avian & livestock assay data sheet
Trichomonas / Tritrichomonas
NOTE: THIS TEST IS NOT PERFORMED
ON SAMPLES TAKEN FROM BOVINES OWNED OR LOCATED IN THE STATE OF
CALIFORNIA.
Test
code:
X0013
-
Qualitative detection but not differentiation of
several common
Trichomonas/Tritrichomonas
species by polymerase chain reaction, including
T. gallinae, T. gallinarum, T. foetus/suis, T. vaginalis and T. equi.
Many species in the genus
Trichomonas
can infect man, but trichomoniasis is also a
major problem in poultry, birds and horses. All
trichomonads have three to five anterior
flagella, an undulating membrane, and a
recurrent flagellum attached to the edge of the
undulating membrane. There is no cyst stage for
this protozoan parasite.
Following are some Trichomonads posing major
health threats to humans, livestock, birds and
other animals:
Trichomonas gallinae
The parasite causes avian trichomoniasis. When
present, it is usually found in the upper
digestive tract of many species of doves and
gallinaceous birds. Some strains may also
produce liver and lung lesions. The parasite is
transferred to young from the mother during
feeding. Transmission between birds may also
occur from contaminated feed and water.
Infection by this trichomonad can be fatal. The
presence of this organism in doves is a common
source of infection of falcons and hawks feeding
on them.
Trichomonas gallinarum
This parasite is mainly detected in cecum
and liver of gallinaceous birds but it can also
be found in other visceral organs of the
infected animals.
T. gallinarum
affects many birds including poultry, and can
cause morbidity and mortality especially in
young birds.
Tritrichomonas foetus/suis
T. foetus
and T. suis
are almost identical in genomic composition,
morphologic structures, ultrastructure,
distribution, host specificity, characteristics
of in vitro cultivation, immunology and
biochemistry (Lun et al., 2005). Thus, it has
been proposed that
T. foetus
and T. suis are synonyms. While the parasite can be found in the
nasal passage, stomach, colon and large
intestine of swine, it does not appear to cause
major health problems in them.
This trichomonad, however, causes trichomoniasis
in cattle, resulting in significant economic
loss. The parasite is sexually transmitted and
resides in the reproductive tract of cattle. In
females, the infection may result in low-grade
inflammation, sterility and poor conception
rate. In males, symptoms vary from no apparent
signs to inflammation of the prepuce. Treatment
is difficult and usually not attempted.
Slaughter or breeding rest (females) are the
usual methods employed in dealing with bovine
trichomoniasis.
Like other trichomonads, this organism
multiplies by simple binary fission and does not
posses a cyst stage. This organism is called
Tritrichomonas foetus because it has three long flagella at
one end.
Traditionally,
diagnosis was mainly based on microscopic
evaluation of the trophozoite stage. Mucus,
exudates or saline washes from the vagina and
preputial cavity are the best samples for
microscopic examination. In cases of abortion,
allantoic and amniotic fluids as well as fetal
tissues and membranes are examined. Serologic
detection by agglutination is
also possible. However, none of these testing
methods are very sensitive, resulting in
high false negative rates.
Trichomonas vaginalis
T. vaginalis
causes human trichomoniasis. This parasite also
resides in the human reproductive tract. This is
one of the most common sexually transmitted
diseases of man and often occurs with other more
severe concurrent infections. Chronic
reproductive and urinary problems may result in
females. The parasite is transmitted sexually.
Prevalence in human populations varies between
10 and 25% among women. Only about 15% of
infected women show clinical signs; many
infected women are asymptomatic carriers.
Other trichomonads known to infect humans
include
Trichomonas tenax from the tarter
and gums of the mouth and
Pentatrichomonas
hominis from the human colon.
Trichomonas equi
This parasite lives in the intestine of
horses and can be a potential cause of diarrhea
in foals.
Diagnosis of trichomoniasis may not be easy due
to clinical symptoms which may resemble those of
poxvirus, candidiasis or vitamin A deficiency.
Trichomonas
can be misidentified in initial microscopic
examination because of its similarity to Giardia.
The other difficulty in identification of this
parasite is that the trichomonad does not
survive long after the death of the host.
Complementary testing by PCR may be used to
eliminate false negative microscopy results.
Molecular detection by PCR
does not require living parasites and provides a
high degree of sensitivity and specificity.
Utilities:
-
Help confirm the disease causing agent
-
Environmental monitoring
-
Help ensure that flocks are free of
Trichomonas/Tritrichomonas
-
Early prevention of spread of these parasites among flocks
-
Minimize human exposure to these parasites
-
Safety monitoring of biological products and vaccines
that derive from birds
References:
Lun, Z.R., Chen, X.G., Zhu, X.Q., Li, X.R. and
Xie, M.Q. (2005) Are Tritrichomonas foetus and
Tritrichomonas suis synonyms? Trends Parasitol.
21:122-125.
Preferred samples:
Rectal, vaginal, cloacal, oral or other mucus
secretion swab, or 0.2 ml feces.
Less preferred samples: 0.2 ml whole blood in EDTA (purple top) tube, 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
Methodology:
Qualitative PCR
Normal range:
Nondetected
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