Viruses

Question 1

Measles

Answer 1

Paramyxovirus family
Resp tract
Group V i.e ssRNA -ve sense
Induces fusion of cells to make syncytium

Question 2

Rabies

Answer 2

Negri bodies seen in murkinje cells

Question 3

Influenza virus

Answer 3

8 segments in genome
Cleaves host capped mRNA
Uses HA to infect, M2 to allow fusion, NA for release
Replicates in nucleus
Group V: ssRNA -ve sense

Question 4

Polio virus

Answer 4

Faeco-oral
Cleaves cap binding complex of ribosome but its own mRNA has an IRES
Group 4: ssRNA +sense so infectious genome
Salk vaccine killed, Sabine is live

Question 5

FMDV

Answer 5

Group 4 so infectious genome

There is a killed vaccine

Question 6

HIV

Answer 6

Retrovirus group 6
ssRNA
Carries reverse transcriptase
Integrates into chromosome to form provirus
Binds CD4 for entry + CCR5 for macrophages/CXCR4 for T cells

Question 7

Herpes virus

Answer 7

Forms circular episome in chromosome so can get latent infections
dsDNA
Infectious genome
Replicated and transcribed in nucleus

Question 8

Varicella zoster

Answer 8

Causes chicken pox/shingles
Herpes virus
Live attenuated vaccine
Latent in sensory neurons and permissive in epithelium

Question 9

Epstein Barr

Answer 9

Latent in memory B cells
Produce vIL-10 to stimulate B cells to divide
Can cause Burkitt’s lymphoma/nasopharyngeal cancer

Question 10

Pox viruses

Answer 10

Replicate in cytoplasm unlike other dsDNA viruses
Non-infectious genome as have lots of transcriptional enzymes packaged

Interfere with interferon in every way

Question 11

Variola virus

Answer 11

Cause of small pox

Question 12

Vaccinia virus

Answer 12

Used for live vaccine against small pox

Produces an epidermal growth factor to stimulate neighbouring cells to act as infection targets

Question 13

Hep A

Answer 13

Picornavirus 
Inactivated and live attenuated vaccines
Acute
\+ve ssRNA
Faeco-oral route

Question 14

Hep B

Answer 14

Hepadnavirus 
Partly dsDNA, reversivirus using RNA intermediate
Chronic; hepatocellular carcinoma
Cant grow in culture
Subunit vaccine

Question 15

Hep C

Answer 15

Flavivirus 
\+ve sense ssRNA 
Uses IRES
Hepatocellular carcinoma 
No vaccine

Question 16

Human cytomegalovirus

Answer 16

Latent in non permissive pre-monocyte

Active in macrophage

Question 17

Drugs for influenza

Answer 17

Amantidine and Rimantidine target M2

Tamiflu = silica acid analogue to target NA

Question 18

Drugs for HIV

Answer 18

AZT: nucleoside analogue; chain terminator

Ritonavir, saquinovir: HIV protease inhibitor

Question 19

Ganciclovir

Answer 19

Chain terminator (nucleoside analogue) to inhibit  viral DNA pol
Used for HCMV

Question 20

Aciclovir

Answer 20

Nucleoside analogue that acts as chain terminator for viral DNA pol used for herpes

Thymidine kinase acts on it first (better substrate for viral one that host)