STEPS IN VIRAL REPLICATION Flashcards
Steps in Viral Replication
(APUMVL)
- Attachment/ Adsorption
- Penetration
- Uncoating
- Macromolecular synthesis
- Viral assembly
- Lysis and release
recognition of HOST CELL and SPECIFIC BINDING between viral capsid proteins and the receptor of the host cell
Attachment/ Adsorption
Attachment/Adsorption
Immunoglobulin –
CD4 –
Acetylcholine –
C3d –
sialic acid –
Angiotensin Convertin Enzyme 2 –
Immunoglobulin – poliovirus
CD4 – HIV
Acetylcholine – rabies virus
C3d – EBV
sialic acid – influenza virus
Angiotensin Convertin Enzyme 2 – Covid
Viruses enter the host cell
Penetration
It can penetrate the cell membrane directly.
Naked virions
It may enter the cell by fusion with the cell membrane or via endocytosis whereby the enveloped virus enters in a vacuole
Enveloped viruses
It is a process by which the capsid is removed
Uncoating
It is usually release the genome into the cytoplasm
RNA viruses
It release their genome into the host nucleus
DNA viruses
process by which structural proteins, genomes, and in some cases viral enzymes are assembled into virus
particles
Viral assembly
- new virions are then released by lysis if they are naked viruses or by budding if they are enveloped viruses
Lysis and release
T/F
In Lysis and release, Naked viruses are more virulent
TRUE
____ stage (acute phase) of infection BEFORE height of fever
Early
Swab use for specimen collection
Dacron, Rayon swab
T/F
You can use calcium alginate swabs in specimen collection
FALSE
NO because they can interfere with PCR testing
Storage temp if they store it for 5 DAYS
4 degC
Storage temp if they store it for >6 DAYS
20°C or –70°C
Storage temp for Transport
-70°C
Transport Medium used (LEASHU)
- Leibovitz-Emory
- Eagle’s Tissue Culture
- Amie’s
- Stuart
- Hank’s (buffered isotonic solution with albumin, gelatin)
- Universal Transport Media/ VTM
- Most rapid method of diagnosis
- For nonculturable viruses (hepatitis virus, norwalk virus)
Electron Microscopy
Detection of cytoplasmic inclusions/cytopathic effects
Light Microscopy
- Rabies (invades nervous system)
- Can be observed only after the autopsy of the dead patient
Negri bodies
Torres Councilman bodies
Yellow fever
- HSV – Herpes SImplex Virus,
- VZV – varicella-zoster virus (Tzanck smear)
Cowdry Type A
CMV – cytomegalovirus
Owl’s eyes
HPV – Human Papillomavirus (Pap smear)
Koilocytes
Molluscum contagiosum (under poxviridae)
Henderson-Patterson bodies
Pox virus
Guarnieri bodies
Cytologic Smear used (PT)
Pap Smear
Tzanck Smear
For detection of HPV carcinoma
Pap Smear
For HSV and VZV; multinucleated giant cell
Tzanck Smear
Cultures used (PDC)
Primary Cell Culture
Diploid Cell Culture
Continuous Cell Culture
obtained from animals
Examples:
- ____ Kidney
- ____ Kidney
- ____ Kidney
Primary Cell Culture
Primary Monkey
Human Embryonic
Rhesus
subcultivated primary culture; normal human cells
Examples: (MWH)
MRC-5
WI-38
Human Diploid Fibroblast (HDF)
Diploid Cell Culture
immortal cell lines; cancer cells
Examples: (HHAA)
HeLa
Hep2
A-549
AGMK
Continuous Cell Culture
In Serology, it detects blockade of cytopathic effects
Neutralization
In Serology, it is for influenza and rubella
Hemagglutination inhibition
Presence of viral DNA or RNA is the gold standard in viral diagnosis
Nucleic Detection
