Wolbachia

Question 1

Population replacement

Answer 1

replace pop with individual refractory to pathogen transmission
eg. wolbachia
transgenic mosquitoes

Question 2

Population suppression

Answer 2

reduce pop to level where can no longer sustain pathogen transmission
eg. insecticides
sterile insect technique
entomopathogenic fungi

Question 3

Mosquito microbiota

Answer 3

-mosq. midgut has 100 microbacteria - some inherently transfered
- naturally acquired microbacteria can have protective effect from pathogens
Flavobacteria in Anopheles
bacteria acquired from aquatic environment during development

Question 4

Enterobacter

Answer 4

bacterium confers refractoriness to p. falciparum infection

production of reactive oxygen species

Question 5

Asia bacteria

Answer 5

present in all life stages and all species of mosquito
- colocalise with plasmodium oocysts - dont influence them
paratransgenesis of Asia inhibits plasmodium - asia siderophore gene fused with antiplasmodial effector genes.

Question 6

sodalis

Answer 6

Tsetse fly symbiont

• gram negative rod shaped commensal symbiont
• transmitted to tsetse progeny through milk secretions –ideal for paratransgenesis

Question 7

Wigglesworthia

Answer 7

Tsetse fly symbiont

• mutualistic gram negative bacteria in anterior midgut
• enables tsetse to survive on just blood
• tiny genome
• transmitted to larva in milk secretions
• plays a role in host immunity

Question 8

symbiont mediated RNA interferance

Answer 8

eg. Rhodococcus - symbiont of rhodnius prolixus bug
genetically transformed and fed back to bug
bacteria colonized insects and competed with wildtype microflora

Question 9

Wolbachia in mosquitoes

Answer 9

endosymbiotic intracellular bacteria
-maternally inherited and manipulate host reproduction to enhance transmission
-first identified in ovaries of culex pipiens (Wpip strain)
-Two resident strains in Ae. albopictus (WAlbA and WAlbB).
absent in:
-Ae.aegypti
-anopheles

Question 10

Wolbachia induced cytoplasmic incompatability (CI)

Answer 10

Matings between infected males and uninfected females = inviable progeny
mating btw infected females and uninfected or infected males = viable wolbachia infected progeny

Question 11

Incompatible insect technique

Answer 11

continual release of wolbachia infected males to crash mosq. population

Question 12

Wolbachia transinfection of Ae. aegypti

Answer 12

wolbachia not found in Ae. aegypti
introduce to eggs via microinjection
female wolbachia infected mosq will then pass on to next generation
using this in singapore
have to inject eggs at 30-45 mins old or too hard

Question 13

drosophila Wolbachia strains

Answer 13

2 strains:

• virulent WMelPop strain - reduces adult lifespan by 50%
• Aviruelnt Wmel strain - protects against insect viruses

could reduce lifespan of mosq and reduce malaria transmission

Question 14

Wolbachia replacement plan

Answer 14

release all mosq life stages to replace wildtype pop with wolbachia infected ones.
need strong cytoplasmic incompatibility and high maternal transmission rates

Question 15

wolbachia superinfection

Answer 15

put two strains in mosquito
WMel and WAlbB
superinfection reduced DENV infection in salivary glands more efficiently than WMel alone