View source for Escherichia coli O157:H7

{{Short description|Serotype of the bacteria Escherichia coli}}
{{DISPLAYTITLE:''Escherichia coli'' O157:H7}}
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| caption       = Topographical images of colonies of ''E. coli'' O157:H7 strains (A) 43895OW (''[[curli]]'' non-producing) and (B) 43895OR (''curli'' producing) grown on agar for 48 h at 28°C
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| field         = [[Infectious disease (speciality)|Infectious disease]]
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'''''Escherichia coli'' O157:H7''' is a [[serotype]] of the bacterial species ''[[Escherichia coli]]'' and is one of the [[Shigatoxigenic and verotoxigenic Escherichia coli|Shiga-like toxin–producing types]] of ''E. coli''. It is a cause of [[disease]], typically [[foodborne illness]], through consumption of contaminated and raw food, including [[raw milk]] and undercooked [[ground beef]].<ref name=Gally_2017>{{cite journal | vauthors = Gally DL, Stevens MP | title = Microbe Profile: Escherichia coli O157:H7 - notorious relative of the microbiologist's workhorse | journal = Microbiology | volume = 163 | issue = 1 | pages = 1–3 | date = January 2017 | pmid = 28218576 | doi = 10.1099/mic.0.000387 | url = https://www.research.ed.ac.uk/portal/files/31527884/1_micro000387.pdf | doi-access = free }}</ref><ref name=Karch_2005>{{cite journal | vauthors = Karch H, Tarr PI, Bielaszewska M | title = Enterohaemorrhagic Escherichia coli in human medicine | journal = International Journal of Medical Microbiology | volume = 295 | issue = 6–7 | pages = 405–18 | date = October 2005 | pmid = 16238016 | doi = 10.1016/j.ijmm.2005.06.009 }}</ref> Infection with this type of [[pathogenic bacteria]] may lead to hemorrhagic [[diarrhea]], and to [[kidney]] failure; these have been reported to cause the deaths of children younger than five years of age, of elderly patients, and of patients whose immune systems are otherwise compromised.

Transmission is via the [[fecal–oral route]], and most illness has been through distribution of contaminated raw leaf green vegetables, undercooked meat and raw milk.<ref>{{cite web|url=https://www.cdc.gov/ecoli/outbreaks.html|title=Reports of Selected E. coli Outbreak Investigations|work=CDC.gov|date=2019-11-22}}</ref>

==Signs and symptoms==
''E. coli'' O157:H7 infection often causes severe, acute hemorrhagic diarrhea (although nonhemorrhagic diarrhea is also possible) and abdominal [[cramp]]s. Usually little or no [[pyrexia|fever]] is present, and the illness resolves in 5 to 10 days.<ref>{{cite journal | vauthors = Ciccarelli S, Stolfi I, Caramia G | title = Management strategies in the treatment of neonatal and pediatric gastroenteritis | journal = Infection and Drug Resistance | volume = 6 | pages = 133–61 | date = October 2013 | pmid = 24194646 | pmc = 3815002 | doi = 10.2147/IDR.S12718 | doi-access = free }}</ref> It can also sometimes be [[asymptomatic]].<ref>{{cite journal | vauthors = Roos V, Ulett GC, Schembri MA, Klemm P | title = The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine | journal = Infection and Immunity | volume = 74 | issue = 1 | pages = 615–24 | date = January 2006 | pmid = 16369018 | pmc = 1346649 | doi = 10.1128/IAI.74.1.615-624.2006 }}</ref>

In some people, particularly children under five years of age, persons whose immunologies are otherwise compromised, and the elderly, the infection can cause [[hemolytic–uremic syndrome]] (HUS), in which the [[red blood cell]]s are destroyed and the kidneys fail. About 2–7% of infections lead to this complication. In the United States, HUS is the principal cause of [[acute kidney failure]] in children, and most cases of HUS are caused by ''E. coli'' O157:H7.{{cn|date=January 2023}}

==Bacteriology==
[[Image:E. Coli 0157.jpg|thumb|450px|''E. coli'' O157:H7]]

Like the other strains of the ''E. coli'', O157:H7 is [[gram-negative bacteria|gram-negative]] and [[oxidase|oxidase-negative]]. Unlike many other strains, it does not ferment [[sorbitol]], which [[#Diagnosis|provides a basis for clinical laboratory differentiation of the strain]]. [[Shigatoxigenic and verotoxigenic Escherichia coli|Strains of ''E. coli'' that express Shiga and Shiga-like toxins]] gained that ability via [[transduction (genetics)|infection with a prophage]] containing the structural gene coding for the toxin, and nonproducing strains may become infected and produce shiga-like toxins after incubation with shiga toxin positive strains. The [[prophage]] responsible seems to have infected the strain's ancestors fairly recently, as viral particles have been observed to replicate in the host if it is stressed in some way (e.g. antibiotics).<ref name="O'Brien_1984_65">{{cite journal | vauthors = O'Brien AD, Newland JW, Miller SF, Holmes RK, Smith HW, Formal SB | title = Shiga-like toxin-converting phages from Escherichia coli strains that cause hemorrhagic colitis or infantile diarrhea | journal = Science | volume = 226 | issue = 4675 | pages = 694–96 | date = November 1984 | pmid = 6387911 | doi = 10.1126/science.6387911 | bibcode = 1984Sci...226..694O }}</ref><ref name=Strockbine_1986_91>{{cite journal | vauthors = Strockbine NA, Marques LR, Newland JW, Smith HW, Holmes RK, O'Brien AD | title = Two toxin-converting phages from Escherichia coli O157:H7 strain 933 encode antigenically distinct toxins with similar biologic activities | journal = Infection and Immunity | volume = 53 | issue = 1 | pages = 135–40 | date = July 1986 | pmid = 3522426 | pmc = 260087 | doi =  10.1128/IAI.53.1.135-140.1986}}</ref>

All clinical isolates of ''E. coli'' O157:H7 possess the [[plasmid]] [[pO157]].<ref name=Lim2010>{{cite journal | vauthors = Lim JY, Yoon J, Hovde CJ | title = A brief overview of Escherichia coli O157:H7 and its plasmid O157 | journal = Journal of Microbiology and Biotechnology | volume = 20 | issue = 1 | pages = 5–14 | date = January 2010 | pmid = 20134227 | pmc = 3645889 | doi =  10.4014/jmb.0908.08007}}</ref>  The periplasmic [[catalase]] is encoded on pO157 and may enhance the virulence of the bacterium by providing additional oxidative protection when infecting the host.<ref name=Brunder_1996_11>{{cite journal | vauthors = Brunder W, Schmidt H, Karch H | title = KatP, a novel catalase-peroxidase encoded by the large plasmid of enterohaemorrhagic Escherichia coli O157:H7 | journal = Microbiology | volume = 142 ( Pt 11) | issue = 11 | pages = 3305–15 | date = November 1996 | pmid = 8969527 | doi = 10.1099/13500872-142-11-3305 | doi-access = free }}</ref> ''E. coli'' O157:H7 non-hemorrhagic strains are converted to hemorrhagic strains by lysogenic conversion after bacteriophage infection of non-hemorrhagic cells.{{cn|date=January 2023}}

===Natural habitat===
While it is relatively uncommon, the ''E. coli'' serotype O157:H7 can naturally be found in the intestinal contents of some cattle, goats, and even sheep.{{cn|date=August 2022}} The digestive tract of cattle lack the Shiga toxin receptor [[globotriaosylceramide]], and thus, these can be asymptomatic carriers of the bacterium.<ref name=Pruimboom-Brees2000>{{cite journal | vauthors = Pruimboom-Brees IM, Morgan TW, Ackermann MR, Nystrom ED, Samuel JE, Cornick NA, Moon HW | title = Cattle lack vascular receptors for Escherichia coli O157:H7 Shiga toxins | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 97 | issue = 19 | pages = 10325–29 | date = September 2000 | pmid = 10973498 | pmc = 27023 | doi = 10.1073/pnas.190329997 | bibcode = 2000PNAS...9710325P | doi-access = free }}</ref> The prevalence of ''E. coli'' O157:H7 in North American [[feedlot]] cattle herds ranges from 0 to 60%.<ref name="pmid23405204">{{cite journal | vauthors = Jeon SJ, Elzo M, DiLorenzo N, Lamb GC, Jeong KC | title = Evaluation of animal genetic and physiological factors that affect the prevalence of Escherichia coli O157 in cattle | journal = PLOS ONE | volume = 8 | issue = 2 | article-number = e55728 | year = 2013 | pmid = 23405204 | pmc = 3566006 | doi = 10.1371/journal.pone.0055728 | bibcode = 2013PLoSO...855728J | doi-access = free }}</ref>
Some cattle may also be so-called "super-shedders" of the bacterium. Super-shedders may be defined as cattle exhibiting rectoanal junction colonization and excreting >10<sup>3 to 4</sup> CFU g<sup>−1</sup> feces. Super-shedders have been found to constitute a small proportion of the cattle in a feedlot (<10%) but they may account for >90% of all ''E. coli'' O157:H7 excreted.<ref>{{cite journal | vauthors = Chase-Topping M, Gally D, Low C, Matthews L, Woolhouse M | title = Super-shedding and the link between human infection and livestock carriage of Escherichia coli O157 | journal = Nature Reviews. Microbiology | volume = 6 | issue = 12 | pages = 904–12 | date = December 2008 | pmid = 19008890 | pmc = 5844465 | doi = 10.1038/nrmicro2029 }}</ref>

==Transmission==
Infection with ''E. coli'' O157:H7 can come from ingestion of contaminated food or water, or oral contact with contaminated surfaces. Examples of this can be undercooked ground beef but also leafy vegetables and raw milk. Fields often become contaminated with the bacterium through irrigation processes or contaminated water naturally entering the soil.<ref>{{Cite news|url=https://www.cnn.com/2018/05/02/health/e-coli-lettuce-explainer/index.html|title=Why deadly E. coli loves leafy greens|last=Scutti|first=Susan |work=CNN|access-date=2018-09-20}}</ref> It is highly [[virulence|virulent]], with a low [[infectious dose]]: an inoculation of fewer than 10 to 100 [[colony-forming unit]]s (CFU) of ''E. coli'' O157:H7 is sufficient to cause infection, compared to over a million CFU for other pathogenic ''E. coli'' strains.<ref>J.D. Greig, E.C.D. Todd, C. Bartleson, and B. Michaels. March 25, 2010. "[http://www.fsis.usda.gov/PDF/Atlanta2010/Slides_FSEC_JGreig_Doses.pdf Infective Doses and Pathen Carriage] {{Webarchive|url=https://web.archive.org/web/20101016000915/http://www.fsis.usda.gov/PDF/Atlanta2010/Slides_FSEC_JGreig_Doses.pdf |date=2010-10-16 }}", pp. 19–20, [[United States Department of Agriculture|USDA]] ''2010 Food Safety Education Conference''.</ref>

==Diagnosis==
A [[stool test|stool culture]] can detect the bacterium. The sample is cultured on [[sorbitol-MacConkey agar|sorbitol-MacConkey]] (SMAC) [[agar]], or the variant cefixime potassium tellurite sorbitol-MacConkey agar (CT-SMAC<ref>{{Cite web |url=http://www.solabia.com/solabia/produitsDiagnostic.nsf/0/27DFE62DDA44AF3AC12574C7003A6377/$file/TDS_BK147_v5.pdf |title=MACCONKEY SORBITOL AGAR (CT-SMAC) |access-date=2010-12-11 |archive-url=https://web.archive.org/web/20110716102617/http://www.solabia.com/solabia/produitsDiagnostic.nsf/0/27DFE62DDA44AF3AC12574C7003A6377/$file/TDS_BK147_v5.pdf |archive-date=2011-07-16 }}</ref>). On SMAC agar, O157:H7 colonies appear clear due to their inability to ferment sorbitol, while the colonies of the usual sorbitol-fermenting serotypes of ''E. coli'' appear red. Sorbitol non-fermenting colonies are tested for the somatic O157 antigen before being confirmed as ''E. coli'' O157:H7. Like all cultures, diagnosis is time-consuming with this method; swifter diagnosis is possible using quick ''E. coli'' DNA extraction method<ref>{{Cite web |url=http://www.fortiusbio.com/Food_Pathogen_E-coli_DNA_Extraction_Strip_Card.html |title=Quick ''E. coli'' DNA extraction filter paper card |access-date=2014-07-11 |archive-url=https://web.archive.org/web/20140717100350/http://www.fortiusbio.com/Food_Pathogen_E-coli_DNA_Extraction_Strip_Card.html |archive-date=2014-07-17 }}</ref> plus [[polymerase chain reaction]] techniques. Newer technologies using [[fluorescent]] and [[antibody]] detection are also under development.{{cn|date=January 2023}}

==Prevention==
Avoiding the consumption of, or contact with, unpasteurized dairy products, undercooked beef, uncleaned vegetables, and non disinfected  water reduces the risk of an ''E. coli'' infection. Proper [[hand washing]] with water that has been treated with adequate levels of chlorine or other effective disinfectants after using the lavatory or changing a diaper, especially among children or those with diarrhea, reduces the risk of transmission.<ref>{{Cite web|url=https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90&ContentID=P02019|title=Viruses, Bacteria, and Parasites in the Digestive Tract - Health Encyclopedia - University of Rochester Medical Center|website=www.urmc.rochester.edu|access-date=2020-01-17}}</ref><ref>{{Cite web |title=Preventing Foodborne Illness: Escherichia coli O157:H7 |url=https://wonder.cdc.gov/wonder/prevguid/p0000417/p0000417.asp#head009000000000000 |access-date=2023-11-28 |website=wonder.cdc.gov |archive-date=2023-09-23 |archive-url=https://web.archive.org/web/20230923134113/https://wonder.cdc.gov/wonder/prevguid/p0000417/p0000417.asp#head009000000000000 }}</ref>

''E. coli'' O157:H7 infection is a nationally [[reportable disease]] in the US, Great Britain, and Germany. It is also reportable in most states of Australia including Queensland.<ref>{{Cite web|url=https://academic.oup.com/cid/article-abstract/69/3/428/5146342?redirectedFrom=fulltext|title=Journal}}</ref>

==Treatment==
While fluid replacement and blood pressure support may be necessary to prevent death from dehydration, most patients recover without treatment in 5–10 days. There is no evidence that antibiotics improve the course of disease, and treatment with [[antibiotic]]s may precipitate [[hemolytic–uremic syndrome]] (HUS).<ref>{{cite journal | vauthors = Walterspiel JN, Ashkenazi S, Morrow AL, Cleary TG | title = Effect of subinhibitory concentrations of antibiotics on extracellular Shiga-like toxin I | journal = Infection | volume = 20 | issue = 1 | pages = 25–29 | year = 1992 | pmid = 1563808 | doi = 10.1007/BF01704889 | s2cid = 39513818 }}</ref> The antibiotics are thought to trigger prophage induction, and the prophages released by the dying bacteria infect other susceptible bacteria, converting them into toxin-producing forms. Antidiarrheal agents, such as [[loperamide]] (imodium), should also be avoided as they may prolong the duration of the infection.{{cn|date=January 2023}}

Certain novel treatment strategies, such as the use of anti-induction strategies to prevent toxin production<ref>{{cite journal | vauthors = Keen EC | title = Paradigms of pathogenesis: targeting the mobile genetic elements of disease | journal = Frontiers in Cellular and Infection Microbiology | volume = 2 | page = 161 | date = December 2012 | pmid = 23248780 | pmc = 3522046 | doi = 10.3389/fcimb.2012.00161 | doi-access = free }}</ref> and the use of anti-Shiga toxin antibodies,<ref>{{cite journal | vauthors = Tzipori S, Sheoran A, Akiyoshi D, Donohue-Rolfe A, Trachtman H | title = Antibody therapy in the management of shiga toxin-induced hemolytic uremic syndrome | journal = Clinical Microbiology Reviews | volume = 17 | issue = 4 | pages = 926–41, table of contents | date = October 2004 | pmid = 15489355 | pmc = 523565 | doi = 10.1128/CMR.17.4.926-941.2004 }}</ref> have also been proposed.

==History==

The common ancestor of Escherichia coli O157:H7 was found to have originated in the Netherlands around 1890 as estimated by molecular biologists. It is thought that international spread was through animal movements, like [[Holstein Friesian cattle]].<ref name="CID">{{Cite journal |last1=Franz |first1=Eelco |last2=Rotariu |first2=Ovidiu |last3=Lopes |first3=Bruno S |last4=MacRae |first4=Marion |last5=Bono |first5=James L |last6=Laing |first6=Chad |last7=Gannon |first7=Victor |last8=Söderlund |first8=Robert |last9=van Hoek |first9=Angela H A M |last10=Friesema |first10=Ingrid |last11=French |first11=Nigel P |last12=George |first12=Tessy |last13=Biggs |first13=Patrick J |last14=Jaros |first14=Patricia |last15=Rivas |first15=Marta |date=2018-10-29 |title=Phylogeographic Analysis Reveals Multiple International transmission Events Have Driven the Global Emergence of Escherichia coli O157:H7 |url=https://academic.oup.com/cid/article/69/3/428/5146342 |journal=Clinical Infectious Diseases |volume=69 |issue=3 |pages=428–437 |doi=10.1093/cid/ciy919 |pmid=30371758 |issn=1058-4838|hdl=2164/13183 |hdl-access=free |url-access=subscription }}</ref> E.coli O157:H7 is thought to have moved from Europe to Australia around 1937, to the United States in 1941, to Canada in 1960, and from Australia to New Zealand in 1966.<ref name="CID" /> 

The first recorded observation of human ''E. coli'' O157:H7 infection was in 1975, in association with a sporadic case of [[hemorrhagic colitis]], but it was not identified as pathogenic then.<ref name=riley-1983>{{cite journal |last1=Riley |first1=Lee W. |last2=Remis |first2=Robert S. |last3=Helgerson |first3=Steven D. |last4=McGee |first4=Harry B. |last5=Wells |first5=Joy G. |last6=Davis |first6=Betty R. |last7=Hebert |first7=Richard J. |last8=Olcott |first8=Ellen S. |last9=Johnson |first9=Linda M. |last10=Hargrett |first10=Nancy T. |last11=Blake |first11=Paul A. |last12=Cohen |first12=Mitchell L. |date=March 24, 1983 |title=Hemorrhagic Colitis Associated with a Rare ''Escherichia coli'' Serotype |url=https://www.nejm.org/doi/full/10.1056/nejm198303243081203 |journal=The New England Journal of Medicine |volume=308 |issue=12 |pages=681–685  |publisher=Massachusetts Medical Society |doi=10.1056/NEJM198303243081203 |pmid=6338386 |access-date=March 15, 2024|url-access=subscription }}</ref> It was first recognized as a human pathogen following a 1982 hemorrhagic colitis outbreak in [[Oregon]] and [[Michigan]], in which at least 47 people were sickened by eating beef hamburger patties from a fast food chain that were found to be contaminated with it.<ref>{{cite web |url=https://www.hopkinsmedicine.org/health/conditions-and-diseases/escherichia-coli-o157-h7 |title=Escherichia coli O157:H7 |author=<!--Not stated--> |date=September 26, 2020 |website=Johns Hopkins Medicine |publisher=Johns Hopkins University |access-date=March 15, 2024 |quote=In 1982, E. coli O157:H7 was initially identified as the cause of bloody diarrhea from eating undercooked or raw hamburger meat that was contaminated with the bacteria.}}</ref><ref>{{cite report |title=Multistate Outbreak of ''Escherichia coli'' O157:H7 Infections Associated with Eating Ground Beef --- United States, June--July 2002 |date=July 26, 2002 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5129a1.htm |publisher=The United States Centers for Disease Control and Prevention (CDC) |quote=''E. coli'' O157:H7 was first described as a cause of human illness and associated with undercooked ground beef in 1982 (1).}}</ref><ref name="riley-1983" />

The [[United States Department of Agriculture]] banned the sale of ground beef contaminated with the O157:H7 strain in 1994.<ref>{{cite news |title=Ban on E. Coli in Ground Beef Is to Extend to 6 More Strains |url=https://www.nytimes.com/2011/09/13/business/federal-officials-extend-e-coli-ban.html?scp=2&sq=Jack%20in%20the%20Box&st=cse |newspaper=[[The New York Times]] |date=September 12, 2011 |access-date=2011-10-08 }}</ref>

==Culture and society==
The pathogen results in an estimated 2,100 hospitalizations annually in the United States. The illness is often misdiagnosed; therefore, expensive and invasive diagnostic procedures may be performed. Patients who develop HUS often require prolonged hospitalization, [[Kidney dialysis|dialysis]], and long-term followup.<ref>{{Cite journal|last1=Berkenpas|first1=E.|last2=Millard|first2=P.|last3=Pereira da Cunha|first3=M.|date=2005-12-13|title=Detection of Escherichia coli O157:H7 with langasite pure shear horizontal surface acoustic wave sensors|journal=Biosensors and Bioelectronics|language=en|volume=21|issue=12|pages=2255–2262|doi=10.1016/j.bios.2005.11.005|pmid=16356708}}</ref>

== See also ==
* [[1993 Jack in the Box E. coli outbreak|1993 Jack in the Box ''E. coli'' outbreak]]
* [[1996 Odwalla E. coli outbreak|1996 Odwalla ''E. coli'' outbreak]]
* [[2011 Germany E. coli O104:H4 outbreak|2011 Germany ''E. coli'' O104:H4 outbreak]]
* [[2024 McDonald's E. coli outbreak|2024 McDonald's ''E. coli'' outbreak]]
* [[Escherichia coli O104:H4|''Escherichia coli'' O104:H4]]
* [[Escherichia coli O121|''Escherichia coli'' O121]]
* [[Food-induced purpura]]
* [[List of foodborne illness outbreaks]]
* [[Walkerton E. coli outbreak|Walkerton ''E. coli'' outbreak]]

== References ==
{{Reflist}}

== External links ==
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* [https://web.archive.org/web/20080928115921/http://www.ecoli-uk.com/ Haemolytic Uraemic Syndrome Help (HUSH) – a UK based charity]
* [https://web.archive.org/web/20120319172413/http://www.aboutkidshealth.ca/En/News/NewsAndFeatures/Pages/E-coli-Protecting-Family.aspx ''E. coli'': Protecting yourself and your family from a sometimes deadly bacterium]
* [https://web.archive.org/web/20110727165934/http://patricbrc.org/portal/portal/patric/Taxon?cType=taxon&cId=83334 Escherichia coli O157:H7] genomes and related information at [http://patricbrc.org/   PATRIC], a Bioinformatics Resource Center funded by [https://www.niaid.nih.gov/   NIAID]
* For more information about reducing your risk of foodborne illness, visit the US Department of Agriculture's [http://www.fsis.usda.gov Food Safety and Inspection Service] website or [http://fightbac.org The Partnership for Food Safety Education | Fight BAC!]
* [https://briandeer.com/e-coli-o157.htm briandeer.com], report from [[The Sunday Times]] on a UK outbreak, May 17, 1998
* [https://web.archive.org/web/20070302044727/http://cbs5.com/topstories/local_story_257194412.html CBS5 report on September 2006 outbreak]

{{Escherichia coli}}
{{Gram-negative bacterial diseases}}
{{Consumer Food Safety}}
{{Authority control}}

{{DEFAULTSORT:Escherichia Coli O157:H7}}
[[Category:Escherichia coli]]
[[Category:Bovine diseases]]
[[Category:Zoonoses]]
[[Category:Foodborne illnesses]]
[[Category:Infraspecific bacteria taxa]]
[[Category:Pathogenic bacteria]]

[[bg:Escherichia coli O157:H7]]