helicobacter pres
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HelicobacterRabia Chaudhry
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Historical Background 1892: Italian pathologist Giulio Bizzozero first
described spirilli in dogs stomach
Several reports over the next century 1954: Palmer biopsy study established dogma
of sterile stomach environment
1979: Robin Warren found spiral bacteria inhuman stomach; association with gastritis
1983: Barry Marshall isolated and culturedbacteriaBizzazeros original drawings
(Figura, 2002)
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Historical Background Initially named Campylobacter pylori
1985 - 1987: Marshall and Morris inoculatedthemselves and developed gastritis
1989: New spiral bacteria named Helicobacterpylori
Scientific community extremely slow toaccept link between H. pyloriand peptic ulcerdisease
2005: Warren and Marshall win Nobel Prize H. heilmanniiin a patient withdyspepsia (Figura, 2002)
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A New Genus: Helicobacter Currently has 18 formally validated species
Non-spore forming, Gram negative, motile,spiral/ curved, microaerophilic bacteria
Human stomachs are primarily colonized byHelicobacter pylorias well as H. heilmanniito alesser degree
Nearly all mammals have associatedHelicobacter species e.g. H. felis (cats and dogs)
and H. mustelae (ferrets)
Infection of a mammal from a differentHelicobacter species is possible
H. pyloriand H. felis (Mobley, 2001)
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Helicobacter pylori Causes gastritis; correlated with peptic ulcers
and progression to cancer
Present in roughly half the worlds population
Most infections are asymptomatic
Most common human infectious agent; higherprevalence in developing regions
Often colonizes lower stomach or upperduodenum; named after pylorus
Colonizes host for life; well adapted to stomachniche environment
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H. pylori: Pathogenisis Propels itself to the mucus layer
Protects itself from stomach acids byproducing urease during transmission
Colonizes the gastric mucosa and mucuslayer of the gastric epithelium
Inflammation of the gastric mucosaprovides nutrients as well as urea
Has a number of adhesion capabilitiesand molecular mimicry techniques to
evade immune systemMontecucco, 2001
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H. pylori: Detection & Treatment
Non invasive: Urea breath testing,ELISA, Stool antigen testing
Invasive: endoscopic biopsy to obtaintissue sample; identification, culture
and PCR
Various antibiotic regimens to treatthe infection
No vaccines have been developedyet
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H. pyloriTransmission Infective dose (data from Rhesus monkeys): 10^4
Animals and water potential environmental sources
- Studies about animal hosts inconclusive
- Never been cultured from water; maybe VBNC.
- PCR techniques have detected H. pylori in environmental water; viable?
Person-to-person most likely more important; not sure how
- Gastro-oral, oral-oral or fecal-oral
- Mixed results for trying to culture
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Current Research Areas
Pathogenicity of H. pylori resultingin many asymptomatic cases
Transmission routes
Mechanisms of gastric cancer
Understanding of viability and
infectivity outside the gastric
environment
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Five Things to Remember H. pylori first isolated and cultured by Warren and
Marshall in 1983
Can cause gastritis, peptic ulcers and cancer
Half the worlds population is infected but many areasymptomatic
Protects itself against stomach acid by secreting urease Can be treated with antibiotics; no vaccine yet
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ReferencesFigura, N., Bianciardi, L. (2002). Helicobacters were discovered in Italy in 1892: AN episode in the scientific life of an eclectic pathologist,
Giulio Bizzozero. In B. Marshall (Ed.),Helicobacter Pioneers (pp. 1-11). Victoria, Australia: Blackwell Science Asia Pty Ltd.
Fukuda, Y., Shimoyoma, T., Shimoyoma, T., Marshall B. J. (2002) Kasai, Kobayashi and Kochs postulates in the history ofHelicbacter pylori . In
B. Marshall (Ed.),Helicobacter Pioneers (pp. 15-23). Victoria, Australia: Blackwell Science Asia Pty Ltd.
Giao, M. S., Azevedo, N. F., Wilks, S. A., Vieira, M. J., Keevil, C. W. (2010). Effect of Chlorine on Incorporation of Helicobacter pylori into
Drinking Water Biofilms.
Applied And Environmental Microbiology, 76 (5), 16691673.
Marshall, B. J. (2002). The discovery thatHelicobacter pylori, a spiral bacterium, caused peptic ulcer disease. In B. Marshall (Ed.),Helicobacter
Pioneers (pp. 165-201). Victoria, Australia: Blackwell Science Asia Pty Ltd.
Mobley, H. L.T., Mendz, G. L., Hazell, S. L., (Ed.). (2001).Helicobacter pylori . Washington (DC): American Society for Microbiology Press.
Montecucco, C., Rappuoli, R. (2001).Living dangerously: how helicobacter pylori survives in the human stomach . Nature Reviews Molecular
Cell Biology, 2, 457-466.
Solnick, J. V., Hansen, L. M., Canfield, D. R., Parsonnet, J. (2001). Determination of the Infectious Dose of Helicobacter pylori during Primaryand Secondary Infection in Rhesus Monkeys (Macaca mulatta).Infection and Immunity, 69 (11), 6887 6892.
Yamamoto, Y., Friedman, H., Hoffman, P. (2002). Helicobacter pylori Infection and Immunity. New York, NY: Kluwer Academic/ Plenum
Publishers.
Yamaoka, Y. (2008).Helicobacter pylori: Molecular genetics and cellular biology. Norfolk, UK: Caister Academic Press.