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 Scanning electron micrograph of Helicobacter bacteria. The scanning electron microscope ( SEM) is a type of Electron microscope that images the sample surface by scanning it with a high-energy beam of Electrons
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H. acinonychis |
Helicobacter is a genus of Gram-negative bacteria possessing a characteristic helix shape. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Gram-negative bacteria are those Bacteria that do not retain Crystal violet dye in the Gram staining protocol The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have A helix (pl helixes or helices) from the Greek word έλιξ, is a special kind of Space curve, i They were initially considered to be members of the Campylobacter genus, but since 1989 they have been grouped in their own genus. The Genus Campylobacter, (meaning 'twisted bacteria' first discovered in 1963 describes Gram-negative, spiral Microaerophilic bacteria Year 1989 ( MCMLXXXIX) was a Common year starting on Sunday (link displays 1989 Gregorian calendar) [1][2][3]
Some species have been found living in the lining of the upper gastrointestinal tract, as well as the liver of mammals and some birds. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. The liver is a vital organ in the human body and is present in Vertebrates and some other animals Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. [4]. The most widely known species of the genus is H. pylori which infects up to 50% of the human population. Helicobacter pylori ( is a Gram-negative, microaerophilic Bacterium that inhabits various areas of the stomach and Duodenum. [3] Some strains of this bacterium are pathogenic to humans as it is strongly associated with peptic ulcers, chronic gastritis, duodenitis, and stomach cancer. A pathogen (from Greek πάθος pathos "suffering passion" and γἰγνομαι (γεν- gignomai (gen- "I give birth to" infectious A peptic ulcer, also known as PUD or peptic ulcer disease, is an Ulcer (defined as mucosal erosions equal to or greater than 0 Gastritis is an inflammation of the lining of the stomach There are many possible causes Duodenitis is Inflammation of the Duodenum. It may persist acutely or chronically Stomach or gastric cancer can develop in any part of the Stomach and may spread throughout the stomach and to other organs particularly the Esophagus and It also serves as the type species of the genus. In Taxonomy, a type species is the species that originally defined a genus.
Helicobacter spp. are able to thrive in the very acidic mammalian stomach by producing large quantities of the enzyme urease, which locally raises the pH from ~2 to a more biocompatible range of 6 to 7. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Urease ( is an Enzyme that catalyzes the Hydrolysis of Urea into Carbon dioxide and Ammonia. pH is the measure of the acidity or alkalinity of a Solution. [5] Bacteria belonging to this genus are usually susceptible to antibiotics such as penicillin, are microaerophilic (require small amounts of oxygen), and are fast-moving with their flagella. In modern usage an antibiotic is a Chemotherapeutic agent with activity against Microorganisms such as Bacteria, fungi or Protozoa Penicillin (sometimes abbreviated PCN or pen) is a group of Beta-lactam antibiotics used in the treatment of Bacterial Infections Microaerophilic Organisms are a specific type of microorganism (especially bacteria that requires Oxygen to survive but requires environments containing lower levels Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it [6][7]
Contents |
Helicobacter Facts. [8]
Curved cells discovered in 1979 in stomach biopsied specimens.
Causes 90% of stomach & duodenal ulcers.
People with type O blood have a 1. 5-2X higher rate of ulcers.
Produces large amounts of urease.
Infection common especially in lower socioeconomic class/developing nations.
Humans primary reservoir.
Person-to-person spread via fecal-oral route.
Ubiquitous, no seasonal incidence.
Gastric and Lymphoid Cancers
In 1994, the World Health Organization’s International Agency for Research on Cancer (IARC) classified H. pylori as a Group 1 carcinogen. This decision was based on the results of numerous studies that confirmed the association between H. pylori infection and gastric adenocarcinoma. H. pylori infection also significantly increases the risk of gastric lymphoma of mucosa-associated lymphoid tissue (MALT) (Suerbaum, 2002).
Diagnosis
H. pylori infection can be confirmed by invasive or noninvasive methods. Invasive tests require upper esophagogastroduodenal (EGD) endoscopy, which is considered the reference method of diagnosis. During endoscopy, biopsy specimens of the stomach and duodenum are obtained, and the diagnosis of H. pylori can be made by urease testing, histology and/or culture. If possible, noninvasive testing is done before tissue testing.
H. pylori stool antigen (HpSA) testing is based on monoclonal antibody immunochromatography of stool samples. This testing method identifies active infection and can be used to detect eradication after treatment. A sensitivity and specificity range of 92–98% is reported in the literature for stool antigen testing.
Serological assays (blood serum) measure specific H. pylori immunoglobulin G (IgG) antibodies that can determine if an individual has been infected. The sensitivity and specificity of these assays range from 80–95%, depending on the assay used. Serological testing has been the mainstay of H. pylori diagnosis, particularly in primary care, due to the accessibility, rapid results and low cost of this testing method.
Urease test, Urease Breath Test (UBT) (positive in as little as 2 hours) [9]
Treatment
Therapy with tetracycline, metronidazole, azithromycine, bismuth (Peptobismol).
References
- ^ Goodwin CS, Armstrong JA, Chilvers T, et al (1989). "Transfer of Campylobacter pylori and Campylobacter mustelae to Helicobacter gen. nov. as Helicobacter pylori comb. nov. and Helicobacter mustelae comb. nov. , respectively. ". Int. J. Syst. Bacteriol. 39: 397–405.
- ^ Vandamme P, Falsen E, Rossaq R, et al (1991). "Revision of Campylobacter, Helicobacter, and Wolinella taxonomy: emendation of generic descriptions and proposal of Arcobacter gen. nov.". Int. J. Syst. Bacteriol. 41: 88–103.
- ^ a b Yamaoka Y (editor). (2008). Helicobacter pylori: Molecular Genetics and Cellular Biology. Caister Academic Press. ISBN 978-1-904455-31-8 .
- ^ Ryan KJ, Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed. , McGraw Hill. ISBN 0-8385-8529-9.
- ^ Dunn BE, Cohen H, Blaser MJ (1997). "Helicobacter pylori.". Clin Microbiol Rev. 10: 720–741.
- ^ Hua JS, Zheng PY, Ho B (1999). "Species differentiation and identification in the genus of Helicobacter.". World Journal of Gastroenterology. 5 (1): 7–9.
- ^ Rust et al (2008). "Helicobacter Flagella, Motility and Chemotaxis", Helicobacter pylori: Molecular Genetics and Cellular Biology (Yamaoka Y, ed. ). Caister Academic Press. ISBN 978-1-904455-31-8 .
- ^ Kathleen Park Talaro (2006). Foundations in Microbiology, 6th ed. , McGraw Hill. ISBN 0072994959.
- ^ Robert P H Logan, Marjorie M Walker (2001). "Epidemiology and diagnosis of Helicobacter pylori infection .". BMJ 2001;323:920-922 ( 20 October ): –741.
See also
External links
Helicobacter pylori ( is a Gram-negative, microaerophilic Bacterium that inhabits various areas of the stomach and Duodenum.Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic