Viral Families and Disease Flashcards
What are the signs of viral propagation?
Presence of intracellular double-stranded RNA > interferon
Presentation of surface antigen > Tc and NK cells
Formation of intracellular inclusion bodies
This is observation of virus-induced cytopathologic effects on cells, e.g.: inclusion bodies, cell lysis, vacuolation, synctia
cytology
For the following structures, name what virus it confirms:
Cowdry type A nuclear inclusion bodies
HSV, VZV
For the following structures, name what virus it confirms: negri bodies
rabies
For the following structures, name what virus it confirms: Nuclear owl’s eye inclusions
CMV
For the following structures, name what virus it confirms: cell lysis
enteroviruses
For the following structures, name what virus it confirms: vacuolation, syncytia
paramyxoviruses, HSV, VZV, HIV
What is the gold standard in diagnosing a virus
a culture or PCR
this is the presence of rubella infecting a cell which prevents growth of picornavirus on the same cells
heterologous interference
What are hemagglutinins?
receptors that cause erthrocytes to bind to the infected cell surfaces
A plaque is a viral “___”
colony
This is a 4-fold increase in titer between acute and convalescent phases (3 weeks apart) and proves identity of the disease agent
virus-specific seroconversion
What is titer?
how far a serum sample can be diluted and still test positive
ex: 1/64 is highest dilution, then titer = 64
Antibody development occurs __-__ days after infection starts
7-10
Low pH of inflammatory exudates
Enzymes
Mucous
Virocidins
These are all what type of host defense mechanisms?
Non-specific (innate) - Humoral factors
Nucleases
Proteases
Interferon
These are all what type of host defense mechanisms?
Non-specific (innate) - cellular factors
antibody
activated lymphocytes
cell-mediated immune system
These are all what type of defense mechanisms?
specific
Animal virus cytolysis tends to be a result from a ____ reaction
hypersensitivity reaction
This occurs when a bacteriophage fills up with cells, causing them to burst
cell lysis
This type of hypersensitivity reaction involves the IgE on mast cells which reacts with viral components and triggers a local anaphylaxis
Type I
This type of hypersensitivity reaction involves IgG or IgM. C’ and viral components are adsorbed or embedded in the cell membrane to induce cytolysis
Type II
This type of hypersensitivity reaction involves IgG or IgM antibodies and forms complexes with viral antigen and complement, generating neutrophil chemotactic factors, with resultant local tissue inflammation and destruction
Type III
ex: vasculitis
In this type of hypersensitivity reaction, antibody is NOT involved. Sensitized T-lymphocytes react directly with viral antigen, usually that antigen expressed on the surface of an infected cell, producing inflammation and cytolysis. This is probably the second most common allergic reaction to viruses
Type IV
In regard to cytotoxicity of preformed viral parts, measles virus produces rapid _____
polykarycytosis (fusion of chromosomes)
Herpesvirus components produce ____ by cell fusion. This leads to a positive ____ test
syncytia; Tzanck
Penton of ____ causes cell rounding and detachment from glass
adenovirus
A double-stranded RNA from ____ causes rapid death, without the production of infectious virus
enterovirus
Capsid fiber antigen (adenovirus) inhibits ___, ___ and ___ synthesis
DNA, RNA, protein
Large quantities of some ___ viruses, such as influenza and poxvirus, cause rapid effects in some animals
killed
____ process involves the integration of viral nucleic acid into the host chromosome
transformation
For each type of structural alteration due to viral infection, give an example:
cytoplasmic changes
nuclear changes
membrane changes
cytoplasmic changes: inclusion bodies, vacuoles
nuclear changes: pyknosis, inclusion bodies
membrane changes: membrane projections (hemagglutinins)
