wildlife, zoo and aquatic assay data sheet
X0026 - Ultrasensitive qualitative detection of
by real time PCR
captive fishes by metazoan parasites (helminths and arthropods)
is of major concern in fish farms and in research facilities.
Water systems in these facilities usually must use unchlorinated
water, creating a risk of the growth of unwanted organisms.
Metazoan parasites which require intermediate hosts in
their cycles are not common in these facilities. However,
capillarid nematodes do not require intermediate hosts and thus
are one of the few metazoans that are of concern. They are
recognized as a major problem in zebrafish facilities
particularly (Kent et al., 2002).
The species infecting zebrafish was first
identified as Pseudocapillaria tomentosa; the junior synonym is
P. brevispicula. The parasite has a broad host specificity,
infecting some 25 fishes in the family Cyprinidae and members of
other orders such as Aguilliformes (eels), Gadiformes (cod
fishes), Salmoniformes (salmon) and Siluriformes (catfishes
Fish heavily infected with this parasite are often dark,
emaciated, and lethargic. Necropsy may reveal liver enlargement
and anemia. Slightly infected fish can appear normal or may show
only subtle abnormalities such as decreased fecundity.
Adult worms may be found in the intestine of infected fish
upon necropsy. Characteristic ova (~30 x 60 µm) may be seen
within gravid female worms or found free within the intestinal
contents or feces. Histological examinations of the gut may
reveal the worms within the lumen or wall of the intestine.
Nematode infection in zebrafish is difficult to eliminate.
Sometimes the entire colony may have to be destroyed and the
water system completely disinfected. Since direct transmission
can occur between fish, the infection can spread within a
population easily. The use of strict quarantine procedures that
allow only the introduction of surface sanitized (bleached)
embryos may help minimize infections. Oligochaete (eg Tubifex)
worms can also carry the parasite and thus should be avoided as
a food source. Routine monitoring of a water system, especially
filters where ova may be concentrated, is helpful. Molecular
detection of these ova by polymerase chain reaction (PCR) is
highly sensitive and is easily used to perform this monitoring.
Kent, M. L., Bishop-Stewart, J. K., Matthews, J. L., and
Spitsbergen, J. M. (2002). Pseudocapillaria tomentosa,
a nematode pathogen, and associated neoplasm of zebrafish (Danio
rerio) kept in research colonies. Comp. Med. 52, 354-358.
Specimen requirement: 0.2 ml feces
or intestinal contents, or vent swab, or 0.2 ml tissue, or swab
of filter medium, or biofilm swab.
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.
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.
2 business days
Qualitative real time PCR
Pseudocapillaria tomentosa PCR test