VIRO: MEpt2 POXVIRIDAE Flashcards
Describe poxviridae
-enveloped
- largest
-most complex
T/F: Are poxviruses pleomorphic?
fq:
-what are the shape of their virions?
-what are the shape of their cores?
True
brick-shaped or ovoid virions
core is dumbbell-shaped
What is the long thread-like structures covering poxviruses?
“ball of yarn”
What lesions does poxviruses cause?
pox/ pock mark lesions
What does pox viruses affects?
how about for skin cells?
What specific cells does it target?
- skin and mucosal surfaces
-causes tropism
-keratinocytes
where is the replication of poxviruses?
in the cytoplasm
what is the compartment in the cytoplasm that poxviruses use for replication?
viral factories
Are poxviruses resistant to desiccation?
yes and they can survive dried scabs
What are intracytoplasmic inclusion bodies that poxviruses have?
Guarnieri bodies or B-type inclusion bodies
T/F poxviruses does not provide lifelong immunity
false, they do
What are the diagnostic tests for poxviruses?
PCR, electron microscopy, virus isolation
where can poxviruses isolate and grown?
chich embryos and cell cultures
What vaccines are available for poxviruses
live- attenuated vaccines
It is the causative agent for small pox
variola virus
When was variola virus eradicated?
1980
pathogenesis of variola virus?
- entry: respiratory droplets/ direct contact
-spread through mucosa then to lymphatics
-causes viremia
Immunity for variola virus
-lifelong immunity
what vaccine is used for variola virus
smallpox vaccine (vaccinia virus)
clinical signs of variola virus?
high fever, rash (macules to pustules)
Host of variola virus
human
Subfamilies of poxviruses?
Chordopoxvirinae,
Entomopoxvirinae
genera of chordopoxvirinae
Orthopoxvirus
Parapoxvirus
Avipoxvirus
Capripoxvirus
Leporipoxvirus
Suipoxvirus
Molluscipoxvirus
Yatapoxvirus
Cervidpoxvirus
Crocodylidpoxvirus
genera of Entomopoxvirinae
Alphaentomopoxvirus- Infects beetles (Coleoptera)
Betaentomopoxvirus- Infects butterflies and moths (Lepidoptera) and grasshoppers and locusts (Orthoptera)
Gammaentomopoxvirus- Infectious mosquitoes,flies,and midges(Diptera)
What geus does variola virus belongs to?
Orthopoxvirus
used as a human vaccine and can cause naturally spreading diseases in domestic animals
Vaccinia virus
Before smallpox was eradicated and human vaccination against it was discontinued, instances of cowpox were frequently caused by?
vaccinia virus infection
causes naturally spreading diseases in domestic animals, for example, teat infections of cattle and oral and skin lesions in horses
Vaccinia virus
serves as a useful model for laboratory study, providing essential information on mechanisms of viral replication and modulation of host innate immune responses
Vaccinia virus
vectored rabies vaccine has been widely used in some enzootic areas to control rabies in wildlife
vaccinia virus
Transmission of myxoma virus
respiratory droplets, more often through mechanical transmission by arthropods like mosquitoes, fleas, black flies, ticks, and lice
Myxoma virus clinical signs
In European rabbits blepharoconjunctivitis and swelling of the muzzle and anogenital region, giving a leonine appearance
Myxoma virus clinical signs in California strain rabbits
may become febrile and listless, often dying within 48 hours of the onset of clinical signs,
T/F Myxoma virus causes localized benign fibromas in its natural hosts, wild rabbits in the Americas (Sylvilagus spp.) In contrast, it causes a severe generalized disease (myxomatosis) in European rabbits (O. cuniculus), with a very high mortality rate
True
pathogenesis of myxoma virus
- eplicates in dermal cells
- spreads to local macrophages, epidermal cells, and the draining lymph node
-Replication in the lymph node leads to lymphoid depletion
-preads via blood leukocytes to tissues including the spleen, lymphoid tissues, testis, lungs, and skin
-epidermis of swollen areas becomes virus-rich, facilitating transmission to arthropods
-virus encodes host response modifiers to manipulate the host’s immune response, aiding replication and spread
In what genus does myxoma virus belongs to?
Leporipoxvirus
Clinical Signs of rabbit fibroma virus
-Less virulent viruses and those that infect their natural hosts tend to produce localized fibromatous lesions
-virulent isolates tend to produce myxomatous lesions in aberrant Oryctolagus hosts
Pathogenesis of rabbit fibroma virus
- Inoculating rabbits with Sylvilagus floridamus papillomavirus type 1 resulted in the development of papillomas that progressed to squamous cell carcinomas
T/F
Rabbit fibroma virus (or Shope fibroma virus) originated in Europe
-Rabbit fibroma virus is related to myxoma virus
-Rabbit fibroma virus was the first virus shown to cause tissue hyperplasia
-False, it was first discoverd in america
- True
-True
in what genus does
Rabbit fibroma virus belong to?
Leporipoxvirus
Reservoir Hosts of cowpox virus?
Rodents are the reservoir hosts
Transmission of cowpox virus
- spreads from rodents to domestic cats, cows, humans, and zoo animals
Clinical Signs of cowpox
- elephant exhibited disseminated ulcerative lesions of the skin and mucosal membranes
-In humans, lesions usually appear as single maculopapular eruptions on the hands, neck, or face with minimal systemic reaction, except in immunosuppressed patients
In what genus does cowpox belongs to?
Orthopox viruses
affecting cattle of all ages, although the incidence is higher in animals less than 2 years of age
Bovine papular stomatitis
Transmission of Bovine papular stomatitis
-direct contact between infected animals
can be spread to unprotected hands of people working with affected cattle
Clinical Signs of Bovine papular stomatitis
lesions on the muzzle, margins of the lips, the oral mucosa and, less frequently, the teats
-ORAL LESIONS!
pathogenesis of Bovine papular stomatitis
-Viral entry through skin cuts or abrasions.
-Replication in cytoplasm, infects skin cells (keratinocytes).
-Lesion development.
-Cause inflammation at the site of the lesion.
-Spread to other areas of the body. –Can lead to lesions on the teats and udders.
-It is self-limiting, meaning it resolves on its own within a few weeks.
In what genus does Bovine papular stomatitis belong?
Parapoxvirus
Causes swinepox
Swinepox virus
Transmission of swinepox virus
pig louse Haematopinus suis (mechanical vector)
Genus of swinepox
suipoxvirus
Manifested by nodular skin lesions and edema
Lumpy skin disease
a highly contagious disease that affects cattle and water buffalo, causing fever, skin nodules, swelling, and weight loss
Lumpy Skin Disease Virus (LSDV)
Genus of Lumpy Skin Disease Virus (LSDV)
cervidpoxvirs
Transmission of fowlpox
transmitted within a flock through minor wounds and abrasions, by fighting and pecking, mechanically by mosquitoes, lice, and ticks, and possibly by aerosols
two forms of fowlpox virus
cutaneous form and diphtheritic form
Clinical signs observed in Cutaneous form
Small papules on the comb, wattles, and around the beak.
◦Lesions occasionally develop on the legs and feet and around the cloaca.
◦Nodules become yellowish and progress to a thick dark scab.
◦Multiple lesions often coalesce.
◦Involvement of the skin around the nares may cause nasal discharge.
◦Lesions on the eyelids can cause excessive lacrimation and predispose poultry to secondary bacterial infections
Clinical signs observed in Diphtheritic form
◦Involves infection of the mucous membranes of the mouth, pharynx, larynx, esophagus, and sometimes the trachea.
◦Lesions coalesce, resulting in a necrotic pseudomembrane, which can cause death by asphyxiation.
◦This form is also referred to as the wet form of fowlpox.
◦The diphtheritic form is more difficult to diagnose because it can occur in the absence of skin lesions
This form is also referred to as the wet form of fowlpox
Diphtheritic form
orf virus host
sheep and goats
other names for Orf virus
contagious ecthyma of sheep, contagious pustular stomatitis,
contagious pustular dermatitis, scabby mouth, sore mouth
clinical sign of pseudocowpox
Produces with ring or horseshoe-shaped scabs in the udder and teats
T/F psuedocowpox virus is not zoonotic.
- what does it cause?
F, they are zoonotic
-it causes Milker’s nodules
