Cerberus Fast Facts
Cerberus Fast Facts
What are Fast Facts ?
We get asked an awful lot of questions! To help you with some of the more commonly asked questions, we've compiled some fact sheets. We will try to keep these up to date, but this is a rapidly expanding area with new knowledge and data becoming available on an almost daily basis. If there are any particular areas or pathogens that you would like to see in this section, please let us know.
Prepare a Serum Sample
We can accept serum samples or serum diluted 1:5 (1 part serum in 4 parts physiologic saline or phosphate buffered saline). If the serum sample has been pre diluted 1:5 please indicate this on the submission form to ensure that the sample is not over diluted at the laboratory.
Serum can be prepared as follows:
Whole blood should be collected aseptically by cardiac puncture, tail vein bleed in or retro-orbital bleeding. Allow the blood to clot at ambient temperature for a minimum of 30 minutes, refrigerate at 4°C for 1 hour to allow the clot to contract, spin at low speed for 5 to 10 minutes and recover the serum into a sterile 1.5mL container (cryovial or eppendorf tube). Insufficient clotting time may result in false positive reactions being obtained in some assay systems.
An approximate 1:5 dilution of serum can be obtained by adding 1 part of whole blood to 2 parts of ambient temperature saline. Refrigerate the diluted blood for 6-12 hours, centrifuge at low speed for 5-10 minutes and recover the diluted serum into a sterile 1.5mL container (cryovial or eppendorf tube).
Do not submit whole blood as haemolysis will occur during freezing or shipping and this may interfere with test performance.
Avoid pooling serum samples if possible as pooled samples may give false negative reactions due to dilution effect.
If sera are pooled to make up a sample then the following applies:
a) MOST IMPORTANT. No more than 2 sera should be pooled.
b) Sera should all be from the same strain housed in the same area.
c) Approximately equal volumes of serum from each animal included in the pool.
Encephalitozoon Cuniculi
Prevalence
Can infect rabbits, mice, rats, hamsters, guinea pigs, dogs, non-human primates and many other mammals. Considered to be extremely common in rabbits, relatively rare in other lab animals species.
Diagnosis
ELISA, IFAT, histopathology.
Screening
Annually or bi-annually
Disease
Natural infections are usually sub-clinical. In mice there are strain differences in susceptibility to experimental infection, ranging from resistant (BALB/c, A/J and SJL) to very susceptible ( C57BL/6, DBA/1, 129/J). Infection is lethal in nude mice.
Strains
Number of strains unknown. Has the synonyms of Nosema cuniculi and Nosema muris. Protozoan of the order Microsporidia.
Transmission
Mainly horizontal by the orofecal route. Organisms shed in urine. Vertical transmission (transplacental) has been demonstrated in rabbits but not in other species. Known to be a contaminant of transplantable tumours
Duration
Chronic, usually latent infection in all species. May be present for greater than 1 year
Durability
Spores are resistant to drying for up to 4 weeks. Other information is sketchy but use of sporicidal disinfectants and high temperatures thought to be effective.
Significance
Usually low in studies involving rats and mice, but significant in studies involving passage of transplantable tumours and other materials. May alter humoral immune responses.
Control
No known effective chemotherapeutic agents. Serologic testing and selection of antibody free breeding stock has successfully been used for eradication in rabbits. Caesarean rederivation, improved sanitation and barrier maintenance in rats and mice, but the possibility of vertical transmission should not be discounted.Mice and rats should not be housed near known infected rabbit stocks
GO TOPLymphocytic Choriomeningitis Virus (LCMV)
Prevalence
Rare in laboratory mice, rats and hamsters. Guinea pigs and rabbits are also susceptible. Wild mice are considered to be the principle host reservoir.
Diagnosis
Serology, MAP, RT-PCR, Isolation
Screening
Bi-annually/annually as part of a normal monitoring program.
Disease
Dependant on a combination of viral and host factors. Usually sub-clinical, may be some runting in mice. Late onset disease may become apparent at 7 –10 months of age, renal disease with lesions associated with immune complex deposition. Experimental disease induction has been achieved by inoculation of the virus i.c., i.p., s.c., or i.v. This may result in viremia with either death within a few days or weeks or recovery with elimination of the virus NOTE Human infection may result in “flu-like” disease, aseptic meningitis or less frequently, encephalitis and myelitis.
Strains
Many strains have been documented and used in experimental situations.
Transmission
Excreted in faeces and urine. Fomites and aerosols are important in transmission. Experimental transmission by mosquitoes, ticks and lice has been demonstrated. Vertical transmission (trans-placental) is well documented.
Duration
Persistent, if animals are infected in utero they will become life long carriers.
Durability
Sensitive to lipid solvents, detergents and disinfectants such as formaldehyde. Infectivity is lost at pH values below 5.5 and above 8.5. Arenavirus (RNA). Disease outbreaks in laboratory staff and animal handlers have been attributed to rats (Belgium) and hamsters (USA) in the past.
Significance
High. Zoonotic (can infect humans). Known contaminant of transplantable tumours and rodent cell lines. Can interfere significantly with in vitro and in vivo experimental results.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Pre-screening of biologicals and transplantable tumours prior to introduction to the facility. Post infection. Destruction and incineration of entire stock affected. Cages and other equipment should be autoclaved. Formalin fumigation of affected areas with at least a 7 day vacancy period. NB. Caesarean rederivation is not an option with this organism.
GO TOPMouse Adenovirus (MAD)
Prevalence
Infects mice only. Rare in contemporary laboratory animal colonies
Diagnosis
Serology
Screening
Bi-annually or Annually
Disease
Sub-clinical. May cause wasting in nude mice.
Strains
Two known mouse strains, FL (Mad-1) and K87 (Mad-2).
Transmission
Urine (Mad-1), orofaecal (Mad-2)
Duration
Mad-1 shed in urine for up to two years. Mad-2 shed in faeces for approximately 3 weeks post infection in immunocompetent mice and intermittently for at least six months in athymic nudes.
Durability
Resistant to ether and acid pH. Stable for over 2 months at 4oC, 2 weeks at room temp and 1 week at 37oC. Inactivated at 50oC for 15 minutes.
Significance
Low
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Post infection. Caesarean rederivation, embryo transfer.
GO TOPMouse Hepatitis Virus
Prevalence
Very common; 2nd most common agent detected by serology in Australian mouse colonies, does not infect rats.
Diagnosis
Serology, Lesions, RT-PCR
Screening
Commercial Breeding colonies: Monthly; All other colonies: Quarterly
Disease
Epizootic - High mortality among neonates to subclinical in adults.
Enzootic - Usually subclinical in all ages.
Wasting syndrome in nu/nu mice (Possibly SCIDs as well) over an 8 - 10 week period.
Strains
Many strains (25 described) which are indistinguishable antigenically. Spectrum of tissue tropisms ranging from respiratory with colonisation of nasal epithelium (minimal lesions apparent) with dissemination possible to liver, lymphoid tissues etc in susceptible hosts (focal necrosis with syncytia) to enteric where virus is largely restricted to bowel mucosa with ascending colon and caecum major target areas. Enteric disease appears to be age dependant with infant mice developing enteritis and adult mice remaining subclinical. Immunosuppression or co-infection with other pathogens can increase susceptibility to MHV during active infection.
Transmission
Orofaecal, fomites, aerosol. Extremely contagious. In utero transmission has been demonstrated under extreme experimental conditions but is not considered to play a part in natural infection. Known to be a contaminant of transplantable tumours.
Duration
Acute in immunocompetent mice, 2-3 week period of virus shedding, lesions may only be apparent for 7-10 days. Longer periods of virus shedding in immunocompromised animals
Durability
Resistant to repeated freeze/thawing. Resistant to heating (56oC for 30 mins). Resistant to acid pH. Sensitive to lipid solvents, drying and disinfectants. Survives 30 days at 4oC and indefinitely at -70oC. Comment: Coronavirus (RNA). Immunity to MHV is virus strain specific and short lived. Coronaviruses readily mutate and recombine, with evolution of new strains and repeated infection being features of enzootic infection.
Significance
High. An extremely large number of effects of MHV on mice and their biologic responses to experimental treatments have been observed.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Screening of transplantable tumours and other murine derived biological material prior to experimental use
Post infection. Caesarean rederivation, embryo transfer or burn out selecting seronegative progeny as breeding stock post isolation (recommendations vary from 3 ? 12 weeks) of individual breeding pairs in micro-isolators. Burn out is usually only successful if population is immunocompetent and may not be effective with transgenic or knockout lines where immune status has not been fully characterised. Strict husbandry protocols and efficient barrier conditions are essential for success.
Murine Cytomegalovirus (MCMV)
Prevalence
Common in wild mice, relatively rare in laboratory mice, although a few sporadic positive antibody titres have been found in some Australian colonies. Not widely screened for overseas
Diagnosis
ELISA, IFAT and PCR, salivary gland lesions.
Screening
All colonies - Quarterly
Disease
Natural infections are sub-clinical. Latent infections can occur in submaxillary glands, B cells, T cells, the prostate and the testicles. Other organs known to be infected are the liver, spleen and pancreas. Note C3H and CBA relatively more resistant to infection than Balb/c, C57BL/6 and C57BL/10
Strains
Number not known, but many isolates have been used in experimental animal models of human cytomegalovirus infection.
Transmission
Saliva, tears, urine. Transmission via water bottle sipper tubes has been demonstrated. The virus does not spread easily from cage to cage, which may result in isolated pockets of infection within colonies which are difficult to detect. Vertical transmission is thought to occur but this phenomenon has not been fully explained.
Duration
Persistent. Latent infections may be activated by immunosuppressive regimes
Durability
Sensitive to ether, lipid solvents and extremes of pH. Relatively thermolabile.
Significance
Low. Natural infections have not been demonstrated to interfere with research, however acute experimental infections may affect a number of immunological systems and susceptibility to infection with other agents.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Screening of transplantable tumours and other murine derived biological material prior to experimental use. Exclusion of wild mice from the facility is essential. Post infection: Identification and culling of infected stock should be enough to contain the spread of infection coupled with rigorous disinfection protocols.
GO TOPMycoplasma Pulmonis
Prevalence
Rats and mice considered to be the primary hosts, but has been isolated from rabbits, guinea pigs and hamsters. Most common in rat colonies.
Diagnosis
Serology, isolation, PCR. NOTE : In sub-clinical infections seropositivity may be sporadic.
Screening
Quarterly
Disease
Often sub-clinical. Indicators may include the following: Snuffling (rats), chattering (mice), rales, polypnea, weight loss, hunched posture, ruffled coat, inactivity, head tilt and accumulation of porphyrin pigment around the eyes and external nares (rats).
Strains
Many different strains of a single serotype. Strains vary in virulence.
Transmission
Intrauterine, aerosol
Duration
Persistent
Durability
Sensitive to environmental conditions, does not survive well outside the host.
Significance
Very high. Has been shown to interfere significantly with many research protocols.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Screening of transplantable tumours and other murine derived biological material prior to experimental use Post infection: Caesarean rederivation. Use dams that are several months old and serologically negative and/or maintained on antibiotics to suppress M pulmonis as much as possible prior to caesarean operation. Use separate isolators for each foster mother and litter. Test placental membranes of each donor for the presence of Mycoplasma.
GO TOPParvovirus
Prevalence
Considered to be of moderate/high prevalence worldwide. Parvoviruses infect both mice (Minute Virus of Mice, Mouse Parvovirus (formerly called Orphan parvovirus)) and rats (Kilham Rat Virus, Toolan?s h3 virus, Rat Parvovirus).
Diagnosis
Serology, Molecular Diagnostics. Serological assays prone to low level false positive reactions if sample preparation, particularly clot formation and retraction is not optimal. The generic rNS1 ELISA should only be used for rats as this test has extremely low sensitivity in mouse serum samples. Mouse sera should be screened by a combination of MVM and MPV ELISA's
Screening
All colonies: Quarterly. Commercial breeding colonies may wish to screen more frequently as this pathogen becomes established in Australia.
Disease
Varies according to parvovirus responsible for infection and age of infected animals. Usually sub-clinical. Infection of pregnant animals may result in increased number of uterine resorption sites in dams and possible runting, ataxia, cerebellar hyperplasia and jaundice in pups.
Strains
Antigenically distinct, however the NS-1 protein is highly conserved across all parvoviruses and can be used in detection assays. If necessary differentiation can be made by HAI tests. Total number of strains of rodent parvoviruses not known.
Transmission
Contact, fomites, faeces, maternal milk, urine. Known contaminants of transplantable tumours and cell lines.
Duration
Considered to be persistent. Virus may be present for up to 14 weeks.
Durability
Extremely tough. Resistant to heat (80oC for 2 hours, 40oC for 60 days), drying, pH 2-11, chloroform, ether, alcohol, lipid solvents. Inactivated by formalin, b-propiolactone and oxidising agents. Comment: Single stranded DNA viruses.
Significance
High. Immune dysfunction in mice probable
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol.
Post infection. Caesarean rederivation, embryo transfer. Strict husbandry protocols, decontamination procedures and efficient barrier conditions are essential for success.
Reading
Laboratory Animal Science Vol 46, No. 4, p370 ?380.
GO TOPPneumonia Virus of Mice
Prevalence
Common in rats. Rare in Australian mouse colonies, but more prevalent in other parts of the world. Common in hamsters
Diagnosis
Serology.
Screening
All colonies; Quarterly
Disease
Subclinical in immunocompetent animals. Can cause lower respiratory disease in experimentally infected animals. Wasting disease in nude and SCID mice due to progressive pneumonia. Lung lesions more common in rats than in mice.
Strains
Number of strains not known. Cross species infection may be possible.
Transmission
Direct contact and aerosol. Susceptibility increased by ether anaesthesia, urethane administration and pyridoxine deficiency
Duration
Short lived in immunocompetent animals, approx 9-10days.
Durability
Labile at 56oC for 30 minutes. Does not survive well outside the host. Paramyxovirus. Antibody titres have been found in rabbits and guinea pigs but no reports of virus isolation
Significance
Low. No reported evidence of interference with research, but may contribute to higher than normal mortality rates under anaesthesia.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Post infection. Caesarean rederivation, embryo transfer or burn out selecting seronegative progeny as breeding stock post isolation of individual breeding pairs in micro-isolators. Strict husbandry protocols and efficient barrier conditions are essential for success.
Reading
“Infectious diseases of Mice and Rats” – National Academy Press: ISBN 0-309-03794-8.
GO TOPReovirus Type 3 (REO)
Prevalence
Very rare in Australia. Can infect mice, rats, guinea pigs and hamsters. Can be a contaminant of transplantable tumours and cell lines.
Diagnosis
Serology, RT-PCR
Screening
Bi-annually or annually.
Disease
Almost always sub-clinical. Report from 1963 showed the following signs in first litters of parents mated at 7-8 weeks of age: stunting, yellow stools, oily coats, abdominal alopecia and jaundice.
Strains
Number not known. 3 mammalian serotypes characterised
Transmission
Faeces, aerosol, fomites
Duration
Acute, 3-4 weeks
Durability
Highly resistant to lipid solvents, acid pH, heating (56oC for 2 hrs ; 60oC for 30 mins) and many disinfectants
Significance
Low
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Screening of transplantable tumours and other murine derived biological material prior to experimental use Post infection. Caesarean rederivation, embryo transfer.
Reading
“Infectious Diseases of Mice and Rats” – National Academy Press: ISBN 0-309-03794-8.
GO TOPRotavirus (epidemic diarrhoea of infant mice)
Prevalence
Very common. Most common agent detected by serology in Australian mouse colonies. Mouse strain of rotavirus does not infect rats. There is a rat strain of rotavirus which is antigenically distinct from mouse rotavirus and which is extremely rare in laboratory colonies. The rat strain is considered zoonotic
Diagnosis
Serology, Lesions (extremely transient, only seen in neonates), RT-PCR. Use of antigen detection kits on faeces not advisable due to false positive reactions attributable to some feed components.
Screening
All colonies; Quarterly (Commercial breeding colonies may wish to screen more frequently due to prevalence of this agent in Australia)
Disease
All ages susceptible to infection. Disease only evident in neonates (< 14days old). Diarrhoea during the first two weeks of life is the only consistent sign of disease. Disease is related to mucosal epithelial turnover kinetics. Infection progresses from duodenum – jejunum – ileum – colon.
Strains
Serotypic and genomic differences have been noted between different isolates with no evident difference in disease patterns.
Transmission
Orofaecal, fomites. Extremely contagious.
Duration
Infants shed high concentrations of virus in faeces from 2 – 10 days post infection. Transient viremia and viruria possible. Animals older than 17days shed lower concentrations of virus for 2 – 4 days with possible shedding of low levels of virus beyond this. SCID mice become persistently infected.
Durability
Unstable at –20, 4 and 37oC. Not resistant to environmental conditions. Family Reovirus. Double stranded RNA virus.
Significance
Low. May affect results of studies using infant mice or where neonate gut is target organ.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Post infection. Caesarean rederivation, embryo transfer (SCID) or burn out selecting seronegative progeny as breeding stock post isolation (recommendations vary from 3 – 12 weeks) of individual breeding pairs in micro-isolators. Strict husbandry protocols and efficient barrier conditions are essential for success.
Reading
“Infectious diseases of Mice and Rats” – National Academy Press: ISBN 0-309-03794-8.
GO TOPSendai Virus
Prevalence
Historically significant but relatively rare in modern mouse and rat colonies. Positive serology reported in Guinea pigs but no reports of virus isolation. Hamsters are susceptible.
Diagnosis
ELISA, IFA, RT-PCR, isolation, lesions.
Screening
Quarterly or bi-annually
Disease
Clinical disease possible in all ages of mice. Marked variation in genetic susceptibility related to kinetics of immune response and mucociliary clearance. In epizootic infections (mice) signs may include chattering and mild respiratory distress, prolonged gestation in adults, neonate and suckling deaths, poor growth in weaners. Enzootic infections are subclinical and maintained by a constant supply of young susceptible animals. Subclinical or mild disease in rats, possible infant mortality. Chronic wasting disease/pneumonitis in immunodeficient strains Resistant strains of mice include SJL/J, RF/J, C57BL6/J. Most susceptible strains include 129/ReJ, 129/J, DBA/1J and DBA/2J.
Strains
Many laboratory strains, all of which are antigenically homologous.
Transmission
Respiratory, contact and airborne transmission. Replication of virus thought to be limited to the respiratory tract with virus shedding for 7 – 10 days in immunocompetent animals This virus is extremely contagious
Duration
Acute (2 – 3 weeks) – except in immunodeficient strains.
Durability
Inactivated by UV light, temperatures above 37oC and lipid solvents
Significance
High, with many reports of interference with research.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Screening of transplantable tumours and other murine derived biological material prior to experimental use. Post infection. Prompt culling of infected sub populations. Caesarean rederivation, embryo transfer or burn out selecting seronegative progeny as breeding stock post isolation (recommendations vary from 6 – 12 weeks) of individual breeding pairs in micro-isolators. Burn out is usually only successful if population is immunocompetent and may not be effective with transgenic or knockout lines where immune status has not been fully characterised. Strict husbandry protocols and efficient barrier conditions are essential for success.
Reading
“Infectious diseases of Mice and Rats” – National Academy Press: ISBN 0-309-03794-8.
GO TOPTheiler’s Murine Encephalomyelitis Virus (TMEV)
Prevalence
Primary host is mice. Antibody titres have been found in rats, but the significance of these findings is in doubt. Rare in contemporary colonies. Prevalence is low in infected colonies. May be a contaminant of rodent cell cultures.
Diagnosis
Serology, Lesions (if present), RT-PCR
Screening
Quarterly
Disease
Most infections sub-clinical with no lesions. Paralytic syndrome rare (0.05 – 0.1%) of infected mice. Paralysis due to neuronolysis and demyelinisation in late stages.
Strains
Several laboratory strains which vary in neurovirulence.
Transmission
Orofaecal, fomites,
Duration
Faecal shedding has been shown to last for up to 53 days. Persistent infection of the intestinal tract thought to be unlikely
Durability
Inactivated by heating at 50–55oC for 30 minutes, treatment with 50% acetone or alcohol. Resistant to ether.
Significance
Low. May interfere with studies involving unrelated viruses.
Control
Pathogen exclusion. Regular health monitoring of supplier sub-populations, transport in filter boxes, quarantine at receiving institution with serology testing 2 weeks post arrival. Maintenance under strict barrier protocol. Screening of transplantable tumours and other murine derived biological material prior to experimental use Post infection. Foster nursing of infants, Caesarean rederivation, embryo transfer.
Reading
“Infectious Diseases of Mice and Rats” – National Academy Press: ISBN 0-309-03794-8.
GO TOPCopyright © 2010 Cerberus Sciences.