Module 1

Question 1

bacteria were discovered to be capable of being infected by viruses. The bacterial invaders were called

Answer 1

Bacteriophages / phages

Question 2

In what year does bacteria were discovered to be capable of being infected by viruses.

Answer 2

1915

Question 3

The concept behind modern virology can be traced back to who, independently in the late 1880’s, discovered what was later to be called tobacco mosaic virus (TMV).

Answer 3

Adolf Mayer
Dimitri Ivanofsky
Martinus Beijerinck

Question 4

The first filterable agent from animals, foot and mouth disease virus, was described by ____ and ___. What year was it discovered?

Answer 4

Loeffler
Frosch
1898

Question 5

first human filterable agent discovered was called

Answer 5

Yellow fever virus

Question 6

first human filterable agent or yelloe fever virus was discovered by _____ and what year?

Answer 6

Walter Reed

1901

Question 7

The term ‘virus’ derives from the Latin word _______.

Answer 7

Slimy liquid / poison

Question 8

The first term for the virus is ________.

Answer 8

Filterable agent

Question 9

The first virus to be visualized by x-ray crystallography and electron microscopy was

Answer 9

TMV

Question 10

The two people who worked independently, are credited with the discovery of viruses which could infect and lyse bacteria. Year?

Answer 10

Frederick Twort
Felix d’Herelle
1941 and 1939

Question 11

Who introduced the term ‘bacteriophages’ for these agents and also described the concepts of virus adsorption to its target, cell lysis and release of infectious particles.

Answer 11

Felix d’Herelle

Question 12

An infectious agent composed of nucleic acid (RNA or DNA), a protein shell (capsid) and, in some cases, a lipid envelope.

Answer 12

VIRUS PARTICLE OR VIRION

Question 13

It has a full capacity for replication when a susceptible target cell is encountered.

Answer 13

Virion

Question 14

The protein coat that surrounds the viral nucleic acid.

Answer 14

Capsid

Question 15

Capsid are composed of repeating protein MID 29 subunits called

Answer 15

Capsomeres

Question 16

The complete protein-nucleic acid complex.

Answer 16

Nucleocapsid

Question 17

Viruses which require a second virus (helper virus) for replication.

Answer 17

SATELLITE OR DEFECTIVE VIRUSES

Question 18

It is an example of defective virus that requires the presence of hepatitis B virus to complete its replication cycle.

Answer 18

Hepatitis D

Question 19

smallest known autonomously replicating molecules. They consist of single- stranded, circular RNA, 240-375 residues in length and are plant pathogens.

Answer 19

Viroids

Question 20

not viruses but are often discussed within this microbiologic category.

Answer 20

Prions

Question 21

It is an infectious protein molecules that contain no definable nucleic acid and are responsible for the transmissible and familial spongiform encephalopathies

Answer 21

Prions

Question 22

The pathogenic prion protein that is formed from a normal human protein, PrPC , through post-translational processing

Answer 22

PrPSc

Question 23

Modern classification is based on what characteristics.

Answer 23

A. Type of viral nucleic acid (RNA or DNA, single- stranded or double-stranded) and its replication strategy.

B. Capsid symmetry (icosahedral or helical).

C. Presence or absence of lipid envelope.

D. Structure

Question 24

What are the four different viral capsid shape?

Answer 24

Helical
Polyhedral
Spherical
Complex

Question 25

ssDNA - nonenveloped

Answer 25

Parvoviridae

Question 26

dsDNA - enveloped

Answer 26

Poxviridae Herpesviridae Hepadnaviridae

Question 27

dsDNA - nonenveloped

Answer 27

Adenoviridae | papillomaviridae

Question 28

dsDNA - enveloped that replicates through an RNA intermediate

Answer 28

Hepadnaviridae

Question 29

dsRNA - nonenveloped

Answer 29

Reoviridae

Question 30

ssRNA - (-) strand - enveloped

Answer 30

``` Filoviridae Bunyaviridae Rhabdoviridae Orthomyxoviridae Paramyxoviridae Arenaviridae ```

Question 31

ssRNA - (+) strand - enveloped

Answer 31

Togaviridae Flaviviridae Coronaviridae Retroviridae

Question 32

ssRNA - (+) strand - nonenveloped

Answer 32

Picornaviridae | Caliciviridae

Question 33

The seven (7) several stages are?

Answer 33

1. Attachment 2. Entry 3. Uncoating 4. Replication 5. Assembly 6. Release ``` According to the picture: Attachment Penetration Uncoating Release Assembly Biosynthesis ```

Question 34

The virus becomes attached to the cell by specific cellular receptors which can be glycoproteins, phospholipids or glycolipids.

Answer 34

Attachment

Question 35

Following attachment the virus can enter the cell, most commonly via receptor mediated endocytosis. This is the same process by which many hormones enter the cell.

Answer 35

Entry

Question 36

Once inside the host cell, the viral capsid must be uncoated to release the viral nucleic acid. Uncoating may be achieved by host or viral enzymes that will degrade the capsid.

Answer 36

Uncoating

Question 37

Once uncoated, viruses (DNA or RNA) replicate by switching the host machinery from cellular protein synthesis to viral synthesis and viral proteins are produced.

Answer 37

Replication

Question 38

Newly synthesised viral proteins are post-transcriptionally modified and packaged into virions that can be released from the infected host cell to infect other cells.

Answer 38

Assembly

Question 39

Virions are released from the cell either by lysis or budding. In lysis, the infected cell dies and the virions are released. In budding, the virion takes some of the host cell’s membrane with it as it leaves – this normally does not kill the infected cell.

Answer 39

Release

Question 40

Explain the Selection of Specimens

Answer 40

The specimen should be collected from the target organ most closely associated with clinical symptoms to identify the etiologic agent responsible for the patient's disease.

Question 41

What reagent prevents the specimen drying, maintains viral viability and retards the growth of microbial contaminants.

Answer 41

VTM | Viral Transport Medium

Question 42

What VTM contains?

Answer 42

VTM contains gelatin and antimicrobial agents in a buffered salt solution.

Question 43

What supplies do you use for certain samples such as urethral swabs?

Answer 43

Sterile cotton | Dacron or rayon-tipped swabs with plastic or aluminum shafts small-tip flexible (fine- shafted aluminum) swabs

Question 44

What supplied to be used for aspirating vesicular fluid?

Answer 44

Tuberculin syringe with 26- or 27-gauge needle

Question 45

What supplies to be used for blood?

Answer 45

Blood collection tubes containing anticoagulant (ACD) | -yellow top

Question 46

What swabs should not be used?

Answer 46

Alginate swabs or wooden-shafted swabs

Question 47

Specimen preparation for throat wash

Answer 47

The patient gargles with 10 mL of sterile balanced salt solution (Hank's or Earles BSS) or trypticase soy broth (TSB); expelled into a sterile container.

Question 48

Specimen preparation for Urine

Answer 48

Random clean catch sample | collected in a sterile container.

Question 49

Specimen preparation for Blood

Answer 49

Collect 7-10 mL of blood in a Yellow ACD tube (Solution A or B). Blood more than 72 hrs old from time of collection to the time of processing will be rejected.

Question 50

Specimen preparation for Naso-pharyngeal swab

Answer 50

Insert a flexible fine-shafted swab through the nostril into the nasopharynx and rotate swab gently a few times. Place into M4 viral transport media.

Question 51

Specimen preparation for vesicle fluids

Answer 51

Withdraw vesicle fluid using a tuberculin syringe or swab the vesicle and place it in an M4 Culture Transport Tube or 1 ml of BSS or TSB; crusted, dry lesions are not vesicles and are not appropriate for virus isolation.

Question 52

Specimen preparation for tissue

Answer 52

Collect aseptically and keep moist by placing in sterile container with 2 mL of BSS (Hanks Phosphate Buffered Saline), TSB, saline or viral transport media M4.

Question 53

Specimen preparation for stool

Answer 53

Approximately 5 gm of stool placed in a tightly-capped sterile container without preservatives. A swab covered with stool is acceptable for culture but not preferred. Swabs are UNACCEPTABLE for Clostridium difficile toxin.