Wolbachia Flashcards
Population replacement
replace pop with individual refractory to pathogen transmission
eg. wolbachia
transgenic mosquitoes
Population suppression
reduce pop to level where can no longer sustain pathogen transmission
eg. insecticides
sterile insect technique
entomopathogenic fungi
Mosquito microbiota
-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
Enterobacter
bacterium confers refractoriness to p. falciparum infection
production of reactive oxygen species
Asia bacteria
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.
sodalis
Tsetse fly symbiont
- gram negative rod shaped commensal symbiont
- transmitted to tsetse progeny through milk secretions –ideal for paratransgenesis
Wigglesworthia
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
symbiont mediated RNA interferance
eg. Rhodococcus - symbiont of rhodnius prolixus bug
genetically transformed and fed back to bug
bacteria colonized insects and competed with wildtype microflora
Wolbachia in mosquitoes
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
Wolbachia induced cytoplasmic incompatability (CI)
Matings between infected males and uninfected females = inviable progeny
mating btw infected females and uninfected or infected males = viable wolbachia infected progeny
Incompatible insect technique
continual release of wolbachia infected males to crash mosq. population
Wolbachia transinfection of Ae. aegypti
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
drosophila Wolbachia strains
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
Wolbachia replacement plan
release all mosq life stages to replace wildtype pop with wolbachia infected ones.
need strong cytoplasmic incompatibility and high maternal transmission rates
wolbachia superinfection
put two strains in mosquito
WMel and WAlbB
superinfection reduced DENV infection in salivary glands more efficiently than WMel alone