Helicobacter PCR test for dogs and cats
dog and cat assay data sheet
Helicobacter
Test codes:
B0021
- Ultrasensitive qualitative detection of
Helicobacter pylori
by real time polymerase chain reaction
B0023
- Ultrasensitive qualitative detection of
Helicobacter heilmannii
by real time polymerase chain reaction
P0010
- Ultrasensitive
Helicobacter species screen by real time polymerase
chain reaction. This screen detects but
does not differentiate
H. pylori, H. heilmannii, H.
bilis, H. hepaticus,
H. rappini, H. felis, H. salomonis and other
Helicobacter species.
P0011
- Ultrasensitive
Helicobacter species identification by real time
polymerase chain reaction and PCR product seqeuence analysis. This 2-stage assay detects
and differentiates H.
pylori, H. heilmannii, H. bilis, H. hepaticus,
H. rappini, H. felis, H. salomonis and
other Helicobacter species.
Many species
of the genus Helicobacter
have been identified in mammals and their pathogenicity varies.
Some species can induce significant disease while others appear
to merely colonize the gastrointestinal tract.
Helicobacter pylori
is a gram-negative spiral bacterium found in gastric mucosa and
associated with active and chronic gastritis.
H. pylori can
establish a chronic, persistent infection, which may lead to
gastric or duodenual ulcers, gastric cancer and gastric
lymphomas. Studies have revealed that approximately 50% of the
world’s human population is infected with
H. pylori.
Biochemically, the bacterium produces catalase, oxidase and
urease enzymes. The urease enzyme permits the bacterium to
metabolize urea present in the gastric mucosa and establish a
microenvironment favorable to the organism.
H. pylori is a
highly motile organism with multiple unipolar flagella. Both the
urease enzyme and the flagella are considered to be important
virulence factors.
Diagnosis of
Helicobacter pylori
infection in humans relies on upper endoscopy or the 13C-urea
breath test (see review by Nakamura, 2001). Although the
endoscopy procedure permits culture of the bacterium from biopsy
specimens (the gold standard for diagnosis), demonstration of
urease activity and histological detection of the germ, the
procedure is expensive and invasive. The 13C-urea breath test is
a well-established, relatively sensitive, specific and
noninvasive method. Molecular tests, such as PCR, can also offer
precise diagnosis of H.
pylori infections. In fact, molecular testing by PCR
can complement other diagnostic tests because it can be applied
to archival fixed tissue, environmental samples, gastric fluid,
oral secretions, and stool samples, in which traditional
diagnostic tests do not have sensitivity and perform poorly.
Studies have shown than PCR detection of
H. pylori in gastric
fluid specimens can reach a sensitivity of 96% and a specificity
of 100% (Westblom et al., 1993; Yoshida et al., 1999). This
capability is especially useful in monitoring active H. pylori
infection in primates and other animals, as the breath test is
difficult to conduct for these animals.
Helicobacter
heilmannii
(previously known as
Gastrospirillum hominis) is a 4-10 µm long, spiral-shaped,
motile bacterium with three to eight coils, a wavelength of about 1
µm, up to 14 uni- or bipolar flagella, and no periplasmic filaments.
Gastric infection with
Helicobacter heilmannii is associated with the development
of chronic gastritis (found in the stomachs of 0.2 to 4% of patients
with gastritis) and low-grade mucosa-associated lymphoid tissue
lymphoma in humans. Eradication of
H. heilmannii by
antibiotic treatment of patients can result in complete remission of
MALT lymphoma, indicating a causal relationship between
H. heilmannii infection
and MALT lymphoma. Unlike H.
pylori infections, gastric infections with
H. heilmannii or
Gastrospirillum-like
organisms are not restricted to humans. A broad range of animals,
including dogs, cats, pigs, and cattle, are naturally infected, with
frequencies ranging from 80% to 100%. It has been suggested that
H. heilmannii infection in
humans is a zoonosis and that animals serve as a reservoir for
transmission to humans.
Definitive culture
of H. heilmannii has
not been achieved to date (Anderson et al., 1996) and diagnosis of
H. heilmannii infection is usually made on the basis of its
distinct spiral morphology, compared with
H. pylori, on silver-
stained tissue sections. However, there are a number large gastric
spiral organisms such as H. felis, H. salomonis, and
H. bizzozeronii are indistinguishable from
H. heilmannii on routine
light microscopy, and H. pylori
grown in a broth culture can also adopt a morphology identical to that
of H. heilmannii
(Fawcett et al., 1999). Molecular detection methods such as PCR are required for more definitive identification (Trebesius et al.,
2001).
Utilities:
-
Help confirm the disease causing agent
-
Shorten the time required to confirm a clinical
diagnosis of Helicobacter
infection
-
Help ensure that animal groups are free of these
bacteria
-
Early prevention of spread of these bacteria
-
Minimize personnel exposure to these bacteria
-
Safety monitoring of biological products and vaccines
that derive from animals
References:
Andersen, L.P., Norgaard, A., Holck, S., Blom, J. and Elsborg, L.
(1996) Isolation of a "Helicobacter heilmannii"-like organism from the
human stomach. Eur. J. Clin. Microbiol. Infect. Dis. 15:95-96.
Fawcett, P.T., Gibney, K.M. and Vinette, K.M. (1999) Helicobacter
pylori can be induced to assume the morphology of Helicobacter
heilmannii. J. Clin. Microbiol. 37:1045-1048. Trebesius, K.,
Adler, K., Vieth, M., Stolte, M. and Haas, R. (2001) Specific
detection and prevalence of Helicobacter heilmannii-like organisms in
the human gastric mucosa by fluorescent in situ hybridization and
partial 16S ribosomal DNA sequencing. J. Clin. Microbiol.
39:1510-1516.
Specimen
requirement:
B0021, B0023,
P0010 - 0.2 ml gastric lavage, or rectal swab or 0.2ml feces,
or 0.2 ml fresh, frozen or fixed tissue P0011 -
0.2 ml gastric lavage, or 0.2 ml fresh, frozen or fixed tissue
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all specimen
types, if there will be a delay in shipping, or during very warm
weather, refrigerate specimens until shipped and ship with a cold pack
unless more stringent shipping requirements are specified. Frozen
specimens should be shipped so as to remain frozen in transit. See
shipping instructions for more
information.
Turnaround
time:
2 business days (1 week for P0011)
Methodology:
B0021, B0023,
P0010 - Qualitative real time
PCR P0011 - Qualitative real time PCR + PCR
product sequence analysis
Normal range:
Nondetected
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