Leishmania

Question 1

what is symbiosis

Answer 1

close biological interaction between two different species

Question 2

what mutualism

Answer 2

is where a symbiotic relationship benefits both species

Question 3

what is commensalism

Answer 3

one species benefits but the other is not harmed

Question 4

what is a parisitism relationship

Answer 4

one species benefits whilst the other is harmed

Question 5

what is visceral leishmaniasis

Answer 5

affects the organs

Question 6

which type of leishmania is the most fatal

Answer 6

visceral

Question 7

what does cutaneous leishmania affect

Answer 7

affects the skin

Question 8

what type of leishmania is the most common

Answer 8

cutaneous leishmania

Question 9

what is the mucotaneous leishmania

Answer 9

affects the skin and mucous membranes

Question 10

why is leishmania more likely to increase

Answer 10

• associated with migration
• more likely to increase
• draught and family can cause people to migrate
• changes in urbanisation

Question 11

what are the two types leishmania cells that invade immune cells

Answer 11

promastigote and amastigote.

Question 12

what are the characteristics of the promastigote form

Answer 12

inoculated by the sandfly, powerful swimmer invades phagocytic immune cells

Question 13

what are the characteristics of the amastigote

Answer 13

formed from the promastigote after first invasion invades phagocytic immune cells. infects the sand flies

Question 14

which leishmania form is mobile

Answer 14

promastigote

Question 15

what is the axonemal paraflagella rod PFR

Answer 15

essential for the beating of the flagellum

Question 16

which leishmania form has the PFR on?

Answer 16

promastigote

Question 17

what are leishmania

Answer 17

single-celled eukaryotes

Question 18

what is the vector of leishmania

Answer 18

sand flies

Question 19

what is the host of leishmania

Answer 19

mammal

Question 20

how is leishmania transmitted

Answer 20

female sandfly

Question 21

how have leishmania survived

Answer 21

subvert normal phagocytosis pathway and evolved to survive in macrophages and neutrophils

Question 22

how does leishmania enter the macrophages

Answer 22

1. parasite bind to phagocytic receptors on macrophage cell surface
2. binding stimulates phagocytosis and leishmania becomes internalised in a parasitophorous vacuole PV

Question 23

what happens after the lesihmanian parasite becomes internalised in the PV

Answer 23

the parasites subvert phagocytosis

Question 24

what are leishmania parasites Called in the midgut of the sandlfly

Answer 24

amastigotes

Question 25

promastigotes transform to amastigotes in response to…

Answer 25

drop in pH and temperature

Question 26

what five stages do promastigotes go through

Answer 26

1. Procyllc
2. Nectomonad
3. Leptomonad
   f. Hapto monad
4. metacyclic

Question 27

what is procylic

Answer 27

colonisation of the gut

Question 28

what is metacylic

Answer 28

ready to infect mammalian host upon biting

Question 29

how can parasites overcome insect defences (sandfly)

sandflys digest blood with proteases:

Answer 29

proteases secrete inhibitors

Question 30

how can parasites overcome insect defences (sandfly)

sandfly produce AMPs that form lytic pores

Answer 30

parasites down regulate the pathway that makes AMPs

Question 31

how can parasites overcome insect defences (sandfly)

blood meal and pathogens are expelled after digestion

Answer 31

parasites insert their flagellum onto the gut microvilli and bind to receptors prevents them from being expelled.

Question 32

how does leishmania travel from sand-fly to human/mammal

Answer 32

1. stomedal valve: allows blood to enter the sandfly during feeding
2. parasites move to this stomedeal valve
3. leishmania produces promastigate secretory gel PSG
4. PSG forms a plug at the stomodel valve containing infectious parasites
5. causes a blockage and forces the valve to remain open
6. promotes delivery of parasite into the host by regurgitation

Question 33

what does the sandfly saliva do?

Answer 33

promotes and exacerbates leishmania’s disease