Helicobacter bilis
Cultural characteristics
Biochemical characters
Phylum Proteobacteria, Class Epsilonproteobacteria, Order Campylobacterales, Family Helicobacteraceae, Genus Helicobacter,
Helicobacter bilis Fox et al. 1997.
Polyphasic analysis of the phenotypic and genotypic characteristics of the Finnish canine and feline "Flexispira" strains, and the
reference strains of "Flexispira" taxa 2, 3, and 8 showed that they are members of the species
Helicobacter bilis.
Gram-negative, fusiform cells, slightly spiral, 0.5 x 4-5 μm. Periplasmic fibers are
coiled around the cell body, giving a crisscross appearance to the bacterial surface.
Coccoid forms appear in older cultures. Motile by means of 3-14 sheathed flagella
arranged in tufts at both cell's ends. Nonsporulated.
Colonies are initially punctiform but often spread out as thin layers on the surface of
agar media after 3-5 days of microaerobic incubation at 37 ºC. Can grow at 42 ºC, but
not at 25 ºC. Grow on media containing up to 20% bile but not 1.5% NaCl. Sensitive to
metronidazole (4 μg) but resistant to cephalothin (30 μg) and nalidixic acid (30 μg) in
disk diffusion tests.
Isolated from human bile and gallbladder samples, from a canine gastric biopsy, from mice colonic crypts, ceca, bile and liver.
Undetermined. Isolated from colonic crypts and ceca of mice, and the bile and livers of mice with hepatitis. Also causes a condition
resembling inflammatory bowel disease (inflammation and hyperplasia of the lower gastrointestinal tract) in immunodeficient rats.
Severe diarrhea in laboratory mice co-infected with
H. bilis and H. rodentium has been noted.
  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. J G Fox, L L Yan, F E Dewhirst, B J Paster, B Shames, J C Murphy, A Hayward, J C Belcher, and E N Mendes. Helicobacter bilis sp.
    nov., a novel Helicobacter species isolated from bile, livers, and intestines of aged, inbred mice. J. Clin. Microbiol. February 1995
    33:2 445-54.
  3. M.-L. Hanninen, R. I. Karenlampi, J. M. K. Koort, T. Mikkonen, and K. J. Bjorkroth. Extension of the species Helicobacter bilis to
    include the reference strains of Helicobacter sp. flexispira taxa 2, 3 and 8 and Finnish canine and feline flexispira strains. Int J Syst
    Evol Microbiol March 2005 55:891-898.
Positive results for catalase, oxidase, urease, nitrate reduction, growth in 1% glycine and gamma-glutamyl transpeptidase.

Negative results for indoxyl acetate hydrolysis, hippurate hydrolysis and alkaline phosphatase.
(c) Costin Stoica
Culture media
Biochemical tests
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