Editing Helicobacter pylori (section)

==History==
{{See also|Timeline of peptic ulcer disease and Helicobacter pylori}}''Helicobacter pylori'' [[Recent African origin of modern humans|migrated out of Africa]] along with its human host around 60,000&nbsp;years ago.<ref name=Correa2012>{{cite journal | vauthors = Correa P, Piazuelo MB | title = Evolutionary History of the Helicobacter pylori Genome: Implications for Gastric Carcinogenesis | journal = Gut and Liver | volume = 6 | issue = 1 | pages = 21–8 | date = January 2012 | pmid = 22375167 | pmc = 3286735 | doi = 10.5009/gnl.2012.6.1.21 |doi-access=free}}
</ref> Research has shown that [[genetic diversity]] in ''H.&nbsp;pylori'', like that of its host, decreases with geographic distance from [[Eastern Africa|East Africa]]. Using the genetic diversity data, researchers have created simulations that indicate the bacteria seem to have spread from East Africa around 58,000&nbsp;years ago. Their results indicate modern humans were already infected by ''H.&nbsp;pylori'' before their migrations out of Africa, and it has remained associated with human hosts since that time.<ref>{{cite journal | vauthors = Linz B, Balloux F, Moodley Y, Manica A, Liu H, Roumagnac P, Falush D, Stamer C, Prugnolle F, van der Merwe SW, Yamaoka Y, Graham DY, Perez-Trallero E, Wadstrom T, Suerbaum S, Achtman M | title = An African origin for the intimate association between humans and Helicobacter pylori | journal = Nature | volume = 445 | issue = 7130 | pages = 915–918 | date = February 2007 | pmid = 17287725 | pmc = 1847463 | doi = 10.1038/nature05562 | bibcode = 2007Natur.445..915L }}</ref>

''H.&nbsp;pylori'' was first discovered in the stomachs of patients with gastritis and [[ulcers]] in 1982 by [[Barry Marshall]] and [[Robin Warren]] of [[Perth, Western Australia]]. At the time, the conventional thinking was that no bacterium could live in the acid environment of the human stomach. In recognition of their discovery, Marshall and Warren were awarded the 2005&nbsp;[[Nobel Prize in Physiology or Medicine]].<ref>{{cite web |url=https://www.nobelprize.org/prizes/medicine/2005/summary/ |title=The Nobel Prize in Physiology or Medicine 2005 |access-date=30 August 2018 |archive-date=23 May 2020 |archive-url=https://web.archive.org/web/20200523072638/https://www.nobelprize.org/prizes/medicine/2005/summary/ |url-status=live }}</ref>

Before the research of Marshall and Warren, German scientists found spiral-shaped [[bacteria]] in the lining of the human stomach in 1875, but they were unable to [[Microbiological culture|culture]] them, and the results were eventually forgotten.<ref name=Blaser_2005>{{cite journal | vauthors = Blaser MJ | title = An endangered species in the stomach | journal = Scientific American | volume = 292 | issue = 2 | pages = 38–45 | date = February 2005 | pmid = 15715390 | doi = 10.1038/scientificamerican0205-38 | bibcode = 2005SciAm.292b..38B }}</ref> The Italian researcher [[Giulio Bizzozero]] described similarly shaped bacteria living in the acidic environment of the stomach of dogs in 1893.<ref>{{cite journal |vauthors=Bizzozero G |s2cid=85338121 |author-link=Giulio Bizzozero |year=1893 |title=Ueber die schlauchförmigen Drüsen des Magendarmkanals und die Beziehungen ihres Epitheles zu dem Oberflächenepithel der Schleimhaut |journal=Archiv für Mikroskopische Anatomie |volume=42 |pages=82–152 |doi=10.1007/BF02975307 |url=https://zenodo.org/record/1702379 |access-date=29 June 2019 |archive-date=2 December 2020 |archive-url=https://web.archive.org/web/20201202011115/https://zenodo.org/record/1702379 |url-status=live }}</ref> Professor [[Walery Jaworski]] of the [[Jagiellonian University]] in [[Kraków]] investigated sediments of gastric washings obtained by [[Gastric lavage|lavage]] from humans in 1899. Among some rod-like bacteria, he also found bacteria with a characteristic spiral shape, which he called ''Vibrio rugula''. He was the first to suggest a possible role of this organism in the pathogenesis of gastric diseases. His work was included in the ''Handbook of Gastric Diseases'', but it had little impact, as it was published only in Polish.<ref>{{cite journal | vauthors = Konturek JW | title = Discovery by Jaworski of Helicobacter pylori and its pathogenetic role in peptic ulcer, gastritis and gastric cancer | journal = Journal of Physiology and Pharmacology | volume = 54 | issue = Suppl 3 | pages = 23–41 | date = December 2003 | pmid = 15075463 | url = http://www.jpp.krakow.pl/journal/archive/1203_s3/pdf/23_1203_s3_article.pdf | access-date = 25 August 2008 | archive-url = https://web.archive.org/web/20040930111720/http://www.jpp.krakow.pl/journal/archive/1203_s3/pdf/23_1203_s3_article.pdf | archive-date = 30 September 2004 }}</ref> Several small studies conducted in the early 20th century demonstrated the presence of curved rods in the stomachs of many people with peptic ulcers and stomach cancers.<ref name="Egan 2007">{{cite journal | vauthors = Egan BJ, O'Morain CA | title = A historical perspective of Helicobacter gastroduodenitis and its complications | journal = Best Practice & Research. Clinical Gastroenterology | volume = 21 | issue = 2 | pages = 335–46 | year = 2007 | pmid = 17382281 | doi = 10.1016/j.bpg.2006.12.002 }}</ref> Interest in the bacteria waned, however, when an American study published in 1954 failed to observe the bacteria in 1180 stomach biopsies.<ref name="Palmer 1954">{{cite journal | vauthors = Palmer ED | title = Investigation of the gastric mucosa spirochetes of the human | journal = Gastroenterology | volume = 27 | issue = 2 | pages = 218–20 | date = August 1954 | pmid = 13183283 | doi = 10.1016/S0016-5085(19)36173-6 }}</ref>

Interest in understanding the role of bacteria in stomach diseases was rekindled in the 1970s, with the visualization of bacteria in the stomachs of people with gastric ulcers.<ref name="Steer 1975">{{cite journal | vauthors = Steer HW | title = Ultrastructure of cell migration {{sic|thro|ught|nolink=y}} the gastric epithelium and its relationship to bacteria | journal = Journal of Clinical Pathology | volume = 28 | issue = 8 | pages = 639–46 | date = August 1975 | pmid = 1184762 | pmc = 475793 | doi = 10.1136/jcp.28.8.639 }}</ref> The bacteria had also been observed in 1979, by Robin Warren, who researched it further with Barry Marshall from 1981. After unsuccessful attempts at culturing the bacteria from the stomach, they finally succeeded in visualizing colonies in 1982, when they unintentionally left their [[Petri dishes]] incubating for five days over the [[Easter]] weekend. In their original paper, Warren and Marshall contended that most stomach ulcers and gastritis were caused by bacterial infection and not by [[stress (medicine)|stress]] or [[Spice|spicy food]], as had been assumed before.<ref name="Unidentified curved bacilli in the">{{cite journal | vauthors = Marshall BJ, Warren JR | title = Unidentified curved bacilli in the stomach of patients with gastritis and peptic ulceration | journal = Lancet | volume = 1 | issue = 8390 | pages = 1311–5 | date = June 1984 | pmid = 6145023 | doi = 10.1016/S0140-6736(84)91816-6 | s2cid = 10066001 }}</ref>

Some skepticism was expressed initially, but within a few years multiple research groups had verified the association of ''H.&nbsp;pylori'' with gastritis and, to a lesser extent, ulcers.<ref>{{cite web |url=http://www.csicop.org/si/show/bacteria_ulcers_and_ostracism_h._pylori_and_the_making_of_a_myth/ |title=Bacteria, Ulcers, and Ostracism? ''H.&nbsp;pylori'' and the making of a myth |year=2004 |last=Atwood |first=K.C. IV |access-date=2 August 2008 |archive-date=5 November 2009 |archive-url=https://web.archive.org/web/20091105131647/http://www.csicop.org/si/show/bacteria_ulcers_and_ostracism_h._pylori_and_the_making_of_a_myth |url-status=live }}</ref> To demonstrate ''H.&nbsp;pylori'' caused gastritis and was not merely a bystander, Marshall drank a beaker of ''H.&nbsp;pylori'' culture. He became ill with nausea and vomiting several days later. An endoscopy 10&nbsp;days after inoculation revealed signs of gastritis and the presence of ''H.&nbsp;pylori''. These results suggested ''H.&nbsp;pylori'' was the causative agent. Marshall and Warren went on to demonstrate antibiotics are effective in the treatment of many cases of gastritis. In 1994, the [[National Institutes of Health]] stated most recurrent duodenal and gastric ulcers were caused by ''H.&nbsp;pylori'', and recommended antibiotics be included in the treatment regimen.<ref>{{cite report |title=''Helicobacter pylori'' in peptic ulcer disease |series=NIH Consensus Statement Online |date=7–9 January 1994 |volume=12 |issue=1 |pages=1–23 |access-date=21 December 2004 |url=http://consensus.nih.gov/1994/1994HelicobacterPyloriUlcer094html.htm |archive-date=19 August 2011 |archive-url=https://web.archive.org/web/20110819144041/http://consensus.nih.gov/1994/1994HelicobacterPyloriUlcer094html.htm |url-status=dead }}</ref>

The bacterium was initially named ''Campylobacter pyloridis'', then renamed ''C.&nbsp;pylori'' in 1987 (''pylori'' being the [[genitive]] of ''[[pylorus]]'', the circular opening leading from the stomach into the duodenum, from the [[Ancient Greek]] word ''πυλωρός'', which means [[gatekeeper]]<ref name=Liddell1980/>).<ref>{{cite journal |vauthors=Marshall BS, Goodwin CS |title=Revised nomenclature of ''Campylobacter pyloridis'' |journal=International Journal of Systematic Bacteriology |volume=37 |issue=1 |year=1987 |pages = 68 |doi=10.1099/00207713-37-1-68|doi-access=free }}</ref> When [[16S ribosomal RNA]] [[DNA sequencing|gene sequencing]] and other research showed in 1989 that the bacterium did not belong in the genus ''[[Campylobacter]]'', it was placed in its own [[genus]], ''Helicobacter'' from the Ancient Greek ''έλιξ'' (''hělix'') "spiral" or "coil".<ref name=Liddell1980>{{cite book |author1-link=Henry George Liddell |last1=Liddell |first1=Henry G. |author2-link=Robert Scott (philologist) |last2=Scott |first2=Robert |title=A Lexicon: Abridged from Liddell and Scott's Greek-English Lexicon |publisher=Oxford University Press |place=Oxford, UK |year=1966 |isbn=978-0-19-910207-5 |url-access=registration |url=https://archive.org/details/lexicon00lidd}}</ref><ref>{{cite journal |vauthors=Goodwin CS, Armstrong JA, Chilvers T, Peters M, Collins MD, Sly L, McConnell W, Harper WE |title=Transfer of ''Campylobacter pylori'' and ''Campylobacter mustelae'' to ''Helicobacter'' gen. nov. as ''Helicobacter pylori'' comb. nov. and ''Helicobacter mustelae'' comb. nov. respectively |journal=International Journal of Systematic Bacteriology |volume=39 |issue=4 |year=1989 |pages=397–405 |doi=10.1099/00207713-39-4-397|doi-access=free }}</ref>

In October 1987, a group of experts met in Copenhagen to found the European Helicobacter Study Group (EHSG), an international multidisciplinary research group and the only institution focused on ''H.&nbsp;pylori''.<ref>{{cite journal | vauthors = Buckley MJ, O'Morain CA | title = Helicobacter biology--discovery | journal = British Medical Bulletin | volume = 54 | issue = 1 | pages = 7–16 | year = 1998 | pmid = 9604426 | doi = 10.1093/oxfordjournals.bmb.a011681 | doi-access = free }}</ref> The Group is involved with the Annual International Workshop on Helicobacter and Related Bacteria,<ref>{{cite journal | vauthors = Mégraud F | title = Evolution of Helicobacter pylori research as observed through the workshops of the European Helicobacter Study Group | journal = Helicobacter | volume = 12 Suppl 2 | issue = Suppl&nbsp;2 | pages = 1–5 | date = November 2007 | pmid = 17991169 | doi = 10.1111/j.1523-5378.2007.00581.x | s2cid = 45841196 | collaboration = European Helicobacter Study Group }}</ref> (renamed as the European Helicobacter and Microbiota Study Group<ref name="EHMSG">{{cite web |title=EHMSG |url=https://www.ehmsg.org/ |website=Ehmsg2019 |access-date=11 January 2024 |language=en |archive-date=11 January 2024 |archive-url=https://web.archive.org/web/20240111084024/https://www.ehmsg.org/ |url-status=live }}</ref>), the Maastricht Consensus Reports (European Consensus on the management of ''H.&nbsp;pylori''),<ref name="Report 2012">{{cite journal | vauthors = Malfertheiner P, Megraud F, O'Morain CA, Atherton J, Axon AT, Bazzoli F, Gensini GF, Gisbert JP, Graham DY, Rokkas T, El-Omar EM, Kuipers EJ | title = Management of Helicobacter pylori infection--the Maastricht IV/ Florence Consensus Report | journal = Gut | volume = 61 | issue = 5 | pages = 646–64 | date = May 2012 | pmid = 22491499 | doi = 10.1136/gutjnl-2012-302084 | url = http://gut.bmj.com/content/61/5/646.long | s2cid = 1401974 | collaboration = European Helicobacter Study Group | doi-access = free | hdl = 1765/64813 | hdl-access = free | access-date = 7 December 2012 | archive-date = 4 July 2021 | archive-url = https://web.archive.org/web/20210704233427/https://gut.bmj.com/content/61/5/646.long | url-status = live }}</ref><ref name=Maastricht_2_Consensus_Report>{{cite journal | vauthors = Malfertheiner P, Megraud F, O'Morain C, Bazzoli F, El-Omar E, Graham D, Hunt R, Rokkas T, Vakil N, Kuipers EJ | title = Current concepts in the management of Helicobacter pylori infection: the Maastricht III Consensus Report | journal = Gut | volume = 56 | issue = 6 | pages = 772–81 | date = June 2007 | pmid = 17170018 | pmc = 1954853 | doi = 10.1136/gut.2006.101634 }}</ref><ref>{{cite journal | vauthors = Malfertheiner P, Mégraud F, O'Morain C, Hungin AP, Jones R, Axon A, Graham DY, Tytgat G | title = Current concepts in the management of Helicobacter pylori infection--the Maastricht 2-2000 Consensus Report | journal = Alimentary Pharmacology & Therapeutics | volume = 16 | issue = 2 | pages = 167–80 | date = February 2002 | pmid = 11860399 | doi = 10.1046/j.1365-2036.2002.01169.x | collaboration = European Helicobacter Pylori Study Group (EHPSG) | s2cid = 6166458 }}</ref><ref>{{cite journal | vauthors = Malfertheiner P, Mégraud F, O'Morain C, Bell D, Bianchi Porro G, Deltenre M, Forman D, Gasbarrini G, Jaup B, Misiewicz JJ, Pajares J, Quina M, Rauws E | title = Current European concepts in the management of Helicobacter pylori infection--the Maastricht Consensus Report. The European Helicobacter Pylori Study Group (EHPSG) | journal = European Journal of Gastroenterology & Hepatology | volume = 9 | issue = 1 | pages = 1–2 | date = January 1997 | pmid = 9031888 | doi = 10.1097/00042737-199701000-00002 | collaboration = European Helicobacter Pylori Study Group (EHPSG) | s2cid = 36930542 }}</ref> and other educational and research projects, including two international long-term projects:
* European Registry on ''H.&nbsp;pylori'' Management (Hp-EuReg) – a database systematically registering the routine clinical practice of European gastroenterologists.<ref>{{cite journal |vauthors=McNicholl AG, Gasbarrini A, Tepes B |display-authors=etal |title=Pan-European registry on ''H.&nbsp;pylori'' management (Hp-EuReg): Interim analysis of 5,792&nbsp;patients |journal=Helicobacter |date=September 2014 |volume=2014 |pages = 69}}</ref>
* Optimal ''H.&nbsp;pylori'' management in primary care (OptiCare) – a long-term educational project aiming to disseminate the evidence based recommendations of the Maastricht&nbsp;IV Consensus to primary care physicians in Europe, funded by an educational grant from [[United European Gastroenterology]].<ref>{{cite web |url=https://www.ueg.eu/education/courses/online-courses/helicobacter-pylori/ |title=Management of ''Helicobacter pylori'' infection |series=Online courses |publisher=[[United European Gastroenterology]] |archive-url=https://web.archive.org/web/20150402195040/https://www.ueg.eu/education/courses/online-courses/helicobacter-pylori/ |archive-date=2 April 2015}}</ref><ref>{{cite web |url=https://www.ueg.eu/fileadmin/ueg/UEG.AnnualReport.2012/page31.html |title=Annual Report 2012 |publisher=[[United European Gastroenterology]] |access-date=25 February 2015 |archive-date=4 June 2016 |archive-url=https://web.archive.org/web/20160604212022/https://www.ueg.eu/fileadmin/ueg/UEG.AnnualReport.2012/page31.html |url-status=dead }}</ref>