(P) Lec 1: INTRO TO VIROLOGY Flashcards
1st written record of a virus infection consists of a ____________ from ______________ depecting ______________
Hieroglyph
Memphis, Egypt
Siptah
A temple priest showing typical clinical signs of paralytic.
Siptah
“Viro”
Virus
“Logy”
Study
Branch of microbiology that deals and focuses on the study of viruses.
VIROLOGY
What is studied in virology?
ALL ABOUT VIRUS
Properties
Structures
Classification
Pathogenicity
Their ways in causing diseases
Multiplication cycle
Ancient writing which usually comes from Egypt.
Hieroglyph
Where does Hieroglyph is written? (Medium)
Stone
Hieroglyph can be the mode of communication in Egypt in the ancient times. (T or F)
TRUE
The very first recorded viral infection according to history was
POLIOVIRUS (POLIOMYELITIS)
POLIOMYELITIS targets the _______________, that is why the signs and symptoms focuses on the ____________ side.
Central Nervous System
Paralytic
Small Pox is caused by the ___________.
Pox virus or Poxviridae
In 1196 BC, he is believed to have died/ succumbed to SMALLPOX.
Pharoh Ramses V
In 1196, pustular lesions on the face of the mummy & those of more past patients are being compared. (T or F)
FALSE (recent patients)
Very first attempt for vaccination process.
Variolation
Difference of variolation with vaccination.
Variolation is targeted specifically on small pox.
In 1000 BC ___________ was endemic in China in response , the practice of ____________ was developed.
Small Pox
Variolation
In 1000 BC, those who acquire small pox also acquires lesions, as it is acquired by inhilation of powderized small pox lesion. Then, the Chinese people gets the lesion, then they dry it out and powderized it which is inhaled by the population which develops the practice of Variolation. (T or F)
TRUE
In 1976, he was one of the first recipient of a vaccine, wherein a dried cowpox material is injected on him.
James Phipps (8 years old)
What is the date wherein e JAMES PHIPPS (8-yr old) using cowpox infected material of Sarah
Nemes (milkmaid)?
May 14, 1796
She was infected by a cowpox infected material which comes from James Phipps.
Sarah Nemes
What is the date wherein Edward Jenner challenged the boy by deliberately inoculating him with
material from a real case of smallpox?
July 1, 1796
____________ challenged James Phipps by deliberately inoculating him with a material from a real case ___________.
Edward Jenner
Small pox
General Characteristics of Viruses
- OBLIGATE INTRACELLULAR PARASITES
- Possess their own genomes
- Do not grow in artificial culture media
- Small infectious units (measured in nanometer; about 20 –300 nm in diameter)
Viruses requires a ____________ to survive.
Living cell
Genetic elements of a virus
DNA
RNA
Viruses only contains one genetic material. NEVER BOTH which helps to differentiate with other microorganism. (T or F)
TRUE
Genetic elements that can replicate only inside a ____________.
Living cell
It is needed for genetic elements or viruses can replicate.
Living cell
Viruses are dependent on the ____________ for energy, metabolic intermediates, and protein synthesis
Host cell
What will happen if virus is outside the cell?
It dries out causing them to die.
- As it requires them a living cell to survive which happens in genetic replication.
Viruses do not grow in an artificial media, but they grow in __________, ___________, and ____________.
Grow in cell culture, chick embryo, animals
If viruses will grow in vitro (in lab), then viruses will be identified by a _____________.
Cell culture line
Viruses is measure using a ___________
Nanometer
Size of a virus in diameter
20-300nm
It is the one that can be used to examine or study the viruses.
Electron Microscope
It is required for the direct examination of the viruses wherein the virus or virus’ structure can be seen.
Electron microscope
Bright field microscope can be used to examine viruses. (T or F)
TRUE
In a bright field microscope, we are INDIRECTLY examining it. As we only see the cell changes in the virus, and it changes as it is affected by a virus.
Cell change in the virus requires a _____________.
Live cell
Cell change that happens in a virally infected host cell.
Cytopathic effect (CPE)
Cytopathic effect (CPE) is a cell change that happens in a ____________.
Virally infected host cell
CPE cannot be seen using a brightfield microscope. (T or F)
FALSE (can)
Ex: agent of a chicken pox (Varicella Zoster Virus which causes ballooning of cells) which indicates the infection of a small pox.
Smallest animal virus
Parvovirus
Largest animal virus
Pox virus
Viral components
- Nucleic acid genome (RNA or DNA)
- Protective protein coat
Capsomeres
Glycoprotein spikes
Nucleic acid genome is protected by a protective protein coat called _____________.
Capsid
Capsid is made up of ____________
Protein
Viruses that contains a capsid that has an envelope underneath.
ENVELOPED VIRUS
Components of an Enveloped virus
Membrane Lipids, Proteins and Glycoproteins
Enveloped viruses are difficult to acquire, as it can be spread in n large droplets, secretions, organ transplants, and blood transfusions. (T or F)
TRUE
Enveloped viruses cannot survive intestinal tract and it does not need to kill a cell to survive. (T or F)
TRUE
Enveloped virus must not stay wet. (T or F)
FALSE (it needs moisture)
Enveloped virus may need _____________ and ___________ for protection and control.
Antibody and Cell-mediated immune response
Enveloped virus elicits hypersensitivity and inflammation to cause ______________.
Immunopathogenesis
Enveloped virus is Environmentally LABILE-disrupted by the following:
Acid , Detergents, Drying, Heat
Enveloped virus modifies ___________ during replication.
Cell membrane
Enveloped virus is released by
budding and cell lysis
If the virus does not contain capsid, it is called as ___________
NAKED VIRUS
Component of Naked Virus
Protein
It makes the naked virus environmentally stable that can withstand harsh and different changing environment.
Protein
Naked virus can dry out and retain infectivity that makes it spread easily. (T or F)
TRUE
Mode of transmission of naked virus
on fomites, from hand to hand, by dust, by small droplets
Naked virus can survive the adverse conditions of the gut
and it is resistant to detergents and poor sewage treatment. (T or F)
TRUE
Antibody may be sufficient for immunoprotection for Naked virus. (T or F)
TRUE
There are instances that enveloped virus modifies a host cell membrane which produces _______________.
GLYCOPROTEIN SPIKES
It can only occur in an enveloped virus.
GLYCOPROTEIN SPIKES
GLYCOPROTEIN SPIKES comes from the _____________.
Host cell membrane
Cell membrane can be modified during replication which causes the production of glycoprotein spike. (T or F)
TRUE
Basis for the symmetry or shape is _______________.
NUCLEOCAPSID STRUCTURES
A term refers to the presence of combination of a nucleic acid and capsid of the virus.
NUCLEOCAPSID STRUCTURES
NUCLEOCAPSID STRUCTURES can also be associated as _____________.
VIRION or VIRAL PARTICLE
VIRION is made up of
nucleic acid and capsid
or nucleic acid and protein.
NUCLEOCAPSID STRUCTURES
- Icosahedral structure (cubic)
- Helical structure
- Complex structure (Poxviridae)
All viruses follow this multiplication cycle.
VIRAL MULTIPLICATION CYCLE
VIRAL MULTIPLICATION CYCLE
- Adsorption (Recognition and Attachment)
- Penetration
- Uncoating
- Synthetic phase
- Assembly
- Release
IDENTIFY THE STAGE OF THE VIRAL MULTIPLICATION CYCLE
Recognizes host cell and attaches the cell on its host cell.
ADSORPTION
By _____________, it recognizes the host cell and attach to it.
Cell adhesion molecules
During adsorption, majority of viruses look for the _____________ as its cell adhesion molecule or host cell.
Glycoprotein
Instead of glycoprotein, this virus finds immunoglobulin superfamily molecule for cell adhesion.
POLIOVIRUS
instead of glycoprotein, this virus finds sialic acid for cell adhesion.
INFLUENZA VIRUS
instead of glycoprotein, this virus finds CD4+ for cell adhesion.
HIV
instead of glycoprotein, this virus finds Acetylcholinesterase enzyme (ACE) for cell adhesion.
COVID/SarsCov2
How does NAKED VIRUS penetrates the cell?
PENETRATE DIRECTLY
How does ENVELOPED VIRUS penetrates the cell?
Enter by Endocytosis process or by vacoules
IDENTIFY THE STAGE OF THE VIRAL MULTIPLICATION CYCLE
Removes capsid to free the genome (DNA/RNA)
UNCOATING STAGE
IDENTIFY THE STAGE OF THE VIRAL MULTIPLICATION CYCLE
New genome is being synthesized. (NEW DNA/RNA)
SYNTHETIC STAGE
Synthetic stage usually happens in the _____________.
Nucleus
IDENTIFY THE STAGE OF THE VIRAL MULTIPLICATION CYCLE
Release a newly formed Virion by cell lysis. If it is an enveloped type of virus, virions are released by BUDDING.
RELEASE STAGE
Newly formed virions are being released by ___________. If it is an enveloped type of virus, virions are released by _______________.
Cell lysis
Budding
ICVT
International Committee on Viral Taxonomy
Virus Classification based on 4 major properties of viruses
- Type of nucleic acid
- Symmetry and shape of the capsid
- Presence or absence of envelope
- Size of the virus particle
IDENTIFY THE VIRUS ACCORDING TO THE VIRUS CLASSIFICATION
Type of Nucleic acid
DNA VIRUS
RNA VIRUS
IDENTIFY THE VIRUS ACCORDING TO THE VIRUS CLASSIFICATION
Symmetry and shape of the capsid
ICOSAHEDRAL VIRUS
HELICAL VIRUS
IDENTIFY THE VIRUS ACCORDING TO THE VIRUS CLASSIFICATION
Presence or absence of envelope
NAKED VIRUS
ENVELOPED VIRUS
Smallest RNA virus
Picornavirus (Enterovirus)
Largest RNA virus
Paramyxovirus
DNA VIRUSES
Hepadnaviridae
Herpesviridae
Adenoviridae
Poxviridae
Parvoviridae
PaPoVaViridae (Papilloma, Polyoma, Vacoulated Viruses)
CLASSIFICATION OF DNA VIRUSES
- All are double straded DNA virus, except PARVOVIRIDAE which is a single stranded DNA virus.
- All icosahendral, except POXVIRIDAE that has a complex structure.
- All multiplies in the nucleus, except POXVIRIDAE which multiplies in the cytoplasm
- Naked DNA viruses is PAP (Parvoviridae, Adenoviridae, and PaPoVaviridae)
All DNA viruses are double straded DNA virus, except ______________ which is a single stranded DNA virus.
PARVOVIRIDAE
All DNA viruses are icosahendral, except _____________ that has a complex structure.
POXVIRIDAE
All DNA viruses multiplies in the nucleus, except ______________ which multiplies in the cytoplasm.
POXVIRIDAE
Naked DNA viruses is a____________
(Parvoviridae, Adenoviridae, and PaPoVaviridae)
CLASSIFICATIONS OF RNA VIRUSES
- All single stranded RNA, except REOVIRUS that is a double stranded RNA.
- Naked RNA virus: Picornavirus, Calicivirus, and Reovirus
- Majority are non-segmented: genome is composed only a single block. But there are segmented or divided into segments: ROBA (Reovirus, Orthomyxovirus, Bunyvirus, and Arenavirus.
- Majority are helical, except positive sense viruses which demonstrates a positive sense strand that acts as mRNA or have direct translation which are usually the Icosahedral RNA (Calicivirus, Flavivirus, Pucornavirus, Togavirus, Coronavirus, and Retrovirus). The rest of the RNA have negative sense strand that has a helical structure, if they will go translation process they must be converted first as positive sense strand.
All RNA viruses are single stranded, except ____________ that is a double stranded RNA.
REOVIRUS
Naked RNA virus
Picornavirus, Calicivirus, and Reovirus
Majority of RNA viruses are non-segmented that is composed of a single block, but there are those that are still segmented. (T or F)
TRUE
Segmented RNA viruses
Reovirus, Orthomyxovirus, Bunyvirus, and Arenavirus.
Majority are helical (negative sense strand), except icosahedral (positive sense viruses) which demonstrates a positive sense strand that acts as mRNA or have direct translation. (T or F)
TRUE
Icosahedral RNA viruses (Sense strand)
Positive sense strand
Icosahedral RNA viruses
Calicivirus, Flavivirus, Pucornavirus, Togavirus, Coronavirus, and Retrovirus
Helical RNA viruses
Negative sense strand
If RNA viruses that has a negative strand or helical structure will go to a translation process, they must be converted first as positive sense strand. (T or F)
TRUE
