micro 5

Question 1

what was the 8th leading cause of mortality in 2016?

Answer 1

diarrhoea

Question 2

what is diarrhoea also known as?

Answer 2

gastroenteritis

Question 3

what is gastroenteritis?

Answer 3

• Inflammation of the GI tract (particularly the stomach and small intestine
• Other things can inflame the GI tract but we are talking about microorganisms here)

Question 4

what is travlers diahorrea?

Answer 4

• Inflammation of the GI tract (particularly the stomach and small intestine
• Other things can inflame the GI tract but we are talking about microorganisms here)

Question 5

what is the most common cause of travlers dihorrea?

Answer 5

e.coli (etec)

Question 6

what is travelers diarrhea usually associated with?

Answer 6

• Traditionally associated with food borne diseases

* Classically water •More commonly poor sanitation/ hygiene practices

Question 7

what is norovirus?

Answer 7

•Very infectious (<100 virus particles)

- can cayse diarohoeea

Question 8

how many subgroupes and genotypes does the norovirus have?

Answer 8

• At least 6 different genogroups(I to VI) and >40 genotypes

* GII causes the most human infections

Question 9

what season is norovirus most common around?

Answer 9

winter

Question 10

what is noroviruses structure?

Answer 10

• Single stranded RNA virus
• Approx. 8Kb long
• Has 2 structural proteins;•VP1: The dominant protein
• VP2: Role not known

Question 11

what is VP1 subdivided into?

Answer 11

• 180 copies form a t=3 icosahedral viron (explanation here)
• Made up of 2 domains;•P (protruding) domain•P1 binds P2 and S domains •P2 involved in antigenicity and cell attachment•S (shell) domain highly conserved

Question 12

how many vp2’s are present in noroviruses?

Answer 12

1/2 copies

Question 13

how many non-surgical protieins are present in norovirus?

Answer 13

6

Question 14

what is rotavirus?

Answer 14

• Rotavirus is a dsRNA viruses
• Genome is only 18555 nucleotides in total
• Most common cause of diarrhoeal disease in infants and young children

Question 15

how many rotavirus particles are neede to cause disease?

Answer 15

<100 virus particles may cause disease

Question 16

how many species are there of rotavirus?

Answer 16

• 8 species of rotavirus

* Classified A-H •Humans primarily infected by A-C•A causes >90% of infections in humans

Question 17

how can you further clasify rotavirus group a ?

Answer 17

based on serotype of 2 viral surface proteins
•G protein
•P protein

Question 18

how is rotavirus usually transmitted?

Answer 18

• Transmission mainly via faecal-oral route

* Improved sanitation/hygiene practices do not decrease prevalence

Question 19

when is the virus contageous?

Answer 19

•Virus may start shedding before symptom onset and continue to be shed after symptoms have been resolved

Question 20

what is the rota virus’ structure?

Answer 20

6 structural and 6 non-structural proteins

Question 21

what are the 6 structural proteins in the rota virus? and what do they do?

Answer 21

• VP1: RNA polymerase
• VP2: Inner core layer binds RNA genome
• VP3: Capping enzyme (guanylyl transferase; protects viral mRNA from nucleases)
• VP4: Surface spike. Involved in binding to target. Determines P-type.•Determines how virulent the virus is
• VP6: Major capsid protein. Used to lab identify rotavirus A.
• VP7: Glycoprotein, makes up outer surface of the virus. Used to determine G-type

Question 22

what are the two main non- structural proteins in the rotavirus and what do they do?

Answer 22

• NSP1: Interferon antagonist

* NSP4: Viral enterotoxin (induces diarrhoea)•Secreted form causes ↑Ca2+ in host cells

Question 23

how do you treat the rota and the nora virus?

Answer 23

• No specific treatments available for Rotavirus and Norovirus infections
• Focus on management of symptoms
• Particularly dehydration due to fluid los

Question 24

when are antivirals used for treatment?

Answer 24

•Antivirals are not used for Rotavirus and Norovirus treatment

Question 25

which virus is there a vaccine available for?

Answer 25

Vaccine available for Rotavirus but not Norovirus

Question 26

how is the rota virus made up?

Answer 26

the vaccine varries depending on where you are

Question 27

what does the rota virus vaccine protect againts?

Answer 27

•Children in UK vaccinated against type A rotavirus•8 weeks and 12 weeks

Question 28

what kind of vaccine is the rota virus?

Answer 28

* Rotarixis a live attenuated vaccine * Produced by growing on verocells * Based on the RIX4414 strain * Each dose contains ≥106CCID50

Question 29

what is eschericha coli?

Answer 29

•E.coli is a very large and diverse group of bacteria

Question 30

where is E.coli usually found?

Answer 30

* Commonly found in human gut/warm blooded mammals | * Facultativelyanaerobic•Can adapt to different ecological niches

Question 31

how can strains subdivided?

Answer 31

* O antigen: Part of the LPS * K antigen: Capsule * H antigen: Flagellin

Question 32

what are the two main types of e.coli that are studied well?

Answer 32

Enterotoxigenic | Shiga toxin producing

Question 33

what is enterotoxinigenec e.coli most assoicated with?

Answer 33

most common cause of travelers diahorrea

Question 34

what are the important virulence factors associated with enterotexigenic e.coli?

Answer 34

•Toxins (plasmid or transposon);•Heat-stable toxin (ST)•Heat-labile toxin (LT) * Surface structures * Colonization factors * Plasmid mediated fimbrialor surface antigens

Question 35

what is the diorrheal process of how enterotexigeneic e.coli toxins work?

Answer 35

1. E. coli attaches to the cell 2. Heat stabile toxin secreted and interacts with guanylate cyclase-C receptor(GC-C) 3. Increases cGMP 4. Increases phosphorylation to CFTR 5. Pumps Cl-out →contributes to osmotic diarrhoea

Question 36

is there a vaccine available for enterotoxigenic e.coli?

Answer 36

no but there is some development on them