Lecture 18: Protists in blood and intestines

Question 1

what is malaria caused by?

Answer 1

Plasmodium protist

Question 2

what is malaria transmitted by?

Answer 2

female anopheles mosquitos

Question 3

what does malaria infect?

Answer 3

red blood cells causing a fever

Question 4

what serious diseases can arise from malaria?

Answer 4

anaemia and blocking of small capillaries

Question 5

how many children die per day in sub-Saharan africa?

Answer 5

1200

Question 6

what facilitates host invasion?

Answer 6

apical complex

Question 7

what are the 4 stages of malaria development?

Answer 7

• skin infection
• liver stage development
• blood stage development
• mosquito stage development

Question 8

what occurs in malarial skin infection?

Answer 8

sporozoites within the mosquito salivary gland are injected into the skin

Question 9

what happens in liver stage development?

Answer 9

• sporozoites invade liver cells and are engulfed by host cell membrane
• divide asexually within hepatocytes forming schizonts

Question 10

what can Plasmodium vivax do in the liver stage development?

Answer 10

form a non-replicating hypnozoite to enable long term survival

Question 11

what do schizonts become?

Answer 11

merozoites that invade red blood cells

Question 12

what do merozoites do?

Answer 12

bind to receptors on red blood cells and are engulfed

Question 13

what happens once merozoites are engulfed?

Answer 13

differentiate into trophozoites and ingest cytoplasm of the red blood cell

Question 14

what is malaria paroxysm?

Answer 14

rupture of haemocyte schizont in the blood releases malaria endotoxin that induces the host to produce high levels of pro-inflammatory cytokines TNF-a inducing a fever

Question 15

what occurs in the blood stage development?

Answer 15

proteins are expressed on the surface of infected red blood cells enabling attachment to the endothelium and can causing rosetting and capillary obstruction

Question 16

what do some trophozoites become?

Answer 16

gametophytes

Question 17

what do the female anopheles mosquitos pick up?

Answer 17

gametocytes from host blood

Question 18

what happens do the gametocytes once ingested?

Answer 18

gametocytogenesis forming a zygote and a ookinete

Question 19

what does the ookinete do?

Answer 19

forms an oocyst that releases sporozites than migrate to the salivary gland

Question 20

which malaria antigen evades immunity using antigenic variation?

Answer 20

PfEMP1

Question 21

what is the first licensed malaria vaccine?

Answer 21

RTS,S

Question 22

what is the newest malaria vaccine?

Answer 22

R21/Matrix-M vaccine

Question 23

what do trypansomes cause?

Answer 23

chagas disease and sleeping sickness (trypanosomiasis)

Question 24

what subgroup of excavata are trypanosomes from?

Answer 24

discoba kinetoplastids

Question 25

what are 4 facts about chagas disease (cruzi)?

Answer 25

- transmitted by triatomine bug - Latin america - acute symptoms: fever, fatigue, headache, rash - chronic symptoms: severe cardiac and intestinal lesions

Question 26

what are 4 facts about sleeping sickness (brucei)?

Answer 26

- transmitted via the tsetse fly - sub-saharan africa - causes skin lesions and sleep disturbance

Question 27

what occurs in the acute phase of trypanosomes life cycle?

Answer 27

binary fission

Question 28

what occurs in the chronic phase of trypanosome life cycle?

Answer 28

10-30 years symptom free

Question 29

what are 3 gastrointestinal symptoms of protozoa in the gut?

Answer 29

diarrhoea, gastroenteritis, and dysentery

Question 30

what is gastroenteritis?

Answer 30

nausea, vomiting, and abdominal distress

Question 31

what is dysentery?

Answer 31

blood and mucus in poo due to large intestine damage

Question 32

what subgroup of the excavata is giardia part of?

Answer 32

metamonada

Question 33

what subgroup of SAR is cryptosporidium part of?

Answer 33

alveolata

Question 34

what are the symptoms of giardia?

Answer 34

NO SYMPTOMS

Question 35

how does giardia live in water?

Answer 35

as a cyst passed in faeces

Question 36

how does giardia live in humans?

Answer 36

in the gut as a trophozoite adhered to the intestine via an adhesive disk

Question 37

how often does antigenic variation occur in giardia?

Answer 37

once every 10 generations

Question 38

what are the 2 main pathogens of cryptosporidium?

Answer 38

C. hominis and C.parvum

Question 39

what does cryptosporidium cause?

Answer 39

inflammation of intestinal epithelial cells impacting nutrient and ion absorption

Question 40

how can diarrhoeal diseases be prevented?

Answer 40

good sanitation and access to clean water