Escherichia coli O157:H7

{{Short description|Serotype of the bacteria Escherichia coli}} {{DISPLAYTITLE:''Escherichia coli'' O157:H7}} {{Infobox medical condition (new) | name = ''Escherichia coli'' O157:H7 | synonyms = | image = EColiCRIS051-Fig2.jpg | 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 | pronounce = | field = Infectious disease | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }}

'''''Escherichia coli'' O157:H7''' is a serotype of the bacterial species ''Escherichia coli'' and one of the Shiga-like toxin–producing types of ''E. coli''. It is a cause of disease, typically foodborne illness, through consumption of contaminated or 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 or 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 cramps. Usually little or no 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 cells 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== thumb|450px|''E. coli'' O157:H7

Like the other strains of the 1x ''E. coli'', O157:H7 is gram-negative and oxidase-negative. Unlike many other strains, it does not ferment sorbitol, which provides a basis for clinical laboratory differentiation of the strain. Strains of ''E. coli'' that express Shiga and Shiga-like toxins gained that ability via 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 bacterium's virulence 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 become 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 is found in the intestinal contents of some cattle, goats, and sheep.{{cn|date=August 2022}} Cows' digestive tracts lack the Shiga toxin receptor globotriaosylceramide, and thus 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 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 include undercooked ground beef, 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 virulent, with a low infectious dose: an inoculation of fewer than 10 to 100 colony-forming units (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, USDA ''2010 Food Safety Education Conference''.</ref>

==Diagnosis== A stool culture can detect the bacterium. The sample is cultured on 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 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 antibiotics 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 infection.{{cn|date=January 2023}}

Certain novel treatments, such as 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= |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, so expensive and invasive diagnostic procedures may be performed. Patients who develop HUS often require prolonged hospitalization, 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>

== References == {{Reflist}}

== External links == {{Medical resources | DiseasesDB = | ICD10 = {{ICD10|A|04|3|a|00}} | ICD9 = {{ICD9|008.04}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = }} * [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]

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

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