Exam 2 Flashcards
why are there only a few effective antiviral medication?
Viruses are intimately dependent on the metabolic pathways of their host cells for replication
Where in the life cycle are possible mechanisms of action of antivirals?
Receptor binding, uncoating, nucleic acid and protein synthesis, assembly, release and to modulate the immune system
Acyclovir is restricted to which virus?
Herpesvirus
What does acyclovir require to be activated?
virus enzymes in the infected host cell. They are necessary to convert the prodrug into active form, which then interferes with virus replication.
Acyclovir is the synthetic nucleoside analog of _________
Deoxyguanosine
Mechanism of antiviral effect of acyclovir?
Stop the growing viral DNA chain (due to lack of necessary attachment points) and Competitive inhibition of viral DNA Polymerase
why is acyclovir nontoxic to the unaffected host cells
the enzymes herpesvirus thymidine kinase and virus DNA polymerase are viral enzymes that are not found in host cells
how can herpesvirus develop resistance to acyclovir?
absence or lack of viral thymidine kinase
Amatadine inhibits replication of most strains of _________ by blocking _________of the virus
Influenza A; uncoating
The M2 ion channel is the target of ______
Amantadine
how does amantadine affect the M2 channels in a virus?
clog the channel and prevent it from pumping protons into the virion. (the protons lower the pH in the interior so that the viral RNA’s can be released)
Amatadine can also alter conformation of _______ and thus also blocks viral assembly
hemagglutinin
Neuraminidase inhibitors enzymes are synthesized by _______
Influenza A and B
Neuraminidase is important is what activity of viruses?
Spreading
targets for Anti-Retroviral therapy
Inhibit fusion, inhibit integration, inhibit reverse transcriptase, inhibit protease
Zidovudine is a potent _____
antiviral (retroviruses)
AZT/ZDV resemble what?
thymine deoxyribonucleotide-triphosphate
Mechanisms of actions for AZT/ZDV?
Competitive inhibition of reverse transcriptase activity and inhibition of growth of the cDNA transcribed from the viral RNA
reverse transcription of virus genome takes place in the _____of a cell
cytoplasm
what are the four “W’s” of immunization?
Where, when, who, why
the original live-attentuated virus vaccine form naturally occurring attenuated viruses?
cowpox
Most of the live-attenuated virus vaccines in common use were derived by ___________________________
attenuation of viruses by serial passage of cluttered cells
__________ and _________ viruses were produced by attenuation of viruses by serial passage in heterologous hosts (specifically which host)
Rinderpest and classical swine fever; Rabbits
Vaccines produced by attenuation of viruses by selection of cold-adapted mutants and reassortments would be safer in what conditions?
lower temps such as nasal cavity bc they would replicate better.
Vaccines produced from inactivated whole virions.
infectivity destroyed while maintaining immunogenicity. Need a large amount of antigen to elicit immune response, usually formulated with chemical adjuvant to do so.
Vaccines produced from purified native viral proteins
the virion is soluble and its components released. Differential centrifugation
Vaccines produced by recombinant DNA and related technologies
things
What is DIVA used for?
differentiating between an animal that was live attenuated vaccinated or had a natural infection (due to the presence of antibodies). Using special “marked” vaccines
Vector Control consists of:
Source reduction, biological and chemical control.
Isolation:
applies to animals that are KNOWN to be ill with contagious disease
Quarantine:
applies to those who have been exposed to a contagious disease
When is isolation not effective?
if detectable pathogen shedding does not occur, as in carriers of incubation period
When does isolation not effective?
with diseases involving chronically infected healthy shedders
Decontamination:
general term that ranges from sterilization to simple cleaning; renders a medical tool safe to handle
Sterilization:
eliminates ALL forms of microbial life
Disinfection:
eliminates all forms of microbial life except bacterial spores
Antisepsis:
application of a liquid microbial chemical to skin or living tissue to inhibit or destroy microorganisms.
Moist heat method of sterilization:
autoclave; 121 degrees for 15 mins
Dry heat method of sterilization:
160 for 2 hours
chemical methods of sterilization
h2o2, ehtylene oxide, ozone
Radiation method of sterilization
UV radiation or Gamma or X rays
Sterile filtration:
microfiltration
2 subfamilies of poxviridae?
Chordopoxvirinae and entomopoxvirinae
Two infectious poxvirus particles: _______ and _________
intracellular mature viruses and extracellular enveloped virus
The genome of poxvirus consists of ________
a single molecule of linear double stranded DNA
Even though Poxviruses are DNA viruses, they replicate in the ______
cytoplasm
Unlike other enveloped viruses, poxviruses show a ____ environmental stability.
high
Poxvirus are less sensitive to organic solvents due to their_______
low lipid content
Pox Virus can be transmitted via:
broken skin, respiratory route, mechanically transmitted via arthropod
T/F. Poxviruses are highly epitheliotropic?
TRUE
poxviruses are _____, while orthopoxviruses infect a wide range of species
Host specific
T/F. Poxviruses can survive in the dried scabs for many months to years?
TRUE
Cowpox is under what Genus?
Orthopoxvirus
cowpox affects which animals?
cattle, cats and humans (rodents are reservoirs)
Cowpox in cattle: how is it transmitted? clinical findings?
milker hands or teat cups, farm cats, rats; papillose on teat and sucking calves may get lesions in mouth
cowpox in cats: transmission? clinical signs?
skin inoculations, nasal passages; skin lesions in head neck and forelimb, widespread secondary lesions may occur
cowpox in humans: transmission? clinical signs?
from cats usually; lesions on hands or face, enlarges lymph nodes, general symptoms.
Monkeypox: possible hosts?
monkeys and humans
Clinical signs of monkeypox in humans? monkeys?
similar to smallpox; generalized skin eruptions, then papules spread elsewhere.
Other orthopoxviruses:
variola, camelpox, extromelia virus, horsepox, rabbitpox, vaccinia virus,
What Genus is pseudo cowpox, Orf virus and bovine papular stomatitis virus under?
Parapoxviruses
Psuedocowpox is referred to as ______ because it can infect humans as well.
milker’s nodule
Psudocowpox transmission?
milker’s hand, teat cup, biting insect, calves from suckling, semen of bulls
Lesions from this virus are characterized by hyperplasia of squamous epithelium?
pseudocowpox
_______ of pseudo cowpox begin with a thick scab and then drop off leaving a horseshoe shaped ring of scabs around a wart-like granuloma.
Acute lesions
________ of pseudo cowpox commences as Erythema with soft scabs that are rubbed off during milking.
Chronic lesion
What is the order that an acute pseudo cowpox lesions develops
Erythema, papule, vesicle, rupture, scab
Contagious ecthyma is the Orf virus
True statement
What are the hosts that are affected by contagious ecthyma?
sheep and goats and humans
Contagious ecthyma transmission?
animal to animal (fallen scab contains virus), contaminated instruments; primarily though damaged skin; oral lesions in nursing lambs or kids
The evolution of contagious ecthyma lesions is…?
Macule, papule, vesicle, pustule, ulcer, then scab formation
Contagious ecthyma clinical signs?
initial mucucutaneous lesions, then spread to muzzle and nostrils. anorexia; severe cases is in genitals, ears, feet
Usually contagious ecthyma resolves in 1-4 weeks when scabs fall off, but complications can result from ________ or _______
secondary bacterial infections, fly invasion
Contagious Ecthyma vaccines: origin? when do you use it?what determines viability? immunity?
from prepared suspension of scabs, ONLY in herds with a problem with ORF, look for local reaction to confirm viability, short term: 1-2 years
Sheep pox, goat pox and lump skin disease belong to which genus?
Capripoxvirus
T/F? Sheep pox is a not a systemic disease?
False
Two forms of sheep pox disease:
Malignant and benign form
Malignant form of sheep pox is found in what animals?
lambs usually
T/F? Sheep pox is a reportable disease?
TRUE
Goatpox is reportable?
Yes
A ________ of capripox is seen in some European goats and this has a high case fatality.
flat hemorrhagic form
Goat pox clinical signs (general)?
young kids suffer systemic disease with lesions on skin, respiratory, and alimentary mucosa. Milder form of disease in adults.
Lumpy skin disease in what host?
cattle
Lumpy skin disease is transmitted how?
arthropod, also direct contact
lumpy skin findings?
fever, lumpy skin, lymphadenopathy
What genus is swinepox under?
suipoxvirus
Swinepox transmission?
through damaged skin, heamatopinus suis (pig lice), flies and insects, transplacental infection
Development of swine pox lesion?
erythematous macule, papule, vesicle, pustule, ulcers, scab
Which genus does fowlpox and other avian poxviruses belong to?
avipoxvirus
Host of fowl pox?
poultry and turkeys
The three forms of fowlpox disease?
Cutaneous form (dry), Diphtheritic form (wet), and Ocular form
Which form of fowlpox disease is more common?
Cutaneous form
Cutaneous form of fowlpox usually a result of arthropod or mechanical transmission to broken skin?
Yes
Diphtheritic form is probably caused by ______
droplet infection
Diphtheritic form of fowlpox results in _______________.
infectious of mouth, pharynx, larynx and trachea. Death by asphyxiation
Ocular form of fowl pox results in __________.
conjuctivitis (cheesy exudate over eyelids)
Turkey pox and canary pox result in cutaneous lesions?
yes
Histologically, what is characteristic of avipoxvirus?
Bollinger and Borrel Bodies
Ulcerative Dermatosis of sheep is a _____ poxvirus.
Unclassified
Ulcerative Dermatosis of sheep is transmitted by?
infection through skin or coitus
Two forms of Ulcerative dermatosis of sheep:
Lip and leg ulceration AND Venereal form
The Poxvirus characteristic intracytoplasmic inclusion bodies:
Guarnieri inclusion bodies and ATI inclusion bodies; Bollinger and Borrel bodies in avipoxvirus
T/F? parapoxviruses do not multiply in chicken embryo?
TRUE
Circoviridae have _____-stranded DNA genomes.
Single
Genus circovirus (under circoviridae family) have what type of DNA?
Circular, single-stranded ambisense DNA
Genus Gyrovirus (under circoviridae family) have what type of DNA?
Circular, single-stranded negative sense DNA
Circoviridae are enveloped or non-enveloped?
non-enveloped
What is characteristic of the chicken infectious anemia virus?
they have 12 trumpet like structures protruding from the capsid
Where do circoviridae DNA replication occur?
Nucleus
Post-weaning multisystemic wasting syndrome is caused by?
Porcine circovirus 2
PMWS is characterized by ? (histologically)
botroid intra cytoplasmic inclusion bodies in infected macrophages
Pathogenesis of PMWS?
lymphoid depletion and lymphopenia in peripheral blood
Transplacental infection of PMWS: 1st and 2nd trimester, and 3rd trimester.
fetal death and abortion; minimal effects during last trimester
Post weaning multisystemic wasting syndrome can be co-infected with?
Porcine parvovirus, porcine arterivirus, mycoplasma hyopneumoniea.
two kinds of vaccines against porcine circovirus (PMWS)
chimeric vaccines using non-pathogenic PCV-1 AND inactivated or baculovirus-expressed vaccines- include capsid proteins of PCV-2.
Along with post weaning multi systemic wasting syndrome, Porcine circovirus 2 can also lead to..?
Porcine dermatitis and Nephropathy syndrome (PDNS)
PDNS: clinical findings? hosts?
necrotizing skin lesions, necrotizing vasculitis, necrotizing and fibrinous glomerulonephritis; older piglets.
Chicken anemia virus is a member of what genus?
gyrovirus
Chicken anemia virus affect which hosts?
chickens; mostly young chickens 2-4 weeks of age
Where are principal sites of chicken anemia replication?
hemocytoblasts in bone marrow, precursor T cells in thymus, and dividing CD4 and CD8 cells in the spleen.
replication of CAV in the hemocytoblasts leads to ______, while replication in the T cells causes _______
anemia, immunosuppression
The ______ protein of CAV induces apoptosis and causes destruction of infected lymphocytes.
apoptin
How is Porcine Circovirus 2 transmitted?
Blood, urine, feces and mucous
The order Herpesvirales has three families; which are?
Herperviridae, alloherpesviridae, malacoherpesviridae
Mardivirus (gallid herpesvirus 2- Marek’s disease) and Iltovirus (galled herpesvirus 1-infectious laryngotracheitis virus) belong to which Genus
Herpesviridae
Proboscivirus- elephantid herpesvirus belong to which genus?
Betaherpesvirinae
Virus from the Gammaherpesvirinae can become ______in lymphocytes.
latent
where does synthesis of viral DNA and capsid assembly occur in herpesviruses?
Nucleus
where does processing of herpesviruses occur?
cytoplasm
Visions are (enveloped or non enveloped) with a simple linear (single or double) stranded DNA.
enveloped; double stranded
Early genes=?
regulatory functions and virus replication
late genes=?
structural proteins
Alpha proteins (herpesvirus) have what function?
transactivate beta gene transcription
beta proteins (herpesvirus) have what function?
involved in replicating the viral DNA
gamma gene expression is stimulated by what activity? (herpesvirus)
DNA synthesis
gamme proteins are involved in what function?
capsid assembly and modifying membranes for virion formation
Transmission of herpesvirus?
mucosal contact or droplet or aerosol transmission
T/F? latent infections of herpesvirus is common?
TRUE
Rhinotracheitis, vulvovaginitis, Balanoposthitis, conjuctivitus, enteritis and abortion in cattle can be caused by…?
Bovine herpesvirus 1
T/F? BHV-1 has a high morbidity but low mortality?
True
Clinical signs of IBR (rhinotracheitis) caused by BHV-1 is
general symptoms with profuse nasal discharge that is serous at first and then mucopurulent; nasal mucosa becomes hyperemic with ulcerations present and a deep cough; conjunctivitis, gastroenteritis, abortion
Clinical signs of IPV (vulvovaginitis)
general symptoms with painful micturition and tail held away from vulvar area (swollen, reddened, pustules/ulceration)
vulvovaginitis (IPV) results from _____ and occurs mostly in ______cattle.
coitus; dairy
Balanoposthitis virus can remain latent in which nerves?
sciatic and trigeminal ganglia
the Eliza test specifically for BHV1 detection in cattle?
pulmotest
T/F? The vaccination against BHV-1 prevents infection?
False; just reduces severity and incidence
T/F? Equine herpesvirus 1 is the most important viral cause of abortion in horses?
True; if mare is infected in last trimester abortion may occur
EHV-1 can also cause respiratory disease and encephalomyelitis?
Yes
Encephalomyelitis in horses infected with EHV-1 is due to…?
destruction of endothelial cells of arterioles of the brain and spinal cord.
Aborted fetuses in EHV-1 have what characteristic lesions?
advanced icterus
Herpesvirus belong to which order?
herpesvirales
Acute disease of EHV-1 has what clinical signs?
mild serous or seromucous nasal discharge with ocular discharge and conjunctivitis.
what organs would you sample for EHV-1 since it is a systemic disease?
lungs, spleen, thymus
Equid herpesvirus 3 results in the the formation of pustules on….?
vaginal mucosa and penis
EHV-3 is systemic and can cause abortions?
NEGATIVE
EHV-3 transmission?
coitus, nasogenital transmission, flies?
Gallid Herpesvirus 2 (Marek’s disease) belongs to which order?
alphaherpesvirus
Marek’s disease is what kind of disease in chickens?
lymphoproliferative
Clinical signs of galled Herpesvirus 2?
paralysis of wings or legs, incoordination, wing drooping
three variations of Marek’s disease:
acute, ocular lymphomatous, and cutaneous mark’s disease
Suid herpes virus 1 is also referred to as Pseudorabies?
Yep
Suid Herpes Virus 1 manifests in three different ways. what are they?
Neurological, respiratory, or reproductive failure
Suid herpes virus 1 transmission?
nose to nose contact, feed and contaminated water
Suid Herpes Virus 1 Clinical signs?
sudden death in young piglets; older pigs= general symptoms, tremors, vomiting, foaming at mouth, convulsions; sows can absorb fetus in 1st trimester and abort in later trimesters
Clinical signs in secondary hosts of Suid herpes virus 1?
intense pruritis in cattle, dogs and humans
Malignant catarrhal fever is caused by which viruses?
Alcelaphine herpesvirus and ovine herpesvirus 2
Malignant catarrhal fever is a generalized lymphoproliferative disease of _______.
cattle and some wild ruminants
Clinical signs of Malignant catarrhal fever?
fever, depression, profuse nasal discharge, ocular discharge and salivation; corneal opacity; nasal and Gi mucosal erosion
Histological findings of Malignant catarrhal fever?
proliferation of lymphocytes
African swine fever virus is the sole member of which family?
asfarviridae
African Swine fever virus is the only ______ arbovirus of animals.
DNA
African Swine fever isn’t very resistant at all?
False
African swine fever transmission?
soft ticks ( sylvatic cycle); direct contact, secretions, blood loss
The effects of African Swine fever is:
hemorrhages, apoptosis, leukopenia, lymphopenia, thrombocytopenia
Peracute African Swine Fever clinical signs?
sudden death or 1-3 days of high fever, hyperpnea hyperemia before death
Acute African Swine Fever clinical signs?
general symptoms, erythema, cyanotic skin blotching, respiratory distress, nasal discharge, abortion, death
Chronic African Swine fever clinical signs?
Stunted growth, swollen joints, ulcers and reddened or raised necrotic skin foci, pneumonia
“Blackberry jam spleen” characteristics to which disease?
African swine fever
You can treat African Swine Fever yourself as a veterinarian?
NOPE, it is reportable!!
African Swine fever is only found in african countries?
Negative, eastern Europe and Russia.
T/F? Papiloma viruses can transform cultured cells?
True
Papillomaviruses infect which cells in the basal layer of the epithelium after micro-wounds occur?
Keratinocytes
In benign/malignant warts, the papillomavirus DNA is episomal.
Benign
In benign/malignant warts are integrated into the host cell.
Malignant
Papillomavirus (example HPV) produces two proteins. which are they?
E6 and E7
Function of the E6 protein produced by HPV
prevents p53 from making damaged cells commit suicide
Function of the E7 protein produced by HPV:
bind to RB and prevents it from stopping damaged cells from growing
Bovine papillomatosis transmission?
contaminated fomites or sexual intercourse
Fibropapilloma in cattle is caused by which viruses?
Bovine papillomavirus type 1, 2, or 5*
Cutaneous papillomas in cattle is caused by which virus?
Bovine Papillomaviruses type 3
T/F? When cattle ingest the plant, Break Fern, it can cause a transition to an invasive carcinoma of the alimentary trect?
Yes, BPV 4 can cause transient papilloma in the Gi tract and the plant contains mutagens, carcinogen and immunosuppresive chemicals.
Also, if with Papilloma type 1 or 2 is can contribute to enzootic hematuria or bladder cancer
T/F? Canine oral papillomatosis is warts that can start on lips and spread down to the esophagus?
False, the warts stop before the epiglottis and esophagus.
Epithelial hyperplasia and cytoplasmic vacuolization are histological characteristics of ________
Canine oral papillomatosis
Canine oral Papillomatosis often doesn’t resolve and can progress to squamous cell carcinoma?
False, self-limiting and malignant progression is rare
Feline papillomatosis is a thing
In the pics there are warty plaque-y crustiness in ears
Equine Sarcoids are associated with what viruses?
Bovine papilomaviruses 1 and 2
The exact transmission of equine sarcoids isn’t confirmed but there are susceptible breeds?
True
T/F? Lesions of equine sarcoid commonly occur in traumatized areas.
True
Virus replication occurs only in cells that pass through ______
mitotic S phase
Viruses in the ________ genus, like parvovirus B19, causes mild rash illness, aplastic anemia and painful joints in children
Erythrovirus
Viruses in the _______ genus cannon replicate on their own and depend on a helper virus to do so.
Dependovirus
Viruses in the ________ genus contain a third ORF (open reading frame) between the nonstructural and structural coding regions. Infect GI and respiratory tract.
Bocaviruses
Feline Parvovirus transmission?
oro-nasally, feces, secretions, contaminated fomites, in-utero transmission, fly transmission.
Hallmarks of panleukopenia?
leukopenia (cells in circulation and in lymphoid tissues destroyed). Thrombocytopenia may also occur.
pathogenesis of enteritis
destroys deep crypt cells. the surface cells are constantly being replaced, but due to parvo they are not. this results in short villi, malabsorption and diarrhea.
Pathogenesis of in-utero infection
early gestation infection=fetal death and absorption
late gestation infection= varying damage to neural tissue; cerebellar hypoplasia, retina damage as well
T/F? Canine Parvovirus 1 is often fatal.
False; mild to inapparent illness. Not Important
Canine Parvovirus 2 transmission?
oro-fecal, in-utero infection, contaminated fomites
Porcine parvovirus disease is an infectious cause of _____________ in swine throughout the world.
Reproductive failure; predilection for mitotically active cells in fetal tissues
Porcine parvovirus transmission?
oronasal, transplacental transmission, veneral transmission is possible
What is the hallmark clinical sign for Porcine parvovirus?
increase in mummified fetuses after a normal gestation period.
Porcine parvovirus is major cause of SMEDI. What does that stand for?
Stillbirth, mummification, embryonic death, infertility
T/F? Like most other parvovirus, Porcine Parvovirus cannot cause persistent infection with periodical shedding.
False, it can cause persistent shedding unlike the other parvoviruses
