Positive
* Growth at
** above 50&nbsp;°C: Negative
* Use of&nbsp;[[citrate]]: Positive

The Central Public Health Laboratory in the United Kingdom tests for motility, hemolysis, rhizoid growth, susceptibility to γ-phage, and fermentation of ammonium salt-based glucose but no mannitol, arabinose, or xylose.<ref name="Foodborne Diseases" />

==Growth==
The optimal growth temperature range for ''B. cereus'' is 30-40&nbsp;°C.<ref name="Karim-2013">{{Cite journal | vauthors = Karim MA, Akhter N, Hoque S |date=2013 |title=Proteolytic activity, growth and nutrient release by Bacillus cereus LW-17 |url=https://www.banglajol.info/index.php/BJB/article/view/18043 |journal=Bangladesh Journal of Botany |language=en |volume=42 |issue=2 |pages=349–353 |doi=10.3329/bjb.v42i2.18043 |issn=2079-9926}}</ref> At {{convert|30|C|F}}, a population of ''B.&nbsp;cereus'' can double in as little as 20 minutes or as long as 3 hours, depending on the food product. Spores of ''B. cereus'' are not [[Metabolism|metabolically]] active, but can rapidly become active and begin [[Fission (biology)|replicating]] once they encounter adequate growth conditions.<ref>{{cite thesis |url=https://helda.helsinki.fi/bitstream/handle/10138/20888/foodandi.pdf |title=Food and indoor air isolated ''Bacillus'' non-protein toxins: structures, physico-chemical properties and mechanisms of effects on eukaryotic cells | vauthors = Mikkola R |publisher=[[University of Helsinki]] |year=2006 |isbn=952-10-3549-8 |page=12 |access-date=24 October 2015 |archive-url= https://web.archive.org/web/20190709153531/https://helda.helsinki.fi/bitstream/handle/10138/20888/foodandi.pdf |archive-date=9 July 2019 |url-status=live}}</ref>{{better source needed|date=November 2022}}

{| class="wikitable" style="text-align:center;"
!Food!! style="width:10em" |Minutes to double, {{convert|30|C|F}}!! style="width:10em" |Hours to multiply by 1,000,000
|-
|Milk||20–36||{{n-life|n=2|t=20|t2=36|end=10^6|scale=60|dec=1}}
|-
|Cooked rice||26–31||{{n-life|n=2|t=26|t2=31|end=10^6|scale=60|dec=1}}
|-
|Infant formula||56||{{n-life|n=2|t=56|end=10^6|scale=60|dec=1}}
|}

==Ecology==
Like most ''[[Bacilli]],'' the most common ecosystem of ''Bacillus cereus'' is the soil. In concert with [[arbuscular mycorrhiza]] (and ''[[Rhizobium leguminosarum]]'' in [[Trifolium repens|clover]]), they can up-regulate plant growth in [[Heavy metals|heavy metal]] [[soil]]s by decreasing heavy metal concentrations via [[bioaccumulation]] and biotransformation in addition to increasing phosphorus, nitrogen, and potassium uptake in certain plants.<ref name="Azcón-2010">{{cite journal | vauthors = Azcón R, Perálvarez M, Roldán A, Barea JM | title = Arbuscular mycorrhizal fungi, Bacillus cereus, and Candida parapsilosis from a multicontaminated soil alleviate metal toxicity in plants | journal = Microbial Ecology | volume = 59 | issue = 4 | pages = 668–677 | date = May 2010 | pmid = 20013261 | doi = 10.1007/s00248-009-9618-5 | s2cid = 12075701 }}</ref> ''B. cereus'' was also shown to aid in survival of earthworms in heavy metal soils resulting from the use of metal-based fungicides, showing increases in biomass, reproduction and reproductive viability, and a decrease in metal content of tissues in those inoculated with the bacterium.<ref name="Oladipo-2019">{{cite journal | vauthors = Oladipo OG, Burt AF, Maboeta MS | title = Effect of Bacillus cereus on the ecotoxicity of metal-based fungicide spiked soils: Earthworm bioassay | journal = Ecotoxicology | volume = 28 | issue = 1 | pages = 37–47 | date = January 2019 | pmid = 30430303 | doi = 10.1007/s10646-018-1997-2 | s2cid = 53440898 }}</ref> These results suggest strong possibilities for its application in ecological [[bioremediation]]. Evidence of bioremediation potential by ''Bacillus cereus'' was also found in the aquatic ecosystem, where organic nitrogen and phosphorus wastes polluting a eutrophic lake were broken down in the presence of ''B. cereus''.<ref name="Karim-2013" />

In a study measuring the ability of ''B. cereus'' to degrade [[keratin]] in chicken feathers, bacteria were found to sufficiently biodegrade keratin via hydrolytic mechanisms. These results indicate its potential to degrade keratinous waste from the poultry industry for potential recycling of the byproducts.<ref>{{Cite journal |title=Keratinolytic Potential of Feather-Degrading Bacillus polymyxa and Bacillus cereus |url=http://www.pjoes.com/Keratinolytic-Potential-of-Feather-Degrading-Bacillus-polymyxa-and-Bacillus-cereus,88393,0,2.html |journal=Polish Journal of Environmental Studies |language=english |volume=19 |issue=2 |pages=371–378 |issn=1230-1485}}</ref>

''B.&nbsp;cereus'' competes with Gram-negative bacteria species such as ''[[Salmonella]]'' and ''[[Campylobacter]]'' in the [[Gut (zoology)|gut]]; its presence reduces the number of Gram-negative bacteria, specifically via antibiotic activity via enzymes such as [[cerein]]s that impede their quorum sensing ability and exhibit [[Bactericide|bactericidal]] activity.<ref name="Swiecicka-2008">{{Cite journal | vauthors = Swiecicka I |date= January 2008 |title= Natural occurrence of Bacillus thuringiensis and Bacillus cereus in eukaryotic organisms: a case for symbiosis |url=https://doi.org/10.1080/09583150801942334 |journal=Biocontrol Science and Technology |volume=18 |issue=3 |pages=221–239 |doi=10.1080/09583150801942334 |s2cid= 85570720 |issn=0958-3157}}</ref><ref>{{cite journal | vauthors = Naclerio G, Ricca E, Sacco M, De Felice M | title = Antimicrobial activity of a newly identified bacteriocin of Bacillus cereus | journal = Applied and Environmental Microbiology | volume = 59 | issue = 12 | pages = 4313–4316 | date = December 1993 | pmid = 8285719 | pmc = 195902 | doi = 10.1128/AEM.59.12.4313-4316.1993 | bibcode = 1993ApEnM..59.4313N }}</ref> In food animals such as [[chickens]],<ref>{{cite journal | vauthors = Vilà B, Fontgibell A, Badiola I, Esteve-Garcia E, Jiménez G, Castillo M, Brufau J | title = Reduction of Salmonella enterica var. Enteritidis colonization and invasion by Bacillus cereus var. toyoi inclusion in poultry feeds | journal = Poultry Science | volume = 88 | issue = 5 | pages = 975–979 | date = May 2009 | pmid = 19359685 | doi = 10.3382/ps.2008-00483 | doi-access = free }}</ref> [[rabbit]]s<ref>{{cite journal | vauthors = Bories G, Brantom P, de Barberà JB, Chesson A, Cocconcelli PS, Debski B, Dierick N, Gropp J, Halle I, Hogstrand C, de Knecht J, Leng L, Lindgren S, Haldorsen AL, Mantovani A, Mézes M, Nebbia C, Rambeck W, Rychen G, von Wright A, Wester P | display-authors = 6 |date=9 December 2008 |title=Safety and efficacy of the product Toyocerin (''Bacillus cereus'' var. ''toyoi'') as feed additive for rabbit breeding does |url=http://www.efsa.europa.eu/de/efsajournal/pub/913 |journal=[[EFSA Journal]] |series=Scientific Opinion of the Panel on Additives and Products or Substances used in Animal Feed |volume=2009 |issue=1 |pages=913 |doi=10.2903/j.efsa.2009.913 |eissn=1831-4732 |id=EFSA-Q-2008-287 |access-date=14 May 2009 |doi-access= }}</ref> and [[pig]]s,<ref>{{cite journal | vauthors = Bories G, Brantom P, de Barberà JB, Chesson A, Cocconcelli PS, Debski B, Dierick N, Franklin A, Gropp J, Halle I, Hogstrand C, de Knecht J, Leng L, Haldorsen AL, Mantovani A, Mézes M, Nebbia C, Rambeck W, Rychen G, von Wright A, Wester P | display-authors = 6 |date=16 March 2007 |title=Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the safety and efficacy of the product Toyocerin (''Bacillus cereus'' var. Toyoi) as a feed additive for sows from service to weaning, in accordance with Regulation (EC) No 1831/2003 |url=http://www.efsa.europa.eu/en/efsajournal/pub/458 |journal=[[EFSA Journal]] |series=Scientific Opinion of the Panel on Additives and Products or Substances used in Animal Feed |volume=2007 |issue=3 |pages=458 |doi=10.2903/j.efsa.2007.458 |eissn=1831-4732 |id=EFSA-Q-2006-037 |access-date=14 May 2009 |doi-access=free }}</ref> some harmless strains of ''B.&nbsp;cereus'' are used as a probiotic [[feed additive]] to reduce ''Salmonella'' in the animals' [[intestine]]s and [[cecum]]. This improves the animals' growth, as well as food safety for humans who eat them. In addition, ''B. cereus'' create and release enzymes that aid in the digestion of materials that are typically difficult to digest, such as woody plant matter, in the guts of other organisms.<ref name="Swiecicka-2008" />

The strain {{visible anchor|B25|text=''B. cereus'' B25}} is a [[biofungicide]].<ref name="Lopez-et-al-2016-bundle">
   {{Unbulleted list citebundle|{{cite book | vauthors = Verma M, Mishra J, Arora NK | date=2019 | chapter=Plant Growth-Promoting Rhizobacteria: Diversity and Applications | veditors = Sobti RC, Arora NK, Kothari R | title=Environmental Biotechnology: For Sustainable Future | pages=129–173 | publisher=[[Springer Singapore]] | doi=10.1007/978-981-10-7284-0_6 | isbn=978-981-10-7283-3 | s2cid=91258998}}|{{cite journal | vauthors = Ndemera M, De Boevre M, De Saeger S | title = Mycotoxin management in a developing country context: A critical review of strategies aimed at decreasing dietary exposure to mycotoxins in Zimbabwe | journal = Critical Reviews in Food Science and Nutrition | volume = 60 | issue = 4 | pages = 529–540 | year = 2020 | pmid = 30501517 | doi = 10.1080/10408398.2018.1543252 | publisher = [[Taylor & Francis]] | s2cid = 54523328 }}|{{cite book | vauthors = Verma RK, Sachan M, Vishwakarma K, Upadhyay N, Mishra RK, Tripathi DK, Sharma S | title=Role of Rhizospheric Microbes in Soil | chapter=Role of PGPR in Sustainable Agriculture: Molecular Approach Toward Disease Suppression and Growth Promotion | publisher=[[Springer Singapore]] | publication-place=[[Singapore]] | year=2018 | isbn=978-981-13-0043-1 | doi=10.1007/978-981-13-0044-8_9 | pages=259–290 | s2cid=90538241}}|{{cite book | vauthors = Shahid M, Zaidi A, Khan MS, Rizvi A, Saif S, Ahmed B | title=Microbial Strategies for Vegetable Production | chapter=Recent Advances in Management Strategies of Vegetable Diseases | publisher=[[Springer International Publishing]] | publication-place=[[Cham, Switzerland]] | year=2017 | isbn=978-3-319-54400-7 | doi=10.1007/978-3-319-54401-4_9 | pages=197–226 | s2cid=91152604}}|{{cite journal | vauthors = Figueroa-López AM, Cordero-Ramírez JD, Martínez-Álvarez JC, López-Meyer M, Lizárraga-Sánchez GJ, Félix-Gastélum R, Castro-Martínez C, Maldonado-Mendoza IE | display-authors = 6 | title = Rhizospheric bacteria of maize with potential for biocontrol of Fusarium verticillioides | journal = SpringerPlus | volume = 5 | issue = 330 | pages = 330 | date = 2016 | pmid = 27066355 | doi = 10.1186/s40064-016-1780-x | pmc = 4792820 | s2cid = 12268357 | doi-access = free }}}}
</ref> A study by Figueroa-López ''et al.'' showed that the presence of this strain reduced ''[[Fusarium verticillioides]]'' growth.<ref name="Lopez-et-al-2016-bundle" /> B25 shows promise for reduction of [[mycotoxin]] concentrations in [[grain]]s.<ref name="Lopez-et-al-2016-bundle" />

==Pathogenesis==
''B.&nbsp;cereus'' is responsible for a minority of foodborne illnesses (2–5%), causing severe [[nausea]], [[vomiting]], and [[diarrhea]].<ref>{{cite journal | vauthors = Kotiranta A, Lounatmaa K, Haapasalo M | title = Epidemiology and pathogenesis of Bacillus cereus infections | journal = Microbes and Infection | volume = 2 | issue = 2 | pages = 189–198 | date = February 2000 | pmid = 10742691 | doi = 10.1016/S1286-4579(00)00269-0 }}</ref> ''Bacillus'' foodborne illnesses occur due to survival of the bacterial endospores when contaminated food is not, or is inadequately, cooked.<ref>{{cite book | vauthors = Turnbull PC |title=Baron's Medical Microbiology |publisher=University of Texas Medical Branch |year=1996 |isbn=978-0-9631172-1-2 | veditors = Baron S |edition=4th |chapter=''Bacillus'' |pmid=21413260 |display-editors=etal |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK7699/#939 |via=NCBI Bookshelf}}</ref> Cooking temperatures less than or equal to {{convert|100|C|F}} allow some ''B.&nbsp;cereus'' [[Endospore|spores]] to survive.<ref name="microorganisms.in.foods.p.242">{{cite book | vauthors = Roberts TA, Baird-Parker AC, Tompkin RB |url= https://books.google.com/books?id=lxycHnaPfCYC&pg=PA24 |title=Characteristics of Microbial Pathogens  |publisher=Blackie Academic & Professional |year=1996 |isbn=978-0-412-47350-0 |location=London |page=24 |access-date=25 November 2010}}</ref> This problem is compounded when food is then improperly [[Refrigeration|refrigerated]], allowing the endospores to germinate.<ref>{{cite journal | vauthors = McKillip JL | title = Prevalence and expression of enterotoxins in Bacillus cereus and other Bacillus spp., a literature review | journal = Antonie van Leeuwenhoek | volume = 77 | issue = 4 | pages = 393–399 | date = May 2000 | pmid = 10959569 | doi = 10.1023/A:1002706906154 | s2cid = 8362130 }}</ref> Cooked foods not meant for either immediate consumption or rapid cooling and refrigeration should be kept at temperatures below {{convert|10|C|F}} or above {{convert|50|C|F}}.<ref name="microorganisms.in.foods.p.242" /> Germination and growth generally occur between 10&nbsp;°C and 50&nbsp;°C,<ref name="microorganisms.in.foods.p.242" /> though some strains can [[Psychrotrophic bacteria|grow at low temperatures]],<ref>{{cite book | vauthors = Lawley R, Curtis L, Davis J |url=https://books.google.com/books?id=KiK9fcE4xvAC&pg=PA17 |title=The Food Safety Hazard Guidebook |publisher=[[Royal Society of Chemistry]] |year=2008 |isbn=978-0-85404-460-3 |location=Cambridge, UK |page=17 |access-date=25 November 2010}}</ref> and Bacillus cytotoxicus strains have been shown to grow at temperatures up to {{convert|52|C|F}}.<ref>{{cite journal | vauthors = Cairo J, Gherman I, Day A, Cook PE | title = Bacillus cytotoxicus-A potentially virulent food-associated microbe | journal = Journal of Applied Microbiology | volume = 132 | issue = 1 | pages = 31–40 | date = January 2022 | pmid = 34260791 | doi = 10.1111/jam.15214 | pmc = 9291862 | s2cid = 235906633 }}</ref> Bacterial growth results in production of [[enterotoxin]]s, one of which is highly resistant to heat and acids ([[pH]] levels between 2 and 11);<ref name="Todar22">{{cite web | vauthors = Todar K |title=''Bacillus cereus'' |url=http://textbookofbacteriology.net/B.cereus.html |access-date=19 September 2009 |work=Todar's Online Textbook of Bacteriology}}</ref> ingestion leads to two types of illness: diarrheal and emetic (vomiting) syndrome.<ref name="pmid155387092">{{cite journal | vauthors = Ehling-Schulz M, Fricker M, Scherer S | title = Bacillus cereus, the causative agent of an emetic type of food-borne illness | journal = Molecular Nutrition & Food Research | volume = 48 | issue = 7 | pages = 479–487 | date = December 2004 | pmid = 15538709 | doi = 10.1002/mnfr.200400055 }}</ref> The enterotoxins produced by ''B. cereus'' have beta-hemolytic activity.<ref name="Drobniewski-1993"/>
* The diarrheal type is associated with a wide range of foods, has an 8-to-16-hour [[Incubation period|incubation time]], and is associated with diarrhea and gastrointestinal pain. Also known as the 'long-incubation' form of ''B.&nbsp;cereus'' food poisoning, it might be difficult to differentiate from poisoning caused by ''[[Clostridium perfringens]]''.<ref name="Todar22"/> Enterotoxin can be inactivated after heating at {{convert|56|C|F}} for 5 minutes, but whether its presence in food causes the symptom is unclear, since it degrades in stomach enzymes; its subsequent production by surviving ''B.&nbsp;cereus'' spores within the [[small intestine]] may be the cause of illness.<ref name="watson19983">{{cite book | vauthors = Millar I, Gray D, Kay H |title=Natural Toxicants in Food |date=1998 |publisher=CRC Press |isbn=978-0-8493-9734-9 | veditors = Watson DH |pages=133–134 |chapter=Bacterial toxins found in foods |chapter-url=https://books.google.com/books?id=yKIy-iHLaiEC&pg=PA134}}</ref>
* The 'emetic' form commonly results from rice which is cooked at a time and temperature insufficient to kill any spores present, then improperly refrigerated. The remaining spores can produce a [[toxin]], [[cereulide]], which is not inactivated by later reheating. This form leads to nausea and vomiting 1–5 hours after consumption. Distinguishing from other short-term bacterial foodborne intoxications, such as by ''[[Staphylococcus aureus]],'' can be difficult.<ref name="Todar22"/> Emetic toxin can withstand {{convert|121|C|F}} for 90 minutes.<ref name="watson19983" /> As a result of the emetic type's association with rice, it is sometimes referred to colloquially as 'fried rice syndrome'.<ref>{{Cite web |last=Ross |first=Rachel |date=2019-05-01 |title=Bacillus Cereus: The Bacterium That Causes 'Fried Rice Sydrome' |url=https://www.livescience.com/65374-bacillus-cereus-fried-rice-syndrome.html |access-date=2023-08-19 |website=livescience.com |language=en}}</ref><ref>{{Cite web |last=Pelegrino |first=Elton N. |date=2021-09-10 |title=Fried Rice Syndrome: A common cause of food poisoning |url=https://www.nnc.gov.ph//regional-offices/mindanao/region-ix-zamboanga-peninsula/5946-fried-rice-syndrome-a-common-cause-of-food-poisoning |access-date=2023-08-19 |website=www.nnc.gov.ph |language=en-gb}}</ref><ref>{{Cite web |title=SFA {{!}} Fried Rice Syndrome |url=https://www.sfa.gov.sg/food-information/risk-at-a-glance/fried-rice-syndrome |access-date=2023-08-19 |website=www.sfa.gov.sg}}</ref>

The diarrhetic syndromes observed in patients are thought to stem from the three toxins: [[hemolysin]] BL (Hbl), nonhemolytic [[enterotoxin]] (Nhe), and [[cytotoxin]] K (CytK).<ref>{{cite journal | vauthors = Guinebretière MH, Broussolle V, Nguyen-The C | title = Enterotoxigenic profiles of food-poisoning and food-borne Bacillus cereus strains | journal = Journal of Clinical Microbiology | volume = 40 | issue = 8 | pages = 3053–3056 | date = August 2002 | pmid = 12149378 | pmc = 120679 | doi = 10.1128/JCM.40.8.3053-3056.2002 }}</ref> The ''nhe''/''hbl''/''cytK'' genes are located on the chromosome of the bacteria. Transcription of these genes is controlled by ''PlcR''. These genes occur in the taxonomically related [[Bacillus thuringiensis|''B.&nbsp;thuringiensis'']] and [[Bacillus anthracis|''B.&nbsp;anthracis'']], as well. These enterotoxins are all produced in the small intestine of the host, thus thwarting digestion by host endogenous enzymes. The Hbl and Nhe toxins are pore-forming toxins closely related to [[ClyA]] of ''[[Escherichia coli|E.&nbsp;coli]]''. The proteins exhibit a conformation known as a "[[beta-barrel]]" that can insert into cellular membranes due to a [[hydrophobic]] exterior, thus creating pores with [[hydrophilic]] interiors. The effect is loss of cellular [[membrane potential]] and eventually cell death.{{citation needed|date=December 2022}}

Previously, it was thought that the timing of the toxin production was responsible for the two different courses of disease, but it has since been found that the emetic syndrome is caused by the toxin [[cereulide]], which is found only in emetic strains and is not part of the "standard toolbox" of ''B.&nbsp;cereus''. Cereulide is a cyclic polypeptide containing three repeats of four amino acids: {{sc|D}}-oxy-{{abbr|[[Leucine|Leu]]|leucine}}—{{sc|D}}-{{abbr|[[Alanine|Ala]]|alanine}}—{{sc|L}}-oxy-{{abbr|[[Valine|Val]]|valine}}—{{sc|L}}-{{abbr|Val|valine}} (similar to [[valinomycin]] produced by ''[[Streptomyces griseus]]'') produced by [[Nonribosomal peptide|nonribosomal peptide synthesis]]. Cereulide is believed to bind to 5-hydroxytryptamine&nbsp;3 (5-HT3) [[serotonin]] receptors, activating them and leading to increased [[Afferent nerve fiber|afferent]] [[vagus nerve stimulation]].<ref>{{cite journal | vauthors = Agata N, Ohta M, Mori M, Isobe M | title = A novel dodecadepsipeptide, cereulide, is an emetic toxin of Bacillus cereus | journal = FEMS Microbiology Letters | volume = 129 | issue = 1 | pages = 17–20 | date = June 1995 | pmid = 7781985 | doi = 10.1016/0378-1097(95)00119-P }}</ref> It was shown independently by two research groups to be encoded on multiple [[plasmid]]s: pCERE01<ref>{{cite journal | vauthors = Hoton FM, Andrup L, Swiecicka I, Mahillon J | title = The cereulide genetic determinants of emetic Bacillus cereus are plasmid-borne | journal = Microbiology | volume = 151 | issue = Pt 7 | pages = 2121–2124 | date = July 2005 | pmid = 16000702 | doi = 10.1099/mic.0.28069-0 | doi-access = free }}</ref> or pBCE4810.<ref>{{cite journal | vauthors = Ehling-Schulz M, Fricker M, Grallert H, Rieck P, Wagner M, Scherer S | title = Cereulide synthetase gene cluster from emetic Bacillus cereus: structure and location on a mega virulence plasmid related to Bacillus anthracis toxin plasmid pXO1 | journal = BMC Microbiology | volume = 6 | pages = 20 | date = March 2006 | pmid = 16512902 | pmc = 1459170 | doi = 10.1186/1471-2180-6-20 | doi-access = free }}</ref> Plasmid pBCE4810 shares homology with the ''B.&nbsp;anthracis'' virulence plasmid pXO1, which encodes the [[anthrax toxin]]. Periodontal isolates of ''B.&nbsp;cereus'' also possess distinct pXO1-like plasmids. Like most of cyclic peptides containing nonproteogenic amino acids, cereulide is resistant to heat, proteolysis, and acid conditions.<ref>{{cite journal | vauthors = Stenfors Arnesen LP, Fagerlund A, Granum PE | title = From soil to gut: Bacillus cereus and its food poisoning toxins | journal = FEMS Microbiology Reviews | volume = 32 | issue = 4 | pages = 579–606 | date = July 2008 | pmid = 18422617 | doi = 10.1111/j.1574-6976.2008.00112.x | doi-access = free }}</ref>

''B.&nbsp;cereus'' is also known to cause difficult-to-eradicate chronic skin infections, though less aggressive than [[necrotizing fasciitis]]. ''B.&nbsp;cereus'' can also cause [[keratitis]].<ref name="pmid115810572">{{cite journal | vauthors = Pinna A, Sechi LA, Zanetti S, Usai D, Delogu G, Cappuccinelli P, Carta F | title = Bacillus cereus keratitis associated with contact lens wear | journal = Ophthalmology | volume = 108 | issue = 10 | pages = 1830–1834 | date = October 2001 | pmid = 11581057 | doi = 10.1016/S0161-6420(01)00723-0 }}</ref>

While often associated with gastrointestinal illness, ''B. cereus'' is also associated with illnesses such as fulminant bacterial infection, central nervous system involvement, respiratory tract infection, and endophthalmitis. Endophthalmitis is the most common form of extra-gastrointestinal pathogenesis, which is an infection of the eye that may cause permanent vision loss. Infections typically cause a corneal ring abscess, followed by other symptoms such as pain, proptosis, and retinal hemorrhage.<ref>{{Cite web | vauthors = McDowell RH, Sands EM, Friedman H |date=September 12, 2022 |title=Bacillus Cereus |pmid=29083665 |url=https://www.ncbi.nlm.nih.gov/books/NBK459121/ |access-date=October 27, 2022}}</ref> While different from ''B. anthracis, B. cereus'' contains some toxin genes originally found in ''B. anthracis'' that are attributed to anthrax-like respiratory tract infections.<ref name="Bottone-2010">{{cite journal | vauthors = Bottone EJ | title = Bacillus cereus, a volatile human pathogen | journal = Clinical Microbiology Reviews | volume = 23 | issue = 2 | pages = 382–398 | date = April 2010 | pmid = 20375358 | pmc = 2863360 | doi = 10.1128/CMR.00073-09 }}</ref>

A case study was published in 2019 of a [[catheter]]-related bloodstream infection of ''B.&nbsp;cereus'' in a 91-year-old male previously being treated with [[hemodialysis]] via PermCath for end-stage [[renal disease]]. He presented with chills, [[tachypnea]], and high-grade fever, his [[white blood cell count]] and [[high-sensitivity C-reactive protein]] (CRP) were significantly elevated, and [[CT imaging]] revealed a thoracic [[aortic aneurysm]]. He was successfully treated for the aneurysm with intravenous [[vancomycin]], oral [[fluoroquinolone]]s, and PermCath removal.<ref>{{cite journal | vauthors = Wu TC, Pai CC, Huang PW, Tung CB | title = Infected aneurysm of the thoracic aorta probably caused by Bacillus cereus: a case report | journal = BMC Infectious Diseases | volume = 19 | issue = 1 | pages = 959 | date = November 2019 | pmid = 31711418 | pmc = 6849281 | doi = 10.1186/s12879-019-4602-2 | doi-access = free }}</ref> Another case study of ''B. cereus'' infection was published in 2021 of a 30-year-old woman with lupus who was diagnosed with infective endocarditis after receiving a catheter. The blood samples were positive for B. cereus and the patient was subsequently treated with vancomycin. PCR was also used to verify toxins that the isolate produces.<ref>{{cite journal | vauthors = Ribeiro RL, Bastos MO, Blanz AM, Rocha JA, Velasco NA, Marre AT, Chamon RC, Rusak LA, Vivoni AM, Martins IS | display-authors = 6 | title = Subacute infective endocarditis caused by Bacillus cereus in a patient with Systemic Lupus Erythematosus | journal = Journal of Infection in Developing Countries | volume = 16 | issue = 4 | pages = 733–736 | date = April 2022 | pmid = 35544639 | doi = 10.3855/jidc.15685 | s2cid = 248717835 | doi-access = free }}</ref>

=== Diagnosis ===

In case of [[foodborne illness]], the diagnosis of ''B.&nbsp;cereus'' can be confirmed by the isolation of more than 100,000 ''B.&nbsp;cereus'' organisms per gram from epidemiologically implicated food, but such testing is often not done because the illness is relatively harmless and usually self-limiting.<ref name="cdc">{{cite journal|url=https://www.cdc.gov/mmwr/pdf/wk/mm4310.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.cdc.gov/mmwr/pdf/wk/mm4310.pdf |archive-date=2022-10-09 |url-status=live|title=''Bacillus cereus'' food poisoning associated with fried rice at two child day care centers|journal=Morbidity and Mortality Weekly Report|publisher=[[Centers for Disease Control and Prevention]]|date=18 March 1994|volume=43|issue=10}}</ref>

=== Prognosis ===
Most emetic patients recover within 6 to 24 hours,<ref name="pmid155387092"/> but in some cases, the toxin can be fatal via [[fulminant hepatic failure]].<ref>{{cite journal | vauthors = Takabe F, Oya M | title = An autopsy case of food poisoning associated with Bacillus cereus | journal = Forensic Science | volume = 7 | issue = 2 | pages = 97–101 | date = March–April 1976 | pmid = 823082 | doi = 10.1016/0300-9432(76)90024-8 }}</ref><ref>{{cite journal | vauthors = Mahler H, Pasi A, Kramer JM, Schulte P, Scoging AC, Bär W, Krähenbühl S | title = Fulminant liver failure in association with the emetic toxin of Bacillus cereus | journal = The New England Journal of Medicine | volume = 336 | issue = 16 | pages = 1142–1148 | date = April 1997 | pmid = 9099658 | doi = 10.1056/NEJM199704173361604 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Dierick K, Van Coillie E, Swiecicka I, Meyfroidt G, Devlieger H, Meulemans A, Hoedemaekers G, Fourie L, Heyndrickx M, Mahillon J | display-authors = 6 | title = Fatal family outbreak of Bacillus cereus-associated food poisoning | journal = Journal of Clinical Microbiology | volume = 43 | issue = 8 | pages = 4277–4279 | date = August 2005 | pmid = 16082000 | pmc = 1233987 | doi = 10.1128/JCM.43.8.4277-4279.2005 }}</ref><ref>{{cite journal | vauthors = Shiota M, Saitou K, Mizumoto H, Matsusaka M, Agata N, Nakayama M, Kage M, Tatsumi S, Okamoto A, Yamaguchi S, Ohta M, Hata D | display-authors = 6 | title = Rapid detoxification of cereulide in Bacillus cereus food poisoning | journal = Pediatrics | volume = 125 | issue = 4 | pages = e951–e955 | date = April 2010 | pmid = 20194285 | doi = 10.1542/peds.2009-2319 | s2cid = 19744459 }}</ref><ref>{{cite journal | vauthors = Naranjo M, Denayer S, Botteldoorn N, Delbrassinne L, Veys J, Waegenaere J, Sirtaine N, Driesen RB, Sipido KR, Mahillon J, Dierick K | display-authors = 6 | title = Sudden death of a young adult associated with Bacillus cereus food poisoning | journal = Journal of Clinical Microbiology | volume = 49 | issue = 12 | pages = 4379–4381 | date = December 2011 | pmid = 22012017 | pmc = 3232990 | doi = 10.1128/JCM.05129-11 }}</ref> In 2014, 23 newborns in the UK receiving [[total parenteral nutrition]] contaminated with ''B.&nbsp;cereus'' developed [[sepsis]], with three of the infants later dying as a result of infection.<ref>{{cite web |date=4 June 2014 |title=Medical safety alert: Lipid Phase only of Parenteral Nutrition – potential contamination with ''Bacillus cereus'' |url=https://www.gov.uk/drug-device-alerts/drug-alert-lipid-phase-only-of-parenteral-nutrition-potential-contamination-with-bacillus-cereus |publisher=UK Medicines and Healthcare products Regulatory Agency}}</ref><ref>{{Cite news | vauthors = Cooper C |date=1 July 2014 |title=Third baby dies from contaminated 'Total Parenteral Nutrition' drip feed |work=[[The Independent]] |url=https://www.independent.co.uk/life-style/health-and-families/health-news/third-baby-dies-from-contaminated-total-parenteral-nutrition-drip-feed-9576663.html |url-status=live |archive-url=https://web.archive.org/web/20190418220544/https://www.independent.co.uk/life-style/health-and-families/health-news/third-baby-dies-from-contaminated-total-parenteral-nutrition-drip-feed-9576663.html |archive-date=18 April 2019}}</ref>

=== Prevention ===
While ''B.&nbsp;cereus'' vegetative cells are killed during normal cooking, spores are more resistant. Viable spores in food can become vegetative cells in the intestines and produce a range of diarrheal enterotoxins, so elimination of spores is desirable. In wet heat (poaching, simmering, boiling, braising, stewing, pot roasting, steaming), spores require more than 5 minutes at {{convert|121|C|F}} at the coldest spot to be destroyed. In dry heat (grilling, broiling, baking, roasting, searing, sautéing), {{convert|120|C|F}} for 1 hour kills all spores on the exposed surface.<ref name="bremer">{{cite journal | vauthors = Soni A, Oey I, Silcock P, Bremer P | title = Bacillus Spores in the Food Industry: A Review on Resistance and Response to Novel Inactivation Technologies | journal = Comprehensive Reviews in Food Science and Food Safety | volume = 15 | issue = 6 | pages = 1139–1148 | date = November 2016 | pmid = 33401831 | doi = 10.1111/1541-4337.12231 | doi-access = free }}</ref> This process of eliminating spores is very important, as spores of ''B. cereus'' are particularly resistant, even after pasteurization or exposure to gamma rays.<ref name="Whole-Genome Characterization of Ba"/>

''B.&nbsp;cereus'' and other members of ''Bacillus'' are not easily killed by alcohol; they have been known to colonize distilled liquors and alcohol-soaked swabs and pads in numbers sufficient to cause infection.<ref>{{cite web |date=25 March 2011 |title=Notes from the Field: Contamination of alcohol prep pads with ''Bacillus cereus'' group and ''Bacillus'' species — Colorado, 2010 | work = Morbidity and Mortality Weekly Report (MMWR) | location = Atlanta, Georgia |url= https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6011a5.htm |url-status=live |archive-url=https://web.archive.org/web/20180701030750/https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6011a5.htm |archive-date=1 July 2018 |publisher=[[Centers for Disease Control and Prevention]]}}</ref><ref>{{cite journal | vauthors = Hsueh PR, Teng LJ, Yang PC, Pan HL, Ho SW, Luh KT | title = Nosocomial pseudoepidemic caused by Bacillus cereus traced to contaminated ethyl alcohol from a liquor factory | journal = Journal of Clinical Microbiology | volume = 37 | issue = 7 | pages = 2280–2284 | date = July 1999 | pmid = 10364598 | pmc = 85137 | doi = 10.1128/JCM.37.7.2280-2284.1999 }}</ref>

A study of an isolate of ''Bacillus cereus'' that was isolated from the stomach of a sheep was shown to be able to break down β-[[cypermethrin]] (β-CY) which has been known to be an antimicrobial agent. This strain, known as GW-01, can break down β-CY at a significant rate when the bacterial cells are in high concentrations relative to the antimicrobial agent. It has also been noted that the ability to break down β-CY is inducible. However, as the concentration of β-CY increases, the rate of β-CY degradation decreases. This suggests that the agent also functions as a toxin against the GW-01 strain. This is significant as it shows that in the right concentrations, β-CY can be used as an antimicrobial agent against ''Bacillus cereus''.<ref>{{Cite journal |last1=Zhao |first1=Jiayuan |last2=Jiang |first2=Yangdan |last3=Gong |first3=Lanmin |last4=Chen |first4=Xiaofeng |last5=Xie |first5=Qingling |last6=Jin |first6=Yan |last7=Du |first7=Juan |last8=Wang |first8=Shufang |last9=Liu |first9=Gang |date=2022-02-15 |title=Mechanism of β-cypermethrin metabolism by Bacillus cereus GW-01 |url=https://www.sciencedirect.com/science/article/pii/S138589472104537X |journal=Chemical Engineering Journal |language=en |volume=430 |pages=132961 |doi=10.1016/j.cej.2021.132961 |s2cid=239126417 |issn=1385-8947}}</ref>

==Diseases in aquatic animals==
''Bacillus cereus'' group bacteria, notably ''B. cereus'' and ''B. thuringiensis'', are also pathogenic to multiple aquatic organisms including Chinese softshell turtle (''[[Pelodiscus sinensis]]''), causing infection characterized by gross lesions such as hepatic congestion and enlarged spleen with high mortality.<ref name="Cheng_2021">{{cite journal | vauthors = Cheng LW, Rao S, Poudyal S, Wang PC, Chen SC | title = Genotype and virulence gene analyses of Bacillus cereus group clinical isolates from the Chinese softshell turtle (Pelodiscus sinensis) in Taiwan | journal = Journal of Fish Diseases | volume = 44 | issue = 10 | pages = 1515–1529 | date = October 2021 | pmid = 34125451 | doi = 10.1111/jfd.13473 | s2cid = 235426384 }}</ref>

== Bacteriophages ==
Bacteria of the ''B.&nbsp;cereus'' group are infected by [[bacteriophage]]s belonging to the family [[Tectivirus|Tectiviridae]]. This family includes tailless phages that have a [[lipid membrane]] or vesicle beneath the icosahedral protein shell and that are formed of approximately equal amounts of virus-encoded proteins and [[lipid]]s derived from the host cell's [[Cell membrane|plasma membrane]]. Upon infection, the lipid membrane becomes a tail-like structure used in genome delivery. The genome is composed of about 15-[[kilobase]], linear, double-stranded [[DNA]] (dsDNA) with long, inverted terminal-repeat sequences (100 base pairs). GIL01, Bam35, GIL16, AP50, and Wip1 are examples of temperate tectiviruses infecting the ''B.&nbsp;cereus'' group.<ref>{{cite journal | vauthors = Gillis A, Mahillon J | title = Prevalence, genetic diversity, and host range of tectiviruses among members of the Bacillus cereus group | journal = Applied and Environmental Microbiology | volume = 80 | issue = 14 | pages = 4138–4152 | date = July 2014 | pmid = 24795369 | pmc = 4068676 | doi = 10.1128/AEM.00912-14 | bibcode = 2014ApEnM..80.4138G }}</ref> [[Bacteriophage PBC1]] is an exampled of a [[Caudoviricetes|tailed virus]] that infects ''B.&nbsp;cereus''.<ref>{{cite journal|last1=Kong|first1=Minsuk|last2=Kim |first2=Minsik |last3=Ryu |first3=Sangryeol |title=Complete Genome Sequence of ''Bacillus cereus'' Bacteriophage PBC1.|journal=Journal of Virology|date=June 2012|volume=86|issue=11|pages=6379–80|pmid=22570248|doi=10.1128/JVI.00706-12|pmc=3372192}}</ref>

== See also ==
* [[Bacillus cereus biovar anthracis|''Bacillus cereus'' biovar ''anthracis'']]

== References ==
{{Reflist|30em}}

== External links ==
{{Commons category|Bacillus cereus}}
{{Wikispecies}}
* [https://web.archive.org/web/20120315134110/http://patricbrc.org/portal/portal/patric/Taxon?cType=taxon&cId=1396 Bacillus cereus] genomes and related information at [http://patricbrc.org/ PATRIC], a Bioinformatics Resource Center funded by [https://www.niaid.nih.gov/ NIAID]
* [https://bacdive.dsmz.de/strain/624 Type strain of ''Bacillus cereus'' at Bac''Dive'' – the Bacterial Diversity Metadatabase]

{{Gram-positive bacterial diseases}}
{{Taxonbar|from=Q131307}}
{{Authority control}}

[[Category:Bacillus|cereus]]
[[Category:Food microbiology]]
[[Category:Foodborne illnesses]]
[[Category:Bacteria described in 1887]]
[[Category:Pathogenic bacteria]]