Virology - General Properties Flashcards
Which virus have Ribosomes
No ribosomes except Arenavirus - contain non - functional ribosome (host ribosome)
Symmetry of DNA Viruses
Icosahedral Symmetry Except Poxvirus
Symmetry of Poxvirus
Complex symmetry
Helical symmetry is shown by
Some RNA Viruses
MRFAB
Myxovirus
Rhabdovirus
Filovirus
Arenavirus
Bunyavirus
Envelope of virus is made up of
Lipoprotein - Lipo from host and Protein from virus
Enveloped Viruses are sensitive to
Ether sensitive
Alcohol sensitive
Heat labile
Can be eliminated by hand sanitization
Examples of Non enveloped DNA Viruses
PAP
Parvovirus
Adenovirus
Papovavirus
Examples of Non enveloped RNA Viruses
PARCH
Picornavirus
Astrovirus
Reovirus
Calicivirus
Hep A
Hep E
Capsid means
The protein shell of a virus particle surrounding its nucleic acid.
Nucleocapsid means
Genome (nucleic acid) + Capsid
Envelope proteins are also known as
Peplomers
Virion means
Nucleic acid with Capsid
Viroid means
Naked ssRNA without capsid
Prion means
Misfolded proteins
Site of nucleic acid replication in DNA Viruses
Nucleus except Poxvirus
Site of nucleic acid replication in RNA Viruses and Exceptions
Cytoplasm except Retrovirus and Orthomyxovirus (Influenza)
Steps of Viral Replication
APPU on a BAR Stool
1) Attachment - most specific step, attachment betw virus and host
2) Penetration/Viropexia - Phagocytosis by Macrophages, Membrane fusion (HIV)
3) Uncoating - Capsule lysed by host lysoszymes
4) Biosynthesis - New virions synthesis
5) Assembly and Maturation
6) Release
Which step of Viral Replication is most specific
Attachment/Adsorption
Which step of viral Replication is absent in Bacteriophages
Uncoating
Eclipse phase means
Time between host entry and First virus formation
Eclipse phase in Bacteriophages and Animal virus last for
Bacteriophage: 15-30 min. (Uncoating absent)
Animal virus : 15-30 hrs
DNA Viruses includes
HHAPPPy
Hepadnaviridae (HBV)
Herpesviridae - HSV, HZV, EBV, CMV, HHV
Adenoviridae
Poxviridae - Variola, vaccinia, Molluscum
Papovaviridae - HPV, BK, JC, Polyoma
Parvoviridae
Bacteriophage
Size of viruses is determined by which Methods
Ultrafiltration
Ultracentrifugation
Electron microscopy
Size of virus ranges from
20nm to 300nm
Largest virus and its size
Poxvirus - 300nm
Smallest virus and its size
Parvovirus - 20nm
Shape of Rabies virus
Bullet shape
Shape of Coronavirus
Crown shape
Shape of Poxvirus
Box/Brick shape with Dumbell DNA core
Shape of Ebola virus
Bowl of spaghetti/Filamentous shape
Shape of Astrovirus
Star shape
Shape of Rotavirus
Rotating wheel
Shape of Adenovirus
Space vehicle shape
Shape of Tobacco mosaic virus (TMV)
Rod shaped (Cigarette)
Strand of DNA Viruses
All are dsDNA except Parvovirus
Which only DNA virus contains ssDNA
Parvovirus
RNA Viruses have how many copies of ssRNA and their segmentation
All RNA Viruses have one copy of ssRNA and are unsegmented With some exceptions
Which RNA virus have 2 copies ssRNA and it’s unsegmented
Retrovirus
Which RNA virus have dsRNA And it’s segmented
Reo/Rotavirus - 11 segments
Which RNA virus have dsRNA And it’s segmented
Reo/Rotavirus
Which RNA Viruses are segmented
BIRA
Bunyavirus
Influenzae (Orthomyxovirus)
Reo/Rotavirus
Arenavirus
How many segments are there in Bunyavirus
3 segments
How many segments are there in Influenza/Orthomyxovirus
8 segments
How many segments are there in Reo/Rotavirus
11 segments
How many segments are there in Arenavirus
2 segments
All RNA Viruses are usually Positive sense RNA Except
MRFAB
Myxoviridae
Rhabdoviridae
Filovirus
Arenavirus
Bunyavirus
Negative sense RNA can be converted into Positive sense RNA with the help of which enzyme
RNA Dependent RNA Polymerase (RdRP)
Which virus have largest Genome
Retrovirus
Which virus have smallest Genome
Hep D virus > Hep B virus
Animal inoculation can be done for which viruses
Brain of suckling mice
Ex. Coxsackie A, B - A causes flaccid paralysis and B causes Spastic paralysis
Arbovirus
Embryonated egg inoculation methods includes
Chorioallantoic Membrane
Yolk sac
Amniotic membrane
Allantoic cavity
Chorioallantoic Membrane is needed to grow which viruses
Vaccinia
Variola
HSV 1 and 2
Yolk sac is used to grow which organisms
CAR
Arbovirus
Chlamydia
Ricketssia
Amniotic membrane is used for isolation of
Influenza isolation
Allantoic cavity is used for which viruses
ALL Protective YARI
Rabies
Vaccine protection of Influenza
Rabies
Cell line methods for tissue culture are classified into
Primary cell lines
Secondary cell lines
Continuos cell lines
Divisions and Examples of Primary cell lines
5-10 divisions
Rhesus kidney cell line
Human amniotic cell line
Chick embryo fibroblast
Divisions and Examples of Secondary cell lines
10-50 divisions
Human fibroblast cell line - CMV
MRC-5
WI38
Divisions and Examples of Continous cell lines
Continous divisions
HeLa
Hep 2, KB
McKoy
Vero
Detroit 6
BHK
Cytopathic effect or Inclusion bodies means
Effect of virus in a cell
Intracytoplasmic Negri bodies are seen in which viral infection
Rabies - seen in cerebellum and Hippocampus
Intracytoplasmic Paschen bodies are seen in
Variola
Intracytoplasmic Guarnieri bodies are seen in
Vaccinia
Intracytoplasmic Bollinger bodies are seen in
Fowlpox
Intracytoplasmic Henderson Peterson Bodies (HP Bodies) are seen in
Molluscum Contagiosum - cup shaped lesion
Intranuclear Cowdry Type A bodies seen in
HAY BAP
Yellow fever - Torres body
Herpes - Lipschultz body
Intranuclear Cowdry Type B Bodies are seen in
HAY BAP
Adenovirus
Poliovirus
Cytopathic effect seen im case of HSV Infection
3M phenomenon
Multinucleated, Moulding, Margination of chromatin + Cowdry A
Both intracytoplasmic and Intranuclear inclusion bodies/Cytopathic effect can be seen in
OW CM
CMV - Owl eye inclusions
Measles - Wartin Finkaldey giant cells
Assays to know infectivity of viruses
Physical Methods - PCR, E/M
Chemical Methods - Endpoint assays (Qualitative), Plaque and Pock Assay (Quantitative)
Interferons are specific to
Cytokines produced by host
Host specific
Types of Interferons
Interferon alpha
Interferon Beta
Interferon Gamma
Source and Functions of Interferon alpha
Source - Leukocytes
Function - antiviral properties
Source and Function of Interferon Beta
Source - Fibroblast
Functions - Antiviral properties, used for treatment of Multiple sclerosis
Source and Function of Interferon gamma
Source - Th1 cells
Functions - For treatment of Chronic Granulomatous disease
