virology

Question 1

Virus and their structure

Answer 1

Picornavirus (poliovirus,rhinovirus) - icosahedral
Tobacco- mosaic Virus - Rod shaped plant virus with helical symmetry
Bacteriophage- CompleX structure with icosahedral head and helical tail
Rhabdovirus (rabies )- Bullet shaped non segmented and have helical nucleocapsid. Has -ssRNA
Adenovirus- have a naked, icosahedral capsid with characteristic spike-like fibers at the vertices.

Question 2

Entry of influenza

Answer 2

HA binds to sialic acid on respiratory cell

Question 3

Rabies

Answer 3

Neurotropic, neuroinvasive
Bullet like shape
-ssRNA , Non-segmented
Rabies enter the muscle cells through bite by nAchR receptor and from there it is transferred to neural cells by NACM receptors through retrograde axonal transport
Rabies is monotropic suggesting it can bind to multiple receptors on host cell
Symptoms include : Hallucination, hydrophobia , confusion etc.
Rabies genome has 5 genes : N, P,M ,G, L
G 9glycoprotein) is key to entery
Prevention and control include
pRep
PEP
Vaccination
Brain-derived -used in some places bbut risky
Inactivated attenuated virus- safer
Both aim to increase anti0- G antibodies

Question 4

Influenza

Answer 4

Segmented , -ssRNA
Belongs to the family of Orthomyxovirado
Influenza A, B, C, D
Is enveloped
8 RNA segment
Has HA glycoprotein that binds to sialic acid on respiratory cells and enter the host cell through endocytosis inside endosome
Has NA for viral release
Concept on antigenic shift and antigenic drift increases genetic diversity

Question 5

HIV

Answer 5

Lentivirus from Retroviradae

+ssRNA-RT
Affects lymphocytes CD4 T cells
progress to AIDs
HAART is a therapy used that targets
Entry inhibitors
Reverse transcriptase inhibitor
integrase inhibitor
protease inhibitor