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Question 1

This course is a challenging and exciting area in Clinical Microbiology. It has changed over the years, from the viral diagnostic testing which is only performed a very few highly specialized laboratories. Usually only the tertiary laboratories which are in tertiary hospitals. ______ are not capable of performing these tests in order to diagnose viral infections.

Answer 1

Secondary laboratories

Question 2

_____was endemic in China by 1000BC. In response, the practice of _____ was developed.

Answer 2

Smallpox

variolation

Question 3

Recognizing that survivors of smallpox outbreaks were protected from subsequent infection, _______ involved inhalation of the dried crusts from smallpox lesions like snuff, or in later modifications, inoculation of the pus from a lesion into a scratch on the forearms of a child.

Answer 3

variolation

Question 4

To develop immunity, dried crusts were inhaled but the infection still continued.

Question 5

Although small pox was totally eradicated in _____(not sure si Ma’am Paz), it’s because the vaccine made was very effective.

Answer 5

1980

Question 6

Smallpox is similar to chickenpox but in terms of its effect, it is ____. Chickenpox does not cover the whole body, just fluid-filled blisters. But in smallpox, almost the whole body is covered in fluid-filled blisters.

Answer 6

deadliest

Question 7

______ are considered universal

Answer 7

Virus infections

Question 8

There is no type of organism that is safe from viral infections.

Answer 8

True

Question 9

In other words, viruses can infect humans, plants, animals, fungi, protozoa, algae, and bacterial cell.

Question 10

Many of these viruses that infect humans are:

Answer 10

• Adenoviruses
• Rotaviruses
• Pox viruses
• Hepadnaviruses
• Herpesviruses

Question 11

Some viruses are called _____ viruses from the term _____ meaning these viruses cause a specific types of cancer including human cancer such as lymphomas, carcinomas, and some types of leukemia.

Answer 11

oncogenic

Question 12

Some viruses are called oncogenic viruses from the term oncogenic, meaning these viruses cause _______

Answer 12

a specific types of cancer

Question 13

Some viruses are called oncogenic viruses from the term oncogenic, meaning these viruses cause a specific types of cancer including human cancer such as _______

Answer 13

lymphomas, carcinomas, and some types of leukemia.

Question 14

Viruses have probably existed as long as bacteria and archaea have existed

Answer 14

true

Question 15

Origin of Viruses – 3 Major Theories

one that has been debated by scientists for so many years.

Answer 15

• The “coevolution theory”
• The retrograde evolution theory”
• The “escaped gene theory”

Question 16

Theory where viruses was originated in the primordial soup and coevolved with bacteria and archaea. However, there are few supporters of this theory.

Answer 16

Coevolution Theory

Question 17

Theory where these scientists believe that viruses evolved from free-living prokaryotes that invaded other living organisms, they gradually lost functions that were provided by the host cell. Just like the coevolution theory, there are only few supporters of this theory.

Answer 17

Retrograde Evolution Theory

Question 18

Theory where these scientists believe that viruses are pieces of host cell RNA or DNA that have escaped from the living cells and are no longer under cellular control.

Answer 18

Escaped Gene Theory

Question 19

The question of whether viruses are alive or not depends on ______.

Answer 19

one’s definition of life

Question 20

more scientists agree that viruses lack most of the basic features of the cell like cell membrane, nucleus, and membrane-bound organelles like mitochondria, golgi apparatus. So these scientists consider viruses as _____. Because viruses are not composed of cells, they are referred to as ______or infectious particles.

Answer 20

non-living entities

cellular microbes

Question 21

There are two types of viruses:

Answer 21

1. Animal viruses

2. Bacteriophages

Question 22

These are viruses that infect humans and animals.

Answer 22

Animal viruses

Question 23

Viruses that infect bacteria. In short, it is also called phages.

Answer 23

Bacteriophages

Question 24

In terms of viral replication, these two viruses differ from each other

Answer 24

Animal viruses

Bacteriophages

Question 25

A virus is an _______ parasite containing ______ surrounded by protein.

Answer 25

obligate intracellular | genetic material

Question 26

_____ meaning in order for them to function, to replicate, they must be inside the cell, whether it’s animal, plant, fungi, bacteria.

Answer 26

Obligate

Question 27

Viruses are either ____but not both.

Answer 27

DNA or RNA

Question 28

Out of the 3 theories, this theory is currently most widely accepted explanation for the origin of viruses.

Answer 28

Escaped Gene Theory

Question 29

The viral DNA or RNA is transcribed now into _____ through the use of the host cell ribosome.

Answer 29

mRNA

Question 30

The viral DNA or RNA is transcribed now into mRNA through the use of the ______

Answer 30

host cell ribosome.

Question 31

They are not called cells because they don’t have those basic structures in order for an organism to replicate. That is why viruses are called infectious particles or infectious agents.

Question 32

These viruses range in size from _____ in diameter but in some book, it’s _____ in diameter.

Answer 32

10-250 μm | 10-300 μm

Question 33

Although some virus like the _____ (largest virus). They can be up to 1 μm in length and that is already big for a virus.

Answer 33

Ebola virus

Question 34

the smallest virus is the _____ it is | about the size of large hemoglobin molecule of the red blood cell.

Answer 34

poliovirus,

Question 35

Because of virus sizes, it cannot be seen under a light compound microscope. Virus particles can only be observed by an _____

Answer 35

electron microscope.

Question 36

The first photograph of viruses was obtained in _____ by means of electron microscope. They were able to observe it by staining the specimen using a ____- procedures.

Answer 36

1940 | negative staining

Question 37

From the first photomicrograph in 1940, different staining techniques were developed and negative staining was developed in ____

Answer 37

1959.

Question 38

The study of viruses was revolutionized making it possible to observe unstained specimens

Question 39

In negative staining, the specimen is unstained because we make use of _______, coloring the background so the microorganism will appear translucent or transparent.

Answer 39

India ink or Nigrosin

Question 40

Recognizing the _____ of different viruses is critical to the study of disease.

Answer 40

shape, size, and structure

Question 41

``` Recognizing the shape, size, and structure of different viruses is critical to the study of disease. ● Pollen – ● Smaller airborne particulate – ● Bacteria – ● Viruses – ```

Answer 41

● Pollen – 15-200 μm ● Smaller airborne particulate – 2.5 μm ● Bacteria – 0.2-2 μm ● Viruses – 20-400nm

Question 42

_____ are capable of causing cowpox virus (food and mumps disease) = Range: _____

Answer 42

Vaccinia | 200-300 nm.

Question 43

Mumps: _______ (Pyromyxo viruses)

Answer 43

Paromixoviridae

Question 44

Herpes simplex virus: measure ______

Answer 44

100-150 nm

Question 45

different parts of a virus.

Answer 45

``` ● Membrane protein ● Genetic material made up of RNA ● Nucleocapsid protein ● Spike protein ● Envelope ```

Question 46

Virus properties: | 5 specific properties that distinguish from living cells.

Answer 46

1. Possess either DNA or RNA but not both 2. Unable to replicate or multiply on their own (instead their replication is directed by the viral nucleic acid once it has been introduced into a host cell) 3. Do not divide by binary fission (replication process of bacteria) , mitosis, or meiosis (process of reproduction of eukaryotic cells) 4. Lack the genes and enzymes for energy production 5. Depend on the ribosomes, enzymes, and metabolites of the host for CHON and nucleic acid production.

Question 47

7 DNA Viruses:

Answer 47

``` ● Papovaviridae ● Parvoviridae ● Adenoviridae ● Poxviridae ● Hepadnaviridae ● Herpesviridae ● Iridovirida ```

Question 48

7 DNA Viruses: | Mnemonic: PaPaAdPoHeHeIr

Answer 48

``` ● Papovaviridae ● Parvoviridae ● Adenoviridae ● Poxviridae ● Hepadnaviridae ● Herpesviridae ● Iridoviridae ```

Question 49

ether sensitive/ether labile viruses

Answer 49

PaPaAd

Question 50

_____ are ether resistant viruses

Answer 50

PoHeHe

Question 51

13 RNA VIRUSES:

Answer 51

``` ● Arenaviridae ● Bunyaviridae ● Caliciviridae ● Coronaviridae ● Filoviridae ● Flaviviridae ● Orthomyxoviridae ● Paramyxoviridae ● Picornaviridae ● Reoviridae ● Rhabdoviridae ● Togaviridae ● Rotaviridae ```

Question 52

RNA VIRUSES: Non enveloped: - Single stranded positive-sense: ___ - Double stranded:_____

Answer 52

Single stranded positive-sense: - Astroviruses - Caliciviruses - Picornaviruses Double stranded: - Reoviruses - Rotaviruses

Question 53

RNA VIRUSES: ``` Enveloped: - Single stranded positive-sense: ___ - Single stranded negative-sense: ~linear: ____ ~Segmented: ____ - Retrovirus:____ ```

Answer 53

Single stranded positive-sense: - Togaviruses - Flaviviruses - Coronaviruses ``` Single stranded negative-sense: ~linear: - Rhabdoviruses - Paramyxoviruses ~Segmented: - Arenaviruses - Bunyaviruses - Orthomyxoviruses ``` Retrovirus - Lentiviruses - Oncoviruses

Question 54

DNA VIRUSES: Non enveloped: - Single-stranded linear:____ - Double-stranded linear: ____ - Double-stranded circular: ____

Answer 54

``` Single-stranded linear: - Parvoviruses Double-stranded linear: - Adenoviruses Double-stranded circular: - Papillomaviruses - Polymaviruses ```

Question 55

DNA VIRUSES: Enveloped - Double-stranded linear: ____ - Double- stranded circular: ____

Answer 55

``` Double-stranded linear: - Herpesviruses - Poxviruses Double- stranded circular: - Hepadnaviruses ```

Question 56

Nucleic acid that virus posses may either be single- or double stranded. Within the host cell, single-stranded positive-sense RNA functions as _____, whereas single-stranded negative-sense RNA serves as a ______ of mRNA

Answer 56

``` messenger RNA (mRNA) template for the production ```

Question 57

Double-stranded Circular viruses are also called ______

Answer 57

Papovaviruses

Question 58

Envelope – ______ | Nucleocapsid - _____

Answer 58

Naked genetic material | envelope and non-envelope

Question 59

Viral Structure - Some Terminology ● Viral particle – _____(Complete, small, simple structure) ● Protein which coats the genome – _____ ● Capsids are composed of many small protein units – ______ ● Capsid usually _____ ● Capsid + genome = _____ ● May have an envelope (Composed of ____ composition)

Answer 59

``` virion capsid capsomere / capsomer. symmetrical nucleocapsid Lipids & Polysaccharides ```

Question 60

Characteristics of a Virus: ● Type of genetic material (either DNA or RNA) ● Whether the virus nucleic acid is single stranded (ss) or double stranded (ds) ● Whether the virus nuclei acid is positive-sense or negative-sense ● Shape of the capsid ● Number of capsomeres ● Size of the capsid ● Presence or absence of envelope ● Type of host that it infects ● Type of disease it produces (Oncoviruses) ● Target cell ● Immunologic or antigenic properties

Question 61

``` How are Viruses named? Based on: ● the disease they cause _____ ● the type of disease _____ ● geographic locations_____ ● their discover ____ ● how they were originally thought to be contracted____ ● combinations of the above ____ ```

Answer 61

``` ○ polioviruses, rabies virus ○ murine leukemia virus ○ Sendai virus, Coxsackie virus ○ Epstein-Barr virus ○ dengue virus; influenza virus ○ Rous Sarcoma virus ```

Question 62

____ (taken form the word “evil spirit”),

Answer 62

dengue virus

Question 63

____ (the influence of bad air)

Answer 63

influenza virus

Question 64

5 Basic Types of Viral Structure:

Answer 64

``` Icosahedral Enveloped Icosahedral Helical Enveloped Helical Complex ```

Question 65

Types of Viruses:

Answer 65

Icosahedral Enveloped Helical More complex structure

Question 66

capsid coat nucleic acid and each of these capsids are made up of several capsomere

Answer 66

Helical

Question 67

made up of lipids and polysaccharides

Answer 67

Enveloped

Question 68

frequently, the enveloped around the capsids makes the virus now appears ____ in shape and can be seen in electron micrograph

Answer 68

spherical/irregular

Question 69

ENVELOPED this is acquired by certain animal virus as they escape from the nucleus or cytoplasm of the host cell by ___ (inside the cell it is just naked) ● derived from either host cells nuclear membrane or host cells cell membrane/cytoplasmic membrane ● apparently, these viruses are able to altered cell membranes ○ By adding proteins/protein fibers, spikes, knobs, to enable the virus to recognize to the next host cell

Answer 69

budding

Question 70

polyhedral capsids in which geometrically they are referred | to as ____

Answer 70

icosahedrons

Question 71

Polyhedral capsids

Answer 71

icosahedral

Question 72

they have 20 sides or facets | and each of these facets consists of several capsomeres

Answer 72

Icosahedral

Question 73

ICOSAHEDRAL the size of the virus is determined by the size of each facet and the number of ____ in each of these facet sometimes, icosahedral have enveloped and non-envelop

Answer 73

capsomeres

Question 74

Based on genetic contents and replication strategies of viruses.

Answer 74

The Baltimore Classification System

Question 75

According to the Baltimore classification, viruses are divided into the following seven classes:

Answer 75

1. dsDNA viruses 2. ssDNA viruses 3. dsRNA viruses 4. (+) sense ssRNA viruses (codes directly for protein) 5. (-) sense ssRNA viruses 6. RNA reverse transcribing viruses 7. DNA reverse transcribing viruses

Question 76

Where “ds” represents _____ and “ss” denotes _____

Answer 76

“double strand” | “single strand”

Question 77

Viral Replication Steps in the Multiplication of Animal viruses:

Answer 77

``` ● Attachment or Adsorption ● Penetration ● Uncoating ● Biosynthesis ● Assembly or maturation ● Release ```

Question 78

Viruses are______parasites; that is, they must be inside a living cell and use the host cell machinery to replicate

Answer 78

obligate intracellular

Question 79

What is the first step for infection of a cell to occur, the complete viral particle called the ____ must absorb or attach to the cell surface (cell attachment or cell absorption).

Answer 79

Attachment of Adsorption virion

Question 80

Viruses can attach only to cells bearing the appropriate_______ receptor on the surface of the host cell.

Answer 80

protein or polysaccharide

Question 81

● Absorption is specific for certain cell receptors, and receptor distribution will determine the entry point into the host. ● Most host cell receptors are _____

Answer 81

glycoproteins

Question 82

receptor site for poliovirus

Answer 82

immunoglobulin superfamily molecules

Question 83

receptor site for rabies virus

Answer 83

acetylcholine

Question 84

receptor site for influenza virus

Answer 84

sialic acid

Question 85

receptor site for HIV

Answer 85

CD4

Question 86

receptor site for Epstein-Barr virus (EBV)

Answer 86

complement receptor C3d

Question 87

The virus attaches to specific receptors on the surface of a susceptible cell by means of specialized structures on its surface called _______

Answer 87

adhesion molecules

Question 88

This step can occur in different ways including fusion, phagocytosis, or injection of the genetic material/genome into the host cell.

Answer 88

Penetration

Question 89

Viruses can penetrate (or inject the genetic material) the cell by several different mechanisms and penetration

Question 90

Once inside the cell, the virus loses its protein coat (capsid), releasing the genome. This process is called _____

Answer 90

uncoating

Question 91

Steps where RNA viruses usually release the genome into the ____, whereas most DNA viruses release their genome into the _____

Answer 91

Uncoating cytoplasm host nucleus.

Question 92

The viral genome then directs the host cell to make viral proteins and replicate the viral genome. This process is called _______

Answer 92

biosynthesis or synthetic phase.

Question 93

Many viral species are produced in which the _____ acts as a template. The viral genetic material ang sugdan kung unsay hitsura paghimo; pinakatemplate for the production of mRNA

Answer 93

viral nucleic acid

Question 94

Can be quite complicated step, depending on what type of virus infect the cell, whether the virus is a single stranded or double stranded virus.

Answer 94

Biosynthesis

Question 95

Protein coat- _____ | Genetic material- _____

Answer 95

hexagonal (piattos) | spiral shape

Question 96

Step/Process where spiral genetic material will be coated with hexagonal protein. Inside host cell, many nucleocapsid will be made

Answer 96

Assembly and maturation

Question 97

Because a host cell is full of nucleocapsid, the cell will burst (depending on the reaction) then the virus replicated inside will be _______

Answer 97

released.

Question 98

Release Either the new virions are released by ____ or by _____ (By ___-mahimo ang nucleocapsid as an enveloped virus kay mu fuse. By __- virions are naked)

Answer 98

lysis | budding

Question 99

_____ is a contagious respiratory infection caused by influenza viruses. Like all viruses, influenza must gain entry into host cells to replicate.

Answer 99

Flu