Mouse diseases Flashcards
What type of virus is mouse hepatitis virus?
Corona virus, SS RNA, enveloped
Infection patterns of Mouse Hepatitis virus are classified as either ____tropic or ____tropic
enterotropic or respiratory (polytropic)
How do B6 and BALB/c mice differ inrespect to their susceptibilitiy to MHV
BALB/c mice more susceptible than C57BL/6 mice (B/c have Th2 biased, B/6 have Th1)
What is the primary tropism for polyropic MHV and how does it attach?
Primary tropism for upper respiratory tract mucosa, attaches to CEACAM1a via spike protein
True or false: Most field strains for Mouse Hepatitis Virus are polytropic (respiratory)
False, most are enterotropic
Describe the role of B and T cells in in the dissemination and clearance of MHV
B cells mediate clearence and T cells prevent dissemination
How does MHV impact research
Respiratory strains deplete NK cells, incites a significant B and T cell response and infects monocytes & dentritic cells
Enterotropic strains infere with coinfections
For MHV serology is the cross reactivity good or bad among strains?
Excellent cross reactivity
How can MHV be confirmed on histology?
Lesions should by confirmed by IHC, PCR or serology (Syncytia are not pathognomic)
What tissue is recommended for PCR testing for MHV
mesenteric LN
Describe 2 ways to control MHV
Immunocompetent colonies by not breeding and no new mice for 6-8 weeks (test 1st). This is so-called “burn-out”
Generally eliminated by rederivation
Describe the capsid of murine parvoviruses
Eicosahedral capsid:
Three proteins: VP1, VP2, VP3
What structural protein determines teh cell specificty of murine parvoviruses
Capsid protein VP2
What protein is the major effector of cytotoxicity in mouse parvoviruses
NS1
What is the most prevalent not culture adpated strain of Mouse Minute virus?
MMVm
Which jas a higher prevalence mouse parvovirus or mouse minute virus?
MPV
Is the cross reactivity good or bad when testing for MPV by ELISA, MFIA?
Not very cross reactive
What strain of mouse parvovirus is also known as hamster parvovirus?
MPV-3
In what strain of mouse should serology testing for parvovirus be cautiously interpreted
B6, tend to be pretty resistant
Describe PCR sampling for parvovirus testing
Mesenteric LN or feces, also can test environmentall swabs and cell cultures
Describe the seasonality of mouse parvoviruses. What does this seasonality indicate?
Spike of cases in June/July, suggests wild rodents involved in transmission
Describe control measures for mouse parvoviruses
Can only eliminate with rederivation and must test offspring andd foster carefully
Test and cull strategy may also work
What does EDIM stand for and what pathogen causes it?
Epizootic Diarrhea of Infant Mice (EDIM)
Caused by group A rotavirus
What type of virus is a Rotavirus
Nonenveloped, dsRNA virus in Reovirus family
Describe the tropism for mouse rotavirus
Primarily infects mature enterocytes at tip of villi (binds to sialylated glycoconjugates)
How are nude and SCID mice different in regards to rotavirus infection?
Nude mice clear infection, but infection persists in SCID mice
What histology finding is classic for rotavirus?
Enterocyte vacuolation (but not specific)
The preferred diagnostic for rotavirus screening is…
Serology (fecal PCR and ELISA also available)
What type of virus is mouse norovirus
Small, nonenveloped, ssRNA viruses in the Caliciviridae. Murine noroviruses (MNV) are Genogroup V.
What unique about young mice in regards norovirus infection
Mice younger than 1 week not susceptible to infection
What are 2 potential problems with using soiled serology from soiled bedding sentinels to detect MNV?
Mice may take up to 8 weeks to seroconvert
Failures of infection transfer by soiled bedding documented
What “triad of infections” are common in GM mice
Murine norovirus (MNV)
Pasteurella pneumotropica
Helicobacter, esp. H. hepaticus
What type of virus is Theiler’s mouse encephalitis virus (family, genus)
Family Picornaviridae; Genus Cardiovirus
Differenitals for mice with flaccid paralysis of the hindlimbs
Lymphosarcoma Traumatic injury (spinal cord or limbs) Genetic disease MHV (natural infection) LDV in immunodeficient mice
Describe the pathogenesis of TMEV including inital cell tropism and the 3 forms of disease.
The virus is enterotropic and reaches the CNS after a transient viremia
Three forms of disease – Acute encephalitis, poliomyelitis (only one that occurs naturally), and demyelinating
What type of virus is lymphocytic choriomeningitis virus (family, genus, +/- envelope, DNA/RNA)
LCM virus (Family Arenaviridae; Genus Arenavirus) – enveloped RNA virus
How do mice become persistantly infected with LCMV?
Only animals infected before 1 week of age will shed the virus. Animals infected after that do not shed.
True or false: LCMV can be vertically transmitted?
Yes if the dam is persistantly infected
Describe the cell tropism of LCMV
pancytotropic (Lymphoreticular system, Brain, Salivary gland, Urogenital system)
Describe the acute onset disease of LCMV
Two forms – Neurologic and visceral
Emaciation, ascites, lymphocytic inflammation
Describe late onset disease of LCMV
In utero transmission results in congenital carrier mice, may develop emaciation and ascites
Histopathologic findings associated with LCMV late onset disease
Immune complex disease
Membranoproliferative GN, Polyarteritis / periarteritis / panarteritis
Extensive lymphocytic infiltration of almost any tissue
What material can be used to test for LCMV in mice
Material contaminated with urine or kidneys
Serology can be used to screen for LCMV but _____ groups may be seronegative
enzootic
Describe the Ectromelia virus
Ectromelia virus (Family Poxviridae, Genus Orthopoxvirus) (enveloped DNA virus)
Clinical signs of ectromelia
Sudden death in highly susceptible strains
Focal to generalized rash (papules, macules, ulcers, and scabs)
Amputated limbs and tail
Conjunctivitis and blepharitis
Internal gross leasions appreciated with ectromelia
Spleen
–Acute: Splenomegaly +/- white foci (necrosis)
–Chronic: Small pale plaques on the capsular surface and/or fibrotic scars
Liver :Hepatomegaly +/- multiple white foci
On histopathology what type of inclusions may be seen in association with ectromelia lesions
Large acidophilic, cytoplasmic inclusions might be observed in lesions
Ddx for ectromelia
–Cutaneous Strep or Staph –Traumatic injury to the tail and extremities –Bedding fibers causing limb necrosis –Ringtail –Mouse hepatitis virus infection –Ectoparasites
Most common causes of ectromelia positive serology results
exposure or vaccination with vaccinia virus
What type of virus is lactate dehydrogenase elevating virus
Arterivirus (genus of Coronaviridae), ssRNA, enveloped
How long do mice shed LDV
Shed for life
What is unique about serology for LDV
animals usually antibody neg, can use PCR to test serum
Mouse thymic virus is also known as
Mouse Thymic Necrosis Virus or Mouse T-Lymphotropic Virus
What family does MTLV belong to?
Herpesviridae
MTLV tropism
T-cells (early) except T suppressor cells Salivary gland (later)
How do infant and adult mice differ in regards to response following MTLV infection
Suckling (esp <48 hr) primary infection of thymus and do not form antibodies. Adults get primary infection of salivary glands and do form abs
Which virus is assocaited with the “Oily Hair Effect”?
Reovirus type-3
What is the disease presentation for Helicobacter hepaticus (consider mouse strain)
Chronic hepatitis and in A/J inbred mice - increased hepatocellular carcinomas, Typhlocolitis in some strains (A/J, C3H/HeN)
In immunodeficient mice (RAG2, SCID, Athymic, IL-10 KO, etc.): Typhlocolitis and prolapsed rectum, hepatitis, may be necrotizing
Diagnostics for Helicobacter detection
PCR is best, also histo w/ silver stain, culture, serology available
True or false: Helicobacter can be eliminated by cross fostering pups to “clean” dams
True as long as the pups are <24 hrs old when fostered
Etiologic agent of transmissible murine colonic hyperplasia
Citrobacter rodentium
True or false TMCH mice are carriers for life
False, mice recover fully
Top 2 bacterial disease consioderations for rectal prolapse
Helicobacter (esp immunocompromised), Citrobacter (esp immunocompetent)
Lesions associated with Pasteurella pneumotropica in immunocompetent mice
Lesions rare but mastitis, conjunctivitis/ dacroadenitis, metritis
Lesions associated with Pasteurella pneumotropica in immunocompromised mice
Necrotizing, suppurative dacryoadenitis
Suppurative dermatitis (abscesses)
Metritis
Sites to culture for P pneumotropica
nasopharynx, repro tract, conjunctiva, cecum
When performing PCR for P pneumotropica primers should be included for what 2 biotypes?
Heyl and Jawetz
