Bacillus cereus: Difference between revisions

Jump to navigation Jump to search
No edit summary
Line 23: Line 23:


==Pathogenesis==
==Pathogenesis==
''B. cereus'' is responsible for a minority of foodborne illnesses (2&ndash;5%). It is known to create heavy nausea, vomiting, and abdominal periods. <ref>{{cite journal | author=Kotiranta A, Lounatmaa K, Haapasalo M | title=Epidemiology and pathogenesis of ''Bacillus cereus'' infections | journal=Microbes Infect | year=2000 | pages=189-98 | volume=2 | issue=2 | id=PMID 10742691}}</ref> Generally speaking, ''Bacillus'' foodborne illnesses occur due to survival of the bacterial spores when food is improperly cooked.<ref>{{ cite book | author = Turnbull PCB | title = Bacillus. ''In:'' Baron's Medical Microbiology ''(Barron S ''et al'', eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996 | id = [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.935#939 (via NCBI Bookshelf)] ISBN 0-9631172-1-1 }}</ref> This problem is compounded when food is then improperly refrigerated, allowing the spores to germinate.<ref>{{cite journal | author=McKillip JL | title=Prevalence and expression of enterotoxins in ''Bacillus cereus'' and other ''Bacillus'' spp., a literature review | journal=Antonie Van Leeuwenhoek | year=2000 | pages=393-9 | volume=77 | issue=4 | id=PMID 10959569}}</ref> Bacterial growth results in production of [[enterotoxin]], and ingestion leads to two types of illness, diarrheal and emetic syndrome.<ref>{{cite journal | author=Ehling-Schulz M, Fricker M, Scherer S | title=''Bacillus cereus'', the causative agent of an emetic type of food-borne illness | journal=Mol Nutr Food Res | year=2004 | pages=479-87 | volume=48 | issue=7 | id=PMID 15538709}}</ref>  
* B. cereus is responsible for a minority of foodborne illnesses (2&ndash;5%). It is known to create heavy nausea, vomiting, and abdominal periods. <ref>{{cite journal | author=Kotiranta A, Lounatmaa K, Haapasalo M | title=Epidemiology and pathogenesis of ''Bacillus cereus'' infections | journal=Microbes Infect | year=2000 | pages=189-98 | volume=2 | issue=2 | id=PMID 10742691}}</ref> Generally speaking, ''Bacillus'' foodborne illnesses occur due to survival of the bacterial spores when food is improperly cooked.<ref>{{ cite book | author = Turnbull PCB | title = Bacillus. ''In:'' Baron's Medical Microbiology ''(Barron S ''et al'', eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996 | id = [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.935#939 (via NCBI Bookshelf)] ISBN 0-9631172-1-1 }}</ref> This problem is compounded when food is then improperly refrigerated, allowing the spores to germinate.<ref>{{cite journal | author=McKillip JL | title=Prevalence and expression of enterotoxins in ''Bacillus cereus'' and other ''Bacillus'' spp., a literature review | journal=Antonie Van Leeuwenhoek | year=2000 | pages=393-9 | volume=77 | issue=4 | id=PMID 10959569}}</ref> Bacterial growth results in production of [[enterotoxin]], and ingestion leads to two types of illness, diarrheal and emetic syndrome.<ref>{{cite journal | author=Ehling-Schulz M, Fricker M, Scherer S | title=''Bacillus cereus'', the causative agent of an emetic type of food-borne illness | journal=Mol Nutr Food Res | year=2004 | pages=479-87 | volume=48 | issue=7 | id=PMID 15538709}}</ref>  
:*The diarrheal type is associated with a wide-range of foods, has an 8&ndash;16 hour incubation time and is associated with diarrhea and [[gastrointestinal]] pain. Also know as the ''long-incubation'' form of ''B. cereus'' food poisoning, it can be difficult to differentiate from poisoning caused by ''[[Clostridium perfringens]]''.<ref name=Todar>{{cite web | title=''Bacillus cereus'' | work=Todar's Online Textbook of Bacteriology  | url=http://textbookofbacteriology.net/B.cereus.html | accessdate=2006-04-10}}</ref>
:*The diarrheal type is associated with a wide-range of foods, has an 8&ndash;16 hour incubation time and is associated with diarrhea and [[gastrointestinal]] pain. Also know as the ''long-incubation'' form of ''B. cereus'' food poisoning, it can be difficult to differentiate from poisoning caused by ''[[Clostridium perfringens]]''.<ref name=Todar>{{cite web | title=''Bacillus cereus'' | work=Todar's Online Textbook of Bacteriology  | url=http://textbookofbacteriology.net/B.cereus.html | accessdate=2006-04-10}}</ref>
:*In the emetic form, cooked rice that is improperly refrigerated is the most common cause, leading to nausea and vomiting 1&ndash;5 hours after consumption. This form can be difficult to distinguish from other short-term bacterial foodborne pathogens (e.g. ''[[Staphylococcus aureus]]'').<ref name=Todar />
:*In the emetic form, cooked rice that is improperly refrigerated is the most common cause, leading to nausea and vomiting 1&ndash;5 hours after consumption. This form can be difficult to distinguish from other short-term bacterial foodborne pathogens (e.g. ''[[Staphylococcus aureus]]'').<ref name=Todar />
It was previously thought that the timing of the toxin production might be responsible for the two different types, but in fact the emetic syndrome is caused by a toxin called cereulide that is found only in emetic strains and is not part of the 'standard toolbox' of ''B. cereus''. Cereulide a dodecadepsipeptide produced by non-ribosomal peptide synthesis (NRPS), which is somewhat unusual in itself. It was shown independently by two research groups to be encoded on a plasmid, which is called pCERE01 <ref>{{cite journal | author=Hoton FM, Andrup L, Swiecicka I, Mahillon J | title=The cereulide genetic determinants of emetic ''Bacillus cereus'' are plasmid-borne. | journal=Microbiology | year=2005 | pages=2121-4 | volume=151 | issue=7 | id=PMID 16000702}}</ref>  or pBCE4810 <ref>{{cite journal | author=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 Microbiol | year=2006 | volume=6 | issue=20 | id=PMID 16512902}}</ref>. Interestingly, this plasmid shares a common backbone with the virulence plasmid pXO1, which encodes the anthrax toxin genes in ''B. anthracis'', but with a different pathogenicity island. Periodontal isolates of ''B. cereus'' also possess distinct pXO1-like plasmids.
* It was previously thought that the timing of the toxin production might be responsible for the two different types, but in fact the emetic syndrome is caused by a toxin called cereulide that is found only in emetic strains and is not part of the 'standard toolbox' of ''B. cereus''. Cereulide a dodecadepsipeptide produced by non-ribosomal peptide synthesis (NRPS), which is somewhat unusual in itself. It was shown independently by two research groups to be encoded on a plasmid, which is called pCERE01 <ref>{{cite journal | author=Hoton FM, Andrup L, Swiecicka I, Mahillon J | title=The cereulide genetic determinants of emetic ''Bacillus cereus'' are plasmid-borne. | journal=Microbiology | year=2005 | pages=2121-4 | volume=151 | issue=7 | id=PMID 16000702}}</ref>  or pBCE4810 <ref>{{cite journal | author=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 Microbiol | year=2006 | volume=6 | issue=20 | id=PMID 16512902}}</ref>. Interestingly, this plasmid shares a common backbone with the virulence plasmid pXO1, which encodes the anthrax toxin genes in ''B. anthracis'', but with a different pathogenicity island. Periodontal isolates of ''B. cereus'' also possess distinct pXO1-like plasmids.


==Gallery==
==Gallery==

Revision as of 12:27, 6 August 2015

Bacillus cereus
B. cereus on sheep blood agar plate.
B. cereus on sheep blood agar plate.
Scientific classification
Kingdom: Bacteria
Phylum: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Bacillaceae
Genus: Bacillus
Species: cereus
Binomial name
Bacillus cereus
Frankland & Frankland 1887

WikiDoc Resources for Bacillus cereus

Articles

Most recent articles on Bacillus cereus

Most cited articles on Bacillus cereus

Review articles on Bacillus cereus

Articles on Bacillus cereus in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Bacillus cereus

Images of Bacillus cereus

Photos of Bacillus cereus

Podcasts & MP3s on Bacillus cereus

Videos on Bacillus cereus

Evidence Based Medicine

Cochrane Collaboration on Bacillus cereus

Bandolier on Bacillus cereus

TRIP on Bacillus cereus

Clinical Trials

Ongoing Trials on Bacillus cereus at Clinical Trials.gov

Trial results on Bacillus cereus

Clinical Trials on Bacillus cereus at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Bacillus cereus

NICE Guidance on Bacillus cereus

NHS PRODIGY Guidance

FDA on Bacillus cereus

CDC on Bacillus cereus

Books

Books on Bacillus cereus

News

Bacillus cereus in the news

Be alerted to news on Bacillus cereus

News trends on Bacillus cereus

Commentary

Blogs on Bacillus cereus

Definitions

Definitions of Bacillus cereus

Patient Resources / Community

Patient resources on Bacillus cereus

Discussion groups on Bacillus cereus

Patient Handouts on Bacillus cereus

Directions to Hospitals Treating Bacillus cereus

Risk calculators and risk factors for Bacillus cereus

Healthcare Provider Resources

Symptoms of Bacillus cereus

Causes & Risk Factors for Bacillus cereus

Diagnostic studies for Bacillus cereus

Treatment of Bacillus cereus

Continuing Medical Education (CME)

CME Programs on Bacillus cereus

International

Bacillus cereus en Espanol

Bacillus cereus en Francais

Business

Bacillus cereus in the Marketplace

Patents on Bacillus cereus

Experimental / Informatics

List of terms related to Bacillus cereus

Overview

Bacillus cereus is an endemic, soil-dwelling, Gram-positive, rod shaped, beta hemolytic bacteria that causes foodborne illness.[1] It is the cause of "Fried Rice Syndrome". B. cereus bacteria are facultative aerobes, and like other members of the genus Bacillus can produce protective endospores.

Pathogenesis

  • B. cereus is responsible for a minority of foodborne illnesses (2–5%). It is known to create heavy nausea, vomiting, and abdominal periods. [2] Generally speaking, Bacillus foodborne illnesses occur due to survival of the bacterial spores when food is improperly cooked.[3] This problem is compounded when food is then improperly refrigerated, allowing the spores to germinate.[4] Bacterial growth results in production of enterotoxin, and ingestion leads to two types of illness, diarrheal and emetic syndrome.[5]
  • The diarrheal type is associated with a wide-range of foods, has an 8–16 hour incubation time and is associated with diarrhea and gastrointestinal pain. Also know as the long-incubation form of B. cereus food poisoning, it can be difficult to differentiate from poisoning caused by Clostridium perfringens.[6]
  • In the emetic form, cooked rice that is improperly refrigerated is the most common cause, leading to nausea and vomiting 1–5 hours after consumption. This form can be difficult to distinguish from other short-term bacterial foodborne pathogens (e.g. Staphylococcus aureus).[6]
  • It was previously thought that the timing of the toxin production might be responsible for the two different types, but in fact the emetic syndrome is caused by a toxin called cereulide that is found only in emetic strains and is not part of the 'standard toolbox' of B. cereus. Cereulide a dodecadepsipeptide produced by non-ribosomal peptide synthesis (NRPS), which is somewhat unusual in itself. It was shown independently by two research groups to be encoded on a plasmid, which is called pCERE01 [7] or pBCE4810 [8]. Interestingly, this plasmid shares a common backbone with the virulence plasmid pXO1, which encodes the anthrax toxin genes in B. anthracis, but with a different pathogenicity island. Periodontal isolates of B. cereus also possess distinct pXO1-like plasmids.

Gallery

Treatment

Antimicrobial Regimen

  • 1. Food poisoning[10]
  • Preferred regimen: Food poisoning is usually self-limited and requires no antibiotic therapy.
  • 2. Bacteremia
  • Preferred regimen: Vancomycin 15 mg/kg IV q12h
  • Alternative regimen: Clindamycin 600 mg IV q8h
  • Note (1): Bacillus cereus is commonly resistant to beta-lactams.
  • Note (2): Pseudobacteremia is transient and usually results from contaminated blood cultures, gloves, or syringes.
  • 3. Meningitis or brain abscess
  • Preferred regimen: Vancomycin 15 mg/kg IV q12h
  • Alternative regimen: Clindamycin 600 mg IV q8h
  • Note: Blood culture isolates are mostly contaminates until proven otherwise, especially in intravenous drug user population.
  • 4. Endophthalmitis
  • Preferred regimen: Clindamycin 450 μg intravitreal AND Gentamicin 400 μg intravitreal OR Dexamethasone intravitreal AND Vancomycin 15 mg/kg IV q12h
  • Alternative regimen: Clindamycin 600 mg IV q8h
  • Note: Ophthalmological consultation, culture ocular fluids, early vitrectomy, and intravitreal antibiotics are necessary.
  • 5. Endocarditis
  • Preferred regimen: Vancomycin 15 mg/kg IV q12h
  • Note: Most blood cultures in intravenous drug users are contaminates or represent transient bacteremia.
  • 6. Soft tissue infection
  • 7. Pneumonia

References

  1. Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. ISBN 0-8385-8529-9.
  2. Kotiranta A, Lounatmaa K, Haapasalo M (2000). "Epidemiology and pathogenesis of Bacillus cereus infections". Microbes Infect. 2 (2): 189–98. PMID 10742691.
  3. Turnbull PCB (1996). Bacillus. In: Baron's Medical Microbiology (Barron S et al, eds.) (4th ed. ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
  4. McKillip JL (2000). "Prevalence and expression of enterotoxins in Bacillus cereus and other Bacillus spp., a literature review". Antonie Van Leeuwenhoek. 77 (4): 393–9. PMID 10959569.
  5. Ehling-Schulz M, Fricker M, Scherer S (2004). "Bacillus cereus, the causative agent of an emetic type of food-borne illness". Mol Nutr Food Res. 48 (7): 479–87. PMID 15538709.
  6. 6.0 6.1 "Bacillus cereus". Todar's Online Textbook of Bacteriology. Retrieved 2006-04-10.
  7. Hoton FM, Andrup L, Swiecicka I, Mahillon J (2005). "The cereulide genetic determinants of emetic Bacillus cereus are plasmid-borne". Microbiology. 151 (7): 2121–4. PMID 16000702.
  8. Ehling-Schulz M, Fricker M, Grallert H, Rieck P, Wagner M, Scherer S (2006). "Cereulide synthetase gene cluster from emetic Bacillus cereus: structure and location on a mega virulence plasmid related to Bacillus anthracis toxin plasmid pXO1". BMC Microbiol. 6 (20). PMID 16512902.
  9. 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 "Public Health Image Library (PHIL)".
  10. Bartlett, John (2012). Johns Hopkins ABX guide : diagnosis and treatment of infectious diseases. Burlington, MA: Jones and Bartlett Learning. ISBN 978-1449625580.