''Helicobacter felis'' is a

bacterial 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 among ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in the

Helicobacteraceae The Campylobacterales are an order of Campylobacterota which make up the epsilon subdivision, together with the small family Nautiliaceae. They are Gram-negative. Most of the species are microaerophilic.Garrity, George M.; Brenner, Don J.; Krieg, ...

family,

Campylobacterales The Campylobacterales are an order of Campylobacterota which make up the epsilon subdivision, together with the small family Nautiliaceae. They are Gram-negative. Most of the species are microaerophilic.Garrity, George M.; Brenner, Don J.; Krieg, ...

order,

Helicobacter ''Helicobacter'' is a genus of Gram-negative bacteria possessing a characteristic helical shape. They were initially considered to be members of the genus '' Campylobacter'', but in 1989, Goodwin ''et al.'' published sufficient reasons to justif ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

. This bacterium is

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

microaerophilic A microaerophile is a microorganism that requires environments containing lower levels of dioxygen than that are present in the atmosphere (i.e. < 21% O₂; typically 2–10% O₂) for optimal growth. A more re ...

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-containin ...

-positive, and spiral-shaped. Its type strain is CS1T (= ATCC 49179T). It can be

pathogenic In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

. ''

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 though ...

'' (''H. pylori'') is by far the best known ''Helicobacter'' species, primarily because humans infected with it may develop

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

diseases such as stomach inflammation,

stomach ulcers 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 ...

duodenal ulcers 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 ...

stomach 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. Lymph ...

s of the nonlymphoma type, and various subtypes of extranodal marginal zone lymphomass, e.g. those of 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 ...

small intestines The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the pa ...

large intestines The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being rem ...

, and rectumn. ''H. pylori'' is also associated with the development of

bile duct cancer Cholangiocarcinoma, also known as bile duct cancer, is a type of cancer that forms in the bile ducts. Symptoms of cholangiocarcinoma may include abdominal pain, yellowish skin, weight loss, generalized itching, and fever. Light colored stool ...

and has been associated with a wide range of other diseases although its role in the development of many of these other diseases requires further study. Humans infected with ''H. felis'' may also develop some of the same gastrointestinal diseases viz., stomach inflammation, stomach ulcers, duodenal ulcers, stomach cancers that are not lymphomas, and extranodal marginal B cell lymphomas of the stomach. Other non-''H. pylori'' species that are known to be associated with these gastrointestinal diseases are ''

Helicobacter bizzozeronii ''Helicobacter bizzozeronii'' is a species within the ''Helicobacter'' genus of Gram-negative bacteria. ''Helicobacter pylori'' is by far the best known ''Helicobacter'' species, primarily because humans infected with it may develop gastrointesti ...

Helicobacter salomonis ''Helicobacter salomonis'' (''H. salomonis'') is a species within the ''Helicobacter'' genus of Gram-negative bacteria. ''Helicobacter pylori'' is by far the best known ''Helicobacter'' species primarily because humans infected with it may devel ...

, Helicobacter suis,'' and '' Helicobacter heilmannii s.s''. Because of their disease associations, these four ''Helicobacter'' species plus ''H. felis'' are often group together and termed '' Helicobacter heilmannii sensu lato''. ''H. felis'' bacteria are detected in the stomachs of their natural hosts - cats, dogs, rabbits, and cheetahs. Reports suggest that individuals, including children, are infected with this bacterium by having close contact with one of these infected animals: ''H. heilmanni s.l.''-associated diseases, including those associated with ''H. felis'', appear to be

zoonotic diseases A zoonosis (; plural zoonoses) or zoonotic disease is an infectious disease of humans caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human (usually a vertebrate) to a human. ...

, i.e.

infectious diseases An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...

that are caused by

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

that spread from animals to humans. It is important to diagnose ''H. felis'' and other ''H. heilmannii sensu lato'' infections in patients with the cited upper gastrointestinal tract diseases, including in particular extranodal marginal zone lymphoma of the stomach, because some of them have been successfully treated and cured using antibiotic-based drug regimens (e.g.

amoxicillin Amoxicillin is an antibiotic medication used to treat a number of bacterial infections. These include middle ear infection, strep throat, pneumonia, skin infections, and urinary tract infections among others. It is taken by mouth, or less c ...

clarithromycin Clarithromycin, sold under the brand name Biaxin among others, is an antibiotic used to treat various bacterial infections. This includes strep throat, pneumonia, skin infections, ''H. pylori'' infection, and Lyme disease, among others. Clarith ...

, plus 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 inhibitors ...

metronidazole Metronidazole, sold under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It is ef ...

, clarithromycin, plus a proton pump inhibitor) directed against the instigating bacterium.

References

External links

*
Type strain of ''Helicobacter felis'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
Campylobacterota Bacteria described in 1991 {{Campylobacterota-stub

References

Further reading

External links