Exam 2: Poxviridae Flashcards
What makes poxviruses unique compared to other viruses?
It is the largest and most complex of all viruses
What are the 2 subfamilies of poxviruses?
Chordopoxvirinae (poxviruses of vertebrates)
Entomopoxvirinae (poxviruses of insects)
What are properties of most genera of poxviruses of vertebrates?
Brick-shaped virion
300 x 240 x 100 nm
irregular arrangement of tubules on the outer membrane
What are properties of parapoxvirus?
Ovoid
260 x 160 nm
Regular spiral arrangement of tubules on outer membrane
What is the complex structure of poxviruses of vertebrates?
Core, lateral bodies, outer membrane, and sometime enveloped
What is the genome of poxviruses of vertebrates?
Linear dsDNA
What are poxviruses of vertebrates resistant to?
Ambient temperatures
How many genes are in the genome of poxviruses of vertebrates?
Approximately 200
What type of replication do poxviruses of vertebrates have?
Cytoplasmic replication
What is the virus associated with genus Orthopoxvirus?
Vaccinia virus
What is the virus associated with genus Parapoxvirus?
Pseudocowpox virus
What is the virus associated with genus Capripoxvirus?
Sheeppox virus
What is the virus associated with genus Suipoxvirus?
Swinepox virus
What is the virus associated with genus Leporipoxvirus?
Myxoma virus
What is the virus associated with genus Avipoxvirus?
Fowlpox virus
What is the virus associated with genus Molluscipoxvirus?
Molluscum contagiosum virus
What is the virus associated with genus Yatapoxvirus?
Yaba monkey tumor poxvirus
What happens between poxviruses of the same genus?
Extensive cross-neutralization and cross-protection
Genetic recombination occurs readily
How do poxviruses of vertebrates enter the cell?
Fusion or endocytosis
What are all poxvirus infections associated with?
Lesions of the skin
What do several poxviruses cause?
Generalized disease throughout the viscera and cause significant mortality
What do generalized poxvirus infections have a stage of?
Cell-associated viremia, which leads to localization in the skin and to a lesser extent in normal internal organs
What is the immunity induced by poxviruses like?
Long immunity
What is the immunity induced by parapoxviruses like?
Short, so reinfection is common
How is poxvirus diagnosed?
- Electron microscopic examination
- Inoculation of chorioallantoic membrane of chicken embryonated egg
- Cell culture
- ELISA
- Histology- intracytoplasmic inclusion bodies
Which diagnostic methods cannot be used for parapoxviruses and molluscum contagiosum virus?
Inoculation of chorioallantoic membrane
Cell cultures
What are the methods of transmission of poxviruses?
Direct contact from skin lesions
Contaminated environment (Orf)
Droplet infection of the respiratory tract (Sheeppox)
Mechanical transmission by insects (Swinepox, Fowlpox, and myxomatosis)
What are the viruses in the Orthopoxvirus genus?
Vaccinia virus
Cowpox virus
Monkeypox virus
Raccoon poxvirus
What animals are found naturally infected with vaccinia virus?
Man Cow Buffalo Pig Rabbit
What animals are found naturally infected with cowpox virus?
Cow Man Rats Cats Large felines
What animals are naturally infected with monkeypox virus?
Squirrels Prairie dog Monkey Great apes Man
What animal is naturaaly infected with raccoon poxvirus?
Raccoon
What is the zoonosis of the Parapoxvirus genus?
They are zoonotic
What are the viruses of the Parapoxvirus genus?
Pseudocowpox virus
Bovine papular stomatitis virus
Orf virus
What animals are found naturally infected with pseudocowpox virus?
Cattle
Man
What animals are found naturally infected with bovine papular stomatitis virus?
Cattle
Man
What animals are naturally infected with Orf virus?
Sheep
Goat
Man
What are the clinical signs of pseudocowpox?
A small papule on the teat
Develops into a small, ark red scab and then scabbed
Ring or horseshoe scab
Similar can develop on the muzzle
What are the methods of transmission of pseudocowpox virus?
Cross-suckling calves
Contaminated milking machines
Mechanical transmission by flies
What does Orf affect?
Muzzle, lips, eyelids, feet, and teats of ewes
What are sheep susceptible to with orf?
Reinfection and chronic infection can occur
Can ewe be vaccinated for orf?
Yes, with live-virus vaccines before lambing
What is the immunity assocated with orf vaccines?
Short-lived
What are the viruses in the capripoxvirus genus?
Sheeppox virus
Goatpox virus
Lumpskin disease virus
What animals are naturally infected with sheeppox virus?
Sheep
Goat
What animals are naturally infected with goatpox virus?
Goat
Sheep
What animals are naturally infected with Lumpyskin disease virus?
Cattle
Buffalo
What is fowlpox characterized by?
Small papules on the comb, wattles, around the beak, feet
How can poultry be protected from fowlpox?
By vaccination with pigeonpox
Is chicken pox a pox virus?
It’s a herpes
