MYCO & VIROLOGY L5 (Semis- Virology Intro) Flashcards
Can be made up with an Ribonucleic Acid (RNA) or Deoxyribonucleic acid (DNA) genome (but can’t be both)
Virion
Virus particles can only be observed by
electron microscope
Morphology
- Helical
- Icosahedral
- Complex
Virus family names have the suffix?
-viridae
Q1: Subdivisions of within each family is called?
Q2: And this is usually based on?
Q1: Genera
Q2: physiochemical and serologic differences
Genus names carry the suffix?
-virus
The only one order that has been currently defined
Mononegavirales which encompasses the Filoviridae, Paramyxoviridae, and Rhabdoviridae families
Recognition of a suitable host cell and specific binding between viral capsid proteins (often glycoprotein spikes) and the carbohydrate receptor of the host cell
Attachment or Adsorption
Viral Tropism
Attachment or Adsorption
Phagocytosis by host cells (endocytosis)
Penetration or Virus Entry
Process by which the capsid is removed
Uncoating
Production of nucleic acids and protein polymers
Macromolecular Synthesis
Fusion of the viral envelope with the host cell membrane
Penetration or Virus Entry
A process by which structural proteins, genomes, and in some cases, viral enzymes are assembled into virus particles
Viral Assembly
In viral assembly, envelopes are acquired during the ___________ from a host cell membrane
viral “budding”
Occurs after cell lysis (lytic virus) or by virus particle budding from cytoplasmic membranes
Release of Intact Virus Particles
Enumerate the stages of Viral Replication
- Attachment or Adsorption
- Penetration or Virus Entry
- Uncoating
- Macromolecular Synthesis
- Viral Assembly
- Release of Intact Virus Particles
Displaying evident signs and symptoms
Acute Infection
Has no visible signs and symptoms, but the virus is still present in the host cell in a lysogenic state (inserted into the host genome in a resting state) or maintained as a nuclear or cytoplasmic episome
Latent Infection
In which low levels of virus are detectable and the degree of visible signs or symptoms varies
Chronic or persistent infection
In latent infection, there are no visible signs and symptoms, however, the virus is still present in the cell in a? (2 pts)
Lysogenic state and maintained as a nuclear or cytoplasmic episome
The term used that refers to the insertion of the virus into the host genome in a resting state
Lysogenic state
Swab specimens should not contain these substances because they may be toxic to cultured cells (2pts)
chemicals or other compounds
These are are considerably more convenient
Swabs
For the recovery of enteroviruses, adenoviruses, and HSV
Throat swabs
Preferred for the detection of
RSV and influenza and parainfluenza viruses
Nasopharyngeal swab or aspirate specimens:
For viruses that infect the lower respiratory tract, especially influenza viruses and
adenoviruses
Bronchial and Bronchoalveolar washings
Washings and lavage fluid are collected during?
Bronchoscopy
Used to detect rotavirus, enteric adenoviruses (serotypes 40 and 41), and enteroviruses
Rectal Swabs and Stool Specimens
Preferred sample for detecting rotavirus, enteric adenoviruses (serotypes 40 and 41), and enteroviruses
Stool sample
Virus recovery for urine
- Centrifugation or filtration
- Neutralize the pH with a 7.5% solution of a sodium bicharbonate
Acceptable for detecting enteroviruses in patients suspected of having an enteroviral disease
Rectal swabs
Method for collecting urine
Clean-catch first-morning urine (first-void urine)
Sample volume for blood spx
5-10mL of anticoagulated blood
Used for detecting CMV: mumps, rubella, and measles viruses; polyomaviruses; and adenovirus
Urine
Used for detecting CMV; however, HSV, VZV, enteroviruses, and adenovirus
Blood
Should be used for samples collected for nucleic acid testing
EDTA
Additives that are acceptable for CMV detection (3pts)
Heparinized, Citrated or EDTA
Should be used when other viruses are being considered
Citrated blood
For serologic tests and nucleic acid assays
Serum
Used for detecting CMV, influenza virus, adenovirus, sin nombre virus, HSV
Tissue
Collected during surgical procedures
Tissue
Used for HSV and human papillomavirus (HPV) detection
Genital specimens
Preferred for nucleic acid assays, but formalin-fixed and paraffin-embedded tissues may be used
Fresh tissue
Collected as soon as possible after the appearance of symptoms
Acute specimens
Collected a minimum of 2 to 3 weeks after the acute specimen
Convalescent specimens
Sample volume for Serum Antibody Testing
3 to 5mL of serum
Viral transport medium used
Saline or trypticase soy broth
The viral transport medium should consist of a buffered isotonic solution with a protein such as? (GAS)
Gelatin, Albumin, Serum
Purpose of buffered isotonic solution with a protein
To protect less stable viruses
Specimens should not be frozen unless a significant delay (________) in processing is anticipated (held at ____________)
> 4 days; -70 degrees Celsius
Samples that can be collected with viral transport media are? (3pts)
Respiratory, swab, and tissue samples
Specimens should be stored at?
4C
Specimens should never be stored at?
-20C!!!!!
Methods in Diagnostic Virology
- Direct detection of the virus in clinical specimens
- Nucleic acid-based detection
- Isolation of viruses in cell cultures
- Serologic assays to detect antibodies to virus
The gold standard method/ equipment used for Viral testing.
Embryonated Hen’s eggs or Isolation of viruses in cell cultures (based sa transes)
What do you call the fusion of the viral envelope with the host cell membrane?
Virus entry
The following are all parts of a virion except for what?
A. Peplomere
B. Capsid
C. Envelope
D. All of the above
E. None of the above
E. None of the above
Which of the following is not a commonly known respiratory virus?
A. Influenza
B. RSV
C. HSV
D. Rhinovirus
D. HSV
This is the preferred sample for nucleic acid assays
Tissues