Helicobacter pylori
7 days culture: active spiral-shaped cells (young)
and inactive coccoid cells (old)
Helicobacter pylori colonies on Sheep Blood Agar
Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Proteobacteria, Class Epsilonproteobacteria, Order Campylobacterales, Family Helicobacteraceae, Genus Helicobacter,
Helicobacter pylori (Marshall et al. 1985) Goodwin et al. 1989. Type species of the genus.

Old synonyms:
Campylobacter pyloridis Marshall et al.1985, Campylobacter pylori Marshall et al. 1985 corrig. Marshall and Goodwin
1987,
Campylobacter pylori subsp. pylori Marshall et al. 1985.

Helicobacter nemestrinae Brondson et al. 1991 is a junior heterotypic synonym.
Gram-negative, helical or curved cells, 2.5-5 x 0.5-1 μm, with rounded ends and spiral
periodicity. Nonencapsulated. Polyphosphate granules seen in cells under certain
conditions. Cells transform to coccoid forms with age. Motile by means of four to
seven unipolar sheathed flagella with distinctive terminal bulbs.
Colonies are nonpigmented, translucent, and 1 to 2 mm in diameter. Grow in Brain–
heart infusion or Brucella broth, Mueller-Hinton broth, growth enhanced by shaking
proteins with hemolytic activity. Grow  microaerophilically and in the presence of air
enriched with 10% CO
2. No anaerobic growth. Some strains grow poorly at 30 ºC and
no growth is obtained at 25 ºC. A few strains from rhesus monkeys grow at 42 ºC.
Initial growth obtained after 4–5 days but will grow in 2 days on subsequent
subculture. No growth in the presence of 1% glycine or 1.5% NaCl. Require amino
acids (arginine, histidine, isoleucine, leucine, methionine, phenylalanine & valine).
Some strains may require alanine or serine.
The principal reservoir of Helicobacter pylori is the human, with infection occurring
mainly in childhood. Found in rhesus monkeys, certain macaque species, and in a
closed colony of barrier-maintained cats. One strain was isolated from pig.
Resistant to nalidixic acid, trimethoprim, sulfonamides, and vancomycin. Sensitive to
penicillin, ampicillin, cephalothin, kanamycin, gentamicin, rifampin, and tetracycline.
Variable resistance to metronidazole and clarithromycin.
Helicobacter nemestrinae was isolated from a pigtailed macaque (Macaca
nemestrina
).
H. pylori is a human pathogen that colonizes the gastric mucus of more than half of the human population and causes chronic
infections. It was found in cases of gastritis and gastric and duodenal ulcers. Infections is more frequent in children under 5 years.
The role of  this organism in duodenal ulceration is probably as a predisposing cause.
Virulence factors: flagella, urease production (neutralization of gastric acid), adhesins, proteolytic enzymes, 120kDa cytotoxin,
vacuolating cytotoxin, phospholipase A (phospholipids digestion in cell membranes), alcohol dehydrogenase (gastric mucosa injury).
Urease activity seems to be essential for colonization.
H. pylori urease-negative mutants were not recovered from experimentally
infected gnotobiotic piglets, while piglets challenged with urease-positive strain, all became infected.
  1. George M. Garrity, Julia A. Bell and Timothy Lilburn, 2001. Family II. Helicobacteraceae. In: Bergey’s Manual of Systematic
    Bacteriology, Second edition, Vol 2, part C, George M. Garrity (Editor-in-Chief), pp 1168-1195.
  2. Sebastian Suerbaum, Christian Kraft, Floyd E Dewhirst, and James G Fox. Helicobacter nemestrinae ATCC 49396T is a strain of
    Helicobacter pylori (Marshall et al. 1985) Goodwin et al. 1989, and Helicobacter nemestrinae Bronsdon et al. 1991 is therefore a
    junior heterotypic synonym of Helicobacter pylori. Int J Syst Evol Microbiol March 2002 52:437-9.
  3. M. Celeste Martino, Richard A. Stabler, Zun W. Zhang, Michael J. G. Farthing, Brendan W. Wren, Nick Dorrell. Helicobacter pylori
    Pore-Forming Cytolysin Orthologue TlyA Possesses In Vitro Hemolytic Activity and Has a Role in Colonization of the Gastric
    Mucosa. Infect Immun. 2001 March; 69(3): 1697–1703. doi: 10.1128/IAI.69.3.1697-1703.2001.
  4. Mobley HLT, Mendz GL, Hazell SL, editors. Helicobacter pylori: Physiology and Genetics. Washington (DC). Lief Percival Andersen
    and Torkel Wadstrom: Chapter 4 Basic Bacteriology and Culture. ASM Press; 2001.
  5. A.A. Al-Sulami, A.M. R. Al-Taee, and M.G. Juma’a. Isolation and identification of Helicobacter pylori from drinking water in Basra
    governorate, Iraq. EMHJ, Vol. 16, No.9, 2010.
  6. C. Stewart Goodwin, John A. Armstrong, Terry Chilvers, Michelle Peters, M. David Collins, Lindsay Sly, William McConnell, and
    William E. S. Harper. 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 October 1989 39:397-405.
  7. K. A. Eaton, C. L. Brooks, D. R. Morgan and S. Krakowka. Essential role of urease in pathogenesis of gastritis induced by
    Helicobacter pylori in gnotobiotic piglets. Infect. Immun. July 1991 vol. 59 no. 7 2470-2475.
Positive results for urease, catalase, oxidase, leucine arylamidase, alkaline
phosphatase and gamma-glutamyltranspeptidase. Metabolize glucose via the
pentose phosphate and the Entner–Doudoroff pathways. Glucose may be fermented
to mixed acid products or provide metabolites to the Krebs cycle.

Negative results for nitrates reduction, hippurate hydrolysis, indoxyl acetate hydrolysis
and H
2S production (TSI).

Tolerance and reduction of 0.04% triphenyl-tetrazoliumchloride is variable. H
2S
production is variable on lead acetate paper.
(c) Costin Stoica
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