POXVIRIDAE Flashcards
(70 cards)
Give the target cells of Poxviridae.
Skin cells and or oral mucosa (keratinocytes)
It is the deliberate exposure of infectious smallpox virus contained in the skin lesions of affected individuals.
Variolation
Jenner’s first vaccine for smallpox came from what animal?
Cattle
It is the first viral pathogen of a laboratory animal to be described.
Myxoma virus
Give the difference of Myxoma virus and Rabbit fibroma virus.
Myxoma virus:
- European rabbits: Oryctalagus cuniculus
- Cause of myxomatosis
Rabbit fibroma virus:
- 1932
- Shope
- North American Rabbits: Sylvilagus spp.
Rabbit fibroma virus is the first virus shown to cause _____ ______.
Tissue hyperplasia
What are the 2 subfamilies of Poxviridae?
- Chordopoxvirinae (vertebrates)
- Entomopoxvirinae (insects)
This method allows rapid visualization of poxviruses but not the particular species.
Negative-stain electron microscopic examination
The new virus order that has been recently proposed that would include the Poxviridae, Asfarviridae and other families of large DNA viruses.
Mononegavirales
Give the distinguishing characteristics of Poxviridae. (e.g. shape)
Large, pleomorphic, brick-shaped with an irregular surface of projecting tubular or globular structures.
Parapoxvirus are in what shape?
Ovoid with a regular surface; covered with long thread-like surface tubules in criss-cross fashion resembling a ball of yarn
Give the shape of poxvirus virions of the reptiles.
Brick-shaped but surface structure similar to that of parapoxvirus
Two types of progeny virions produced by poxvirus-infected cells
- Mature virions (MV) - stable
- Enveloped virions (EV) - fragile
The core of virions of poxvirus is in what shape?
Dumbbell shape; 2 lateral bodies
MV type virions are released by?
Budding or after cell lysis
EV type virions are released by?
Exocytosis
Give the main difference of MV and EV virions based on their transmission capabilities.
MV’s are very stable and are thought to mediate transmission between hosts, whereas the more fragile EV’s are best suited to exiting the intact cell and spreading within the host.
What is the symmetry of nucleocapsid core of Poxviruses?
None making them “complex structure”
Poxviridae has double-stranded DNA and is non-enveloped. True or False?
False, enveloped.
Give the mode of transmission of Poxviruses.
Direct contact or indirect contact of infectious material with broken skin and, for some viruses, the upper respiratory tract; transmitted mechanically by biting arthropods
What is the site of replication of poxviruses?
Cytoplasm
Poxvirus DNA replication can usually be detected within ___ hours of infection.
2
Specific cellular receptors for poxviruses have been identified. True or False?
False
Poxvirus infection has been described in how many species and orders of birds?
232; 23