primate assay data sheet
Simian retrovirus (SRV)
group D by PCR
Test codes:
P0001
- Qualitative screen for SRV serogroups 1, 2, 3,
4 and 5 by
polymerase chain reaction
P0027
- Qualitative detection of
RNA of SRV
serogroups 1, 2, 3, 4 and 5 by reverse transcription coupled real
time PCR
S0001
- Qualitative detection of SRV-1 by polymerase chain reaction
S0002
- Qualitative detection of SRV-2 by polymerase chain reaction
S0003
- Qualitative detection of SRV-3 by polymerase chain reaction
S0004
- Qualitative detection of SRV-5 by polymerase chain reaction
The type D
subfamily of retroviruses is composed of five distinct but
genetically related serogroups. They are found in both New World
and Old World monkeys. The retroviruses found in Old World
macaques (genus Macaca) are exogenous to the species and upon
injection induce a fatal simian acquired immune deficiency
syndrome (SAIDS).
Two
serotypes of type D virus, SAIDS retrovirus types 1 and 2 (SRV-1
and SRV-2), are found in captive macaques in primate centers in
the United States. In addition to SAIDS, neoplasms,
retroperitoneal fibromatosis (RF) and subcutaneous fibrosarcomas
(SF), have been found in macaques infected with type D
retroviruses. Only SRV-2 is found in association with RF, and
about 35% of SRV-2 infected macaques develop RF. SF is found in
association with both serotypes, but less than 5% of infected
monkeys develop SF. RF in macaques is a potential model for
human disease since the lesions in macaques are similar to
idiopathic RF described in humans. Thus far, RF has not been
found in species other than macaque and human.
Mason–Pfizer
monkey virus (MPMV) or SRV-3 is a primate retrovirus that was
first detected by electron microscopy in a mammary carcinoma of
a female rhesus macaque, from which it was molecularly cloned
and characterized. Newborn rhesus macaques experimentally
inoculated with this prototypic D-type retrovirus develop a
wasting disease within a few weeks that is accompanied by
opportunistic infections including pneumonia, enteritis and
rashes.
SRV-4 was first
characterized at the Tsukuba Primate Center in Japan and is also
referred to as SRV-Tsukuba.
Serogroup 5
contains a single prototype virus, D5/RHE/OR, isolated from
rhesus macaques imported to the Oregon Primate Research Center
from the People's Republic of China; this isolate produces
severe immunodeficiency when transmitted into juvenile rhesus
macaques.
For reasons
of occupational safety and animal health, as well as to improve
the quality of nonhuman primates used in biomedical research,
the establishment and maintenance of specific retrovirus-free
breeding colonies of macaques are now high priorities. The type
D group of simian retroviruses continually poses challenges to
successful screening. Testing protocols for group D retroviruses
include virus isolation, antibody screening, western blot and
PCR. Because some SRV-infected animals lack detectable antibody
or exhibit a prolonged interval between infection and
seroconversion, parallel testing for both SRV antibody and SRV
virus is useful.
Indeterminate immunoblot results continue to pose a problem of
interpretation, and serological testing for group D retroviruses
has a high false positive rate (Chen, 1992). Cross-reactivity is
a major source of false positives in SRV testing by serology (Benveniste,
1993). Although a combination of serological testing and western
blot can reduce but not eliminate false positives, western blots
are generally too costly for use in ongoing screening and
monitoring programs.
The
frequency of false negatives is also unacceptably high when
serological testing alone is used. It has been found that
antibody levels can vary in inverse proportion to viral titres,
so that clinically asymptomatic animals with very low antibody
levels may actually be highly viremic (Rosenblum, 2000).
Even the
combination of serology and culture results in significant false
negative levels (Lerche, 1997). In contrast, PCR has been found
to be highly effective for the detection of the presence of SRV.
Alone or in combination with antibody testing, detection of SRV
by PCR is a rapid, specific and highly sensitive technique for
the development and maintenance of specific pathogen free
colonies.
Utilities:
-
Establish diagnosis of retroviral infection
-
Rapid screening to maintain research subjects free of
SRV
-
Differentiate the various subtypes of SRV
-
Safety monitoring of experimental subjects
-
Safety monitoring of biological products and vaccines
that derive from primates
-
Prevent further spread of viruses by identifying
affected nonhuman primates
-
Screen P0001 identifies generalized SRV
diagnosis. Assays S0001, S0002, S0003 and S0004 identify the
specific SRV serogroup.
References:
Benveniste R.E., Hill R.W., Knott W.B., Tsai C.C., Kuller L.,
Morton W.R. (1993). Detection of serum antibodies in Ethiopian
baboons that cross-react with SIV, HTLV-I, and type D retroviral
antigens. J Med Primatol. 22(2-3):124-128.
Chen Z., Ben K.,
Tian B., Zheng Y. (1992). Serological survey of a captive
macaque colony in China for antibodies to simian type D
retroviruses. J Med Primatol. 21(7-8):377-380.
Lerche N.W.,
Cotterman R.F., Dobson M.D., Yee J.L., Rosenthal A.N., Heneine
W.M. (1997). Screening for simian type-D retrovirus infection in
macaques, using nested polymerase chain reaction. Lab Anim Sci.
47(3):263-268.
Rosenblum L.L., Weiss R.A., McClure M.O.
(2000). Virus load and sequence variation in simian retrovirus
type 2 infection. Journal of Virology 74(8):3449-3454.
Specimen requirement: 0.5 ml whole blood in EDTA (purple top) tube.
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
Methodologies:
P0001, S0001, S0002,
S0003 and S0004 - Qualitative PCR
P0027 -
Qualitative reverse transcription coupled real time PCR
Normal range:
Nondetected