This is a timeline of the events relating to the discovery that peptic ulcer disease and some cancers are caused by ''H. pylori''. In 2005,

Barry Marshall Barry James Marshall (born 30 September 1951) is an Australian physician, Nobel Prize Laureate in Physiology or Medicine, Professor of Clinical Microbiology and Co-Director of the Marshall Centre at the University of Western Australia. Mars ...

and

Robin Warren John Robin Warren (born 11 June 1937, in Adelaide) is an Australian pathologist, Nobel Laureate and researcher who is credited with the 1979 re-discovery of the bacterium '' Helicobacter pylori'', together with Barry Marshall. The duo proved ...

were awarded the

Nobel Prize in Physiology or Medicine The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accordi ...

for their discovery that

peptic ulcer disease Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines ...

(PUD) was primarily caused by ''

Helicobacter pylori ''Helicobacter pylori'', previously known as ''Campylobacter pylori'', is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape (from which the genus name, helicobacter, derives) is thoug ...

'', a

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

with affinity for acidic environments, such as the

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

. As a result, PUD that is associated with ''H. pylori'' is currently treated with

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

s used to eradicate the infection. For decades prior to their discovery, it was widely believed that PUD was caused by excess

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...

in the

. During this time, acid control was the primary method of treatment for PUD, to only partial success. Among other effects, it is now known that acid suppression alters the stomach milieu to make it less amenable to ''H. pylori'' infection.

Background

Before the 1950s, there were many microbiological descriptions of bacteria in the stomach and in gastric acid secretions, lending credence to both the infective theory and the hyperacidity theory as being causes of peptic ulcer disease. A single study, conducted in 1954, did not find evidence of bacteria on biopsies of the stomach stained traditionally; this effectively established the acid theory as

dogma Dogma is a belief or set of beliefs that is accepted by the members of a group without being questioned or doubted. It may be in the form of an official system of principles or doctrines of a religion, such as Roman Catholicism, Judaism, Islam ...

. This paradigm was altered when Warren and Marshall effectively proved

Koch's postulates Koch's postulates ( )"Koch"
''

lymphomas and adenocarcinomas of the stomach, and has been classified by the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...

as a

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive sub ...

. Advances in

molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and phys ...

in the late 20th century led to the sequencing of the ''H. pylori'' genome, resulting in a better understanding of

virulence factor Virulence factors (preferably known as pathogenicity factors or effectors in plant science) are cellular structures, molecules and regulatory systems that enable microbial pathogens (bacteria, viruses, fungi, and protozoa) to achieve the following ...

s responsible for its colonization and infection, on the DNA level.

Pre-20th century

;Pre 16th century :

Hippocrates Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history o ...

first describes

gastric The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

symptoms. :

Avicenna Ibn Sina ( fa, ابن سینا; 980 – June 1037 CE), commonly known in the West as Avicenna (), was a Persian polymath who is regarded as one of the most significant physicians, astronomers, philosophers, and writers of the Islamic ...

notes the relationship between gastric pain and mealtimes. ;1586 :Marcellus Donatus of Mantua performs autopsies and describes

gastric ulcer Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines i ...

s. ;1688 :Johannes von Murault observes

duodenal ulcer Peptic ulcer disease (PUD) is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines i ...

s. ;1728 :Stahl hypothesizes that some

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

s are related to gastric inflammation and ulceration. ;1761 :Pain is associated with stomach ulcers. ;1799 :

Matthew Baillie Matthew Baillie FRS (27 October 1761 – 23 September 1823) was a British physician and pathologist, credited with first identifying transposition of the great vessels (TGV) and situs inversus. Early life and education He was born in the manse ...

publishes a description of ulcers. ;1812 : Broussais discovers that if acute

gastritis Gastritis is inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain (see dyspepsia). Other possi ...

is untreated, it can become chronic. ;1821 :Nepveu argues for a relationship between gastritis and

gastric cancer Stomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lym ...

. ;1822 :

William Beaumont William Beaumont (November 21, 1785 – April 25, 1853) was a surgeon in the U.S. Army who became known as the "Father of Gastric Physiology" following his research on human digestion.

first demonstrates the acidity of the stomach and a relationship between acid levels and mood. ;1868 : Kussmaul suggests using

bismuth Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs ...

compounds, an antibacterial agent, to treat peptic ulcers (

bismuth subsalicylate Bismuth subsalicylate, sold generically as pink bismuth and under the brand names Pepto-Bismol and BisBacter, is an antacid medication used to treat temporary discomforts of the stomach and gastrointestinal tract, such as nausea, heartburn, indig ...

has since been used in many commercial drugs, including Pepto Bismol as part of antibacterial ''H. pylori'' treatment). The antibacterial properties of bismuth were not known until much later. ;1875 :G. Bottcher and M. Letulle hypothesize that ulcers are caused by

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

. ;1880 : J. Cohnheim suggests that ulcers may be caused by chemical factors. ;1881 : Klebs notes the presence of bacteria-like organisms in the lumen of the gastric glands.Fukuda, Yoshihiro et al., "Kasai, Kobayashi and Koch's postulates in the history of ''Helicobacter pylori''", in ''Helicobacter Pioneers'', pp. 15–24. ;1889 :

Walery Jaworski Walery Jaworski (born March 20, 1849 in Florynka – died July 17, 1924 in Kraków) was one of the pioneers of gastroenterology in Poland. In 1899 he described bacteria living in the human stomach that he named ''Vibrio rugula''. He speculated ...

describes spiral organisms in sediment washings of humans. He suggests these organisms might be involved with gastric disease. ;1892 :

Giulio Bizzozero Giulio Bizzozero (; 20 March 1846 – 8 April 1901) was an Italian doctor and medical researcher. He was a pioneer of histology and is credited with the coining of the term platelets and identifying their function in coagulation. Background ...

observes spiral organisms in the stomach of dogs.Figura, Natale & Laura Bianciardi, "Helicobacters were discovered in Italy in 1892: An episode in the scientific life of an eclectic pathologist, Giulio Bizzozero", in ''Helicobacter Pioneers'', pp. 1–13. ;1896 :Saloon finds spirochetes in the stomachs of cats and mice.

1900–1950

;1905 :F. Reigel suggests that ulcers are caused by excess acid. ;1906 :Krienitz finds bacteria in the stomach of people with gastric cancer. :Turck feeds dogs ''Bacillus coli'' and produces ulcers. ;1907 :Berkley Moynihan suggests that acid is a cause of ulcers. ;1910 :Schwartz publishes the excess acid theory of the ulcer, coining the famous phrase "no acid, no ulcer." :Gibelli claims to be unable to reproduce Turck's study where he artificially created ulcers by feeding dogs bacteria. ;1913 :Rosenow suggests that

streptococci ''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occu ...

produce ulcers. ;1915 :

Antacid An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach. Some antacids have been used in the treatment of constipation and diarrhea. Marketed antacids contain salts of alu ...

s are first recommended for the treatment of PUD. :Bacteria are associated with PUD, but it is assumed that the bacteria reside in the mouth. ;1919 :Katsuya Kasai and Rokuzo Kobayashi isolate

spirochete A spirochaete () or spirochete is a member of the phylum Spirochaetota (), (synonym Spirochaetes) which contains distinctive diderm (double-membrane) gram-negative bacteria, most of which have long, helically coiled (corkscrew-shaped or s ...

s in cats and transmit them to rabbits, producing ulcers. ;1921 :Luger discovers spirochetes in the gastric juice, and associates their presence with gastric cancer. ;1924 :Luck and Seth discover

urease Ureases (), functionally, belong to the superfamily of amidohydrolases and phosphotriesterases. Ureases are found in numerous bacteria, fungi, algae, plants, and some invertebrates, as well as in soils, as a soil enzyme. They are nickel-contai ...

in the human stomach, which they believe is naturally occurring. ;1925 :Hoffman injects a small sample from a human with PUD into a guinea pig, producing ulcers, and isolates a bacterium which he believes caused the ulcers. ;1936 :First edition of the Russian ''Large Medical Encyclopedia'' suggests infection is one of the causes of PUD.Mozorov, Igor A., "''Helicobacter pylori'' was discovered in Russia in 1974", in ''Helicobacter Pioneers'', pp. 105–118. ;1939 :A. Stone Freedberg begins a study to look for bacteria in the human stomach at Beth Israel Hospital. He finds ''H. pylori''. It is rumored that others cannot reproduce the results, although no negative results are published.Freedberg, A. Stone, "An Early Study of Human Stomach Bacteria", in ''Helicobacter Pioneers'', pp. 25–28. :James Doenges describes spirochetes in autopsies. ;1940 :Freedberg and Baron observe spirochetes in autopsies. Freedberg abandons his research, however, after his boss advises him to move to another subject. In 2005, Marshall speculates that Freedberg would have won the Nobel Prize in 1951 had he continued his work. ;1948 :Fitzgerald and Murphy hypothesize that PUD is caused by acid eating away mucosa, and demonstrate the effectiveness of

urea Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important ...

as a treatment for PUD.O'Connor, Humphrey J. and Colm A. O'Morain, "Gastric urease in ulcer patients in the 1940s: The Irish connection", in ''Helicobacter Pioneers'', pp. 29–38.

1950–1970

;1951 :J. Allende publishes a book describing the treatment of gastric ulcers with

penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from '' Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum usin ...

. ;1953 :Dintzis and Hastings are able to stop

production in mice with

s, suggesting a relationship between urease and a bacterial infection. ;1954 :Palmer publishes a study which finds no bacteria in the human stomach. He concludes earlier discoveries were a result of contamination. Unfortunately, he chooses not to use a silver

stain A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. They are caused by the chemical or physical interaction of two dissimilar materials. Accidental staining may make materials ap ...

ing method, which will be later used to reveal ''H. pylori'' by Warren and Marshall. ;1955 :Tarnopolskaya observes that penicillin seems to cure some peptic ulcers. :Moutier and Cornet suggest treating gastritis with antibiotics. :Kornberg and Davies observe that antibiotics reduce urease in cats. ;1957 :Charles Lieber and Andre Lefèvre discover that antibiotics reduce gastric urea to

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...

conversion. ;1958 :Gordon observes that penicillin cures some peptic ulcers. : John Lykoudis successfully treats his own

gastroenteritis Gastroenteritis, also known as infectious diarrhea and gastro, is an inflammation of the gastrointestinal tract including the stomach and intestine. Symptoms may include diarrhea, vomiting, and abdominal pain. Fever, lack of energy, and dehydr ...

with antibiotics.Rigas, Basil and Efstathios D. Papavassiliou, "John Lykoudis: The general practitioner in Greece who in 1958 discovered etiology of, and a treatment for, peptic ulcer disease", in ''Helicobacter Pioneers'', pp. 75–84. :Lieber and Lefèvre present their results at the World Congress of Gastroenterology in Washington. It is not well received because of the widespread belief that bacteria cannot survive in the human stomach, due to Palmer.Lieber, Charles S. J., "How it was discovered in Belgium and the USA (1955–1976) that Gastric Urease was Caused by a Bacterial Infectio", in ''Helicobacter Pioneers'', pp. 39–52. ;1959 :Lieber and Lefèvre publish a follow-up study demonstrating that antibiotics prevent the conversion of urea to ammonia in the human stomach. :Conway et al. call into question the extent of urease produced by bacteria in mice, as an argument against the bacterial theory of PUD. ;1960 :Vital and Orrego observe ''

Campylobacter ''Campylobacter'' (meaning "curved bacteria") is a genus of Gram-negative bacteria. ''Campylobacter'' typically appear comma- or s-shaped, and are motile. Some ''Campylobacter'' species can infect humans, sometimes causing campylobacteriosis, ...

''-like organisms in the stomachs of cats and dogs. :Lykoudis is awarded a Greek patent (#22,453) for his antibiotic treatment of PUD. ;1962 :Susser and Stein publish a paper identifying a cohort phenomenon of PUD in England. This is taken as evidence for stress causing PUD. ;1964 :Lykoudis presents his antibiotic treatment for PUD at a meeting of the Medico-Surgical Society in Greece. He is largely shunned by the medical establishment. ;1966 :Lykoudis' manuscript is rejected by the

Journal of the American Medical Association ''The Journal of the American Medical Association'' (''JAMA'') is a peer-reviewed medical journal published 48 times a year by the American Medical Association. It publishes original research, reviews, and editorials covering all aspects of b ...

. ;1967 :Susumu Ito describes ''Campylobacter''-like organisms attached to a gastric

epithelial cell Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellul ...

. ;1968 :Lykoudis is fined 4,000 drachmas for treating PUD patients with his treatment, which includes antibiotics.

1970–21st century

;1971 :Howard Steer observes ''H. pylori'' from biopsies of a patient with ulcers. ;1972 :The first report of successfully using

furazolidone Furazolidone is a nitrofuran antibacterial agent and monoamine oxidase inhibitor (MAOI). It is marketed by Roberts Laboratories under the brand name Furoxone and by GlaxoSmithKline as Dependal-M. Medical uses Furazolidone has been used in human ...

(an antibacterial agent) to treat PUD in China. ;1974 :Morozov observes ''H. pylori''; he does not connect this discovery to PUD. :A well regarded study of PUD is published which does not mention bacteria. ;1975 :Steer and Colin-Jones publish their results regarding ''H. pylori'' and its relation to PUD. They decide that it was ''

Pseudomonas ''Pseudomonas'' is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able t ...

'', a contaminant, and not related to PUD. ;1978 :At a meeting of the American Gastroenterology Association in Las Vegas, several papers are presented which suggest that acid control via H₂ blockers is ineffective at curing PUD. ;1979 :Ramsey publishes a study demonstrating that bismuth can help eradicate PUD. Bismuth is an antibacterial agent, although this is not recognized by Ramsey. :J. Robin Warren first observes ''H. pylori'' in a gastric biopsy. :Fung, Papadimitriou, and Matz observe ''H. pylori''. ;1981 :Yao Shi observes bacteria in the stomach, but he believes they are passing through the stomach and not colonizing it. :''July'': Barry Marshall joins gastroenterology division of

Royal Perth Hospital Royal Perth Hospital (RPH) is a 450-bed adult and teaching hospital located on the northeastern edge of the central business district of Perth, Western Australia. History The hospital traces its history back to the first colonial hospital, whi ...

and meets Robin Warren :''October'': Marshall and Warren successfully treat their first PUD patient with antibiotics. ;1982 :Satoha et al. find evidence for an infectious cause of ulcers in rats. :Marshall and Warren begin their first study to determine the relationship between ''H. pylori'' and PUD. :First successful culturing of ''H. pylori'' performed; it occurs almost by accident. :''October'': Marshall discovers the bacteria he is investigating are not campylobacteria, by looking at

electron micrograph A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a mi ...

s. :''October 2'': Marshall presents his and Warren's results at a local College of Physicians meeting. He meets with criticism, which Marshall later admits was well-founded (at least in part). ;1983 :''January'': Two letters authored by Warren and Marshall, respectively, are sent to ''The Lancet'' describing their results. :''February'': Gastroenterological Society of Australia rejects Marshall's abstract to present his research at their yearly conference. They deem it in the bottom 10% of papers submitted. The same abstract is accepted for presentation at a ''Campylobacter'' workshop in Brussels. :''April'': Marshall and Ian Hislop begin a study to compare bismuth treatment with

cimetidine Cimetidine, sold under the brand name Tagamet among others, is a histamine H2 receptor antagonist that inhibits stomach acid production. It is mainly used in the treatment of heartburn and peptic ulcers. The development of longer-acting H2 r ...

. The study is abandoned because it is inconclusive. :''June'': Warren and Marshall's letter appears in ''The Lancet''. :''September'': ''H. pylori'' is observed in patients outside of Australia. :After the appearance of the letters in ''The Lancet'', groups around the world begin isolating ''H. pylori''. ;1984 :A paper describing Marshall and Warren's results is accepted by the Gastroenterological Society of Australia for presentation. :Marshall and Goodwin attempt to infect pigs with ''H. pylori'' in an attempt to demonstrate that it causes PUD. The experiment fails. :Marshall and Warren's paper is accepted by ''The Lancet'' in May and published in June. Many reviewers dislike the paper. :McNulty and Watson are able to reproduce Marshall and Warren's results. :''June 12'': Marshall intentionally consumes ''H. pylori'' and becomes ill. He takes antibiotics and is relieved of his symptoms. :The

National Health and Medical Research Council The National Health and Medical Research Council (NHMRC) is the main statutory authority of the Australian Government responsible for medical research. It was the eighth largest research funding body in the world in 2016, and NHMRC-funded rese ...

of Australia fully funds Marshall's research into ''H. pylori''. :A study is published in China about the effectiveness of treating PUD with an antibacterial agent. :''July 31'': ''

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...

'' publishes an article by its medical correspondent Dr. Lawrence K. Altman on the possible link between ''H. pylori'' and PUD. He states in 2002, "I’ve never seen the medical community more defensive or more critical of a story" since he joined the newspaper in 1969. :

Thomas Borody Thomas J. Borody (born 1950) is an Australian gastroenterologist. In the 1980s Borody contributed to development of a treatment for ''Helicobacter pylori''. During the COVID-19 pandemic he became embroiled in controversy for advocating an iverm ...

developed the bismuth-based "Triple Therapy" consisting of bismuth and two antibiotics. This became the first truly successful treatment for ''H. pylori'' with an eradication rate greater than 90%. ;1985 :Marshall publishes the results of self-induced infection. ;1987 :Drumm and colleagues following a study of children reported in the New England Journal of Medicine that Helicobacter pylori was specifically associated with primary or unexplained gastric inflammation and primary duodenal ulceration, whereas the bacteria were not found in association with secondary gastric inflammation and ulcers due to causes such as Crohn's disease or critical illness. Because gastritis and duodenal ulceration are rare in children, this study had the capacity to demonstrate that Warren and Marshall were correct in claiming that H. pylori was a specific pathogen rather than, as had been suggested by some, merely an opportunistic colonizer of an inflamed or ulcerated mucosal surface. This was the first time that New England Journal of Medicine, the world's leading medical journal, published a study on Helicobacter pylori. :Morris intentionally consumes ''H. pylori''. Like Marshall, he becomes ill, but unlike Marshall, he is not completely cured by antibiotics. The infection will remain with him for three years. :An extensive study in Dublin demonstrates that eradicating ''H. pylori'' substantially reduces recurrence of ulcers. ;1990 :Borody's triple therapy became commercialized in the United States under the product name ''Helidac''. :Rauws and Tytgat describe cure of duodenal ulcer by eradication of ''H. pylori'' using Borody's triple therapy combination. Triple-therapy, modernized to a

proton pump inhibitor Proton-pump inhibitors (PPIs) are a class of medications that cause a profound and prolonged reduction of stomach acid production. They do so by irreversibly inhibiting the stomach's H+/K+ ATPase proton pump. They are the most potent inhibitor ...

and two antibiotics, soon becomes first line therapy for eradication. :World Congress of Gastroenterology recommends eradicating ''H. pylori'' to cure duodenal ulcers. :First report of resistance of ''H. pylori'' to the antibiotic metronidazole. Resistance of ''H. pylori'' to treatment will lead to the development of many different antibiotic and proton pump inhibitor regimens for eradication. ;1992 :Fukuda et al. prove ingestion of ''H. pylori'' causes gastritis in rhesus monkeys. :Covacci et al. sequence the ''CagA'' gene, which encodes for a

cytotoxin Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating c ...

-associated surface protein, which correlated strongly with strains of ''H. pylori'' that caused duodenal ulcers. This was the first description of a

for ''H. pylori'' infection determined by molecular techniques. ;1994 :Fujioka et al. prove similar results as those from Fukuda et al. :

Patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

s for acid reducing drugs expire, removing financial incentive to resist antibiotics as treatment of PUD. :A conference held by National Institute of Health (USA) demonstrates the general acceptance of ''H. pylori'' as cause of PUD in the US. :The

's International Agency for Research on Cancer declares ''H. pylori'' a Group 1

. : Parsonnet et al. describe an association between ''H. pylori'' and lymphomas of the gastrointestinal tract. These

malignant Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...

ulcers can also be treated by eradicating ''Helicobacter''. ;1997 :Tomb et al. complete sequencing of the entire 1,667,867 base pairs of the ''H. pylori'' genome. This assists in identifying new

s for the infectivity of ''H. pylori'' on the molecular level. ;2001 :Chan et al. show in a randomized control trial that eradication of ''H. pylori'' even prevents bleeding from ulcers that is caused by aspirin and non-steroidal anti-inflammatory drugs. ;2002 :The European Helicobacter Pylori Study Group published the Maastricht 2-2000 Consensus Report, suggesting a "test-and-treat" strategy for ''H. pylori'' in young patients without atypical symptoms. This strategy advocates the use of noninvasive testing to evaluate for ''H. pylori'' and simply treating if found, even in the absence of ulcer disease documented on

endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are inse ...

. ;2005 :Warren and Marshall are awarded the

for their work on ''H. pylori'' and PUD.

References

External links

* Barry J. Marshall (2001)
"One hundred years of discovery and rediscovery of ''Helicobacter pylori'' and its association with peptic ulcer disease"
Chapter 3 o
Helicobacter pylori:'' Physiology and Genetics''
ed. by Harry L. T. Mobley, George L. Mendz, and Stuart L. Hazell. ASM Press. . {{Featured list Peptic ulcer disease and Helicobacter pylori Helicobacter pylori Infectious causes of cancer