Final (new)

Question 1

Reoviridae

Answer 1

• non-envoloped
• spherical
• 3 layers
• dsRNA
• replication: cytoplasm
• gene reassortment

Question 2

African Horse Sickness

Answer 2

• reoviridae: sedoreovirinae: orbivirus
• infectious, non-contagious arthropod borne (culicoides) disease or equine
• zebra: inapparent infection, resivor
• dogs get via ingestion of infectious carcass
• outer capsid protein
• acute: pulmonary; dunkop; edema; nasal discharge, fluid in trachea
• subacute: dikkop: edema or eye; cardiac and GI
• dx: PCR
• vaccine

Question 3

Bluetounge

Answer 3

• reoviridae: sedoreovirinae: orbivirus
• infectious, contagious, insect born (culicodes midge)
• also transplacental and veneral in cattle
• sheep and deer
• innapparent infection in other ruminants
• list A disease: economic loss
• 5-10 day incubation
• mucopurulent nasal discharge
• cyanosis and ulveration of the tounge
• abortion, CNS malformation
• dx: virus isolation via tissue culture of chicken embryo, PCR, Ab detection w/ agar gel or competitive ELISA and necropsy
• 2 types of vaccines

Question 4

RVA

Answer 4

• reoviridae: sedoreovirinae: rotavirus
• most common diarrhea of young
• VP6 middle layer (naming)
• VP7 and VP4 for vaccines
• fecal oral transmission
• survive in environment; fomite
• viral multi. on villi of upper SI
• NSP4 acts as enterotoxin –> malabsorbtion and fluid secretion –> diarrhea
• calves,, lambs, pigles
• yellow, watery diarrhea
• dx: PAGE
• vaccines
• zoonotic

Question 5

avian reovirus

Answer 5

• reoviridae: spinareovirinae: orthoreovirus
• viral arthrisis/tenosynovitis in chickens (meat)
• turkeys, ducks necrotic foci on liver, spleen and kidney
• fecal oral
• intestinal replication –> blood –> localize in hock joint –> arthrisis
• clear synovial fluid; atropy pancreas
• killed and live vaccines (breeder hens)

Question 6

Rhabdovirus

Answer 6

• ssRNA, linear, negative sense , envoloped
• surface G proteins
• N, P, M and L protein
• stable in environment: pH
• sensitive to UV and disinfectants
• replication: cytoplasm
• receptor binding –> endocytosis –> fusion –>transciption

Question 7

Rabies virus

Answer 7

• rhabdovirus: lyssavirus
• ALL mammals
• most caused by rabid dogs
• skunks, raccons, fox and wolves in NA
• resivor: silver haired bats
• central and S america vampire bats transmit to cattle
• zoonotic
• urban (dog) and sylvatic cycle
• incubation 14-90 days (years)
  A) prodromal phase: agressive, daytime in nocturnal, no fear of ppl
  B) excitative(fury) phase: adgitation and agression; salivary shedding
  C) paralytic (dumb) phase: excesive salivation, paralysis, hydrophobia and death
• replicates in muscle tissue, binds to receptor of acetlycholine at neurmuscular junction, lumbic system replication
• eosinophilic intracytoplasmic inclusion bodies (negri bodies)
• dx: tissue from brain stem and cerebellum
• AG, nucleic acid or viable virus in REFRENCE lab
• FAT is gold standard
• vaccines

Question 8

lyssavirus

Answer 8

• rhabdovirus
• all viruses cause rabies like disease
• bat resivoir

Question 9

vesiculovirus

Answer 9

• rhabdovirus
• vesicular stomatitis indiana virus: americas
• vesicular stomatitis NJ virus: americas
• vesicular stomatitis alagoas virus: SA
• cocal virus: SA
• zoonotic
• horse, cattle swine and ppl
• isolated from carp and salmonid

Question 10

novirhabdovirus

Answer 10

• rhabdovirus
• infectious hematopoetic necrosis virus: america, EU, asia
• viral hemorrhagic septicemia virus: EU, NA, asia

Question 11

vesicular stomatitis virus

Answer 11

• rhabdovirudae: vesiculovirus
• cattle, swine, horse
• notifiable
• vesicular stomatitis
• incubation 1-5 days
• lameness in pig
• cattle and horse: salivation, fever
• vesicles on tounge
• in horses tounge lesions most pronounced
• replicate: intraepithelium of mucosa and skin
• -> edema, vesicles
• no virema (exp. pig)
• biting insect
• stable in environment
• dx: vesicular fluid RT-PCR; refrence labs only
• indistinguishable from other vesicular diseases
• ONLY infecting horse
• zoonotic
• vaccines not commercially available

Question 12

spring viremia of carp virus

Answer 12

rhabdovirus: vesiculovirus

- wild and cultured fish

Question 13

viral hemorrhagic septicemia virus

Answer 13

rhabdovirus: novirhabdovirus
- wild and cultured fish
- systemic infection in salmon
- EU, NA, japan
- fish of all ages
- 100% mortality
- exopthalmia, hemorhage at base of fin and darkened body color
- internal hemorhage in organs mottled liver
- no vaccines

Question 14

infectious hematopoetic necrosis virus

Answer 14

rhabdovirus: novirhabdovirus
- wild and cultured fish
- distension of abdomen due to ascites
- in salmonids
- enzootic in NA and WU
- juvinile fish, less mortality then VHSV

Question 15

Retroviridae

Answer 15

• exist as stable components in host genome
• encode reverse transcriptase needed for replication (RNA-dependent polymerase)
• positive RNA; diploid genome with 2 copies
• formed by budding; envoloped
• integrate into genome using integrase
• spherical; lipid membrane bilayer envelope w/ glycoprotein
• easily inactivated by lipid solvents or detergents and heating
• resistant to UV or X-ray
• gag, pol, env, pro
• can become oncogenic when c-onc gene becomes v-onc gene

Question 16

alpharetroviruses

Answer 16

• membrane anchored glycoprotein
• simple: gag,pro,pol and env
• type C
• endogeneous: transmitted horozontally
• exogeneous: included in host genome
• Avian leucosis virus
• Avian sarcoma virus
• Avian myeloblastosis virus
• Rous sarcoma virus

Question 17

Betaretroviruses

Answer 17

• transferrin receptor tfr-1
• gag, pro, pol, env
• MMTV has sag gene superantigen
• endogeneous and exogeneous
• MMTV and Jaagsikte virus of sheep

Question 18

Gammaretroviruses

Answer 18

- several receptors
>mCat1 - mouse viruses
> GLVR1 - dog, cat and primate viruses
> FeLIX and Pit for FeLV
- feline leukemia virus
- feline sarcoma virus
- avian reticuloendotheliosis virus

Question 19

deltaretrovirus

Answer 19

• • AP-3 complex receptor
• complex; type c morphology
• bovine leukemia; human t-lymphotropic virus
• gag, pol, pro, env and regulatory genes REX and TAG
• rex and tag control synthesis and processing of viral RNA
• only exogeneous

Question 20

epsilonretroviruses

Answer 20

• complex; type C
• walleye dermal sarcoma virus
• gag, pro, pol, env and ORF A, B and C
• endogeneous

Question 21

Lentivirus

Answer 21

• CD4 on T helper cell and CCR5 and CXCR4 on lymphoid cells
• complex, cylindrical core
• HIV, caprine arthritis encephalitis virus and meadi visna virus
• acessory genes
• exogeneous
• tat encodes a transactivator that enhances RNA polymerase
• rev: transport of nonspliced viral RNA
• nef: essential for replication in target host, can downregulate expression of CD4
• vif: enhances replication in lymphocytes

Question 22

spumaviruses

Answer 22

• complex
• human foamy virus
• assemble in cytoplasm and budded into endoplasmic reticulum and plasma membrane

Question 23

Feline Leukemia

Answer 23

• gammaretrovirus
• affecting domestic cats
• env encodes for glycoprotein gp70(SU) and transmembrane protein p15E(TM)
• pol codes reverse transcriptase and integrase
• gag ecodes p27
• 4 subtypes
  > A: most common
  > B recombination
  > C: mutations in env
  > T: t-lymphocytes
• exogeneous and endogeneous (enFLV and RD114 virus)
• cant survive in environment
• high in multi-cat household
• viremia is source of infection
• shed in saliva, grooming and bites
• viremic queens –> embryonnic death
• young kittens susceptible and aged resistant
• SU protein determines pathogenicity
• spreads via monocytes and lymphocytes
• viremia in weeks