<unk>  is a genus of Gram-negative bacteria possessing a characteristic<unk> elix shape.  They were initially considered to be members of the Campylobacter genus, but since 1989 they<unk> ave been grouped in their own genus.
Some species<unk> ave been found living in the lining of the upper gastrointestinal tract, as well as the liver of mammals and some birds.. The most widely known species of the genus is<unk> . pylori which infects up to 50% of the<unk> uman population.  Some strains of this bacterium are pathogenic to<unk> umans as it is strongly associated with peptic ulcers, chronic gastritis, duodenitis, and stomach cancer.  It also serves as the type species of the genus.<unk>  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. 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.
Curved cells discovered in 1979 in stomach biopsied specimens.
Causes 90% of stomach & duodenal ulcers.
People with type O blood<unk> ave a 1.5-2X<unk> igher rate of ulcers.
Produces large amounts of urease.
Infection common especially in lower socioeconomic class/developing nations.<unk> umans primary reservoir.
Person-to-person spread via fecal-oral route.
Ubiquitous, no seasonal incidence.
In 1994, the World<unk> ealth Organization’s International Agency for Research on Cancer (IARC) classified<unk> . pylori as a Group 1 carcinogen. This decision was based on the results of numerous studies that confirmed the association between<unk> . pylori infection and gastric adenocarcinoma.<unk> . pylori infection also significantly increases the risk of gastric lymphoma of mucosa-associated lymphoid tissue (MALT) (Suerbaum, 2002).
While<unk> . pylori remains the most medically important bacterial inhabitant of the<unk> uman stomach, other species of the genus<unk> <unk> ave been identified in other mammals and some birds, and some of these can infect<unk> umans.<unk>  species<unk> ave also been found to infect the livers of certain mammals and to cause liver disease.<unk> . 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<unk> . pylori can be made by urease testing,<unk> istology and/or culture. If possible, noninvasive testing is done before tissue testing.<unk> . pylori stool antigen <unk> pSA) 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<unk> . pylori immunoglobulin G (IgG) antibodies that can determine if an individual<unk> as been infected. The sensitivity and specificity of these assays range from 80–95%, depending on the assay used. Serological testing<unk> as been the mainstay of<unk> . 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<unk> ours)
Helicobacter
Salmonella
Bacteroides
Salmonella enterica
Arcobacter
Bartonella
Listeria
Brucella