Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiota On Mucosal > B6- Gut Parasites And Giardia SAV > Flashcards

B6- Gut Parasites And Giardia SAV Flashcards

1
Q

Which 2 gut parasites are common in the whole world because they are zoonotic

A

Cryptosporidium and giardia (micro is also zoonotic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does this compare to entamoeba histolytica

A

Low levels in eu and us more in developing countries eg due to poor sanitation of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which way do they all transmit

A

Faecal oral with resistant cysts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Although giardia is extracellular where is it

A

Close to epi surfaces (contacts with them)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is acute vs chronic diarrhoea

A

Acute is below 14 days
Chronic is over 30 and seem more in immunocompromised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 2 main cryptosporidium

A

Parvum and hominis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do they cause if severe infections

A

Profuse watery diarrhoea, vomiting, malabsorption and death (in under 2 second biggest death after rv)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What proteases do they have for ezcystarion

A

Serine protease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is gp900 and TRAP proteins for and found to be from

A

Found in invading sporozoites and required for host cell invasion

From microneme release of apical organelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which cells do they infect

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What transporter in c.Parvum found for feeding on nutrients in the parasitophorous vacuole

A

CpABC transporters (another virulence factor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which pid affecting cd4 are eveidence for crucial role of cd4 cells in crypto

A

Scid and cd4 lymphophenia severity of disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What cells induced by the th1 in particular also important in the crypto response

A

CD8 and NK cells potentially

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens in hiv infection for collapse

A

Hiv load comes in
Not fully removed by your immune system so persists and replicates
High viral load causes loss first of mucosal cd4 and then blood cd4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Below what cell count of CD4 sees increased micro and crypto

A

100 mm^4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where can excystarion occur to release 4 sporozoites in crypto

A

Stomach acid ph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What histological changes seen in infection

A

Villous atrophy and immune infiltration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which neuropeptide triggered by crypto from monocytes/macrophages is released which increase Cl secretion for diarrhoea

A

Neuropeptide P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In what disease is neuropeptide p seen more of

A

AIDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Give some examples of proteins crypto has which disrupts tj and cytoskeleton for permeability and proinflam responses (for diarrhoea)

A

Aminopeptidases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Recognition of c Parvum by enterocyte tlr important for the release of chemotactic cytokines for neutrophils like RANTES and il8, why?

A

Because macrophages are isolated from them since at the apical site

Need neutrophil response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which hiv protein downrwgs the tlr4 responses of crypto

A

Tat protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which cytokines important for reduced crypto burden and is low in hiv and chronic uncontrolled cryptosporidiosis

A

Il15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does it do and where from

A

Activated monocytes release it and
Induces the ilc1/NK response

causes NK cell prolif and crypto toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How does malnutrition affect complement mediated opsonisation and phagocytosis
Reduced mbl which binds crypto needed for complement mediated opsonisation and phagocytosis
26
Which amp defensin is anticrypto
B defensin 2
27
Balance of th1 with what necessary to stop inflammatory induced diarrhoea
Th2 responses/ th2 cytokines eg il13 needed for m2 phenotype
28
How could this link to Microbiota potentially
Since they can release tslp and il25 from cells causing ilc2 responses
29
Which anti apoptotic gene upreg in crypto in infection as evasion mechanism for survival in enterocytes
Osteoprotegerin (acts as a decoy receptor for trail = antiapoptotic )
30
Where is EH usually situated
Outer mucus layer on the colon (not intracellular)
31
What % of cases are noninvasive amebiasis and what is this
90% Where you get non dysenteric diarrhoea (non bloody) , might be asymptomatic or also get abdominal pain and spread cysts
32
What happens to invasive 10%
Induced colitis Can either cause bloody diarrhoea with flask shaped lesions forming as they invade the submucosa (this can form chronic lesions) Or can even disseminate into the portal circulation where it can reach liver and cause liver abscesses which you can die from
33
What immediate innate are important in EH which can be modulated by microbiota
Mucus barrier effective Amps Tj integrity Iga
34
Which enzymes do eh have for degrading mucus
Glycosidases and cysteine proteinases
35
What can this be excacerbated by host dependant to therefore increase interaction with epi cells and inflam
Diet- low fibre = more mucin degrading
36
What inflam response can occur if they make contact
Proinflam cytokines the usual leading to neutrophil and mac Ifny also involved causing ros and no (antiparasitic) Aswell as degranulation
37
Which ilc is involved in response and can lead to so much inflammation and damage it will cause dissemination potentially
Ilc3
38
Binding of what to epi cells leads to these inflam responses
Gal/galnac-lectins
39
What does eh do to Microbiota that potentially exacerbates penetration
Dysbiosis eg increased p copri - makes sense due to inflammatory environment link with this (th17/3 inducing) - associated with RA commonly Also reduced butyrate clostridium and bacteroides which are immunomod
40
What is meant by contact dependant cell lysis which allows there dissemination/mucosal lesion formation
They insert an ion pore (amebopore) disrupting the membrane and causing death
41
Why would il17 be important here (and Microbiota)
Potent Siga responses important for eh
42
How is it suggested they can be resistant to ox stresses from inflammation they cause
Oxygen reductases they have
43
How do they affect effective iga and complement
Cysteine protease mediated degradation Degrade c3b and c3a
44
Is Giardia invasive
No it will stay on the si lumen and interact with si by central sucking disc
45
In most cases what are the symptoms
Asymptomatic or acute/cleared diarrhoea, cramps, nausea
46
Can this become chronic / what chronic effects can happen
Yes it can, Due to impairment of absorption With recurring episodes of diarrhoea, can lead to cramps, anorexia/weight loss and nutritional disorders bc of malnutrition
47
Why can trophozoites often unlike EH interact with epi cells
Because low mucus barrier in si
48
Give some issues in so it can cause to histology and enzymes
Shortening of microvilli so malabsorption Cell apoptosis via direct contact Also affects enzymes like lactase gaining access to the si and therefore also causing increase diarrhoea due to water flow
49
What can malabsorption and diarrhoea lead to in long run
IBS, cognitive impairment, tiredness and stunted development
50
What ilc response is there like EH and which cytokines is particularly important
Ilc3 Il17 required for pigr expression as iga most important adaptive protection against Giardia
51
Is the effects of the Microbiota dysbiosis Giardia causes known
No but it is present
52
Why is flagella and adhesive disc essential
Peristalsis induced by NO release on surface = sm contraction
53
What same proteases as EH do they have and disrupts tj and also appptosis of cells and most importantly degrades iga
Cysteine proteases
54
Which amps essential for anti Giardia
Defensins and cathelicidins (showing role of il22 and also Microbiota) cathelcidin ll37 speicfically induced by b producta and b theta via hif 1a
55
What chemical from cells and immune cells inhibits excystation and trophozoites proliferation - particularly important innate control of Giardia
NO
56
Which KO of mice caused chronic infection with increased trophozoites in small intestine
Iga, pigr and J chain (showing importance of Siga and the role of Microbiota)
57
Other than vsp immune evasion, what do they have to control NO production
Arginine deaminases reducing levels of no
58
Whcih genetic pid can therefore affect severity/chronic of Giardia
X linked b cell immunodeficiency
59
VSP GIARDIA ANTIGEN SWITCH
60
Explain the structure of vsp proteins on surface of Giardia
Intracellular C domain ( cytoplasmictail) and is conserved Tmd Then middle part of extracellular is semi conserved N terminus is variable and has cxxc motifs
61
How many expressed on trophozoites at once
1 or 2
62
Why are they important
Very immunogenic (both cell and humoral)
63
What enzymes does it protect parasite from
Intestinal and pancreatic proteases
64
Around how many genes compared to trypanosoma
300 genes (all transcribed) vs 1000 vsg copies
65
How is it similar only way to trypanosoma vsg
Called ‘true’ ag switch where there are homologous genes that can be expressed alternatively
66
Explain the rnai process used for mono allelic exp
Hairpin premirna from rna dep rna pol is transcribed This then goes to cytoplasm meeting dicer rnase which processes it to ds mirna Dsmirna binds argonaute ago protein and form mirna-risc complex which either cleaves the transcript or blocks translation via complementary binding
67
Downregulation of which proteins in this process of mirna silencing causes multiple allele expressions in Giardia showing rnai is important
Dicer ko or rdrp (ago would kill them) Rdrp required for production of hairpin loop mirna
68
What special motifs did a bioinformatics study find that 73 out of total vsp have which make them able to be presented on cell surface and complete switching
2 conserved motifs that were not present in around half (suggesting they don’t have effect)
69
Why is using bio informatics on vsp difficult
Different studies will annotate diff proteins as vsp depending on the tools they use. Hard to figure out
70
Give example of why 3’ utr specifically isn’t used in Giardia repression (saraiya 2014 study into whole coding sequence mirna binding to vsp)
Vsp-2 doesn’t even have a 3’ targeting site for mirna but still silenced
71
What happened to vsp117 silenced by no overlapping 6mirna compared to only 2 non overlapping
There was additive effect where vsp 117 silenced to only 2% exp vs 48% for 2 mirna
72
What does this indicate
Giardia relies on multiple mirna targeting sites within the orf to fully silence as only having 1 on 3’ utr is insufficient
73
In comparison to vsg, are vsp in subtelmoeres?
No only 3 are out of 75 working
74
Explain what they found in gerbils suggesting vsp could be used in future for vaccines
injection of trophozoites exp all of them (rnai mutants) protected from secondary infections
75
What did using oral vaccines injecting all vsp protein repertoires (solely the proteins) done in dogs and cats also find
That they were protected from subsequent infections with giardiasis and chronic infection and it also reduced spread to children from dogs in shanty towns ie affecting zoonotic transmission rates
76
Why would using vsp- coated vlps with Ha and na be useful for influenza
Highly immunogenic ie Found better igG and iga responses orally to HA and NA Also it protects them from being degraded by enzymes
77
How are these gut protozoans different to MICROSPORIDIA
MICROSPORIDIA is opportunistic- meaning that it won’t cause symptoms in healthy These are obligate pathogens and can cause complications
78
Which nutrient from diet could impact host ability to fight infection via redox activity in macrophages for example
Can be pumped into the phagosome and kill them via ros generation
79
What vaccine was initially found worked for crypto in calves but wasn’t replicated
Y-irradiated oocysts
80
Why would th1 cytokines like ifny be important for crypto
Can starve the vacuole of tryptophan via breakdown Also induced production of NO/ROS VIA INOS = kill cells and crypto
81
How would entamoeba even get to the liver
Trophozoites into the portal vein through intestinal lesions
82
Which is the most common protozoan found in stool
Giardia
83
How do Giardia excysting trophozoites replicate
They adhere close to surface and replicate extracellularly before encystation
84
Which enzyme does Giardia have which maybe makes NO response less important
arginine deaminase which degrades arginine required for NO production
85
How does mirna work in mammals
Mirna sites usually near 3’ utr and there is cleavage of the poly A tail causing de adenylation exonuclease activity
86
Since b-defensin 2 is important for cryptococcus, which probiotic could be useful and why
Ecoli nissle 1917- shown to induce the release of b-defensin 2 via nfkb induction (similar to the tlr9 mediated degranulation)

Microbiota On Mucosal (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions